Random forest variable selection in spatial malaria transmission modelling in Mpumalanga Province, South Africa

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Thandi Kapwata

2016-11-01

Full Text Available Malaria is an environmentally driven disease. In order to quantify the spatial variability of malaria transmission, it is imperative to understand the interactions between environmental variables and malaria epidemiology at a micro-geographic level using a novel statistical approach. The random forest (RF statistical learning method, a relatively new variable-importance ranking method, measures the variable importance of potentially influential parameters through the percent increase of the mean squared error. As this value increases, so does the relative importance of the associated variable. The principal aim of this study was to create predictive malaria maps generated using the selected variables based on the RF algorithm in the Ehlanzeni District of Mpumalanga Province, South Africa. From the seven environmental variables used [temperature, lag temperature, rainfall, lag rainfall, humidity, altitude, and the normalized difference vegetation index (NDVI], altitude was identified as the most influential predictor variable due its high selection frequency. It was selected as the top predictor for 4 out of 12 months of the year, followed by NDVI, temperature and lag rainfall, which were each selected twice. The combination of climatic variables that produced the highest prediction accuracy was altitude, NDVI, and temperature. This suggests that these three variables have high predictive capabilities in relation to malaria transmission. Furthermore, it is anticipated that the predictive maps generated from predictions made by the RF algorithm could be used to monitor the progression of malaria and assist in intervention and prevention efforts with respect to malaria.

Simulation of malaria epidemiology and control in the highlands of western Kenya

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Stuckey Erin M

2012-10-01

Full Text Available Abstract Background Models of Plasmodium falciparum malaria epidemiology that provide realistic quantitative predictions of likely epidemiological outcomes of existing vector control strategies have the potential to assist in planning for the control and elimination of malaria. This work investigates the applicability of mathematical modelling of malaria transmission dynamics in Rachuonyo South, a district with low, unstable transmission in the highlands of western Kenya. Methods Individual-based stochastic simulation models of malaria in humans and a deterministic model of malaria in mosquitoes as part of the OpenMalaria platform were parameterized to create a scenario for the study area based on data from ongoing field studies and available literature. The scenario was simulated for a period of two years with a population of 10,000 individuals and validated against malaria survey data from Rachuonyo South. Simulations were repeated with multiple random seeds and an ensemble of 14 model variants to address stochasticity and model uncertainty. A one-dimensional sensitivity analysis was conducted to address parameter uncertainty. Results The scenario was able to reproduce the seasonal pattern of the entomological inoculation rate (EIR and patent infections observed in an all-age cohort of individuals sampled monthly for one year. Using an EIR estimated from serology to parameterize the scenario resulted in a closer fit to parasite prevalence than an EIR estimated using entomological methods. The scenario parameterization was most sensitive to changes in the timing and effectiveness of indoor residual spraying (IRS and the method used to detect P. falciparum in humans. It was less sensitive than expected to changes in vector biting behaviour and climatic patterns. Conclusions The OpenMalaria model of P. falciparum transmission can be used to simulate the impact of different combinations of current and potential control interventions to help plan

Molecular Epidemiology of Plasmodium falciparum Malaria Outbreak, Tumbes, Peru, 2010–2012

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Okoth, Sheila Akinyi; Arrospide, Nancy; Gonzalez, Rommell V.; Sánchez, Juan F.; Macedo, Silvia; Conde, Silvia; Tapia, L. Lorena; Salas, Carola; Gamboa, Dionicia; Herrera, Yeni; Edgel, Kimberly A.; Udhayakumar, Venkatachalam; Lescano, Andrés G.

2015-01-01

During 2010–2012, an outbreak of 210 cases of malaria occurred in Tumbes, in the northern coast of Peru, where no Plasmodium falciparum malaria case had been reported since 2006. To identify the source of the parasite causing this outbreak, we conducted a molecular epidemiology investigation. Microsatellite typing showed an identical genotype in all 54 available isolates. This genotype was also identical to that of parasites isolated in 2010 in the Loreto region of the Peruvian Amazon and closely related to clonet B, a parasite lineage previously reported in the Amazon during 1998–2000. These findings are consistent with travel history of index case-patients. DNA sequencing revealed mutations in the Pfdhfr, Pfdhps, Pfcrt, and Pfmdr1 loci, which are strongly associated with resistance to chloroquine and sulfadoxine/pyrimethamine, and deletion of the Pfhrp2 gene. These results highlight the need for timely molecular epidemiology investigations to trace the parasite source during malaria reintroduction events. PMID:25897626

Spatial distribution of malaria in Peninsular Malaysia from 2000 to 2009.

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Alias, Haridah; Surin, Johari; Mahmud, Rohela; Shafie, Aziz; Mohd Zin, Junaidden; Mohamad Nor, Mahadzir; Ibrahim, Ahmad Shah; Rundi, Christina

2014-04-15

Malaria is still an endemic disease of public health importance in Malaysia. Populations at risk of contracting malaria includes indigenous people, traditional villagers, mobile ethnic groups and land scheme settlers, immigrants from malaria endemic countries as well as jungle workers and loggers. The predominant species are Plasmodium falciparum and P. vivax. An increasing number of P. knowlesi infections have also been encountered. The principal vectors in Peninsular Malaysia are Anopheles maculatus and An. cracens. This study aims to determine the changes in spatial distribution of malaria in Peninsular Malaysia from year 2000-2009. Data for the study was collected from Ministry of Health, Malaysia and was analysed using Geographic Information System (GIS). Changes for a period of 10 years of malaria spatial distribution in 12 states of Peninsular Malaysia were documented and discussed. This is illustrated by digital mapping according to five variables; incidence rate (IR), fatality rate (FR), annual blood examination rate (ABER), annual parasite index (API) and slide positivity rate (SPR). There is a profound change in the spatial distribution of malaria within a 10-year period. This is evident from the digital mapping of the infection in Peninsular Malaysia.

Spatial evolutionary epidemiology of spreading epidemics.

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Lion, S; Gandon, S

2016-10-26

Most spatial models of host-parasite interactions either neglect the possibility of pathogen evolution or consider that this process is slow enough for epidemiological dynamics to reach an equilibrium on a fast timescale. Here, we propose a novel approach to jointly model the epidemiological and evolutionary dynamics of spatially structured host and pathogen populations. Starting from a multi-strain epidemiological model, we use a combination of spatial moment equations and quantitative genetics to analyse the dynamics of mean transmission and virulence in the population. A key insight of our approach is that, even in the absence of long-term evolutionary consequences, spatial structure can affect the short-term evolution of pathogens because of the build-up of spatial differentiation in mean virulence. We show that spatial differentiation is driven by a balance between epidemiological and genetic effects, and this quantity is related to the effect of kin competition discussed in previous studies of parasite evolution in spatially structured host populations. Our analysis can be used to understand and predict the transient evolutionary dynamics of pathogens and the emergence of spatial patterns of phenotypic variation. © 2016 The Author(s).

The past, present and future use of epidemiological intelligence to plan malaria vector control and parasite prevention in Uganda.

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Talisuna, Ambrose O; Noor, Abdisalan M; Okui, Albert P; Snow, Robert W

2015-04-15

An important prelude to developing strategies to control infectious diseases is a detailed epidemiological evidence platform to target cost-effective interventions and define resource needs. A review of published and un-published reports of malaria vector control and parasite prevention in Uganda was conducted for the period 1900-2013. The objective was to provide a perspective as to how epidemiological intelligence was used to design malaria control before and during the global malaria eradication programme (GMEP) and to contrast this with the evidence generated in support of the Roll Back Malaria (RBM) initiative from 1998 to date. During the GMEP era, comprehensive investigations were undertaken on the effectiveness of vector and parasite control such as indoor residual house-spraying (IRS) and mass drug administration (MDA) at different sites in Uganda. Nationwide malariometric surveys were undertaken between 1964 and 1967 to provide a profile of risk, epidemiology and seasonality leading to an evidence-based national cartography of risk to characterize the diversity of malaria transmission in Uganda. At the launch of the RBM initiative in the late 1990s, an equivalent level of evidence was lacking. There was no contemporary national evidence-base for the likely impact of insecticide-treated nets (ITN), no new malariometric data, no new national cartography of malaria risk or any evidence of tailored intervention delivery based on variations in the ecology of malaria risk in Uganda. Despite millions of dollars of overseas development assistance over the last ten years in ITN, and more recently the resurrection of the use of IRS, the epidemiological impact of vector control remains uncertain due to an absence of nationwide basic parasite and vector-based field studies. Readily available epidemiological data should become the future business model to maximize malaria funding from 2015. Over the next five to ten years, accountability, impact analysis, financial

Spatial association between malaria pandemic and mortality

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B M Dansu

2007-12-01

Full Text Available Malaria pandemic (MP has been linked to a range of serious health problems including premature mortality. The main objective of this research is to quantify uncertainties about impacts of malaria on mortality. A multivariate spatial regression model was developed for estimation of the risk of mortality associated with malaria across Ogun State in Nigeria, West Africa. We characterize different local governments in the data and model the spatial structure of the mortality data in infants and pregnant women. A flexible Bayesian hierarchical model was considered for a space-time series of counts (mortality by constructing a likelihood-based version of a generalized Poisson regression model that combines methods for point-level misaligned data and change of support regression. A simple two-stage procedure for producing maps of predicted risk is described. Logistic regression modeling was used to determine an approximate risk on a larger scale, and geo-statistical ("Kriging" approaches were used to improve prediction at a local level. The results suggest improvement of risk prediction brought about in the second stage. The advantages and shortcomings of this approach highlight the need for further development of a better analytical methodology.

Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia

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Midekisa, Alemayehu; Senay, Gabriel; Wimberly, Michael C.

2014-01-01

Malaria is a major global public health problem, particularly in Sub-Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district-level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single-sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region.

Epidemiology of malaria in the forest-savanna transitional zone of Ghana

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Newton Sam

2009-09-01

Full Text Available Abstract Background Information on the epidemiology of malaria is essential for designing and interpreting results of clinical trials of drugs, vaccines and other interventions. As a background to the establishment of a site for anti-malarial drugs and vaccine trials, the epidemiology of malaria in a rural site in central Ghana was investigated. Methods Active surveillance of clinical malaria was carried out in a cohort of children below five years of age (n = 335 and the prevalence of malaria was estimated in a cohort of subjects of all ages (n = 1484 over a 12-month period. Participants were sampled from clusters drawn around sixteen index houses randomly selected from a total of about 22,000 houses within the study area. The child cohort was visited thrice weekly to screen for any illness and a blood slide was taken if a child had a history of fever or a temperature greater than or equal to 37.5 degree Celsius. The all-age cohort was screened for malaria once every eight weeks over a 12-month period. Estimation of Entomological Inoculation Rate (EIR and characterization of Anopheline malaria vectors in the study area were also carried out. Results The average parasite prevalence in the all age cohort was 58% (95% CI: 56.9, 59.4. In children below five years of age, the average prevalence was 64% (95% CI: 61.9, 66.0. Geometric mean parasite densities decreased significantly with increasing age. More than 50% of all children less than 10 years of age were anaemic. Children less than 5 years of age had as many as seven malaria attacks per child per year. The attack rates decreased significantly with increasing cut-offs of parasite density. The average Multiplicity of Infection (MOI was of 6.1. All three pyrimethamine resistance mutant alleles of the Plasmodium falciparum dhfr gene were prevalent in this population and 25% of infections had a fourth mutant of pfdhps-A437G. The main vectors were Anopheles funestus and Anopheles gambiae and the EIR

THE SPOROZOITE ENZYME-LINKED IMMUNOSORBENT ASSAY : APPLICATION IN MALARIA EPIDEMIOLOGY

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Michael J. Bangs

2012-09-01

Full Text Available Recent biotechnological breakthroughs have led to the development of various methods for detection and identification of human pathogens in their vectors. Monoclonal antibodies produced against malaria sporozoite antigens have permitted the development of several sensitive, species specific immunological tests (IFA, IRMA, ELIS A. One of these, a two-site enzyme-linked immunosorbent assay (ELIS A has been developed as a useful epidemiological tool in the identification of malaria-infected mosquitoes. This method employs highly species specific monoclonal antibodies that recognize the repetitive immunodominant epitope of the circumsporozoite (CS protein. Monoclonal antibodies have been developed for all four species of human malaria The key feature of the ELISA technique is the use of an enzyme indicator for an immunological reaction. The antigen capture or "sandwich" ELISA configuration uses the purified monoclonal both as the solid phase and, conjugated to enzyme, as a marker for the presence of CS protein in a mosquito homogenate incubated in the wells of a microtitration plate. This technology has shown advantages over other methods for epidemiological data collection. Mosquitoes can be caught, dried and stored until a time convenient for examination. The sporozoite rate by Plasmodium species can be identified easily, and when combined with the man-biting rate provides the sporozoite inoculation rate, an important entomologic estimate of the number of potential infective bites a person could expect over a given period of time. Presently, mosquitoes can be tested individually or pooled up to 20 anophe lines. The assay is sensitive enough to detect 1 infected mosquito per pool or as few as 25 sporozoites per 50 pi of mosquito extract. Basic principles and procedures are covered concerning solid substrate, adsorption to solid substrate, buffers and wash solutions, conjugates and enzyme substrates. The advantages and limitations of this technique

Using Structured Additive Regression Models to Estimate Risk Factors of Malaria: Analysis of 2010 Malawi Malaria Indicator Survey Data

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Chirombo, James; Lowe, Rachel; Kazembe, Lawrence

2014-01-01

Background After years of implementing Roll Back Malaria (RBM) interventions, the changing landscape of malaria in terms of risk factors and spatial pattern has not been fully investigated. This paper uses the 2010 malaria indicator survey data to investigate if known malaria risk factors remain relevant after many years of interventions. Methods We adopted a structured additive logistic regression model that allowed for spatial correlation, to more realistically estimate malaria risk factors. Our model included child and household level covariates, as well as climatic and environmental factors. Continuous variables were modelled by assuming second order random walk priors, while spatial correlation was specified as a Markov random field prior, with fixed effects assigned diffuse priors. Inference was fully Bayesian resulting in an under five malaria risk map for Malawi. Results Malaria risk increased with increasing age of the child. With respect to socio-economic factors, the greater the household wealth, the lower the malaria prevalence. A general decline in malaria risk was observed as altitude increased. Minimum temperatures and average total rainfall in the three months preceding the survey did not show a strong association with disease risk. Conclusions The structured additive regression model offered a flexible extension to standard regression models by enabling simultaneous modelling of possible nonlinear effects of continuous covariates, spatial correlation and heterogeneity, while estimating usual fixed effects of categorical and continuous observed variables. Our results confirmed that malaria epidemiology is a complex interaction of biotic and abiotic factors, both at the individual, household and community level and that risk factors are still relevant many years after extensive implementation of RBM activities. PMID:24991915

Morbidity in the marshes: using spatial epidemiology to investigate skeletal evidence for Malaria in Anglo-Saxon England (AD 410-1050).

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Gowland, R L; Western, A G

2012-02-01

Concerns over climate change and its potential impact on infectious disease prevalence have contributed to a resurging interest in malaria in the past. A wealth of historical evidence indicates that malaria, specifically Plasmodium vivax, was endemic in the wetlands of England from the 16th century onwards. While it is thought that malaria was introduced to Britain during the Roman occupation (AD first to fifth centuries), the lack of written mortality records prior to the post-medieval period makes it difficult to evaluate either the presence or impact of the disease. The analysis of human skeletal remains from archaeological contexts is the only potential means of examining P. vivax in the past. Malaria does not result in unequivocal pathological lesions in the human skeleton; however, it results in hemolytic anemia, which can contribute to the skeletal condition cribra orbitalia. Using geographical information systems (GIS), we conducted a spatial analysis of the prevalence of cribra orbitalia from 46 sites (5,802 individuals) in relation to geographical variables, historically recorded distribution patterns of indigenous malaria and the habitat of its mosquito vector Anopheles atroparvus. Overall, those individuals living in low-lying and Fenland regions exhibited higher levels of cribra orbitalia than those in nonmarshy locales. No corresponding relationship existed with enamel hypoplasia. We conclude that P. vivax malaria, in conjunction with other comorbidities, is likely to be responsible for the pattern observed. Studies of climate and infectious disease in the past are important for modeling future health in relation to climate change predictions. Copyright © 2011 Wiley Periodicals, Inc.

Malaria and health in Africa: the present situation and epidemiological trends.

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Brinkmann, U; Brinkmann, A

1991-09-01

The World Health Organization does not give any data on the malaria situation in Africa in its regular reports because of the "insufficiency and irregularity of reporting". Estimates on the total number of cases and the number of deaths vary considerably. They range from 35 million to 189 million per year depending on whose figures one uses. An intensive search of the literature using computer-based systems identified more than 1000 titles on the epidemiology of malaria. Out of them and from other sources finally 426 articles were used to describe the current malaria situation and observable trends in Africa. Major findings were that malaria is responsible for about 40% of fever cases, mortality is about 5 per 1000 per year, case fatality ranges from 2% to 24%. Admissions for malaria account for 20% to 50% of all admissions in African health services although only 8% to 25% of persons with malaria visit health services. Self-treatment is more common in urban areas (more than 60%) but an increasing number of people use some form of self protection in rural areas (2% to 25%). The resistance of malaria parasites to chloroquine and other drugs is widespread. Chloroquine resistance has reached a prevalence of about 30% at the RII level in most countries. Malaria incidence shows annual growth rates of 7.3% for Zambia, 10.4% for Togo, and 21.0% for Rwanda. The data for Burkina Faso show a downward trend of--14.7% during the years from 1973 to 1981. Since then malaria incidence is increasing at 11.0% per year. Hospital data reported from Zambia indicate that mortality is rising 5.2% per annum in children and 9.7% per annum in adults. Reasons for the increase of malaria and its role for development are discussed.

Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission across Seven Diverse ICEMR Network Sites

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Wilson, Mark L.; Krogstad, Donald J.; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U.; Ndiaye, Daouda; Mathanga, Don P.; Eapen, Alex

2015-01-01

A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. PMID:26259941

A micro-epidemiological analysis of febrile malaria in Coastal Kenya showing hotspots within hotspots.

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Bejon, Philip; Williams, Thomas N; Nyundo, Christopher; Hay, Simon I; Benz, David; Gething, Peter W; Otiende, Mark; Peshu, Judy; Bashraheil, Mahfudh; Greenhouse, Bryan; Bousema, Teun; Bauni, Evasius; Marsh, Kevin; Smith, David L; Borrmann, Steffen

2014-04-24

Malaria transmission is spatially heterogeneous. This reduces the efficacy of control strategies, but focusing control strategies on clusters or 'hotspots' of transmission may be highly effective. Among 1500 homesteads in coastal Kenya we calculated (a) the fraction of febrile children with positive malaria smears per homestead, and (b) the mean age of children with malaria per homestead. These two measures were inversely correlated, indicating that children in homesteads at higher transmission acquire immunity more rapidly. This inverse correlation increased gradually with increasing spatial scale of analysis, and hotspots of febrile malaria were identified at every scale. We found hotspots within hotspots, down to the level of an individual homestead. Febrile malaria hotspots were temporally unstable, but 4 km radius hotspots could be targeted for 1 month following 1 month periods of surveillance.DOI: http://dx.doi.org/10.7554/eLife.02130.001. Copyright © 2014, Bejon et al.

[Imported malaria and HIV infection in Madrid. Clinical and epidemiological features].

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Ramírez-Olivencia, G; Herrero, M D; Subirats, M; de Juanes, J R; Peña, J M; Puente, S

2012-01-01

Few data are available in Spain data on human immunodeficiency virus (HIV) patients coinfected with malaria. This study has aimed to determine the epidemiological and clinical characteristics of imported malaria in patients coinfected with HIV. A case-series retrospective study was performed using the patient's medical records. The study population consisted on patients diagnosed with malaria attended in our center from january 1, 2002 to december 31, 2007. A total of 484 episodes of malaria, 398 of which were included in this study, were identified. Co-infection with HIV was described in 32 cases. All of them occurred in individuals presumably with some degree of semi-immunity. In the coinfected group, there were 13 cases (40.6%) asymptomatic, whereas this event occurred in 99 cases of patients not coinfected (37.2%) (P=0.707). The greater presence of anemia in co-infected patients (62.5% vs 32.3% in non-coinfected [P=0.001]) stands out. In present study, the clinical presentation forms were similar, regardless of the presence or absence of HIV infection. Although the study population does not reflect all possible scenarios of malaria and HIV coinfection, our results indicate the reality of patients attended in the Autonomous Community of Madrid. Copyright © 2011 Elsevier España, S.L. All rights reserved.

Spatial prediction of malaria prevalence in an endemic area of Bangladesh

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Islam Akramul

2010-05-01

Full Text Available Abstract Background Malaria is a major public health burden in Southeastern Bangladesh, particularly in the Chittagong Hill Tracts region. Malaria is endemic in 13 districts of Bangladesh and the highest prevalence occurs in Khagrachari (15.47%. Methods A risk map was developed and geographic risk factors identified using a Bayesian approach. The Bayesian geostatistical model was developed from previously identified individual and environmental covariates (p Results Predicted high prevalence areas were located along the north-eastern areas, and central part of the study area. Low to moderate prevalence areas were predicted in the southwestern, southeastern and central regions. Individual age and nearness to fragmented forest were associated with malaria prevalence after adjusting the spatial auto-correlation. Conclusion A Bayesian analytical approach using multiple enabling technologies (geographic information systems, global positioning systems, and remote sensing provide a strategy to characterize spatial heterogeneity in malaria risk at a fine scale. Even in the most hyper endemic region of Bangladesh there is substantial spatial heterogeneity in risk. Areas that are predicted to be at high risk, based on the environment but that have not been reached by surveys are identified.

Successful malaria elimination in the Ecuador-Peru border region: epidemiology and lessons learned.

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Krisher, Lyndsay K; Krisher, Jesse; Ambuludi, Mariano; Arichabala, Ana; Beltrán-Ayala, Efrain; Navarrete, Patricia; Ordoñez, Tania; Polhemus, Mark E; Quintana, Fernando; Rochford, Rosemary; Silva, Mercy; Bazo, Juan; Stewart-Ibarra, Anna M

2016-11-28

In recent years, malaria (Plasmodium vivax and Plasmodium falciparum) has been successfully controlled in the Ecuador-Peru coastal border region. The aim of this study was to document this control effort and to identify the best practices and lessons learned that are applicable to malaria control and to other vector-borne diseases. A proximal outcome evaluation was conducted of the robust elimination programme in El Oro Province, Ecuador, and the Tumbes Region, Peru. Data collection efforts included a series of workshops with local public health experts who played central roles in the elimination effort, review of epidemiological records from Ministries of Health, and a review of national policy documents. Key programmatic and external factors are identified that determined the success of this eradication effort. From the mid 1980s until the early 2000s, the region experienced a surge in malaria transmission, which experts attributed to a combination of ineffective anti-malarial treatment, social-ecological factors (e.g., El Niño, increasing rice farming, construction of a reservoir), and political factors (e.g., reduction in resources and changes in management). In response to the malaria crisis, local public health practitioners from El Oro and Tumbes joined together in the mid-1990s to forge an unofficial binational collaboration for malaria control. Over the next 20 years, they effectively eradicated malaria in the region, by strengthening surveillance and treatment strategies, sharing of resources, operational research to inform policy, and novel interventions. The binational collaboration at the operational level was the fundamental component of the successful malaria elimination programme. This unique relationship created a trusting, open environment that allowed for flexibility, rapid response, innovation and resilience in times of crisis, and ultimately a sustainable control programme. Strong community involvement, an extensive microscopy network and

Urban Malaria: Understanding its Epidemiology, Ecology, and Transmission Across Seven Diverse ICEMR Network Sites.

Science.gov (United States)

Wilson, Mark L; Krogstad, Donald J; Arinaitwe, Emmanuel; Arevalo-Herrera, Myriam; Chery, Laura; Ferreira, Marcelo U; Ndiaye, Daouda; Mathanga, Don P; Eapen, Alex

2015-09-01

A major public health question is whether urbanization will transform malaria from a rural to an urban disease. However, differences about definitions of urban settings, urban malaria, and whether malaria control should differ between rural and urban areas complicate both the analysis of available data and the development of intervention strategies. This report examines the approach of the International Centers of Excellence for Malaria Research (ICEMR) to urban malaria in Brazil, Colombia, India (Chennai and Goa), Malawi, Senegal, and Uganda. Its major theme is the need to determine whether cases diagnosed in urban areas were imported from surrounding rural areas or resulted from transmission within the urban area. If infections are being acquired within urban areas, malaria control measures must be targeted within those urban areas to be effective. Conversely, if malaria cases are being imported from rural areas, control measures must be directed at vectors, breeding sites, and infected humans in those rural areas. Similar interventions must be directed differently if infections were acquired within urban areas. The hypothesis underlying the ICEMR approach to urban malaria is that optimal control of urban malaria depends on accurate epidemiologic and entomologic information about transmission. © The American Society of Tropical Medicine and Hygiene.

Spatial and temporal distribution of falciparum malaria in China

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Lin Hualiang

2009-06-01

characterized by the predominance of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted.

Spatial and spatio-temporal analysis of malaria in the state of Acre, western Amazon, Brazil

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Leonardo Augusto Kohara Melchior

2016-11-01

Full Text Available Since 2005, the State of Acre, western Amazon, Brazil, has reported the highest annual parasite incidence (API of malaria among the Brazilian states. This study examines malaria incidence in Acre using spatial and spatio-temporal analysis based on an ecological time series study analyzing malaria cases and deaths for the time period 1992- 2014 and using secondary data. API indexes were calculated by age, sex, parasite species, ratio of Plasmodium vivax to P. falciparum malaria, malaria mortality rate and case fatality rate. SaTScan was used to detect spatial and spatio-temporal clusters of malaria cases and data were represented in the form of choropleth maps. A high-risk cluster of malaria was detected in Vale do Juruá and three low-risk clusters in Vale do Acre for both parasite species. Those younger than 19 years of age and females showed a high incidence of malaria in Vale do Juruá, but working-age males were the most affected in Vale do Acre. The malaria mortality rate showed a decreasing trend across the state, while the case fatality rate increased only in the micro-region of Rio Branco during the study period. We conclude that malaria is a focal disease in Acre showing different spatial and spatio-temporal patterns of cases and deaths that vary by age, sex, and parasite species. Malaria incidence is thought to be influenced by factors related to regional characteristics; therefore, appropriate disease and vector control strategies must be implemented at each locality.

Spatial modeling of malaria incidence rates in Sistan and Baluchistanprovince, Islamic Republic of Iran

International Nuclear Information System (INIS)

Salehi, M.; Mohammad, K.; Frahani, Mahmud M.; Zeraati, H.; Nourijelyani, K.; Zayeri, F.

2008-01-01

Objective was to identify the effect of environmental factors on malariarisk and to visualize spatial map of malaria standard incidence rates inSistan and Baluchistan province, Islamic Republic of Iran. In thiscross-sectional study, the data from 42, 162 registered new malaria casesfrom 21 March 2001 (Iran new year) to 21 of March 2006 were studied. Todescribe the statistical association between environmental factors andmalaria risk, a generalized linear mixed model approach was utilized. Inaddition, we used the second ordered stationary Kriging and a variogram todetermine the appropriate spatial correlation structure among the malariastandard incidence rates, and provide a proper malaria risk map in the areaunder study. The obtained results from the spatial modeling revealed thathumidity (p=0.0004), temperature (p<0.0001) and elevation (p<0.0001) werepositively, and precipitation (p=0.0029) was inversely correlated with themalaria risk. Moreover, the malaria risk amp based on the predicted valuesshowed that the south part of this province (Baluchistan) has a higher riskof malaria, compared to the northern area (Sistan). Since the effectiveenvironmental factors on malaria risk are out of human's control, the healthpolicy makers in this province should pay more attention to the areas withhigher temperature, elevation and humidity, as well as, low rainfalldistricts. (author)

Nested PCR detection of malaria directly using blood filter paper samples from epidemiological surveys.

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Li, Peipei; Zhao, Zhenjun; Wang, Ying; Xing, Hua; Parker, Daniel M; Yang, Zhaoqing; Baum, Elizabeth; Li, Wenli; Sattabongkot, Jetsumon; Sirichaisinthop, Jeeraphat; Li, Shuying; Yan, Guiyun; Cui, Liwang; Fan, Qi

2014-05-08

Nested PCR is considered a sensitive and specific method for detecting malaria parasites and is especially useful in epidemiological surveys. However, the preparation of DNA templates for PCR is often time-consuming and costly. A simplified PCR method was developed to directly use a small blood filter paper square (2 × 2 mm) as the DNA template after treatment with saponin. This filter paper-based nested PCR method (FP-PCR) was compared to microscopy and standard nested PCR with DNA extracted by using a Qiagen DNA mini kit from filter paper blood spots of 204 febrile cases. The FP-PCR technique was further applied to evaluate malaria infections in 1,708 participants from cross-sectional epidemiological surveys conducted in Myanmar and Thailand. The FP-PCR method had a detection limit of ~0.2 parasites/μL blood, estimated using cultured Plasmodium falciparum parasites. With 204 field samples, the sensitivity of the FP-PCR method was comparable to that of the standard nested PCR method, which was significantly higher than that of microscopy. Application of the FP-PCR method in large cross-sectional studies conducted in Myanmar and Thailand detected 1.9% (12/638) and 6.2% (66/1,070) asymptomatic Plasmodium infections, respectively, as compared to the detection rates of 1.3% (8/638) and 0.04% (4/1,070) by microscopy. This FP-PCR method was much more sensitive than microscopy in detecting Plasmodium infections. It drastically increased the detection sensitivity of asymptomatic infections in cross-sectional surveys conducted in Thailand and Myanmar, suggesting that this FP-PCR method has a potential for future applications in malaria epidemiology studies.

Malaria and protective behaviours: is there a malaria trap?

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Berthélemy, Jean-Claude; Thuilliez, Josselin; Doumbo, Ogobara; Gaudart, Jean

2013-06-13

In spite of massive efforts to generalize efficient prevention, such as insecticide-treated mosquito nets (ITN) or long-lasting insecticidal nets (LLINs), malaria remains prevalent in many countries and ITN/LLINs are still only used to a limited extent. This study proposes a new model for malaria economic analysis by combining economic epidemiology tools with the literature on poverty traps. A theoretical model of rational protective behaviour in response to malaria is designed, which includes endogenous externalities and disease characteristics. Survey data available for Uganda provide empirical support to the theory of prevalence-elastic protection behaviours, once endogeneity issues related to epidemiology and poverty are solved. Two important conclusions emerge from the model. First, agents increase their protective behaviour when malaria is more prevalent in a society. This is consistent with the literature on "prevalence-elastic behaviour". Second, a 'malaria trap' defined as the result of malaria reinforcing poverty while poverty reduces the ability to deal with malaria can theoretically exist and the conditions of existence of the malaria trap are identified. These results suggest the possible existence of malaria traps, which provides policy implications. Notably, providing ITN/LLINs at subsidized prices is not sufficient. To be efficient an ITN/LLINs dissemination campaigns should include incentive of the very poor for using ITN/LLINs.

Malaria prevalence, spatial clustering and risk factors in a low endemic area of Eastern Rwanda: a cross sectional study

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Rulisa, Stephen; Kateera, Fredrick; Bizimana, Jean Pierre; Agaba, Steven; Dukuzumuremyi, Javier; Baas, Lisette; de Dieu Harelimana, Jean; Mens, Petra F.; Boer, Kimberly R.; de Vries, Peter J.

2013-01-01

Rwanda reported significant reductions in malaria burden following scale up of control intervention from 2005 to 2010. This study sought to; measure malaria prevalence, describe spatial malaria clustering and investigate for malaria risk factors among health-centre-presumed malaria cases and their

Spatial patterns of malaria in a land reform colonization project, Juruena municipality, Mato Grosso, Brazil

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Souza-Santos Reinaldo

2011-06-01

Full Text Available Abstract Background In Brazil, 99% of malaria cases are concentrated in the Amazon, and malaria's spatial distribution is commonly associated with socio-environmental conditions on a fine landscape scale. In this study, the spatial patterns of malaria and its determinants in a rural settlement of the Brazilian agricultural reform programme called "Vale do Amanhecer" in the northern Mato Grosso state were analysed. Methods In a fine-scaled, exploratory ecological study, geocoded notification forms corresponding to malaria cases from 2005 were compared with spectral indices, such as the Normalized Difference Vegetation Index (NDVI and the third component of the Tasseled Cap Transformation (TC_3 and thematic layers, derived from the visual interpretation of multispectral TM-Landsat 5 imagery and the application of GIS distance operators. Results Of a total of 336 malaria cases, 102 (30.36% were caused by Plasmodium falciparum and 174 (51.79% by Plasmodium vivax. Of all the cases, 37.6% (133 cases were from residents of a unique road. In total, 276 cases were reported for the southern part of the settlement, where the population density is higher, with notification rates higher than 10 cases per household. The local landscape mostly consists of open areas (38.79 km². Training forest occupied 27.34 km² and midsize vegetation 7.01 km². Most domiciles with more than five notified malaria cases were located near areas with high NDVI values. Most domiciles (41.78% and malaria cases (44.94% were concentrated in areas with intermediate values of the TC_3, a spectral index representing surface and vegetation humidity. Conclusions Environmental factors and their alteration are associated with the occurrence and spatial distribution of malaria cases in rural settlements.

Epidemiology of Disappearing Plasmodium vivax Malaria: A Case Study in Rural Amazonia

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Lima, Nathália F.; Batista, Camilla L.; Bastos, Melissa da Silva; Nicolete, Vanessa C.; Fontoura, Pablo S.; Gonçalves, Raquel M.; Viana, Susana Ariane S.; Menezes, Maria José; Scopel, Kézia Katiani G.; Cavasini, Carlos E.; Malafronte, Rosely dos Santos; da Silva-Nunes, Mônica; Vinetz, Joseph M.; Castro, Márcia C.; Ferreira, Marcelo U.

2014-01-01

Background New frontier settlements across the Amazon Basin pose a major challenge for malaria elimination in Brazil. Here we describe the epidemiology of malaria during the early phases of occupation of farming settlements in Remansinho area, Brazilian Amazonia. We examine the relative contribution of low-density and asymptomatic parasitemias to the overall Plasmodium vivax burden over a period of declining transmission and discuss potential hurdles for malaria elimination in Remansinho and similar settings. Methods Eight community-wide cross-sectional surveys, involving 584 subjects, were carried out in Remansinho over 3 years and complemented by active and passive surveillance of febrile illnesses between the surveys. We used quantitative PCR to detect low-density asexual parasitemias and gametocytemias missed by conventional microscopy. Mixed-effects multiple logistic regression models were used to characterize independent risk factors for P. vivax infection and disease. Principal Findings/Conclusions P. vivax prevalence decreased from 23.8% (March–April 2010) to 3.0% (April–May 2013), with no P. falciparum infections diagnosed after March–April 2011. Although migrants from malaria-free areas were at increased risk of malaria, their odds of having P. vivax infection and disease decreased by 2–3% with each year of residence in Amazonia. Several findings indicate that low-density and asymptomatic P. vivax parasitemias may complicate residual malaria elimination in Remansinho: (a) the proportion of subpatent infections (i.e. missed by microscopy) increased from 43.8% to 73.1% as P. vivax transmission declined; (b) most (56.6%) P. vivax infections were asymptomatic and 32.8% of them were both subpatent and asymptomatic; (c) asymptomatic parasite carriers accounted for 54.4% of the total P. vivax biomass in the host population; (d) over 90% subpatent and asymptomatic P. vivax had PCR-detectable gametocytemias; and (e) few (17.0%) asymptomatic and subpatent P

Micro-spatial distribution of malaria cases and control strategies at ward level in Gwanda district, Matabeleland South, Zimbabwe.

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Manyangadze, Tawanda; Chimbari, Moses J; Macherera, Margaret; Mukaratirwa, Samson

2017-11-21

Although there has been a decline in the number of malaria cases in Zimbabwe since 2010, the disease remains the biggest public health threat in the country. Gwanda district, located in Matabeleland South Province of Zimbabwe has progressed to the malaria pre-elimination phase. The aim of this study was to determine the spatial distribution of malaria incidence at ward level for improving the planning and implementation of malaria elimination in the district. The Poisson purely spatial model was used to detect malaria clusters and their properties, including relative risk and significance levels at ward level. The geographically weighted Poisson regression (GWPR) model was used to explore the potential role and significance of environmental variables [rainfall, minimum and maximum temperature, altitude, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rural/urban] and malaria control strategies [indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLINs)] on the spatial patterns of malaria incidence at ward level. Two significant clusters (p malaria cases were identified: (1) ward 24 south of Gwanda district and (2) ward 9 in the urban municipality, with relative risks of 5.583 and 4.316, respectively. The semiparametric-GWPR model with both local and global variables had higher performance based on AICc (70.882) compared to global regression (74.390) and GWPR which assumed that all variables varied locally (73.364). The semiparametric-GWPR captured the spatially non-stationary relationship between malaria cases and minimum temperature, NDVI, NDWI, and altitude at the ward level. The influence of LLINs, IRS and rural or urban did not vary and remained in the model as global terms. NDWI (positive coefficients) and NDVI (range from negative to positive coefficients) showed significant association with malaria cases in some of the wards. The IRS had a protection effect on

Malaria burden and control in Bangladesh and prospects for elimination: an epidemiological and economic assessment.

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Haque, Ubydul; Overgaard, Hans J; Clements, Archie C A; Norris, Douglas E; Islam, Nazrul; Karim, Jahirul; Roy, Shyamal; Haque, Waziul; Kabir, Moktadir; Smith, David L; Glass, Gregory E

2014-02-01

Malaria is endemic in 13 of 64 districts in Bangladesh. About 14 million people are at risk. Some evidence suggests that the prevalence of malaria in Bangladesh has decreased since the the Global Fund to Fight AIDS, Tuberculosis and Malaria started to support the National Malaria Control Program (NMCP) in 2007. We did an epidemiological and economic assessment of malaria control in Bangladesh. We obtained annually reported, district-level aggregated malaria case data and information about disbursed funds from the NMCP. We used a Poisson regression model to examine the associations between total malaria, severe malaria, malaria-attributable mortality, and insecticide-treated net coverage. We identified and mapped malaria hotspots using the Getis-Ord Gi* statistic. We estimated the cost-effectiveness of the NMCP by estimating the cost per confirmed case, cost per treated case, and cost per person of insecticide-treated net coverage. During the study period (from Jan 1, 2008, to Dec 31, 2012) there were 285,731 confirmed malaria cases. Malaria decreased from 6.2 cases per 1000 population in 2008, to 2.1 cases per 1000 population in 2012. Prevalence of all malaria decreased by 65% (95% CI 65-66), severe malaria decreased by 79% (78-80), and malaria-associated mortality decreased by 91% (83-95). By 2012, there was one insecticide-treated net for every 2.6 individuals (SD 0.20). Districts with more than 0.5 insecticide-treated nets per person had a decrease in prevalence of 21% (95% CI 19-23) for all malaria, 25% (17-32) for severe malaria, and 76% (35-91) for malaria-associated mortality among all age groups. Malaria hotspots remained in the highly endemic districts in the Chittagong Hill Tracts. The cost per diagnosed case was US$0.39 (SD 0.02) and per treated case was $0.51 (0.27); $0.05 (0.04) was invested per person per year for health education and $0.68 (0.30) was spent per person per year for insecticide-treated net coverage. Malaria elimination is an achievable

Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae bionomics and malaria epidemiology

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Jordi Sanchez-Ribas

2012-08-01

Full Text Available Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas. Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.

A census-weighted, spatially-stratified household sampling strategy for urban malaria epidemiology

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Slutsker Laurence

2008-02-01

Full Text Available Abstract Background Urban malaria is likely to become increasingly important as a consequence of the growing proportion of Africans living in cities. A novel sampling strategy was developed for urban areas to generate a sample simultaneously representative of population and inhabited environments. Such a strategy should facilitate analysis of important epidemiological relationships in this ecological context. Methods Census maps and summary data for Kisumu, Kenya, were used to create a pseudo-sampling frame using the geographic coordinates of census-sampled structures. For every enumeration area (EA designated as urban by the census (n = 535, a sample of structures equal to one-tenth the number of households was selected. In EAs designated as rural (n = 32, a geographically random sample totalling one-tenth the number of households was selected from a grid of points at 100 m intervals. The selected samples were cross-referenced to a geographic information system, and coordinates transferred to handheld global positioning units. Interviewers found the closest eligible household to the sampling point and interviewed the caregiver of a child aged Results 4,336 interviews were completed in 473 of the 567 study area EAs from June 2002 through February 2003. EAs without completed interviews were randomly distributed, and non-response was approximately 2%. Mean distance from the assigned sampling point to the completed interview was 74.6 m, and was significantly less in urban than rural EAs, even when controlling for number of households. The selected sample had significantly more children and females of childbearing age than the general population, and fewer older individuals. Conclusion This method selected a sample that was simultaneously population-representative and inclusive of important environmental variation. The use of a pseudo-sampling frame and pre-programmed handheld GPS units is more efficient and may yield a more complete sample than

An epidemiological overview of malaria in Bangladesh.

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Islam, Nazrul; Bonovas, Stefanos; Nikolopoulos, Georgios K

2013-01-01

Bangladesh is one of the four major malaria-endemic countries in South-East Asia having approximately 34% of its population at risk of malaria. This paper aims at providing an overview of the malaria situation in this country. Relevant information was retrieved from published articles and reports in PubMed and Google Scholar. Malaria in Bangladesh is concentrated in 13 districts with a prevalence ranging between 3.1% and 36%, and is mostly caused by Plasmodium falciparum. Geographical conditions pose a potential risk for Plasmodium knowlesi malaria. Resistance to a number of drugs previously recommended for treatment has been reported. Low socio-economic status, poor schooling and close proximity to water bodies and forest areas comprise important risk factors. Despite the significant steps in Long Lasting Insecticide Net (LLIN)/Insecticide Treated Net (ITN) coverage in Bangladesh, there are still many challenges including the extension of malaria support to the remote areas of Bangladesh, where malaria prevalence is higher, and further improvements in the field of referral system and treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

A multi-level spatial analysis of clinical malaria and subclinical Plasmodium infections in Pailin Province, Cambodia

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Daniel M. Parker

2017-11-01

Full Text Available Background: The malaria burden is decreasing throughout the Greater Mekong Subregion, however transmission persists in some areas. Human movement, subclinical infections and complicated transmission patterns contribute to the persistence of malaria. This research describes the micro-geographical epidemiology of both clinical malaria and subclinical Plasmodium infections in three villages in Western Cambodia. Methods: Three villages in Western Cambodia were selected for the study based on high reported Plasmodium falciparum incidence. A census was conducted at the beginning of the study, including demographic information and travel history. The total population was 1766. Cross-sectional surveys were conducted every three months from June 2013 to June 2014. Plasmodium infections were detected using an ultra-sensitive, high-volume, quantitative polymerase chain reaction (uPCR technique. Clinical episodes were recorded by village health workers. The geographic coordinates (latitude and longitude were collected for all houses and all participants were linked to their respective houses using a demographic surveillance system. Written informed consent was obtained from all participants. Results: Most clinical episodes and subclinical infections occurred within a single study village. Clinical Plasmodium vivax episodes clustered spatially in each village but only lasted for a month. In one study village subclinical infections clustered in geographic proximity to clusters of clinical episodes. The largest risk factor for clinical P. falciparum episodes was living in a house where another clinical P. falciparum episode occurred (model adjusted odds ratio (AOR: 6.9; CI: 2.3–19. 8. Subclinical infections of both P. vivax and P. falciparum were associated with clinical episodes of the same species (AOR: 5.8; CI: 1.5–19.7 for P. falciparum and AOR: 14.6; CI: 8.6–25.2 for P. vivax and self-reported overnight visits to forested areas (AOR = 3.8; CI: 1.8�

Integrating malaria surveillance with climate data for outbreak detection and forecasting: the EPIDEMIA system.

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Merkord, Christopher L; Liu, Yi; Mihretie, Abere; Gebrehiwot, Teklehaymanot; Awoke, Worku; Bayabil, Estifanos; Henebry, Geoffrey M; Kassa, Gebeyaw T; Lake, Mastewal; Wimberly, Michael C

2017-02-23

Early indication of an emerging malaria epidemic can provide an opportunity for proactive interventions. Challenges to the identification of nascent malaria epidemics include obtaining recent epidemiological surveillance data, spatially and temporally harmonizing this information with timely data on environmental precursors, applying models for early detection and early warning, and communicating results to public health officials. Automated web-based informatics systems can provide a solution to these problems, but their implementation in real-world settings has been limited. The Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system was designed and implemented to integrate disease surveillance with environmental monitoring in support of operational malaria forecasting in the Amhara region of Ethiopia. A co-design workshop was held with computer scientists, epidemiological modelers, and public health partners to develop an initial list of system requirements. Subsequent updates to the system were based on feedback obtained from system evaluation workshops and assessments conducted by a steering committee of users in the public health sector. The system integrated epidemiological data uploaded weekly by the Amhara Regional Health Bureau with remotely-sensed environmental data freely available from online archives. Environmental data were acquired and processed automatically by the EASTWeb software program. Additional software was developed to implement a public health interface for data upload and download, harmonize the epidemiological and environmental data into a unified database, automatically update time series forecasting models, and generate formatted reports. Reporting features included district-level control charts and maps summarizing epidemiological indicators of emerging malaria outbreaks, environmental risk factors, and forecasts of future malaria risk. Successful implementation and

Epidemiology of Plasmodium vivax Malaria in Peru.

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Rosas-Aguirre, Angel; Gamboa, Dionicia; Manrique, Paulo; Conn, Jan E; Moreno, Marta; Lescano, Andres G; Sanchez, Juan F; Rodriguez, Hugo; Silva, Hermann; Llanos-Cuentas, Alejandro; Vinetz, Joseph M

2016-12-28

Malaria in Peru, dominated by Plasmodium vivax, remains a public health problem. The 1990s saw newly epidemic malaria emerge, primarily in the Loreto Department in the Amazon region, including areas near to Iquitos, the capital city, but sporadic malaria transmission also occurred in the 1990s-2000s in both north-coastal Peru and the gold mining regions of southeastern Peru. Although a Global Fund-supported intervention (PAMAFRO, 2005-2010) was temporally associated with a decrease of malaria transmission, from 2012 to the present, both P. vivax and Plasmodium falciparum malaria cases have rapidly increased. The Peruvian Ministry of Health continues to provide artemesinin-based combination therapy for microscopy-confirmed cases of P. falciparum and chloroquine-primaquine for P. vivax Malaria transmission continues in remote areas nonetheless, where the mobility of humans and parasites facilitates continued reintroduction outside of ongoing surveillance activities, which is critical to address for future malaria control and elimination efforts. Ongoing P. vivax research gaps in Peru include the following: identification of asymptomatic parasitemics, quantification of the contribution of patent and subpatent parasitemics to mosquito transmission, diagnosis of nonparasitemic hypnozoite carriers, and implementation of surveillance for potential emergence of chloroquine- and 8-aminoquinoline-resistant P. vivax Clinical trials of tafenoquine in Peru have been promising, and glucose-6-phosphate dehydrogenase deficiency in the region has not been observed to be a limitation to its use. Larger-scale challenges for P. vivax (and malaria in general) in Peru include logistical difficulties in accessing remote riverine populations, consequences of government policy and poverty trends, and obtaining international funding for malaria control and elimination. © The American Society of Tropical Medicine and Hygiene.

Epidemiology of Plasmodium vivax Malaria in Peru

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Rosas-Aguirre, Angel; Gamboa, Dionicia; Manrique, Paulo; Conn, Jan E.; Moreno, Marta; Lescano, Andres G.; Sanchez, Juan F.; Rodriguez, Hugo; Silva, Hermann; Llanos-Cuentas, Alejandro; Vinetz, Joseph M.

2016-01-01

Malaria in Peru, dominated by Plasmodium vivax, remains a public health problem. The 1990s saw newly epidemic malaria emerge, primarily in the Loreto Department in the Amazon region, including areas near to Iquitos, the capital city, but sporadic malaria transmission also occurred in the 1990s–2000s in both north-coastal Peru and the gold mining regions of southeastern Peru. Although a Global Fund-supported intervention (PAMAFRO, 2005–2010) was temporally associated with a decrease of malaria transmission, from 2012 to the present, both P. vivax and Plasmodium falciparum malaria cases have rapidly increased. The Peruvian Ministry of Health continues to provide artemesinin-based combination therapy for microscopy-confirmed cases of P. falciparum and chloroquine–primaquine for P. vivax. Malaria transmission continues in remote areas nonetheless, where the mobility of humans and parasites facilitates continued reintroduction outside of ongoing surveillance activities, which is critical to address for future malaria control and elimination efforts. Ongoing P. vivax research gaps in Peru include the following: identification of asymptomatic parasitemics, quantification of the contribution of patent and subpatent parasitemics to mosquito transmission, diagnosis of nonparasitemic hypnozoite carriers, and implementation of surveillance for potential emergence of chloroquine- and 8-aminoquinoline-resistant P. vivax. Clinical trials of tafenoquine in Peru have been promising, and glucose-6-phosphate dehydrogenase deficiency in the region has not been observed to be a limitation to its use. Larger-scale challenges for P. vivax (and malaria in general) in Peru include logistical difficulties in accessing remote riverine populations, consequences of government policy and poverty trends, and obtaining international funding for malaria control and elimination. PMID:27799639

Wetlands and Malaria in the Amazon: Guidelines for the Use of Synthetic Aperture Radar Remote-Sensing

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Catry, Thibault; Li, Zhichao; Roux, Emmanuel; Herbreteau, Vincent; Dessay, Nadine

2018-01-01

The prevention and control of mosquito-borne diseases, such as malaria, are important health issues in tropical areas. Malaria transmission is a multi-scale process strongly controlled by environmental factors, and the use of remote-sensing data is suitable for the characterization of its spatial and temporal dynamics. Synthetic aperture radar (SAR) is well-adapted to tropical areas, since it is capable of imaging independent of light and weather conditions. In this study, we highlight the contribution of SAR sensors in the assessment of the relationship between vectors, malaria and the environment in the Amazon region. More specifically, we focus on the SAR-based characterization of potential breeding sites of mosquito larvae, such as man-made water collections and natural wetlands, providing guidelines for the use of SAR capabilities and techniques in order to optimize vector control and malaria surveillance. In light of these guidelines, we propose a framework for the production of spatialized indicators and malaria risk maps based on the combination of SAR, entomological and epidemiological data to support malaria risk prevention and control actions in the field. PMID:29518988

Wetlands and Malaria in the Amazon: Guidelines for the Use of Synthetic Aperture Radar Remote-Sensing

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Thibault Catry

2018-03-01

Full Text Available The prevention and control of mosquito-borne diseases, such as malaria, are important health issues in tropical areas. Malaria transmission is a multi-scale process strongly controlled by environmental factors, and the use of remote-sensing data is suitable for the characterization of its spatial and temporal dynamics. Synthetic aperture radar (SAR is well-adapted to tropical areas, since it is capable of imaging independent of light and weather conditions. In this study, we highlight the contribution of SAR sensors in the assessment of the relationship between vectors, malaria and the environment in the Amazon region. More specifically, we focus on the SAR-based characterization of potential breeding sites of mosquito larvae, such as man-made water collections and natural wetlands, providing guidelines for the use of SAR capabilities and techniques in order to optimize vector control and malaria surveillance. In light of these guidelines, we propose a framework for the production of spatialized indicators and malaria risk maps based on the combination of SAR, entomological and epidemiological data to support malaria risk prevention and control actions in the field.

Plasmodium knowlesi malaria an emerging public health problem in Hulu Selangor, Selangor, Malaysia (2009-2013): epidemiologic and entomologic analysis.

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Vythilingam, Indra; Lim, Yvonne Al; Venugopalan, Balan; Ngui, Romano; Leong, Cherng Shii; Wong, Meng Li; Khaw, LokeTim; Goh, XiangTing; Yap, NanJiun; Sulaiman, Wan Yusoff Wan; Jeffery, John; Zawiah, Ab Ghani Ct; Nor Aszlina, Ismail; Sharma, Reuben Sk; Yee Ling, Lau; Mahmud, Rohela

2014-09-15

While transmission of the human Plasmodium species has declined, a significant increase in Plasmodium knowlesi/Plasmodium malariae cases was reported in Hulu Selangor, Selangor, Malaysia. Thus, a study was undertaken to determine the epidemiology and the vectors involved in the transmission of knowlesi malaria. Cases of knowlesi/malariae malaria in the Hulu Selangor district were retrospectively reviewed and analyzed from 2009 to 2013. Mosquitoes were collected from areas where cases occurred in order to determine the vectors. Leucosphyrus group of mosquitoes were genetically characterized targeting the nuclear internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit I (CO1). In addition, temporal and spatial analyses were carried out for human cases and vectors. Of the 100 microscopy diagnosed P. knowlesi/P. malariae cases over the 5 year period in the Hulu Selangor district, there was predominance of P. knowlesi/P. malariae cases among the young adults (ages 20-39 years; 67 cases; 67%). The majority of the infected people were involved in occupations related to agriculture and forestry (51; 51%). No death was recorded in all these cases.Five hundred and thirty five mosquitoes belonging to 14 species were obtained during the study. Anopheles maculatus was the predominant species (49.5%) followed by Anopheles letifer (13.1%) and Anopheles introlatus (11.6%). Molecular and phylogenetic analysis confirmed the species of the Leucosphyrus group to be An. introlatus. In the present study, only An. introlatus was positive for oocysts. Kernel Density analysis showed that P. knowlesi hotspot areas overlapped with areas where the infected An. introlatus was discovered. This further strengthens the hypothesis that An. introlatusis is the vector for P. knowlesi in the Hulu Selangor district.Unless more information is obtained on the vectors as well as macaque involved in the transmission, it will be difficult to plan effective control strategies

Integrating remote sensing and spatially explicit epidemiological modeling

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Finger, Flavio; Knox, Allyn; Bertuzzo, Enrico; Mari, Lorenzo; Bompangue, Didier; Gatto, Marino; Rinaldo, Andrea

2015-04-01

Spatially explicit epidemiological models are a crucial tool for the prediction of epidemiological patterns in time and space as well as for the allocation of health care resources. In addition they can provide valuable information about epidemiological processes and allow for the identification of environmental drivers of the disease spread. Most epidemiological models rely on environmental data as inputs. They can either be measured in the field by the means of conventional instruments or using remote sensing techniques to measure suitable proxies of the variables of interest. The later benefit from several advantages over conventional methods, including data availability, which can be an issue especially in developing, and spatial as well as temporal resolution of the data, which is particularly crucial for spatially explicit models. Here we present the case study of a spatially explicit, semi-mechanistic model applied to recurring cholera outbreaks in the Lake Kivu area (Democratic Republic of the Congo). The model describes the cholera incidence in eight health zones on the shore of the lake. Remotely sensed datasets of chlorophyll a concentration in the lake, precipitation and indices of global climate anomalies are used as environmental drivers. Human mobility and its effect on the disease spread is also taken into account. Several model configurations are tested on a data set of reported cases. The best models, accounting for different environmental drivers, and selected using the Akaike information criterion, are formally compared via cross validation. The best performing model accounts for seasonality, El Niño Southern Oscillation, precipitation and human mobility.

Malaria prevalence, risk factors and spatial distribution in a hilly forest area of Bangladesh.

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Ubydul Haque

Full Text Available BACKGROUND: Malaria is a major public health concern in Bangladesh and it is highly endemic in the Chittagong Hill Tracts where prevalence was 11.7% in 2007. One sub-district, Rajasthali, had a prevalence of 36%. Several interventions were introduced in early 2007 to control malaria. This study was undertaken to evaluate the impacts of these intensive early stage interventions on malaria in Bangladesh. This prevalence study assesses whether or not high malaria prevalence remains, and if so, which areas and individuals remain at high risk of infection. METHODS AND PRINCIPAL FINDINGS: A 2-stage cluster sampling technique was used to sample 1,400 of 5,322 (26.3% households in Rajasthali, and screened using a rapid diagnostic test (Falci-vax. Overall malaria prevalence was 11.5%. The proportions of Plasmodium falciparum, Plasmodium vivax and infection with both species were 93.2%, 1.9% and 5.0%, respectively. Univariate, multivariate logistic regression, and spatial cluster analyses were performed separately. Sex, age, number of bed nets, forest cover, altitude and household density were potential risk factors. A statistically significant malaria cluster was identified. Significant differences among risk factors were observed between cluster and non-cluster areas. CONCLUSION AND SIGNIFICANCE: Malaria has significantly decreased within 2 years after onset of intervention program. Both aspects of the physical and social environment, as well as demographic characteristics are associated with spatial heterogeneity of risk. The ability to identify and locate these areas provides a strategy for targeting interventions during initial stages of intervention programs. However, in high risk clusters of transmission, even extensive coverage by current programs leaves transmission ongoing at reduced levels. This indicates the need for continued development of new strategies for identification and treatment as well as improved understanding of the patterns and

Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India.

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Mauricio Santos-Vega

2016-12-01

Full Text Available The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria.Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors.Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a

Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India.

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Santos-Vega, Mauricio; Bouma, Menno J; Kohli, Vijay; Pascual, Mercedes

2016-12-01

The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria. Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India) that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors. Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a basis for more

Developing a spatial-statistical model and map of historical malaria prevalence in Botswana using a staged variable selection procedure

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Mabaso Musawenkosi LH

2007-09-01

Full Text Available Abstract Background Several malaria risk maps have been developed in recent years, many from the prevalence of infection data collated by the MARA (Mapping Malaria Risk in Africa project, and using various environmental data sets as predictors. Variable selection is a major obstacle due to analytical problems caused by over-fitting, confounding and non-independence in the data. Testing and comparing every combination of explanatory variables in a Bayesian spatial framework remains unfeasible for most researchers. The aim of this study was to develop a malaria risk map using a systematic and practicable variable selection process for spatial analysis and mapping of historical malaria risk in Botswana. Results Of 50 potential explanatory variables from eight environmental data themes, 42 were significantly associated with malaria prevalence in univariate logistic regression and were ranked by the Akaike Information Criterion. Those correlated with higher-ranking relatives of the same environmental theme, were temporarily excluded. The remaining 14 candidates were ranked by selection frequency after running automated step-wise selection procedures on 1000 bootstrap samples drawn from the data. A non-spatial multiple-variable model was developed through step-wise inclusion in order of selection frequency. Previously excluded variables were then re-evaluated for inclusion, using further step-wise bootstrap procedures, resulting in the exclusion of another variable. Finally a Bayesian geo-statistical model using Markov Chain Monte Carlo simulation was fitted to the data, resulting in a final model of three predictor variables, namely summer rainfall, mean annual temperature and altitude. Each was independently and significantly associated with malaria prevalence after allowing for spatial correlation. This model was used to predict malaria prevalence at unobserved locations, producing a smooth risk map for the whole country. Conclusion We have

Demography, maternal health and the epidemiology of malaria and other major infectious diseases in the rural department Tsamba-Magotsi, Ngounie Province, in central African Gabon

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R. Zoleko Manego

2017-01-01

Full Text Available Abstract Background Sub-Saharan Africa is undergoing an epidemiological transition from a predominance of infectious diseases to non-communicable and lifestyle related conditions. However, the pace of this transition and the pattern of disease epidemiology are uneven between affluent urban and rural poor populations. To address this question for a remote rural region located in the central African rainforest region of Gabon, this study was conducted to assess reasons for health care attendance and to characterize the epidemiology of malaria and other major infectious diseases for the department of Tsamba Magotsi. Methods Major causes for health care attendance were collected from local hospital records. Cross sectional population based surveys were performed for the assessment of local malaria epidemiology. Pregnant women attending antenatal care services were surveyed as a sentinel population for the characterization of chronic viral and parasitic infections in the community. Results Infectious diseases were responsible for 71% (7469 of a total of 10,580 consultations at the formal health care sector in 2010. Overall, malaria – defined by clinical syndrome – remained the most frequent cause for health care attendance. A cross sectional malaria survey in 840 asymptomatic individuals residing in Tsamba Magotsi resulted in a Plasmodium spp. infection prevalence of 37%. The infection rate in 2–10 year old asymptomatic children – a standard measure for malaria endemicity – was 46% (100 of 217 with P. falciparum as predominant species (79%. Infection with other plasmodial species (P. ovale and P. malariae presented most commonly as coinfections (23.2%. Prevalence of HIV, HBV, and syphilis were 6.2, 7.3, and 2.5%, respectively, in cross-sectional assessments of antenatal care visits of pregnant women. Urogenital schistosomiasis and the filarial pathogens Loa loa and Mansonella perstans are highly prevalent chronic parasitic infections

A global model of malaria climate sensitivity: comparing malaria response to historic climate data based on simulation and officially reported malaria incidence

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Edlund Stefan

2012-09-01

Full Text Available Abstract Background The role of the Anopheles vector in malaria transmission and the effect of climate on Anopheles populations are well established. Models of the impact of climate change on the global malaria burden now have access to high-resolution climate data, but malaria surveillance data tends to be less precise, making model calibration problematic. Measurement of malaria response to fluctuations in climate variables offers a way to address these difficulties. Given the demonstrated sensitivity of malaria transmission to vector capacity, this work tests response functions to fluctuations in land surface temperature and precipitation. Methods This study of regional sensitivity of malaria incidence to year-to-year climate variations used an extended Macdonald Ross compartmental disease model (to compute malaria incidence built on top of a global Anopheles vector capacity model (based on 10 years of satellite climate data. The predicted incidence was compared with estimates from the World Health Organization and the Malaria Atlas. The models and denominator data used are freely available through the Eclipse Foundation’s Spatiotemporal Epidemiological Modeller (STEM. Results Although the absolute scale factor relating reported malaria to absolute incidence is uncertain, there is a positive correlation between predicted and reported year-to-year variation in malaria burden with an averaged root mean square (RMS error of 25% comparing normalized incidence across 86 countries. Based on this, the proposed measure of sensitivity of malaria to variations in climate variables indicates locations where malaria is most likely to increase or decrease in response to specific climate factors. Bootstrapping measures the increased uncertainty in predicting malaria sensitivity when reporting is restricted to national level and an annual basis. Results indicate a potential 20x improvement in accuracy if data were available at the level ISO 3166–2

Epidemiology of imported malaria among children and young adults in Barcelona (1990-2008

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Garcia-Villarrubia Mireia

2011-11-01

Full Text Available Abstract Background Increasing international travel and migration is producing changes in trends in infectious diseases, especially in children from many European cities. The objective of this study was to describe the epidemiology and determine the trends of imported malaria in patients under 20 years old in the city of Barcelona, Spain, during an 18-year period. Methods The study included malaria cases that were laboratory confirmed and reported to the malaria register at the Public Health Agency of Barcelona from 1990 to 2008, residing in Barcelona and less than 20 years old. Patients were classified as natives (born in Spain or immigrants. Differences in the distribution of demographic, clinical characteristics, and incidence per 100,000 person-year evolution were analysed. Natives and immigrants were compared by logistic regression by calculating the odds ratio (OR with a 95% confidence interval (CI and Chi-square for a linear trend (p Results Of the total 174 cases, 143 (82.1% were immigrants, 100 (57.5% were female, 121 (69.5% Plasmodium falciparum, and 108 (62.1% were visiting friends and relatives (VFR as the reason for travel. Among the immigrants, 99 (67.8% were from Equatorial Guinea. Immigrant cases more frequently travelled to Africa than natives (p = 0.02. The factors associated with imported malaria among immigrant residents was travelling for VFR (OR: 6.2 CI 1.9-20.2 and age 15-19 (OR: 3.7 CI 1-13.3. The incidence increased from 1990 to 1999 (p Conclusions The majority of cases of malaria in population less than 20 years in Barcelona were immigrants, travelling to Africa for VFR and Plasmodium falciparum was most frequently detected. The trend analysis of the entire study period did not show a statistically significant decline. It is recommended to be aware of malaria, especially among children of immigrants who travel to their parent's home country for VFR. Better access to pre travel advice should be provided.

Malaria in Children.

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Cohee, Lauren M; Laufer, Miriam K

2017-08-01

Malaria is a leading cause of morbidity and mortality in endemic areas, leading to an estimated 438,000 deaths in 2015. Malaria is also an important health threat to travelers to endemic countries and should be considered in evaluation of any traveler returning from a malaria-endemic area who develops fever. Considering the diagnosis of malaria in patients with potential exposure is critical. Prompt provision of effective treatment limits the complications of malaria and can be life-saving. Understanding Plasmodium species variation, epidemiology, and drug-resistance patterns in the geographic area where infection was acquired is important for determining treatment choices. Copyright © 2017 Elsevier Inc. All rights reserved.

A micro-epidemiological analysis of febrile malaria in Coastal Kenya showing hotspots within hotspots

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Bejon, P.; Williams, T.N.; Nyundo, C.; Hay, S.I.; Benz, D.; Gething, P.W.; Otiende, M.; Peshu, J.; Bashraheil, M.; Greenhouse, B.; Bousema, T.; Bauni, E.; Marsh, K.; Smith, D.L.; Borrmann, S.

2014-01-01

Malaria transmission is spatially heterogeneous. This reduces the efficacy of control strategies, but focusing control strategies on clusters or 'hotspots' of transmission may be highly effective. Among 1500 homesteads in coastal Kenya we calculated (a) the fraction of febrile children with positive

Meteorological, environmental remote sensing and neural network analysis of the epidemiology of malaria transmission in Thailand

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Richard Kiang

2006-11-01

Full Text Available In many malarious regions malaria transmission roughly coincides with rainy seasons, which provide for more abundant larval habitats. In addition to precipitation, other meteorological and environmental factors may also influence malaria transmission. These factors can be remotely sensed using earth observing environmental satellites and estimated with seasonal climate forecasts. The use of remote sensing usage as an early warning tool for malaria epidemics have been broadly studied in recent years, especially for Africa, where the majority of the world’s malaria occurs. Although the Greater Mekong Subregion (GMS, which includes Thailand and the surrounding countries, is an epicenter of multidrug resistant falciparum malaria, the meteorological and environmental factors affecting malaria transmissions in the GMS have not been examined in detail. In this study, the parasitological data used consisted of the monthly malaria epidemiology data at the provincial level compiled by the Thai Ministry of Public Health. Precipitation, temperature, relative humidity, and vegetation index obtained from both climate time series and satellite measurements were used as independent variables to model malaria. We used neural network methods, an artificial-intelligence technique, to model the dependency of malaria transmission on these variables. The average training accuracy of the neural network analysis for three provinces (Kanchanaburi, Mae Hong Son, and Tak which are among the provinces most endemic for malaria, is 72.8% and the average testing accuracy is 62.9% based on the 1994-1999 data. A more complex neural network architecture resulted in higher training accuracy but also lower testing accuracy. Taking into account of the uncertainty regarding reported malaria cases, we divided the malaria cases into bands (classes to compute training accuracy. Using the same neural network architecture on the 19 most endemic provinces for years 1994 to 2000, the

Human biting activity, spatial-temporal distribution and malaria vector role of Anopheles calderoni in the southwest of Colombia.

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Orjuela, Lorena I; Ahumada, Martha L; Avila, Ivonni; Herrera, Sócrates; Beier, John C; Quiñones, Martha L

2015-06-24

Anopheles calderoni was first recognized in Colombia in 2010 as this species had been misidentified as Anopheles punctimacula due to morphological similarities. An. calderoni is considered a malaria vector in Peru and has been found naturally infected with Plasmodium falciparum in Colombia. However, its biting behaviour, population dynamics and epidemiological importance have not been well described for Colombia. To assess the contribution of An. calderoni to malaria transmission and its human biting behaviour and spatial/temporal distribution in the southwest of Colombia, human landing catches (HLC) and larval collections were carried out in a cross-sectional, entomological study in 22 localities between 2011 and 2012, and a longitudinal study was performed in the Boca de Prieta locality in Olaya Herrera municipality between July 2012 and June 2013. All mosquitoes determined as An. calderoni were tested by ELISA to establish infection with Plasmodium spp. Larvae of An. calderoni were found in four localities in 12 out of 244 breeding sites inspected. An. calderoni adults were collected in 14 out of 22 localities during the cross-sectional study and represented 41.3% (459 of 1,111) of the collected adult specimens. Other species found were Anopheles albimanus (54.7%), Anopheles apicimacula (2.1%), Anopheles neivai (1.7%), and Anopheles argyritarsis (0.2%). In the localities that reported the highest malaria Annual Parasite Index (>10/1,000 inhabitants) during the year of sampling, An. calderoni was the predominant species (>90% of the specimens collected). In the longitudinal study, 1,528 An. calderoni were collected by HLC with highest biting rates in February, May and June 2013, periods of high precipitation. In general, the species showed a preference to bite outdoors (p Colombia. Its observed preference for outdoor biting is a major challenge for malaria control.

Spatial analysis and mapping of malaria risk in Malawi using point-referenced prevalence of infection data

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Kazembe Lawrence N

2006-09-01

Full Text Available Abstract Background Current malaria control initiatives aim at reducing malaria burden by half by the year 2010. Effective control requires evidence-based utilisation of resources. Characterizing spatial patterns of risk, through maps, is an important tool to guide control programmes. To this end an analysis was carried out to predict and map malaria risk in Malawi using empirical data with the aim of identifying areas where greatest effort should be focussed. Methods Point-referenced prevalence of infection data for children aged 1–10 years were collected from published and grey literature and geo-referenced. The model-based geostatistical methods were applied to analyze and predict malaria risk in areas where data were not observed. Topographical and climatic covariates were added in the model for risk assessment and improved prediction. A Bayesian approach was used for model fitting and prediction. Results Bivariate models showed a significant association of malaria risk with elevation, annual maximum temperature, rainfall and potential evapotranspiration (PET. However in the prediction model, the spatial distribution of malaria risk was associated with elevation, and marginally with maximum temperature and PET. The resulting map broadly agreed with expert opinion about the variation of risk in the country, and further showed marked variation even at local level. High risk areas were in the low-lying lake shore regions, while low risk was along the highlands in the country. Conclusion The map provided an initial description of the geographic variation of malaria risk in Malawi, and might help in the choice and design of interventions, which is crucial for reducing the burden of malaria in Malawi.

Epidemiology and control of malaria and other arthropod born diseases

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F. J. López-Antuñano

1992-01-01

Full Text Available Malaria and other arthropod born diseases remain a serious public health problem affecting the lives and health of certain social groups when the two basic strategies to control fail due to : (1 the lack of effective chemoprophylaxis/chemotherapy or the rapid development of drug resistance of the infectious agents and (2 the ineffectiveness of pesticides or the arthropod vectors develop resistance to them. These situations enhances the need for the design and implementation of other alternatives for sustainable health programmes. The application of the epidemiological methods is essential not only for analyzing the relevant data for the understanding of the biological characteristics of the infectious agents, their reservoirs and vectors and the methods for their control, but also for the assessment of the human behaviour, the environmental, social and economic factors involved in disease transmission and the capacity of the health systems to implement interventions for both changes in human behaviour and environmental management to purpose guaranteed prevention and control of malaria and other arthropod born diseases with efficiency, efficacy and equity. This paper discuss the evolution of the malaria arthropod diseases programmes in the American Region and the perspectives for their integration into health promotion programs and emphasis is made in the need to establish solid basis in the decision-making process for the selection of intervention strategies to remove the risk factors determining the probability to get sick or die from ABDs. The implications of the general planning and the polices to be adopted in an area should be analyzed in the light of programme feasibility at the local level, in the multisectoral context specific social groups and taking in consideration the principles of stratification and equity

Modelling homogeneous regions of social vulnerability to malaria in Rwanda.

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Bizimana, Jean Pierre; Kienberger, Stefan; Hagenlocher, Michael; Twarabamenye, Emmanuel

2016-03-31

Despite the decline in malaria incidence due to intense interventions, potentials for malaria transmission persist in Rwanda. To eradicate malaria in Rwanda, strategies need to expand beyond approaches that focus solely on malaria epidemiology and also consider the socioeconomic, demographic and biological/disease-related factors that determine the vulnerability of potentially exposed populations. This paper analyses current levels of social vulnerability to malaria in Rwanda by integrating a set of weighted vulnerability indicators. The paper uses regionalisation techniques as a spatially explicit approach for delineating homogeneous regions of social vulnerability to malaria. This overcomes the limitations of administrative boundaries for modelling the trans-boundary social vulnerability to malaria. The utilised approach revealed high levels of social vulnerability to malaria in the highland areas of Rwanda, as well as in remote areas where populations are more susceptible. Susceptibility may be due to the populations' lacking the capacity to anticipate mosquito bites, or lacking resilience to cope with or recover from malaria infection. By highlighting the most influential indicators of social vulnerability to malaria, the applied approach indicates which vulnerability domains need to be addressed, and where appropriate interventions are most required. Interventions to improve the socioeconomic development in highly vulnerable areas could prove highly effective, and provide sustainable outcomes against malaria in Rwanda. This would ultimately increase the resilience of the population and their capacity to better anticipate, cope with, and recover from possible infection.

Epidemiology and Clinical Burden of Malaria in the War-Torn Area, Orakzai Agency in Pakistan.

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Asad Mustafa Karim

2016-01-01

Full Text Available Military conflict has been a major challenge in the detection and control of emerging infectious diseases such as malaria. It poses issues associated with enhancing emergence and transmission of infectious diseases by destroying infrastructure and collapsing healthcare systems. The Orakzai agency in Pakistan has witnessed a series of intense violence and destruction. Military conflicts and instability in Afghanistan have resulted in the migration of refugees into the area and possible introduction of many infectious disease epidemics. Due to the ongoing violence and Talibanization, it has been a challenge to conduct an epidemiological study.All patients were sampled within the transmission season. After a detailed clinical investigation of patients, data were recorded. Baseline venous blood samples were taken for microscopy and nested polymerase chain reaction (nPCR analysis. Plasmodium species were detected using nested PCR (nPCR and amplification of the small subunit ribosomal ribonucleic acid (ssrRNA genes using the primer pairs. We report a clinical assessment of the epidemic situation of malaria caused by Plasmodium vivax (86.5% and Plasmodium falciparum (11.79% infections with analysis of complications in patients such as decompensated shock (41%, anemia (8.98%, hypoglycaemia (7.3%, multiple convulsions (6.7%, hyperpyrexia (6.17%, jaundice (5%, and hyperparasitaemia (4.49%.This overlooked distribution of P. vivax should be considered by malaria control strategy makers in the world and by the Government of Pakistan. In our study, children were the most susceptible population to malaria infection while they were the least expected to use satisfactory prevention strategies in such a war-torn deprived region. Local health authorities should initiate malaria awareness programs in schools and malaria-related education should be further promoted at the local level reaching out to both children and parents.

Modelling malaria treatment practices in Bangladesh using spatial statistics

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Haque Ubydul

2012-03-01

Full Text Available Abstract Background Malaria treatment-seeking practices vary worldwide and Bangladesh is no exception. Individuals from 88 villages in Rajasthali were asked about their treatment-seeking practices. A portion of these households preferred malaria treatment from the National Control Programme, but still a large number of households continued to use drug vendors and approximately one fourth of the individuals surveyed relied exclusively on non-control programme treatments. The risks of low-control programme usage include incomplete malaria treatment, possible misuse of anti-malarial drugs, and an increased potential for drug resistance. Methods The spatial patterns of treatment-seeking practices were first examined using hot-spot analysis (Local Getis-Ord Gi statistic and then modelled using regression. Ordinary least squares (OLS regression identified key factors explaining more than 80% of the variation in control programme and vendor treatment preferences. Geographically weighted regression (GWR was then used to assess where each factor was a strong predictor of treatment-seeking preferences. Results Several factors including tribal affiliation, housing materials, household densities, education levels, and proximity to the regional urban centre, were found to be effective predictors of malaria treatment-seeking preferences. The predictive strength of each of these factors, however, varied across the study area. While education, for example, was a strong predictor in some villages, it was less important for predicting treatment-seeking outcomes in other villages. Conclusion Understanding where each factor is a strong predictor of treatment-seeking outcomes may help in planning targeted interventions aimed at increasing control programme usage. Suggested strategies include providing additional training for the Building Resources across Communities (BRAC health workers, implementing educational programmes, and addressing economic factors.

Forecasting Malaria in the Western Amazon

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Pan, W. K.; Zaitchik, B. F.; Pizzitutti, F.; Berky, A.; Feingold, B.; Mena, C.; Janko, M.

2017-12-01

Reported cases of malaria in the western Amazon regions of Peru, Colombia and Ecuador have more than tripled since 2011. Responding to this epidemic has been challenging given large-scale environmental impacts and demographic changes combined with changing financial and political priorities. In Peru alone, malaria cases increased 5-fold since 2011. Reasons include changes in the Global Malaria Fund, massive flooding in 2012, the "mega" El Nino in 2016, and continued natural resource extraction via logging and mining. These challenges prompted the recent creation of the Malaria Cero program in 2017 with the goal to eradicate malaria by 2021. To assist in malaria eradiation, a team of investigators supported by NASA have been developing an Early Warning System for Malaria. The system leverages demographic, epidemiological, meteorological and land use/cover data to develop a four-component system that will improve detection of malaria across the western Amazon Basin. System components include a land data assimilation system (LDAS) to estimate past and future hydrological states and flux, a seasonal human population model to estimate population at risk and spatial connectivity to high risk transmission areas, a sub-regional statistical model to identify when and where observed malaria cases have exceeded those expected, and an Agent Based Model (ABM) to integrate human, environmental, and entomological transmission dynamics with potential strategies for control. Data include: daily case detection reports between 2000 and 2017 from all health posts in the region of Loreto in the northern Peruvian Amazon; LDAS outputs (precipitation, temperature, humidity, solar radiation) at a 1km and weekly scale; satellite-derived estimates of land cover; and human population size from census and health data. This presentation will provide an overview of components, focusing on how the system identifies an outbreak and plans for technology transfer.

A validated agent-based model to study the spatial and temporal heterogeneities of malaria incidence in the rainforest environment.

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Pizzitutti, Francesco; Pan, William; Barbieri, Alisson; Miranda, J Jaime; Feingold, Beth; Guedes, Gilvan R; Alarcon-Valenzuela, Javiera; Mena, Carlos F

2015-12-22

The Amazon environment has been exposed in the last decades to radical changes that have been accompanied by a remarkable rise of both Plasmodium falciparum and Plasmodium vivax malaria. The malaria transmission process is highly influenced by factors such as spatial and temporal heterogeneities of the environment and individual-based characteristics of mosquitoes and humans populations. All these determinant factors can be simulated effectively trough agent-based models. This paper presents a validated agent-based model of local-scale malaria transmission. The model reproduces the environment of a typical riverine village in the northern Peruvian Amazon, where the malaria transmission is highly seasonal and apparently associated with flooding of large areas caused by the neighbouring river. Agents representing humans, mosquitoes and the two species of Plasmodium (P. falciparum and P. vivax) are simulated in a spatially explicit representation of the environment around the village. The model environment includes: climate, people houses positions and elevation. A representation of changes in the mosquito breeding areas extension caused by the river flooding is also included in the simulation environment. A calibration process was carried out to reproduce the variations of the malaria monthly incidence over a period of 3 years. The calibrated model is also able to reproduce the spatial heterogeneities of local scale malaria transmission. A "what if" eradication strategy scenario is proposed: if the mosquito breeding sites are eliminated through mosquito larva habitat management in a buffer area extended at least 200 m around the village, the malaria transmission is eradicated from the village. The use of agent-based models can reproduce effectively the spatiotemporal variations of the malaria transmission in a low endemicity environment dominated by river floodings like in the Amazon.

Patterns of malaria-related hospital admissions and mortality among Malawian children: an example of spatial modelling of hospital register data

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Kleinschmidt Immo

2006-10-01

Full Text Available Abstract Background Malaria is a leading cause of hospitalization and in-hospital mortality among children in Africa, yet, few studies have described the spatial distribution of the two outcomes. Here spatial regression models were applied, aimed at quantifying spatial variation and risk factors associated with malaria hospitalization and in-hospital mortality. Methods Paediatric ward register data from Zomba district, Malawi, between 2002 and 2003 were used, as a case study. Two spatial models were developed. The first was a Poisson model applied to analyse hospitalization and minimum mortality rates, with age and sex as covariates. The second was a logistic model applied to individual level data to analyse case-fatality rate, adjusting for individual covariates. Results and conclusion Rates of malaria hospitalization and in-hospital mortality decreased with age. Case fatality rate was associated with distance, age, wet season and increased if the patient was referred to the hospital. Furthermore, death rate was high on first day, followed by relatively low rate as length of hospital stay increased. Both outcomes showed substantial spatial heterogeneity, which may be attributed to the varying determinants of malaria risk, health services availability and accessibility, and health seeking behaviour. The increased risk of mortality of children referred from primary health facilities may imply inadequate care being available at the referring facility, or the referring facility are referring the more severe cases which are expected to have a higher case fatality rate. Improved prognosis as the length of hospital stay increased suggest that appropriate care when available can save lives. Reducing malaria burden may require integrated strategies encompassing availability of adequate care at primary facilities, introducing home or community case management as well as encouraging early referral, and reinforcing interventions to interrupt malaria

How well are malaria maps used to design and finance malaria control in Africa?

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Omumbo, Judy A; Noor, Abdisalan M; Fall, Ibrahima S; Snow, Robert W

2013-01-01

Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures. National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs. The use of cartography in planning malaria control has never been methodically reviewed. An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken by examining the most recent national malaria strategies, monitoring and evaluation plans, malaria programme reviews and applications submitted to the Global Fund. The types of maps presented and how they have been used to define priorities for investment and control was investigated. 91% of endemic countries in Africa have defined malaria risk at sub-national levels using at least one risk map. The range of risk maps varies from maps based on suitability of climate for transmission; predicted malaria seasons and temperature/altitude limitations, to representations of clinical data and modelled parasite prevalence. The choice of maps is influenced by the source of the information. Maps developed using national data through in-country research partnerships have greater utility than more readily accessible web-based options developed without inputs from national control programmes. Although almost all countries have stratification maps, only a few use them to guide decisions on the selection of interventions allocation of resources for malaria control. The way information on the epidemiology of malaria is presented and used needs to be addressed to ensure evidence-based added value in planning control. The science on modelled impact of interventions must be integrated into new mapping products to allow a translation of risk into rational decision making for malaria control. As overseas and domestic funding diminishes, strategic planning will be necessary to guide appropriate financing for malaria

How well are malaria maps used to design and finance malaria control in Africa?

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Judy A Omumbo

Full Text Available Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures. National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs. The use of cartography in planning malaria control has never been methodically reviewed.An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken by examining the most recent national malaria strategies, monitoring and evaluation plans, malaria programme reviews and applications submitted to the Global Fund. The types of maps presented and how they have been used to define priorities for investment and control was investigated.91% of endemic countries in Africa have defined malaria risk at sub-national levels using at least one risk map. The range of risk maps varies from maps based on suitability of climate for transmission; predicted malaria seasons and temperature/altitude limitations, to representations of clinical data and modelled parasite prevalence. The choice of maps is influenced by the source of the information. Maps developed using national data through in-country research partnerships have greater utility than more readily accessible web-based options developed without inputs from national control programmes. Although almost all countries have stratification maps, only a few use them to guide decisions on the selection of interventions allocation of resources for malaria control.The way information on the epidemiology of malaria is presented and used needs to be addressed to ensure evidence-based added value in planning control. The science on modelled impact of interventions must be integrated into new mapping products to allow a translation of risk into rational decision making for malaria control. As overseas and domestic funding diminishes, strategic planning will be necessary to guide appropriate

How Well Are Malaria Maps Used to Design and Finance Malaria Control in Africa?

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Omumbo, Judy A.; Noor, Abdisalan M.; Fall, Ibrahima S.; Snow, Robert W.

2013-01-01

Introduction Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures. National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs. The use of cartography in planning malaria control has never been methodically reviewed. Materials and Methods An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken by examining the most recent national malaria strategies, monitoring and evaluation plans, malaria programme reviews and applications submitted to the Global Fund. The types of maps presented and how they have been used to define priorities for investment and control was investigated. Results 91% of endemic countries in Africa have defined malaria risk at sub-national levels using at least one risk map. The range of risk maps varies from maps based on suitability of climate for transmission; predicted malaria seasons and temperature/altitude limitations, to representations of clinical data and modelled parasite prevalence. The choice of maps is influenced by the source of the information. Maps developed using national data through in-country research partnerships have greater utility than more readily accessible web-based options developed without inputs from national control programmes. Although almost all countries have stratification maps, only a few use them to guide decisions on the selection of interventions allocation of resources for malaria control. Conclusion The way information on the epidemiology of malaria is presented and used needs to be addressed to ensure evidence-based added value in planning control. The science on modelled impact of interventions must be integrated into new mapping products to allow a translation of risk into rational decision making for malaria control. As overseas and domestic funding diminishes, strategic planning will be

STUDI BIO-EPIDEMIOLOGI DAN ANALISIS SPASIAL KASUS MALARIA DAERAH LINTAS BATAS INDONESIA – MALAYSIA (PULAU SEBATIK KABUPATEN NUNUKAN, PROVINSI KALIMANTAN TIMUR

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Damar Tri Boewono

2013-02-01

Full Text Available Abstract. Malaria remains to be a public health problem in Nunukan District (especially Sebatik island, East Kalimantan Province. Vector control programs using  long lasting insecticide nets (LLINs, have been conducted by the Health Office. Yet malaria cases were still occurred on the previous years. Comprehensive research was conducted to determine the specific vector control strategies based on the vectors bionomic, spatial distributions of malaria cases and breeding habitats (GIS mapping and distance index analyses and susceptible status of malaria  vectors against insecticides. The study revealed that three mosquito species were remain as potential malaria vectors such as: An. balabacensis and An. maculatus, the breeding habitats were fresh water wells/ponds and streams. In the coastal areas brackish water ponds and  lagoon were found as the breeding habitats of An. sundaicus  was recognized as malaria vector. Both malaria vectors (An. balabacensis and An. maculatus, were found resistant to insecticides Permethrin and  Lambdacyhalothrin and tolerance against Malathion. Alternative insecticide should be considered as a replacement. Spatial analysis found that malaria cases were distributed on clumped/cluster, buffer zones against breeding habitat (<400 meters, indicate local transmission (indigenous due to vector behaviour. Integrated vector management by using  indoors treatment and breeding habitats application by using bio-larvicides such as bacillus or insect growth regulator/IGR, is recommended. In an effort to maintain sustainability of the malaria programs, community participation should be developed. Key Words:  Malaria, Spatial distribition, Cases Distance Index, Sebatik Island Abstrak. Malaria masih menjadi masalah kesehatan utama di kabupaten Nunukan (khususnya Pulau sebatik, provinsi Kalimantan Timur.  Program pengendalian vektor menggunakan kelabu berinsektisida /Long Lasting Insecticide Net (LLIN, telah dilakukan oleh

Bayesian disease mapping: hierarchical modeling in spatial epidemiology

National Research Council Canada - National Science Library

Lawson, Andrew

2013-01-01

.... Exploring these new developments, Bayesian Disease Mapping: Hierarchical Modeling in Spatial Epidemiology, Second Edition provides an up-to-date, cohesive account of the full range of Bayesian disease mapping methods and applications...

Landscape Epidemiology Modeling Using an Agent-Based Model and a Geographic Information System

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S. M. Niaz Arifin

2015-05-01

Full Text Available A landscape epidemiology modeling framework is presented which integrates the simulation outputs from an established spatial agent-based model (ABM of malaria with a geographic information system (GIS. For a study area in Kenya, five landscape scenarios are constructed with varying coverage levels of two mosquito-control interventions. For each scenario, maps are presented to show the average distributions of three output indices obtained from the results of 750 simulation runs. Hot spot analysis is performed to detect statistically significant hot spots and cold spots. Additional spatial analysis is conducted using ordinary kriging with circular semivariograms for all scenarios. The integration of epidemiological simulation-based results with spatial analyses techniques within a single modeling framework can be a valuable tool for conducting a variety of disease control activities such as exploring new biological insights, monitoring epidemiological landscape changes, and guiding resource allocation for further investigation.

Field assessment of a novel spatial repellent for malaria control: a feasibility and acceptability study in Mondulkiri, Cambodia.

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Liverani, Marco; Charlwood, Jacques Derek; Lawford, Harriet; Yeung, Shunmay

2017-10-13

Large-scale use of insecticide-treated nets and indoor residual spraying have contributed to a significant decrease in malaria transmission worldwide. Further reduction and progress towards elimination, however, require complementary control measures which can address the remaining gaps in protection from mosquito bites. Following the development of novel pyrethroids with high knockdown effects on malaria vectors, programmatic use of spatial repellents has been suggested as one potential strategy to fill the gaps. This report explores social and contextual factors that may influence the relevance, uptake and sustainable use of a spatial repellent in two remote villages in Mondulkiri province, Cambodia, with endemic malaria transmission. The repellent consisted of polyethylene emanators, held in an open plastic frame and impregnated with 10% metofluthrin. In a baseline survey, 90.9% of households in Ou Chra (n = 30/33) and 96.6% in Pu Cha (n = 57/59) were interviewed. Behavioural data were collected for all household occupants (n = 448). In both villages, there were times and places in which people remained exposed to mosquito bites. Prior to the installation of the repellent, 50.6 and 59.5% of respondents noted that bites occurred "very often" inside the house and in the outdoor area surrounding the house, respectively. Indoor biting was reported to occur more frequently in the evening, followed by at night, while outdoor biting occurred more frequently in the early morning. In a follow-up survey, spatial repellents were well received in both villages, although 63.2% of respondents would not replace bed nets with repellents. Most participants (96.6%) were willing to use the product again; the mean willingness to pay was US$ 0.3 per unit. A preference for local procurement methods emerged. Widespread use of spatial repellents would not fill all protective gaps, but, if their entomological efficacy can be ascertained, outdoor application has the potential to

Impact of a spatial repellent on malaria incidence in two villages in Sumba, Indonesia.

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Syafruddin, Din; Bangs, Michael J; Sidik, Dian; Elyazar, Iqbal; Asih, Puji B S; Chan, Krisin; Nurleila, Siti; Nixon, Christian; Hendarto, Joko; Wahid, Isra; Ishak, Hasanuddin; Bøgh, Claus; Grieco, John P; Achee, Nicole L; Baird, J Kevin

2014-12-01

A randomized, double-blinded, placebo-controlled study was conducted to examine the effect of spatial repellent (SR) in households at risk of malaria in Indonesia. Following presumptive radical cure for malaria in 180 adult men representing sentinels of new infection in four clusters within two villages, all households were given either metofluthrin or placebo mosquito coils. Weekly blood smear screening and human-landing mosquito catches were done throughout the 6 months intervention. Malaria infections occurred in 61 subjects living in placebo households and 31 subjects living in SR coil households, suggesting a 52% protective effect of SR. Likewise, anopheles indoor human landing rates were 32% lower in homes receiving SR coils. Differences in the malaria attack rate between SR- and placebo-treated homes was significant when not accounting for the effects of clustering. When the analysis was adjusted for intra-cluster correlation, the differences between SR- and placebo-treated homes were not statistically significant. The findings provide evidence of SR public health benefit and support a larger trial statistically powered to detect those effects. © The American Society of Tropical Medicine and Hygiene.

Malaria successes and challenges in Asia.

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Bhatia, Rajesh; Rastogi, Rakesh Mani; Ortega, Leonard

2013-12-01

Asia ranks second to Africa in terms of malaria burden. In 19 countries of Asia, malaria is endemic and 2.31 billion people or 62% of the total population in these countries are at risk of malaria. In 2010, WHO estimated around 34.8 million cases and 45,600 deaths due to malaria in Asia. In 2011, 2.7 million cases and > 2000 deaths were reported. India, Indonesia, Myanmar and Pakistan are responsible for >85% of the reported cases (confirmed) and deaths in Asia. In last 10 yr, due to availability of donor's fund specially from Global fund, significant progress has been made by the countries in Asia in scaling-up malaria control interventions which were instrumental in reducing malaria morbidity and mortality significantly. There is a large heterogeneity in malaria epidemiology in Asia. As a result, the success in malaria control/elimination is also diverse. As compared to the data of the year 2000, out of 19 malaria endemic countries, 12 countries were able to reduce malaria incidence (microscopically confirmed cases only) by 75%. Two countries, namely Bangladesh and Malaysia are projected to reach 75% reduction by 2015 while India is projected to reach 50-75% only by 2015. The trend could not be assessed in four countries, namely Indonesia, Myanmar, Pakistan and Timor-Leste due to insufficient consistent data. Numerous key challenges need to be addressed to sustain the gains and eliminate malaria in most parts of Asia. Some of these are to control the spread of resistance in Plasmodium falciparum to artemisinin, control of outdoor transmission, control of vivax malaria and ensuring universal coverage of key interventions. Asia has the potential to influence the malaria epidemiology all over the world as well as to support the global efforts in controlling and eliminating malaria through production of quality-assured ACTs, RDTs and long-lasting insecticidal nets.

Remote Sensing-Driven Climatic/Environmental Variables for Modelling Malaria Transmission in Sub-Saharan Africa

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Osadolor Ebhuoma

2016-06-01

Full Text Available Malaria is a serious public health threat in Sub-Saharan Africa (SSA, and its transmission risk varies geographically. Modelling its geographic characteristics is essential for identifying the spatial and temporal risk of malaria transmission. Remote sensing (RS has been serving as an important tool in providing and assessing a variety of potential climatic/environmental malaria transmission variables in diverse areas. This review focuses on the utilization of RS-driven climatic/environmental variables in determining malaria transmission in SSA. A systematic search on Google Scholar and the Institute for Scientific Information (ISI Web of KnowledgeSM databases (PubMed, Web of Science and ScienceDirect was carried out. We identified thirty-five peer-reviewed articles that studied the relationship between remotely-sensed climatic variable(s and malaria epidemiological data in the SSA sub-regions. The relationship between malaria disease and different climatic/environmental proxies was examined using different statistical methods. Across the SSA sub-region, the normalized difference vegetation index (NDVI derived from either the National Oceanic and Atmospheric Administration (NOAA Advanced Very High Resolution Radiometer (AVHRR or Moderate-resolution Imaging Spectrometer (MODIS satellite sensors was most frequently returned as a statistically-significant variable to model both spatial and temporal malaria transmission. Furthermore, generalized linear models (linear regression, logistic regression and Poisson regression were the most frequently-employed methods of statistical analysis in determining malaria transmission predictors in East, Southern and West Africa. By contrast, multivariate analysis was used in Central Africa. We stress that the utilization of RS in determining reliable malaria transmission predictors and climatic/environmental monitoring variables would require a tailored approach that will have cognizance of the geographical

Remote Sensing-Driven Climatic/Environmental Variables for Modelling Malaria Transmission in Sub-Saharan Africa.

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Ebhuoma, Osadolor; Gebreslasie, Michael

2016-06-14

Malaria is a serious public health threat in Sub-Saharan Africa (SSA), and its transmission risk varies geographically. Modelling its geographic characteristics is essential for identifying the spatial and temporal risk of malaria transmission. Remote sensing (RS) has been serving as an important tool in providing and assessing a variety of potential climatic/environmental malaria transmission variables in diverse areas. This review focuses on the utilization of RS-driven climatic/environmental variables in determining malaria transmission in SSA. A systematic search on Google Scholar and the Institute for Scientific Information (ISI) Web of Knowledge(SM) databases (PubMed, Web of Science and ScienceDirect) was carried out. We identified thirty-five peer-reviewed articles that studied the relationship between remotely-sensed climatic variable(s) and malaria epidemiological data in the SSA sub-regions. The relationship between malaria disease and different climatic/environmental proxies was examined using different statistical methods. Across the SSA sub-region, the normalized difference vegetation index (NDVI) derived from either the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) or Moderate-resolution Imaging Spectrometer (MODIS) satellite sensors was most frequently returned as a statistically-significant variable to model both spatial and temporal malaria transmission. Furthermore, generalized linear models (linear regression, logistic regression and Poisson regression) were the most frequently-employed methods of statistical analysis in determining malaria transmission predictors in East, Southern and West Africa. By contrast, multivariate analysis was used in Central Africa. We stress that the utilization of RS in determining reliable malaria transmission predictors and climatic/environmental monitoring variables would require a tailored approach that will have cognizance of the geographical

Early detection and monitoring of Malaria

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Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Miller, Howard; Rosy, Dilara A.

2015-05-01

Global Earth Observation Systems of Systems (GEOSS) are bringing vital societal benefits to people around the globe. In this research article, we engage undergraduate students in the exciting area of space exploration to improve the health of millions of people globally. The goal of the proposed research is to place students in a learning environment where they will develop their problem solving skills in the context of a world crisis (e.g., malaria). Malaria remains one of the greatest threats to public health, particularly in developing countries. The World Health Organization has estimated that over one million die of Malaria each year, with more than 80% of these found in Sub-Saharan Africa. The mosquitoes transmit malaria. They breed in the areas of shallow surface water that are suitable to the mosquito and parasite development. These environmental factors can be detected with satellite imagery, which provide high spatial and temporal coverage of the earth's surface. We investigate on moisture, thermal and vegetation stress indicators developed from NOAA operational environmental satellite data. Using these indicators and collected epidemiological data, it is possible to produce a forecast system that can predict the risk of malaria for a particular geographical area with up to four months lead time. This valuable lead time information provides an opportunity for decision makers to deploy the necessary preventive measures (spraying, treated net distribution, storing medications and etc) in threatened areas with maximum effectiveness. The main objective of the proposed research is to study the effect of ecology on human health and application of NOAA satellite data for early detection of malaria.

A global assessment of closed forests, deforestation and malaria risk

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GUERRA, C. A.; SNOW, R. W.; HAY, S. I.

2011-01-01

Global environmental change is expected to affect profoundly the transmission of the parasites that cause human malaria. Amongst the anthropogenic drivers of change, deforestation is arguably the most conspicuous, and its rate is projected to increase in the coming decades. The canonical epidemiological understanding is that deforestation increases malaria risk in Africa and the Americas and diminishes it in South–east Asia. Partial support for this position is provided here, through a systematic review of the published literature on deforestation, malaria and the relevant vector bionomics. By using recently updated boundaries for the spatial limits of malaria and remotely-sensed estimates of tree cover, it has been possible to determine the population at risk of malaria in closed forest, at least for those malaria-endemic countries that lie within the main blocks of tropical forest. Closed forests within areas of malaria risk cover approximately 1.5 million km2 in the Amazon region, 1.4 million km2 in Central Africa, 1.2 million km2 in the Western Pacific, and 0.7 million km2 in South–east Asia. The corresponding human populations at risk of malaria within these forests total 11.7 million, 18.7 million, 35.1 million and 70.1 million, respectively. By coupling these numbers with the country-specific rates of deforestation, it has been possible to rank malaria-endemic countries according to their potential for change in the population at risk of malaria, as the result of deforestation. The on-going research aimed at evaluating these relationships more quantitatively, through the Malaria Atlas Project (MAP), is highlighted. PMID:16630376

Malaria Disease Mapping in Malaysia based on Besag-York-Mollie (BYM) Model

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Azah Samat, Nor; Mey, Liew Wan

2017-09-01

Disease mapping is the visual representation of the geographical distribution which give an overview info about the incidence of disease within a population through spatial epidemiology data. Based on the result of map, it helps in monitoring and planning resource needs at all levels of health care and designing appropriate interventions, tailored towards areas that deserve closer scrutiny or communities that lead to further investigations to identify important risk factors. Therefore, the choice of statistical model used for relative risk estimation is important because production of disease risk map relies on the model used. This paper proposes Besag-York-Mollie (BYM) model to estimate the relative risk for Malaria in Malaysia. The analysis involved using the number of Malaria cases that obtained from the Ministry of Health Malaysia. The outcomes of analysis are displayed through graph and map, including Malaria disease risk map that constructed according to the estimation of relative risk. The distribution of high and low risk areas of Malaria disease occurrences for all states in Malaysia can be identified in the risk map.

CASE STUDY: Mexico — Fighting malaria without DDT | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2010-12-23

Dec 23, 2010 ... ... spraying techniques, Mexico has dramatically reduced malaria transmission. ... and the parasite, community perceptions of malaria, statistical analyses, and ... epidemiology, informatics, entomology, and the social sciences.

Plasmodium knowlesi transmission: integrating quantitative approaches from epidemiology and ecology to understand malaria as a zoonosis.

Science.gov (United States)

Brock, P M; Fornace, K M; Parmiter, M; Cox, J; Drakeley, C J; Ferguson, H M; Kao, R R

2016-04-01

The public health threat posed by zoonotic Plasmodium knowlesi appears to be growing: it is increasingly reported across South East Asia, and is the leading cause of malaria in Malaysian Borneo. Plasmodium knowlesi threatens progress towards malaria elimination as aspects of its transmission, such as spillover from wildlife reservoirs and reliance on outdoor-biting vectors, may limit the effectiveness of conventional methods of malaria control. The development of new quantitative approaches that address the ecological complexity of P. knowlesi, particularly through a focus on its primary reservoir hosts, will be required to control it. Here, we review what is known about P. knowlesi transmission, identify key knowledge gaps in the context of current approaches to transmission modelling, and discuss the integration of these approaches with clinical parasitology and geostatistical analysis. We highlight the need to incorporate the influences of fine-scale spatial variation, rapid changes to the landscape, and reservoir population and transmission dynamics. The proposed integrated approach would address the unique challenges posed by malaria as a zoonosis, aid the identification of transmission hotspots, provide insight into the mechanistic links between incidence and land use change and support the design of appropriate interventions.

Assessing the quality of service of village malaria workers to strengthen community-based malaria control in Cambodia

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Ly Po

2010-04-01

Full Text Available Abstract Background Malaria continues to be a major public health problem in remote forested areas in Cambodia. As a national strategy to strengthen community-based malaria control, the Cambodian government has been running the Village Malaria Worker (VMW project since 2001. This study sought to examine the nature and quality of the VMWs' services. Methods Data collection was carried out in February and March 2008 through interviews with one of the two VMWs who takes the lead in malaria control activities in each of the 315 VMW villages (n = 251. The questionnaire addressed 1 the sociodemographic characteristics of VMWs, 2 service quality, 3 actions for malaria prevention and vector control, and 4 knowledge of malaria epidemiology and vector ecology. Results VMWs were effective in conducting diagnosis with Rapid Diagnostic Tests (RDTs and prescribing anti-malarials to those who had positive RDT results, skills that they had acquired through their training programmes. However, most other services, such as active detection, explanations about compliance, and follow-up of patients, were carried out by only a small proportion of VMWs. The variety of actions that VMWs took for malaria prevention and vector control was small (average action index score 12.8/23, and their knowledge was very limited with less than 20% of the VMWs giving correct answers to six out of seven questions on malaria epidemiology and vector ecology. Knowledge of vector breeding places and malaria transmission were significant determinants of both the quality of VMWs' services and the variety of their actions for malaria prevention and vector control. Conclusions VMWs' services focused primarily on diagnosis and treatment. Their focus needs to be broadened to cover other aspects of malaria control in order to further strengthen community-based malaria control. VMWs' actions and knowledge also need substantial improvement. Strengthening training programmes can help achieve better

Large-scale drivers of malaria and priority areas for prevention and control in the Brazilian Amazon region using a novel multi-pathogen geospatial model.

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Valle, Denis; Lima, Joanna M Tucker

2014-11-20

Most of the malaria burden in the Americas is concentrated in the Brazilian Amazon but a detailed spatial characterization of malaria risk has yet to be undertaken. Utilizing 2004-2008 malaria incidence data collected from six Brazilian Amazon states, large-scale spatial patterns of malaria risk were characterized with a novel Bayesian multi-pathogen geospatial model. Data included 2.4 million malaria cases spread across 3.6 million sq km. Remotely sensed variables (deforestation rate, forest cover, rainfall, dry season length, and proximity to large water bodies), socio-economic variables (rural population size, income, and literacy rate, mortality rate for children age under five, and migration patterns), and GIS variables (proximity to roads, hydro-electric dams and gold mining operations) were incorporated as covariates. Borrowing information across pathogens allowed for better spatial predictions of malaria caused by Plasmodium falciparum, as evidenced by a ten-fold cross-validation. Malaria incidence for both Plasmodium vivax and P. falciparum tended to be higher in areas with greater forest cover. Proximity to gold mining operations was another important risk factor, corroborated by a positive association between migration rates and malaria incidence. Finally, areas with a longer dry season and areas with higher average rural income tended to have higher malaria risk. Risk maps reveal striking spatial heterogeneity in malaria risk across the region, yet these mean disease risk surface maps can be misleading if uncertainty is ignored. By combining mean spatial predictions with their associated uncertainty, several sites were consistently classified as hotspots, suggesting their importance as priority areas for malaria prevention and control. This article provides several contributions. From a methodological perspective, the benefits of jointly modelling multiple pathogens for spatial predictions were illustrated. In addition, maps of mean disease risk were

Over-diagnosis of malaria is not a lost cause

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Chandramohan Daniel

2006-12-01

Full Text Available Abstract Background Recent studies have highlighted the over-diagnosis of malaria in clinical settings in Africa. This study assessed the impact of a training programme implemented as part of an intervention trial on diagnostic behaviour of clinicians in a rural district hospital in a low-moderate malaria transmission setting. Methods From the beginning of 2005, a randomized controlled trial (RCT of intermittent preventive treatment for malaria in infants (IPTi has been conducted at the study hospital. As part of the RCT, the study team offered laboratory quality assurance, and supervision and training of paediatric ward staff using information on malaria epidemiology in the community. Data on clinical and blood slide confirmed cases of malaria from 2001 to 2005 were extracted from the hospital records. Results The proportion of blood slides positive for malaria parasites had decreased from 21% in 2001 to 7% in 2005 (p Conclusion It may be possible to change the diagnostic behaviour of clinicians by rigorous training using local malaria epidemiology data and supportive supervision.

Analytical Hierarchy Process modeling for malaria risk zones in Vadodara district, Gujarat

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Bhatt, B.; Joshi, J. P.

2014-11-01

Malaria epidemic is one of the complex spatial problems around the world. According to WHO, an estimated 6, 27, 000 deaths occurred due to malaria in 2012. In many developing nations with diverse ecological regions, it is still a large cause of human mortality. Owing to the incompleteness of epidemiological data and their spatial origin, the quantification of disease incidence burdening basic public health planning is a major constrain especially in developing countries. The present study focuses on the integrated Geospatial and Multi-Criteria Evaluation (AHP) technique to determine malaria risk zones. The study is conducted in Vadodara district, including 12 Taluka among which 4 Taluka are predominantly tribal. The influence of climatic and physical environmental factors viz., rainfall, hydro geomorphology; drainage, elevation, and land cover are used to score their share in the evaluation of malariogenic condition. This was synthesized on the basis of preference over each factor and the total weights of each data and data layer were computed and visualized. The district was divided into three viz., high, moderate and low risk zones .It was observed that a geographical area of 1885.2sq.km comprising 30.3% fall in high risk zone. The risk zones identified on the basis of these parameters and assigned weights shows a close resemblance with ground condition. As the API distribution for 2011overlaid corresponds to the risk zones identified. The study demonstrates the significance and prospect of integrating Geospatial tools and Analytical Hierarchy Process for malaria risk zones and dynamics of malaria transmission.

Severe malaria in Europe

DEFF Research Database (Denmark)

Kurth, Florian; Develoux, Michel; Mechain, Matthieu

2017-01-01

BACKGROUND: Malaria remains one of the most serious infections for travellers to tropical countries. Due to the lack of harmonized guidelines a large variety of treatment regimens is used in Europe to treat severe malaria. METHODS: The European Network for Tropical Medicine and Travel Health (Trop......Net) conducted an 8-year, multicentre, observational study to analyse epidemiology, treatment practices and outcomes of severe malaria in its member sites across Europe. Physicians at participating TropNet centres were asked to report pseudonymized retrospective data from all patients treated at their centre...... for microscopically confirmed severe Plasmodium falciparum malaria according to the 2006 WHO criteria. RESULTS: From 2006 to 2014 a total of 185 patients with severe malaria treated in 12 European countries were included. Three patients died, resulting in a 28-day survival rate of 98.4%. The majority of infections...

Future malaria spatial pattern based on the potential global warming impact in South and Southeast Asia

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Hassan M. Khormi

2016-11-01

Full Text Available We used the Model for Interdisciplinary Research on Climate-H climate model with the A2 Special Report on Emissions Scenarios for the years 2050 and 2100 and CLIMEX software for projections to illustrate the potential impact of climate change on the spatial distributions of malaria in China, India, Indochina, Indonesia, and The Philippines based on climate variables such as temperature, moisture, heat, cold and dryness. The model was calibrated using data from several knowledge domains, including geographical distribution records. The areas in which malaria has currently been detected are consistent with those showing high values of the ecoclimatic index in the CLIMEX model. The match between prediction and reality was found to be high. More than 90% of the observed malaria distribution points were associated with the currently known suitable climate conditions. Climate suitability for malaria is projected to decrease in India, southern Myanmar, southern Thailand, eastern Borneo, and the region bordering Cambodia, Malaysia and the Indonesian islands, while it is expected to increase in southern and south-eastern China and Taiwan. The climatic models for Anopheles mosquitoes presented here should be useful for malaria control, monitoring, and management, particularly considering these future climate scenarios.

Future malaria spatial pattern based on the potential global warming impact in South and Southeast Asia.

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Khormi, Hassan M; Kumar, Lalit

2016-11-21

We used the Model for Interdisciplinary Research on Climate-H climate model with the A2 Special Report on Emissions Scenarios for the years 2050 and 2100 and CLIMEX software for projections to illustrate the potential impact of climate change on the spatial distributions of malaria in China, India, Indochina, Indonesia, and The Philippines based on climate variables such as temperature, moisture, heat, cold and dryness. The model was calibrated using data from several knowledge domains, including geographical distribution records. The areas in which malaria has currently been detected are consistent with those showing high values of the ecoclimatic index in the CLIMEX model. The match between prediction and reality was found to be high. More than 90% of the observed malaria distribution points were associated with the currently known suitable climate conditions. Climate suitability for malaria is projected to decrease in India, southern Myanmar, southern Thailand, eastern Borneo, and the region bordering Cambodia, Malaysia and the Indonesian islands, while it is expected to increase in southern and south-eastern China and Taiwan. The climatic models for Anopheles mosquitoes presented here should be useful for malaria control, monitoring, and management, particularly considering these future climate scenarios.

History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting.

Science.gov (United States)

Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

2008-10-26

Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of population movements and inadequate

History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting

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Utzinger Jürg

2008-10-01

Full Text Available Abstract Background Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. Methods The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007 in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. Results One case of P. vivax was detected among the 363 schoolchildren examined (0.28%. The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%. Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. Conclusion The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against

Spatial epidemiology of cancer: a review of data sources, methods and risk factors

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Rita Roquette

2017-05-01

Full Text Available Cancer is a major concern among chronic diseases today. Spatial epidemiology plays a relevant role in this matter and we present here a review of this subject, including a discussion of the literature in terms of the level of geographic data aggregation, risk factors and methods used to analyse the spatial distribution of patterns and spatial clusters. For this purpose, we performed a websearch in the Pubmed and Web of Science databases including studies published between 1979 and 2015. We found 180 papers from 63 journals and noted that spatial epidemiology of cancer has been addressed with more emphasis during the last decade with research based on data mostly extracted from cancer registries and official mortality statistics. In general, the research questions present in the reviewed papers can be classified into three different sets: i analysis of spatial distribution of cancer and/or its temporal evolution; ii risk factors; iii development of data analysis methods and/or evaluation of results obtained from application of existing methods. This review is expected to help promote research in this area through the identification of relevant knowledge gaps. Cancer’s spatial epidemiology represents an important concern, mainly for public health policies design aimed to minimise the impact of chronic disease in specific populations.

Outcomes of imported malaria during pregnancy within Venezuelan states: implications for travel advice.

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Rodríguez-Morales, Alfonso J; Arria, Melissa; Sánchez, Elia; Vargas, Miguel; Piccolo, Carmelina; Colina, Rosa; Franco-Paredes, Carlos

2007-01-01

Prevention of malaria in pregnant women is an utmost priority because the disease can cause serious maternal and neonatal complications. Maternal complications include marked anemia, increased risk of severe disease, and mortality, while the fetus or neonate is at risk of prematurity, anemia, and low birthweight. Pregnant women living in malaria endemic areas may be semiimmune to a particular Plasmodium spp. but when traveling to other regions, sometimes within their same country, where malaria epidemiology is different, may develop severe malaria complications. Here, we describe our experience in northeastern Venezuela associated with unfavorable outcomes of imported malaria cases among pregnant women who traveled to other Venezuelan regions with different malaria epidemiology. Travel medicine practitioners should be aware and educate their pregnant patients regarding the risk of malaria even when living in malaria endemic areas and traveling to other endemic areas such as occurs in Venezuela.

Malaria vaccines and their potential role in the elimination of malaria

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Greenwood Brian M

2008-12-01

Full Text Available Abstract Research on malaria vaccines is currently directed primarily towards the development of vaccines that prevent clinical malaria. Malaria elimination, now being considered seriously in some epidemiological situations, requires a different vaccine strategy, since success will depend on killing all parasites in the community in order to stop transmission completely. The feature of the life-cycles of human malarias that presents the greatest challenge to an elimination programme is the persistence of parasites as asymptomatic infections. These are an important source from which transmission to mosquitoes can occur. Consequently, an elimination strategy requires a community-based approach covering all individuals and not just those who are susceptible to clinical malaria. The progress that has been made in development of candidate malaria vaccines is reviewed. It is unlikely that many of these will have the efficacy required for complete elimination of parasites, though they may have an important role to play as part of future integrated control programmes. Vaccines for elimination must have a high level of efficacy in order to stop transmission to mosquitoes. This might be achieved with some pre-erythrocytic stage candidate vaccines or by targeting the sexual stages directly with transmission-blocking vaccines. An expanded malaria vaccine programme with such objectives is now a priority.

Effect of permethrin-treated bed nets on the spatial distribution of malaria vectors in western Kenya

NARCIS (Netherlands)

Gimnig, John E.; Kolczak, Margarette S.; Hightower, Allen W.; Vulule, John M.; Schoute, Erik; Kamau, Luna; Phillips-Howard, Penelope A.; ter Kuile, Feiko O.; Nahlen, Bernard L.; Hawley, William A.

2003-01-01

The effect of insecticide (permethrin)-treated bed nets (ITNs) on the spatial distribution of malaria vectors in neighboring villages lacking ITNs was studied during a randomized controlled trial of ITNs in western Kenya. There was a trend of decreased abundance of Anopheles gambiae with decreasing

Epidemiological and entomological studies of a malaria outbreak among French armed forces deployed at illegal gold mining sites reveal new aspects of the disease's transmission in French Guiana.

Science.gov (United States)

Pommier de Santi, Vincent; Girod, Romain; Mura, Marie; Dia, Aissata; Briolant, Sébastien; Djossou, Félix; Dusfour, Isabelle; Mendibil, Alexandre; Simon, Fabrice; Deparis, Xavier; Pagès, Frédéric

2016-01-22

In December 2010, a Plasmodium vivax malaria outbreak occurred among French forces involved in a mission to control illegal gold mining in French Guiana. The findings of epidemiological and entomological investigations conducted after this outbreak are presented here. Data related to malaria cases reported to the French armed forces epidemiological surveillance system were collected during the epidemic period from December 2010 to April 2011. A retrospective cohort study was conducted to identify presumed contamination sites. Anopheles mosquitoes were sampled at the identified sites using Mosquito Magnet and CDC light traps. Specimens were identified morphologically and confirmed using molecular methods (sequencing of ITS2 gene and/or barcoding). Anopheles infections with Plasmodium falciparum and P. vivax were tested by both enzyme-linked immunosorbent assay and real-time PCR. Seventy-two P. vivax malaria cases were reported (three were mixed P. falciparum/P. vivax infections), leading to a global attack rate of 26.5% (72/272). Lack of compliance with vector control measures and doxycycline chemoprophylaxis was reported by patients. Two illegal gold mining sites located in remote areas in the primary forest were identified as places of contamination. In all, 595 Anopheles females were caught and 528 specimens were formally identified: 305 Anopheles darlingi, 145 Anopheles nuneztovari s.l., 63 Anopheles marajoara and 15 Anopheles triannulatus s.l. Three An. darlingi were infected by P. falciparum (infection rate: 1.1%) and four An. marajoara by P. vivax (infection rate: 6.4%). The main drivers of the outbreak were the lack of adherence by military personnel to malaria prevention measures and the high level of malaria transmission at illegal gold mining sites. Anopheles marajoara was clearly implicated in malaria transmission for the first time in French Guiana. The high infection rates observed confirm that illegal gold mining sites must be considered as high level

Scale-dependent approaches to modeling spatial epidemiology of chronic wasting disease.

Science.gov (United States)

Conner, Mary M.; Gross, John E.; Cross, Paul C.; Ebinger, Michael R.; Gillies, Robert; Samuel, Michael D.; Miller, Michael W.

2007-01-01

This e-book is the product of a second workshop that was funded and promoted by the United States Geological Survey to enhance cooperation between states for the management of chronic wasting disease (CWD). The first workshop addressed issues surrounding the statistical design and collection of surveillance data for CWD. The second workshop, from which this document arose, followed logically from the first workshop and focused on appropriate methods for analysis, interpretation, and use of CWD surveillance and related epidemiology data. Consequently, the emphasis of this e-book is on modeling approaches to describe and gain insight of the spatial epidemiology of CWD. We designed this e-book for wildlife managers and biologists who are responsible for the surveillance of CWD in their state or agency. We chose spatial methods that are popular or common in the spatial epidemiology literature and evaluated them for their relevance to modeling CWD. Our opinion of the usefulness and relevance of each method was based on the type of field data commonly collected as part of CWD surveillance programs and what we know about CWD biology, ecology, and epidemiology. Specifically, we expected the field data to consist primarily of the infection status of a harvested or culled sample along with its date of collection (not date of infection), location, and demographic status. We evaluated methods in light of the fact that CWD does not appear to spread rapidly through wild populations, relative to more highly contagious viruses, and can be spread directly from animal to animal or indirectly through environmental contamination.

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

Science.gov (United States)

Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

2014-02-01

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

International Nuclear Information System (INIS)

Rasam, A R A; Ghazali, R; Noor, A M M; Mohd, W M N W; Hamid, J R A; Bazlan, M J; Ahmad, N

2014-01-01

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia

Variation in the immune responses against Plasmodium falciparum merozoite surface protein-1 and apical membrane antigen-1 in children residing in the different epidemiological strata of malaria in Cameroon.

Science.gov (United States)

Kwenti, Tebit Emmanuel; Moye, Adzemye Linus; Wiylanyuy, Adzemye Basil; Njunda, Longdoh Anna; Nkuo-Akenji, Theresa

2017-11-09

Studies to assess the immune responses against malaria in Cameroonian children are limited. The purpose of this study was to assess the immune responses against Plasmodium falciparum merozoite surface protein-1 (MSP-1 19 ) and apical membrane antigen-1 (AMA-1) in children residing in the different epidemiological strata of malaria in Cameroon. In a cross-sectional survey performed between April and July 2015, 602 children between 2 and 15 years (mean ± SD = 5.7 ± 3.7), comprising 319 (53%) males were enrolled from five epidemiological strata of malaria in Cameroon including: the sudano-sahelian (SS) strata, the high inland plateau (HIP) strata, the south Cameroonian equatorial forest (SCEF) strata, the high western plateau (HWP) strata, and the coastal (C) strata. The children were screened for clinical malaria (defined by malaria parasitaemia ≥ 5000 parasites/µl plus axillary temperature ≥ 37.5 °C). Their antibody responses were measured against P. falciparum MSP-1 19 and AMA-1 vaccine candidate antigens using standard ELISA technique. A majority of the participants were IgG responders 72.1% (95% CI 68.3-75.6). The proportion of responders was higher in females (p = 0.002) and in children aged 10 years and above (p = 0.005). The proportion of responders was highest in Limbe (C strata) and lowest in Ngaoundere (HIP strata) (p malaria (p malaria parasites. The immune responses varied considerably across the different strata: the highest levels observed in the C strata and the lowest in the HIP strata. Furthermore, malaria transmission in Cameroon could be categorized into two major groups based on the serological reaction of the children: the southern (comprising C and SCEF strata) and northern (comprising HWP, HIP and SS strata) groups. These findings may have significant implications in the design of future trials for evaluating malaria vaccine candidates in Cameroon.

The ecology of malaria--as seen from Earth-observation satellites.

Science.gov (United States)

Thomson, M C; Connor, S J; Milligan, P J; Flasse, S P

1996-06-01

Data from sensors on board geostationary and polar-orbiting, meteorological satellites (Meteosat and NOAA series) are routinely obtained free, via local reception systems, in an increasing number of African countries. Data collected by these satellites are processed to produce proxy ecological variables which have been extensively investigated for monitoring changes in the distribution and condition of different natural resources, including rainfall and vegetation state. How these data products (once incorporated, along with other data, into a geographical information system) could contribute to the goals of monitoring patterns of malaria transmission, predicting epidemics and planning control strategies is the subject of the present review. By way of illustration, an analysis of two of these products, normalized difference vegetation index (NVDI) and cold-cloud duration (CCD), is given in conjunction with epidemiological and entomological data from The Gambia, a country where extensive studies on malaria transmission have been undertaken in recent years. Preliminary results indicate that even simple analysis of proxy ecological variables derived from satellite data can indicate variation in environmental factors affecting malaria-transmission indices. However, it is important to note that the associations observed will vary depending on the local ecology, season and species of vector. Whilst further quantitative research is required to validate the relationship between satellite-data products and malaria-transmission indices, this approach offers a means by which detailed knowledge of the underlying spatial and temporal variation in the environment can be incorporated into a decision-support system for malaria control.

Geo-additive modelling of malaria in Burundi

Directory of Open Access Journals (Sweden)

Gebhardt Albrecht

2011-08-01

Full Text Available Abstract Background Malaria is a major public health issue in Burundi in terms of both morbidity and mortality, with around 2.5 million clinical cases and more than 15,000 deaths each year. It is still the single main cause of mortality in pregnant women and children below five years of age. Because of the severe health and economic burden of malaria, there is still a growing need for methods that will help to understand the influencing factors. Several studies/researches have been done on the subject yielding different results as which factors are most responsible for the increase in malaria transmission. This paper considers the modelling of the dependence of malaria cases on spatial determinants and climatic covariates including rainfall, temperature and humidity in Burundi. Methods The analysis carried out in this work exploits real monthly data collected in the area of Burundi over 12 years (1996-2007. Semi-parametric regression models are used. The spatial analysis is based on a geo-additive model using provinces as the geographic units of study. The spatial effect is split into structured (correlated and unstructured (uncorrelated components. Inference is fully Bayesian and uses Markov chain Monte Carlo techniques. The effects of the continuous covariates are modelled by cubic p-splines with 20 equidistant knots and second order random walk penalty. For the spatially correlated effect, Markov random field prior is chosen. The spatially uncorrelated effects are assumed to be i.i.d. Gaussian. The effects of climatic covariates and the effects of other spatial determinants are estimated simultaneously in a unified regression framework. Results The results obtained from the proposed model suggest that although malaria incidence in a given month is strongly positively associated with the minimum temperature of the previous months, regional patterns of malaria that are related to factors other than climatic variables have been identified

Epidemiological factors that promote the development of severe ...

African Journals Online (AJOL)

... that promote the development of severe malaria anaemia in children in Ibadan. ... and epidemiological factors that affect the development of malaria anaemia. ... of parents or guardians to fever in the children;parents\\' preoccupation with ...

Changing pattern of malaria in Bissau, Guinea Bissau

DEFF Research Database (Denmark)

Rodrigues, Amabelia; Schellenberg, Joanna Armstrong; Kofoed, Poul-Erik

2008-01-01

OBJECTIVE: To describe the epidemiology of malaria in Guinea-Bissau, in view of the fact that more funds are available now for malaria control in the country. METHODS: From May 2003 to May 2004, surveillance for malaria was conducted among children less than 5 years of age at three health centres...... covering the study area of the Bandim Health Project (BHP) and at the outpatient clinic of the national hospital in Bissau. Cross-sectional surveys were conducted in the community in different malaria seasons. RESULTS: Malaria was overdiagnosed in both health centres and hospital. Sixty-four per cent...... of the children who presented at a health centre were clinically diagnosed with malaria, but only 13% of outpatient children who tested for malaria had malaria parasitaemia. Only 44% (963/2193) of children admitted to hospital with a diagnosis of malaria had parasitaemia. The proportion of positive cases...

Epidemiology and Synergistic Hepatopathology of Malaria and Hepatitis C Virus Coinfection.

Science.gov (United States)

Nasir, Idris Abdullahi; Yakubu, Sa'adatu; Mustapha, Jelili Olaide

2017-01-01

Malaria and hepatitis C virus (HCV) infections are very common causes of human suffering with overlapping global geographic distributions. With the growing incidence of HCV infections in malaria-endemic zones and malaria in areas with exceptionally high HCV prevalence, coinfections and syndemism of both pathogens are likely to occur. However, studies of malaria and HCV coinfections are very rare despite the fact that liver-stage plasmodiasis and hepatitis C develop in hepatocytes which may synergistically interact. The fact that both pathogens share similar entry molecules or receptors in early invasive steps of hepatocytes further makes hepatopathologic investigations of coinfected hosts greatly important. This review sought to emphasize the public health significance of malaria/HCV coinfections and elucidate the mechanisms of pathogens' entrance and invasion of susceptible host to improve on existing or develop antiplasmodial drugs and hepatitis C therapeutics that can intervene at appropriate stages of pathogens' life cycles.

Micro-heterogeneity of malaria transmission in the Peruvian Amazon: a baseline assessment underlying a population-based cohort study.

Science.gov (United States)

Rosas-Aguirre, Angel; Guzman-Guzman, Mitchel; Gamboa, Dionicia; Chuquiyauri, Raul; Ramirez, Roberson; Manrique, Paulo; Carrasco-Escobar, Gabriel; Puemape, Carmen; Llanos-Cuentas, Alejandro; Vinetz, Joseph M

2017-08-04

Understanding the dynamics of malaria transmission in diverse endemic settings is key for designing and implementing locally adapted and sustainable control and elimination strategies. A parasitological and epidemiological survey was conducted in September-October 2012, as a baseline underlying a 3-year population-based longitudinal cohort study. The aim was to characterize malaria transmission patterns in two contrasting ecological rural sites in the Peruvian Amazon, Lupuna (LUP), a riverine environment, and Cahuide (CAH), associated with road-linked deforestation. After a full population census, 1941 individuals 3 years and older (829 in LUP, 1112 in CAH) were interviewed, clinically examined and had a blood sample taken for the detection of malaria parasites by microscopy and PCR. Species-specific parasite prevalence was estimated overall and by site. Multivariate logistic regression models assessed risk factors for parasite infection by PCR, while SaTScan detected spatial clusters of PCR-positive individuals within each site. In addition, data from routine malaria surveillance in the period 2009-2012 were obtained. Parasite prevalence by PCR was higher in CAH than in LUP for Plasmodium vivax (6.2% vs. 3.9%) and for Plasmodium falciparum (2.6% vs. 1.2%). Among PCR-confirmed infections, asymptomatic (Asy) parasite carriers were always more common than symptomatic (Sy) infections for P. vivax (Asy/Sy ratio: 2/1 in LUP and 3.7/1 in CAH) and for P. falciparum (Asy/Sy ratio: 1.3/1 in LUP and 4/1 in CAH). Sub-patent (Spat) infections also predominated over patent (Pat) infections for both species: P. vivax (Spat/Pat ratio: 2.8/1 in LUP and 3.7/1 in CAH) and P. falciparum malaria (Spat/Pat ratio: 1.9/1 in LUP and 26/0 in CAH). For CAH, age, gender and living in a household without electricity were significantly associated with P. vivax infection, while only age and living in a household with electricity was associated with P. falciparum infection. For LUP, only

Worldwide Report, Epidemiology, No. 327

National Research Council Canada - National Science Library

1983-01-01

Partial Contents: Epidemiology, Human Diseases, Health, Malaria, AIDS, Homosexual Male, Medical Administration, Rabies, Tuberculosis, Encephalitis Statistics, Gastroenteritie, Mystery Diseases, Children, Epidemics...

Alternative transmission routes in the malaria elimination era: an overview of transfusion-transmitted malaria in the Americas.

Science.gov (United States)

Alho, Regina M; Machado, Kim Vinícius Amaral; Val, Fernando F A; Fraiji, Nelson A; Alexandre, Marcia A A; Melo, Gisely C; Recht, Judith; Siqueira, André M; Monteiro, Wuelton M; Lacerda, Marcus V G

2017-02-15

Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature. Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved. A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant

Malaria and World War II: German malaria experiments 1939-45.

Science.gov (United States)

Eckart, W U; Vondra, H

2000-06-01

The epidemiological and pharmacological fight against malaria and German malaria research during the Nazi dictatorship were completely under the spell of war. The Oberkommando des Heeres (German supreme command of the army) suffered the bitter experience of unexpected high losses caused by malaria especially at the Greek front (Metaxes line) but also in southern Russia and in the Ukraine. Hastily raised anti-malaria units tried to teach soldiers how to use the synthetic malaria drugs (Plasmochine, Atebrine) properly. Overdoses of these drugs were numerous during the first half of the war whereas in the second half it soon became clear that it would not be possible to support the army due to insufficient quantities of plasmochine and atebrine. During both running fights and troop withdrawals at all southern and southeastern fronts there was hardly any malaria prophylaxis or treatment. After war and captivity many soldiers returned home to endure heavy malaria attacks. In German industrial (Bayer, IG-Farben) and military malaria laboratories of the Heeres-Sanitäts-Akademie (Army Medical Academy) the situation was characterised by a hasty search for proper dosages of anti-malaria drugs, adequate mechanical and chemical prophylaxis (Petroleum, DDT, and other insecticides) as well as an anti-malaria vaccine. Most importantly, large scale research for proper atebrine and plasmochine dosages was conducted in German concentration camps and mental homes. In Dachau Professor Claus Schilling tested synthetic malaria drugs and injected helpless prisoners with high and sometimes lethal doses. Since the 1920s he had been furiously looking for an anti-malaria vaccine in Italian mental homes and from 1939 he continued his experiments in Dachau. Similar experiments were also performed in Buchenwald and in a psychiatric clinic in Thuringia, where Professor Gerhard Rose tested malaria drugs with mentally ill Russian prisoners of war. Schilling was put to death for his criminal

Malaria in the Greater Mekong Subregion: Heterogeneity and Complexity

Science.gov (United States)

Cui, Liwang; Yan, Guiyun; Sattabongkot, Jetsumon; Cao, Yaming; Chen, Bin; Chen, Xiaoguang; Fan, Qi; Fang, Qiang; Jongwutiwes, Somchai; Parker, Daniel; Sirichaisinthop, Jeeraphat; Kyaw, Myat Phone; Su, Xin-zhuan; Yang, Henglin; Yang, Zhaoqing; Wang, Baomin; Xu, Jianwei; Zheng, Bin; Zhong, Daibin; Zhou, Guofa

2011-01-01

The Greater Mekong Subregion (GMS), comprised of six countries including Cambodia, China's Yunnan Province, Lao PDR, Myanmar (Burma), Thailand and Vietnam, is one of the most threatening foci of malaria. Since the initiation of the WHO's Mekong Malaria Program a decade ago, malaria situation in the GMS has greatly improved, reflected in the continuous decline in annual malaria incidence and deaths. However, as many nations are moving towards malaria elimination, the GMS nations still face great challenges. Malaria epidemiology in this region exhibits enormous geographical heterogeneity with Myanmar and Cambodia remaining high-burden countries. Within each country, malaria distribution is also patchy, exemplified by ‘border malaria’ and ‘forest malaria’ with high transmission occurring along international borders and in forests or forest fringes, respectively. ‘Border malaria’ is extremely difficult to monitor, and frequent malaria introductions by migratory human populations constitute a major threat to neighboring, malaria-eliminating countries. Therefore, coordination between neighboring countries is essential for malaria elimination from the entire region. In addition to these operational difficulties, malaria control in the GMS also encounters several technological challenges. Contemporary malaria control measures rely heavily on effective chemotherapy and insecticide control of vector mosquitoes. However, the spread of multidrug resistance and potential emergence of artemisinin resistance in Plasmodium falciparum make resistance management a high priority in the GMS. This situation is further worsened by the circulation of counterfeit and substandard artemisinin-related drugs. In most endemic areas of the GMS, P. falciparum and P. vivax coexist, and in recent malaria control history, P. vivax has demonstrated remarkable resilience to control measures. Deployment of the only registered drug (primaquine) for the radical cure of vivax malaria is

Elimination of malaria due to Plasmodium vivax in central part of the People’s Republic of China: analysis and prediction based on modelling

Directory of Open Access Journals (Sweden)

Zhao Chen

2014-11-01

Full Text Available Five provinces in central People’s Republic of China (P.R. China have successfully reduced the burden of malaria due to Plasmodium vivax in the last 7 years. The results of the Action Plan of China Malaria Elimination (APCME that com- menced in 2010 are analysed against the background of the progress reached by the national malaria control programme (NMEP that was launched in 2006. We examined the epidemiological changes in the number of autochthonous cases over time and discuss the feasibility of achieving the goal of malaria elimination by 2020. There was a total decline of 34,320 malaria cases between 2006 and 2012 arriving at an average annual incidence of 0.04 per 10,000 people by 2012. At the same time, the number of counties reporting autochthonous cases declined from 290 to 19. Spatial autocorrelation and Bayesian modelling were used to evaluate the datasets and predict the spatio-temporal pattern in the near future. The former approach showed that spatial clusters of P. vivax malaria existed in the study region during the study period, while the risk prediction map generated by the Bayesian model indicates that only sporadic malaria cases will appear during in the future. The results suggest that the initial NMEP approach and the follow-up APCME strategy have played a key role in reducing the threat of malaria in central P.R. China. However, to achieve the goal of malaria elimination by the end of the current decade, interven- tion plans must be adjusted with attention paid to those endemic counties still at risk according to the prediction map.

Out of the net: An agent-based model to study human movements influence on local-scale malaria transmission.

Directory of Open Access Journals (Sweden)

Francesco Pizzitutti

Full Text Available Though malaria control initiatives have markedly reduced malaria prevalence in recent decades, global eradication is far from actuality. Recent studies show that environmental and social heterogeneities in low-transmission settings have an increased weight in shaping malaria micro-epidemiology. New integrated and more localized control strategies should be developed and tested. Here we present a set of agent-based models designed to study the influence of local scale human movements on local scale malaria transmission in a typical Amazon environment, where malaria is transmission is low and strongly connected with seasonal riverine flooding. The agent-based simulations show that the overall malaria incidence is essentially not influenced by local scale human movements. In contrast, the locations of malaria high risk spatial hotspots heavily depend on human movements because simulated malaria hotspots are mainly centered on farms, were laborers work during the day. The agent-based models are then used to test the effectiveness of two different malaria control strategies both designed to reduce local scale malaria incidence by targeting hotspots. The first control scenario consists in treat against mosquito bites people that, during the simulation, enter at least once inside hotspots revealed considering the actual sites where human individuals were infected. The second scenario involves the treatment of people entering in hotspots calculated assuming that the infection sites of every infected individual is located in the household where the individual lives. Simulations show that both considered scenarios perform better in controlling malaria than a randomized treatment, although targeting household hotspots shows slightly better performance.

Out of the net: An agent-based model to study human movements influence on local-scale malaria transmission.

Science.gov (United States)

Pizzitutti, Francesco; Pan, William; Feingold, Beth; Zaitchik, Ben; Álvarez, Carlos A; Mena, Carlos F

2018-01-01

Though malaria control initiatives have markedly reduced malaria prevalence in recent decades, global eradication is far from actuality. Recent studies show that environmental and social heterogeneities in low-transmission settings have an increased weight in shaping malaria micro-epidemiology. New integrated and more localized control strategies should be developed and tested. Here we present a set of agent-based models designed to study the influence of local scale human movements on local scale malaria transmission in a typical Amazon environment, where malaria is transmission is low and strongly connected with seasonal riverine flooding. The agent-based simulations show that the overall malaria incidence is essentially not influenced by local scale human movements. In contrast, the locations of malaria high risk spatial hotspots heavily depend on human movements because simulated malaria hotspots are mainly centered on farms, were laborers work during the day. The agent-based models are then used to test the effectiveness of two different malaria control strategies both designed to reduce local scale malaria incidence by targeting hotspots. The first control scenario consists in treat against mosquito bites people that, during the simulation, enter at least once inside hotspots revealed considering the actual sites where human individuals were infected. The second scenario involves the treatment of people entering in hotspots calculated assuming that the infection sites of every infected individual is located in the household where the individual lives. Simulations show that both considered scenarios perform better in controlling malaria than a randomized treatment, although targeting household hotspots shows slightly better performance.

Implementing intermittent preventive treatment for malaria in pregnancy

DEFF Research Database (Denmark)

Mubyazi, Godfrey Martin; Magnussen, Pascal; Goodman, Catherine

2011-01-01

Introduction Implementing Intermittent Preventive Treatment for malaria in Pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) through antenatal care (ANC) clinics is recommended for malaria endemic countries. The vast biomedical literature on malaria prevention focuses more on the epidemiological...... of the recommended interventions. Objective To review literature on policy advances, achievements, constraints and challenges to malaria IPTp implementation, emphasising its operational feasibility in the context of health-care financing, provision and uptake, resource constraints and psychosocial factors in Africa...... discriminatory socio-cultural values on and attitudes towards SP, malaria, and quality of ANC; supply and cost of SP at health facilities; understaffing and demoralised staff; ambiguity and impracticability of user-fee exemption policy guidelines on essential ANC services; implementing IPTp, bednets, HIV...

The Social Epidemiology and Burden of Malaria in Bali Nyonga, Northwest Cameroon

Directory of Open Access Journals (Sweden)

N. V. Pemunta

2013-05-01

Full Text Available Malaria is an infectious disease caused by the anopheles mosquito that kills at least one million people in Sub-Saharan Africa every year, leading to human suffering and enormous economic loses. This paper examines the complex web of cultural, poor socio-economic conditions and environmental factors for the prevalence of malaria in Bali Nyonga. The study outlines and assesses the multiple notions of malaria causation with dirty environment (80.76% and the mosquito (76.92% as the leading causes. Other causes are poor hygiene (46.15%, impure sources of portable water (23.08%, malnutrition (15.38%, witchcraft (11.54%, human-vector contact (34.61%,and palm wine drinking (32.69%.It reveals  that any effective management of malaria must be based on an understanding of traditional cultural views and insights concerning the cause, spread and treatment of the disease, as well as gender roles within a given community since women bear a greater  burden of the disease than men. This study further  underscores the need to incorporate folk theories of disease causation, gender and malaria issues into malaria control strategies in order to improve their coverage and effectiveness in different contexts.

The Molecular Epidemiology of Malaria in Western Kenya

National Research Council Canada - National Science Library

Amon, Joseph

2002-01-01

...) Plasmodium falciparum growth dynamics. The first two research topics were examined in a cohort of 248 males recruited from three highly endemic villages in western Kenya where severe malaria anemia is common...

Enteroparasite and vivax malaria co-infection on the Brazil-French Guiana border: Epidemiological, haematological and immunological aspects.

Directory of Open Access Journals (Sweden)

Rubens Alex de Oliveira Menezes

Full Text Available Malaria-enteroparasitic co-infections are known for their endemicity. Although they are prevalent, little is known about their epidemiology and effect on the immune response. This study evaluated the effect of enteroparasite co-infections with malaria caused by Plasmodium vivax in a border area between Brazil and French Guiana. The cross sectional study took place in Oiapoque, a municipality of Amapá, on the Amazon border. Malaria was diagnosed using thick blood smears, haemoglobin dosage by an automated method and coproparasitology by the Hoffman and Faust methods. The anti-PvMSP-119 IgG antibodies in the plasma were evaluated using ELISA and Th1 (IFN-γ, TNF-α and IL-2, and Th2 (IL-4, IL-5 and IL-10 cytokine counts were performed by flow cytometry. The participants were grouped into those that were monoinfected with vivax malaria (M, vivax malaria-enteroparasite co-infected (CI, monoinfected with enteroparasite (E and endemic controls (EC, who were negative for both diseases. 441 individuals were included and grouped according to their infection status: [M 6.9% (30/441], [Cl 26.5% (117/441], [E 32.4% (143/441] and [EC 34.2% (151/441]. Males prevailed among the (M 77% (23/30 and (CI 60% (70/117 groups. There was a difference in haemoglobin levels among the different groups under study for [EC-E], [EC-Cl], [E-M] and [Cl-M], with (p < 0.01. Anaemia was expressed as a percentage between individuals [CI-EC (p < 0.05]. In terms of parasitaemia, there were differences for the groups [CI-M (p < 0.05]. Anti-PvMSP-119 antibodies were detected in 51.2% (226/441 of the population. The level of cytokines evaluation revealed a large variation in TNF-α and IL-10 concentrations in the co-infected group. In this study we did not observe any influence of coinfection on the acquisition of IgG antibodies against PvMSP119, as well as on the profile of the cytokines that characterize the Th1 and Th2 patterns. However, co-infection increased TNF-α and IL-10

Malaria in Africa: vector species' niche models and relative risk maps.

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Alexander Moffett

2007-09-01

Full Text Available A central theoretical goal of epidemiology is the construction of spatial models of disease prevalence and risk, including maps for the potential spread of infectious disease. We provide three continent-wide maps representing the relative risk of malaria in Africa based on ecological niche models of vector species and risk analysis at a spatial resolution of 1 arc-minute (9 185 275 cells of approximately 4 sq km. Using a maximum entropy method we construct niche models for 10 malaria vector species based on species occurrence records since 1980, 19 climatic variables, altitude, and land cover data (in 14 classes. For seven vectors (Anopheles coustani, A. funestus, A. melas, A. merus, A. moucheti, A. nili, and A. paludis these are the first published niche models. We predict that Central Africa has poor habitat for both A. arabiensis and A. gambiae, and that A. quadriannulatus and A. arabiensis have restricted habitats in Southern Africa as claimed by field experts in criticism of previous models. The results of the niche models are incorporated into three relative risk models which assume different ecological interactions between vector species. The "additive" model assumes no interaction; the "minimax" model assumes maximum relative risk due to any vector in a cell; and the "competitive exclusion" model assumes the relative risk that arises from the most suitable vector for a cell. All models include variable anthrophilicity of vectors and spatial variation in human population density. Relative risk maps are produced from these models. All models predict that human population density is the critical factor determining malaria risk. Our method of constructing relative risk maps is equally general. We discuss the limits of the relative risk maps reported here, and the additional data that are required for their improvement. The protocol developed here can be used for any other vector-borne disease.

Antibody reactivities to glutamate-rich peptides of Plasmodium falciparum parasites in humans from areas of different malaria endemicity

DEFF Research Database (Denmark)

Jakobsen, P H; Theander, T G; Hviid, L

1996-01-01

Synthetic P. falciparum peptides were evaluated as tools in epidemiological investigations of malaria. Plasma IgM and IgG antibody reactivities against synthetic peptides covering sequences of glutamate-rich protein (GLURP) and acidic-basic repeat antigen (ABRA) were measured by ELISA...... in individuals from malaria-endemic areas of Sudan, Indonesia and The Gambia to study antibody responses to these peptides in donors living in areas of different malaria endemicity. IgG and IgM reactivities to the peptides increased with malaria endemicity, although there were no differences in reactivities...... tested were shortlived in most patients. In Gambian children with malaria, IgM reactivities but not IgG antibody reactivities against the ABRA peptide were higher in those with mild malaria than in those with severe malaria. The peptides may be useful in future epidemiological studies, especially...

Malaria vaccines: lessons from field trials

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Claudio J. Struchiner

1994-07-01

Full Text Available Malaria vaccine candidates have already been tested and new trials are being carried out. We present a brief description of specific issues of validity that are relevant when assessing vaccine efficacy in the field and illustrate how the application of these principles might improve our interpretation of the data being gathered in actual malaria vaccine field trials. Our discussion assumes that vaccine evaluation shares the same general principles of validity with epidemiologic causal inference, i.e., the process of drawing inferences from epidemiologic data aiming at the identification of causes of diseases. Judicious exercise of these principles indicates that, for meaningful interpretation, measures of vaccine efficacy require definitions based upon arguments conditional on the amount of exposure to infection, and specification of the initial and final states in which one believes the effect of interest takes place.

Mapping hypoendemic, seasonal malaria in rural Bandarban, Bangladesh: a prospective surveillance

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Glass Gregory

2011-05-01

Full Text Available Abstract Background Until recently the Chittagong Hill tracts have been hyperendemic for malaria. A past cross-sectional RDT based survey in 2007 recorded rates of approximately 15%. This study was designed to understand the present epidemiology of malaria in this region, to monitor and facilitate the uptake of malaria intervention activities of the national malaria programme and to serve as an area for developing new and innovative control strategies for malaria. Methods This research field area was established in two rural unions of Bandarban District of Bangladesh north of Bandarban city, which are known to be endemic for malaria due to Plasmodium falciparum. The project included the following elements: a a demographic surveillance system including an initial census with updates every four months, b periodic surveys of knowledge attitude and practice, c a geographic information system, d weekly active and continuous passive surveillance for malaria infections using smears, rapid tests and PCR, f monthly mosquito surveillance, and e daily weather measures. The programme included both traditional and molecular methods for detecting malaria as well as lab methods for speciating mosquitoes and detecting mosquitoes infected with sporozoites. Results The demographic surveillance enumerated and mapped 20,563 people, 75% of which were tribal non-Bengali. The monthly mosquito surveys identified 22 Anopheles species, eight of which were positive by circumsporozoite ELISA. The annual rate of malaria was close to 1% with 85% of cases in the rainy months of May-October. Definitive clustering identified in the low transmission season persisted during the high transmission season. Conclusion This demographically and geographically defined area, near to the Myanmar border, which is also hypoendemic for malaria, will be useful for future studies of the epidemiology of malaria and for evaluation of strategies for malaria control including new drugs and

Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control

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Ndenga Bryson A

2006-11-01

Full Text Available Abstract Background Recent resurgence of malaria in the highlands of Western Kenya has called for a more comprehensive understanding of the previously neglected complex highland vector ecology. Besides other drivers of malaria epidemiology, topography is likely to have a major effect on spatial vector and parasite distribution. The aim of this study was to determine the effects of topography on malaria spatial vector distribution and parasite prevalence. Methodology Indoor resting adult malaria vectors and blood parasites were collected in three villages along a 4 km transect originating from the valley bottom and ending at the hilltop for 13 months. Members of the Anopheles gambiae complex were identified by PCR. Blood parasites were collected from children 6–13 years old and densities categorized by site of home location and age of the children. Results Ninety eight percent (98% of An. gambiae s.s. and (99% Anopheles funestus were collected in houses located at the edge of the valley bottom, whereas 1% of An. gambiae s.s. were collected at mid hill and at the hilltop respectively. No An. funestus were collected at the hilltop. Malaria prevalence was 68% at the valley bottom, 40.2% at mid hill and 26.7% at the hilltop. Children aged six years and living at the edge of the valley bottom had an annual geometric mean number of 66.1 trophozoites for every 200 white blood cells, while those living at mid-hill had a mean of 84.8, and those living at hilltop had 199.5 trophozoites. Conclusion Malaria transmission in this area is mainly confined to the valley bottom. Effective vector control could be targeted at the foci. However, the few vectors observed at mid-hill maintained a relatively high prevalence rate. The higher variability in blood parasite densities and their low correlation with age in children living at the hilltop suggests a lower stability of transmission than at the mid-hill and valley bottom.

A molecular epidemiological study of var gene diversity to characterize the reservoir of Plasmodium falciparum in humans in Africa.

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Donald S Chen

2011-02-01

Full Text Available The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to mosquito.We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1% var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences.Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population exists.

A Molecular Epidemiological Study of var Gene Diversity to Characterize the Reservoir of Plasmodium falciparum in Humans in Africa

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Leliwa-Sytek, Aleksandra; Smith, Terry-Ann; Peterson, Ingrid; Brown, Stuart M.; Migot-Nabias, Florence; Deloron, Philippe; Kortok, Moses M.; Marsh, Kevin; Daily, Johanna P.; Ndiaye, Daouda; Sarr, Ousmane; Mboup, Souleymane; Day, Karen P.

2011-01-01

Background The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to mosquito. Methodology/Principal Findings We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1%) var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences. Conclusions/Significance Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population

Malaria control and elimination, Venezuela, 1800s –1970s.

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Griffing, Sean M; Villegas, Leopoldo; Udhayakumar, Venkatachalam

2014-10-01

Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920,malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world's interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication.Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization.We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines.

Malaria Control and Elimination,1 Venezuela, 1800s–1970s

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Villegas, Leopoldo; Udhayakumar, Venkatachalam

2014-01-01

Venezuela had the highest number of human malaria cases in Latin American before 1936. During 1891–1920, malaria was endemic to >600,000 km2 of this country; malaria death rates led to major population decreases during 1891–1920. No pathogen, including the influenza virus that caused the 1918 pandemic, caused more deaths than malaria during 1905–1945. Early reports of malaria eradication in Venezuela helped spark the world’s interest in global eradication. We describe early approaches to malaria epidemiology in Venezuela and how this country developed an efficient control program and an approach to eradication. Arnoldo Gabaldón was a key policy maker during this development process. He directed malaria control in Venezuela from the late 1930s to the end of the 1970s and contributed to malaria program planning of the World Health Organization. We discuss how his efforts helped reduce the incidence of malaria in Venezuela and how his approach diverged from World Health Organization guidelines.

Malaria Control In the Northern Transvaal

African Journals Online (AJOL)

epidemiology as it affects control operations in the Trans- vaal followed by an outline of .... every case of malaria is a danger and must be detected, given adequate .... mosquito-borne viruses, possibly Chikungunya virus. The Arbor virus unit of ...

Malaria epidemiology in the Pakaanóva (Wari') Indians, Brazilian Amazon.

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Sá, D Ribeiro; Souza-Santos, R; Escobar, A L; Coimbra, C E A

2005-04-01

This paper reports the results of a longitudinal study of malaria incidence (1998-2002) among the Pakaanóva (Wari') Indians, Brazilian southwest Amazon region, based on data routinely gathered by Brazilian National Health Foundation outposts network in conjunction with the Indian health service. Malaria is present yearlong in the Pakaanóva. Statistically significant differences between seasons or months were not noticed. A total of 1933 cases of malaria were diagnosed in the Pakaanóva during this period. The P. vivax / P. falciparum ratio was 3.4. P. vivax accounted for 76.5% of the cases. Infections with P. malariae were not recorded. Incidence rates did not differ by sex. Most malaria cases were reported in children < 10 years old (45%). About one fourth of all cases were diagnosed on women 10-40 years old. An entomological survey carried out at two Pakaanóva villages yielded a total of 3.232 specimens of anophelines. Anopheles darlingi predominated (94.4%). Most specimens were captured outdoors and peak activity hours were noted at early evening and just before sunrise. It was observed that Pakaanóva cultural practices may facilitate outdoor exposure of individuals of both sexes and all age groups during peak hours of mosquito activities (e.g., coming to the river early in the morning for bathing or to draw water, fishing, engaging in hunting camps, etc). In a context in which anophelines are ubiquitous and predominantly exophilic, and humans of both sexes and all ages are prone to outdoor activities during peak mosquito activity hours, malaria is likely to remain endemic in the Pakaanóva, thus requiring the development of alternative control strategies that are culturally and ecologically sensitive.

Changing spatial epidemiology of pertussis in continental USA.

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Choisy, Marc; Rohani, Pejman

2012-11-22

Prediction and control of the geographical spread of emerging pathogens has become a central public health issue. Because these infectious diseases are by definition novel, there are few data to characterize their dynamics. One possible solution to this problem is to apply lessons learnt from analyses of historical data on familiar and epidemiologically similar pathogens. However, the portability of the spatial ecology of an infectious disease in a different epoch to other infections remains unexamined. Here, we study this issue by taking advantage of the recent re-emergence of pertussis in the United States to compare its spatial transmission dynamics throughout the 1950s with the past decade. We report 4-year waves, sweeping across the continent in the 1950s. These waves are shown to emanate from highly synchronous foci in the northwest and northeast coasts. In contrast, the recent resurgence of the disease is characterized by 5.5-year epidemics with no particular spatial structure. We interpret this to be the result of dramatic changes in patterns of human movement over the second half of the last century, together with changing age distribution of pertussis. We conclude that extrapolation regarding the spatial spread of contemporaneous pathogens based on analyses of historical incidence may be potentially very misleading.

Diversidad genética de Plasmodium falciparum y sus implicaciones en la epidemiología de la malaria.

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Judy Natalia Jiménez

2005-12-01

Full Text Available La diversidad genética le confiere a Plasmodium falciparum la capacidad de evadir la respuesta inmune del hospedero y producir variantes resistentes a medicamentos y a vacunas, aspectos que juegan un papel importante en el establecimiento de medidas de control contra la malaria. Diferentes autores han documentado la existencia de diversas cepas o clones de P. falciparum, cuya diversidad genética se ha confirmado a través de distintos ensayos de PCR (reacción en cadena de la polimerasa. Numerosas investigaciones realizadas en poblaciones con diferente grado de transmisión de malaria han mostrado la relación existente entre la estructura de la población de P. falciparum y la epidemiología de la enfermedad. En este artículo se describen las fases del ciclo de vida en las que los eventos de recombinación originan la diversidad genética de P. falciparum, se revisan los estudios realizados sobre este aspecto en regiones con diferentes grados de endemicidad, así como sobre sus implicaciones en la adquisición de inmunidad y en el desarrollo de medidas de control.

Mapping to Support Fine Scale Epidemiological Cholera Investigations: A Case Study of Spatial Video in Haiti

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Andrew Curtis

2016-02-01

Full Text Available The cartographic challenge in many developing world environments suffering a high disease burden is a lack of granular environmental covariates suitable for modeling disease outcomes. As a result, epidemiological questions, such as how disease diffuses at intra urban scales are extremely difficult to answer. This paper presents a novel geospatial methodology, spatial video, which can be used to collect and map environmental covariates, while also supporting field epidemiology. An example of epidemic cholera in a coastal town of Haiti is used to illustrate the potential of this new method. Water risks from a 2012 spatial video collection are used to guide a 2014 survey, which concurrently included the collection of water samples, two of which resulted in positive lab results “of interest” (bacteriophage specific for clinical cholera strains to the current cholera situation. By overlaying sample sites on 2012 water risk maps, a further fifteen proposed water sample locations are suggested. These resulted in a third spatial video survey and an additional “of interest” positive water sample. A potential spatial connection between the “of interest” water samples is suggested. The paper concludes with how spatial video can be an integral part of future fine-scale epidemiological investigations for different pathogens.

Analysing malaria incidence at the small area level for developing a spatial decision support system: A case study in Kalaburagi, Karnataka, India.

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Shekhar, S; Yoo, E-H; Ahmed, S A; Haining, R; Kadannolly, S

2017-02-01

Spatial decision support systems have already proved their value in helping to reduce infectious diseases but to be effective they need to be designed to reflect local circumstances and local data availability. We report the first stage of a project to develop a spatial decision support system for infectious diseases for Karnataka State in India. The focus of this paper is on malaria incidence and we draw on small area data on new cases of malaria analysed in two-monthly time intervals over the period February 2012 to January 2016 for Kalaburagi taluk, a small area in Karnataka. We report the results of data mapping and cluster detection (identifying areas of excess risk) including evaluating the temporal persistence of excess risk and the local conditions with which high counts are statistically associated. We comment on how this work might feed into a practical spatial decision support system. Copyright © 2017 Elsevier Ltd. All rights reserved.

a Novel Approach to Veterinary Spatial Epidemiology: Dasymetric Refinement of the Swiss Dog Tumor Registry Data

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Boo, G.; Fabrikant, S. I.; Leyk, S.

2015-08-01

In spatial epidemiology, disease incidence and demographic data are commonly summarized within larger regions such as administrative units because of privacy concerns. As a consequence, analyses using these aggregated data are subject to the Modifiable Areal Unit Problem (MAUP) as the geographical manifestation of ecological fallacy. In this study, we create small area disease estimates through dasymetric refinement, and investigate the effects on predictive epidemiological models. We perform a binary dasymetric refinement of municipality-aggregated dog tumor incidence counts in Switzerland for the year 2008 using residential land as a limiting ancillary variable. This refinement is expected to improve the quality of spatial data originally aggregated within arbitrary administrative units by deconstructing them into discontinuous subregions that better reflect the underlying population distribution. To shed light on effects of this refinement, we compare a predictive statistical model that uses unrefined administrative units with one that uses dasymetrically refined spatial units. Model diagnostics and spatial distributions of model residuals are assessed to evaluate the model performances in different regions. In particular, we explore changes in the spatial autocorrelation of the model residuals due to spatial refinement of the enumeration units in a selected mountainous region, where the rugged topography induces great shifts of the analytical units i.e., residential land. Such spatial data quality refinement results in a more realistic estimation of the population distribution within administrative units, and thus, in a more accurate modeling of dog tumor incidence patterns. Our results emphasize the benefits of implementing a dasymetric modeling framework in veterinary spatial epidemiology.

Space-time clustering of childhood malaria at the household level: a dynamic cohort in a Mali village

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Ouattara Amed

2006-11-01

Full Text Available Abstract Background Spatial and temporal heterogeneities in the risk of malaria have led the WHO to recommend fine-scale stratification of the epidemiological situation, making it possible to set up actions and clinical or basic researches targeting high-risk zones. Before initiating such studies it is necessary to define local patterns of malaria transmission and infection (in time and in space in order to facilitate selection of the appropriate study population and the intervention allocation. The aim of this study was to identify, spatially and temporally, high-risk zones of malaria, at the household level (resolution of 1 to 3 m. Methods This study took place in a Malian village with hyperendemic seasonal transmission as part of Mali-Tulane Tropical Medicine Research Center (NIAID/NIH. The study design was a dynamic cohort (22 surveys, from June 1996 to June 2001 on about 1300 children (Plasmodium falciparum, P. malariae and P. ovale infection and P. falciparum gametocyte carriage by means of time series and Kulldorff's scan statistic for space-time cluster detection. Results The time series analysis determined that malaria parasitemia (primarily P. falciparum was persistently present throughout the population with the expected seasonal variability pattern and a downward temporal trend. We identified six high-risk clusters of P. falciparum infection, some of which persisted despite an overall tendency towards a decrease in risk. The first high-risk cluster of P. falciparum infection (rate ratio = 14.161 was detected from September 1996 to October 1996, in the north of the village. Conclusion This study showed that, although infection proportions tended to decrease, high-risk zones persisted in the village particularly near temporal backwaters. Analysis of this heterogeneity at the household scale by GIS methods lead to target preventive actions more accurately on the high-risk zones identified. This mapping of malaria risk makes it possible

Selective Intermittent Preventive Treatment of Vivax Malaria: Reduction of Malaria Incidence in an Open Cohort Study in Brazilian Amazon

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Gil, Luiz Herman Soares; de Lima, Alzemar Alves; Freitag, Elci Marlei; dos Santos, Tatiana Marcondes; do Nascimento Filha, Maria Teixeira; dos Santos Júnior, Alcides Procópio Justiniano; da Silva, Josiane Mendes; Rodrigues, Aline de Freitas; Tada, Mauro Shugiro; Fontes, Cor Jesus Fernandes; Pereira da Silva, Luiz Hildebrando

2013-01-01

In children, the Intermittent Preventive Treatment (IPTc), currently called Seasonal Malaria Chemoprevention (SMC), was considered effective on malaria control due to the reduction of its incidence in Papua New Guinea and in some areas with seasonal malaria in Africa. However, the IPT has not been indicated because of its association with drug resistance and for hindering natural immunity development. Thus, we evaluated the alternative IPT impact on malaria incidence in three riverside communities on Madeira River, in the municipality of Porto Velho, RO. We denominate this scheme Selective Intermittent Preventive Treatment (SIPT). The SIPT consists in a weekly dose of two 150 mg chloroquine tablets for 12 weeks, for adults, and an equivalent dose for children, after complete supervised treatment for P. vivax infection. This scheme is recommend by Brazilian Health Ministry to avoid frequent relapses. The clinic parasitological and epidemiological surveillance showed a significant reduction on vivax malaria incidence. The results showed a reduction on relapses and recurrence of malaria after SIPT implementation. The SIPT can be effective on vivax malaria control in localities with high transmission risk in the Brazilian Amazon. PMID:23577276

Selective Intermittent Preventive Treatment of Vivax Malaria: Reduction of Malaria Incidence in an Open Cohort Study in Brazilian Amazon

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Tony Hiroshi Katsuragawa

2013-01-01

Full Text Available In children, the Intermittent Preventive Treatment (IPTc, currently called Seasonal Malaria Chemoprevention (SMC, was considered effective on malaria control due to the reduction of its incidence in Papua New Guinea and in some areas with seasonal malaria in Africa. However, the IPT has not been indicated because of its association with drug resistance and for hindering natural immunity development. Thus, we evaluated the alternative IPT impact on malaria incidence in three riverside communities on Madeira River, in the municipality of Porto Velho, RO. We denominate this scheme Selective Intermittent Preventive Treatment (SIPT. The SIPT consists in a weekly dose of two 150 mg chloroquine tablets for 12 weeks, for adults, and an equivalent dose for children, after complete supervised treatment for P. vivax infection. This scheme is recommend by Brazilian Health Ministry to avoid frequent relapses. The clinic parasitological and epidemiological surveillance showed a significant reduction on vivax malaria incidence. The results showed a reduction on relapses and recurrence of malaria after SIPT implementation. The SIPT can be effective on vivax malaria control in localities with high transmission risk in the Brazilian Amazon.

Human movement data for malaria control and elimination strategic planning.

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Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

2012-06-18

Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

Imported malaria in a cosmopolitan European city: a mirror image of the world epidemiological situation.

Science.gov (United States)

Millet, Juan Pablo; Garcia de Olalla, Patricia; Carrillo-Santisteve, Paloma; Gascón, Joaquim; Treviño, Begoña; Muñoz, José; Gómez I Prat, Jordi; Cabezos, Juan; González Cordón, Anna; Caylà, Joan A

2008-04-08

International travel and migration have been related with an increase of imported malaria cases. There has been considerable immigration to Barcelona from low-income countries (LIC) in recent years. The objective is to describe the epidemiology and to determine the trends of the disease in Barcelona. Analysis of the cases notified among city residents between 1989 and 2005. Patients were classified as: tourists, voluntary workers, resident immigrants (visiting friends and relatives, VFR) and recently arrived immigrants. An analysis was conducted using the chi2 test and comparison of means. As a measure of association we calculated the Relative Risk (RR) and Odds Ratio (OR) with a Confidence Interval of 95% (CI) and carried out a trends analysis. Of the total of 1,579 imported cases notified, 997 (63.1%) lived in Barcelona city, and 55.1% were male. The mean age of patients was 32.7 years. The incidence increased from 2.4 cases/100,000 in 1989 to 3.5 cases/100,000 in 2005 (RR 1.46 CI:1.36-1.55). This increase was not statistically significant (trends analysis, p = 0.36). In terms of reason for travelling, 40.7% were VFR, 33.6% tourists, 12.1% voluntary workers and 13.6% were recently arrived immigrants. The most frequent species found was Plasmodium falciparum (71.3%), mainly in visitors to Africa (OR = 2.3, CI = 1.7-3.2). The vast majority (82.2%) had had some contact with Africa (35.9% with Equatorial Guinea, a Spanish ex-colony) and 96.6% had not completed chemoprophylaxis. Six deaths were observed, all tourists who had travelled to Africa and not taken chemoprophylaxis (3.9% fatality rate). Over the period studied there is an increase in malaria incidence, however the trend is not statistically significant. Lack of chemoprophylaxis compliance and the association between Africa and P. falciparum are very clear in the imported cases. Most of the patients with malaria did not take chemoprophylaxis.

Imported malaria in a cosmopolitan European city: A mirror image of the world epidemiological situation

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Gómez i Prat Jordi

2008-04-01

Full Text Available Abstract Background International travel and migration have been related with an increase of imported malaria cases. There has been considerable immigration to Barcelona from low-income countries (LIC in recent years. The objective is to describe the epidemiology and to determine the trends of the disease in Barcelona. Methods Analysis of the cases notified among city residents between 1989 and 2005. Patients were classified as: tourists, voluntary workers, resident immigrants (visiting friends and relatives, VFR and recently arrived immigrants. An analysis was conducted using the chi2 test and comparison of means. As a measure of association we calculated the Relative Risk (RR and Odds Ratio (OR with a Confidence Interval of 95% (CI and carried out a trends analysis. Results Of the total of 1,579 imported cases notified, 997 (63.1% lived in Barcelona city, and 55.1% were male. The mean age of patients was 32.7 years. The incidence increased from 2.4 cases/100,000 in 1989 to 3.5 cases/100,000 in 2005 (RR 1.46 CI:1.36–1.55. This increase was not statistically significant (trends analysis, p = 0.36. In terms of reason for travelling, 40.7% were VFR, 33.6% tourists, 12.1% voluntary workers and 13.6% were recently arrived immigrants. The most frequent species found was Plasmodium falciparum (71.3%, mainly in visitors to Africa (OR = 2.3, CI = 1.7–3.2. The vast majority (82.2% had had some contact with Africa (35.9% with Equatorial Guinea, a Spanish ex-colony and 96.6% had not completed chemoprophylaxis. Six deaths were observed, all tourists who had travelled to Africa and not taken chemoprophylaxis (3.9% fatality rate. Conclusion Over the period studied there is an increase in malaria incidence, however the trend is not statistically significant. Lack of chemoprophylaxis compliance and the association between Africa and P. falciparum are very clear in the imported cases. Most of the patients with malaria did not take chemoprophylaxis.

Malaria incidence in Myanmar 2005–2014: steady but fragile progress towards elimination

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Thet Thet Mu

2016-10-01

Full Text Available Abstract Background There has been an impressive recent reduction in the global incidence of malaria, but the development of artemisinin resistance in the Greater Mekong Region threatens this progress. Increasing artemisinin resistance is particularly important in Myanmar, as it is the country in the Greater Mekong Region with the greatest malaria burden. If malaria is to be eliminated in the region, it is essential to define the spatial and temporal epidemiology of the disease in Myanmar to inform control strategies optimally. Results Between the years 2005 and 2014 there was an 81.1 % decline in the reported annual incidence of malaria in Myanmar (1341.8 cases per 100,000 population to 253.3 cases per 100,000 population. In the same period, there was a 93.5 % decline in reported annual mortality from malaria (3.79 deaths per 100,000 population to 0.25 deaths per 100,000 population and a 87.2 % decline in the proportion of hospitalizations due to malaria (7.8 to 1.0 %. Chin State had the highest reported malaria incidence and mortality at the end of the study period, although socio-economic and geographical factors appear a more likely explanation for this finding than artemisinin resistance. The reduced malaria burden coincided with significant upscaling of disease control measures by the national government with support from international partners. These programmes included the training and deployment of over 40,000 community health care workers, the coverage of over 60 % of the at-risk population with insecticide-treated bed nets and significant efforts to improve access to artemesinin-based combination treatment. Beyond these malaria-specific programmes, increased general investment in the health sector, changing population demographics and deforestation are also likely to have contributed to the decline in malaria incidence seen over this time. Conclusions There has been a dramatic fall in the burden of malaria in Myanmar since 2005

Epidemiological Study of the Association Between Malaria and Helminth Infections in Nigeria

DEFF Research Database (Denmark)

Efunshile, Akinwale Michael; Olawale, Temitope; Stensvold, Christen Rune

2015-01-01

The relationship between intestinal helminth infection and susceptibility to malaria remains unclear. We studied the relationship between these infections. Seven schools in Ilero, Nigeria referred all pupils with febrile illness to our study center for free malaria treatment during a 3-month stud...

Towards the implementation of malaria elimination policy in South Africa: the stakeholders' perspectives.

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Hlongwana, Khumbulani Welcome; Tsoka-Gwegweni, Joyce

2017-01-01

The past decade has seen substantial global reduction in malaria morbidity and mortality due to increased international funding and decisive steps by the international malaria community to fight malaria. South Africa has been declared ready to institute malaria elimination. However, research on the factors that would affect this policy implementation is inadequate. To investigate the stakeholders' understanding of the malaria elimination policy in South Africa, including their perceived barriers and facilitators to effective policy implementation. The study followed a constructivist epistemological approach which manifests in phenomenological study design. Twelve purposively selected key informants from malaria researchers, provincial and national malaria programmes were interviewed using semi-structured interviews. Interview questions elicited interviewees' knowledge of the policy and its achievability, including any perceived barriers and facilitating factors to effective implementation. The hybrid approach was used to perform thematic data analysis. The dominant view was that malaria remains a problem in South Africa, exacerbated by staff attitudes and poor capacity, lack of resources, lack of new effective intervention tools, lack of intra- and inter-departmental collaboration, poor cross-border collaboration and weak stakeholder collaboration. Informants were concerned about the target year (2018) for elimination, and about the process followed in developing the policy, including the perceived malaria epidemiology shortfalls, regulatory issues and political context of the policy. Achievability of malaria elimination remains a subject of intense debate for a variety of reasons. These include the sporadic nature of malaria resurgence, raising questions about the contributions of malaria control interventions and climate to the transmission trends in South Africa. The shortage of resources, inadequate staff capacity, lack of any new effective intervention tools

Epidemiological models for the spread of anti-malarial resistance

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Antia R

2003-02-01

Full Text Available Abstract Background The spread of drug resistance is making malaria control increasingly difficult. Mathematical models for the transmission dynamics of drug sensitive and resistant strains can be a useful tool to help to understand the factors that influence the spread of drug resistance, and they can therefore help in the design of rational strategies for the control of drug resistance. Methods We present an epidemiological framework to investigate the spread of anti-malarial resistance. Several mathematical models, based on the familiar Macdonald-Ross model of malaria transmission, enable us to examine the processes and parameters that are critical in determining the spread of resistance. Results In our simplest model, resistance does not spread if the fraction of infected individuals treated is less than a threshold value; if drug treatment exceeds this threshold, resistance will eventually become fixed in the population. The threshold value is determined only by the rates of infection and the infectious periods of resistant and sensitive parasites in untreated and treated hosts, whereas the intensity of transmission has no influence on the threshold value. In more complex models, where hosts can be infected by multiple parasite strains or where treatment varies spatially, resistance is generally not fixed, but rather some level of sensitivity is often maintained in the population. Conclusions The models developed in this paper are a first step in understanding the epidemiology of anti-malarial resistance and evaluating strategies to reduce the spread of resistance. However, specific recommendations for the management of resistance need to wait until we have more data on the critical parameters underlying the spread of resistance: drug use, spatial variability of treatment and parasite migration among areas, and perhaps most importantly, cost of resistance.

Human movement data for malaria control and elimination strategic planning

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Pindolia Deepa K

2012-06-01

Full Text Available Abstract Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i discuss relevant types of HPM across spatial and temporal scales, (ii document where datasets exist to quantify HPM, (iii highlight where data gaps remain and (iv briefly put forward methods for integrating these datasets in a Geographic Information System (GIS framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

Identifying malaria hotspots in Keur Soce health and demographic surveillance site in context of low transmission.

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Ndiath, Mansour; Faye, Babacar; Cisse, Badara; Ndiaye, Jean Louis; Gomis, Jules François; Dia, Anta Tal; Gaye, Oumar

2014-11-24

Malaria is major public health problem in Senegal. In some parts of the country, it occurs almost permanently with a seasonal increase during the rainy season. There is evidence to suggest that the prevalence of malaria in Senegal has decreased considerably during the past few years. Recent data from the Senegalese National Malaria Control Programme (NMCP) indicates that the number of malaria cases decrease from 1,500,000 in 2006 to 174,339 in 2010. With the decline of malaria morbidity in Senegal, the characterization of the new epidemiological profile of this disease is crucial for public health decision makers. SaTScan™ software using the Kulldorf method of retrospective space-time permutation and the Bernoulli purely spatial model was used to identify malaria clusters using confirmed malaria cases in 74 villages. ArcMAp was used to map malaria hotspots. Logistic regression was used to investigate risk factors for malaria hotspots in Keur Soce health and demographic surveillance site. A total of 1,614 individuals in 440 randomly selected households were enrolled. The overall malaria prevalence was 12%. The malaria prevalence during the study period varied from less than 2% to more than 25% from one village to another. The results showed also that rooms located between 50 m to 100 m away from livestock holding place [adjusted O.R = 0.7, P = 0.044, 95% C.I (1.02 - 7.42)], bed net use [adjusted O.R = 1.2, P = 0.024, 95% C.I (1.02 -1.48)], are good predictors for malaria hotspots in the Keur Soce health and demographic surveillance site. The socio economic status of the household also predicted on hotspots patterns. The less poor household are 30% less likely to be classified as malaria hotspots area compared to the poorest household [adjusted O.R = 0.7, P = 0.014, 95% C.I (0.47 - 0.91)]. The study investigated risk factors for malaria hotspots in small communities in the Keur Soce site. The result showed considerable variation of malaria

Estimating the global clinical burden of Plasmodium falciparum malaria in 2007.

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Simon I Hay

2010-06-01

Full Text Available The epidemiology of malaria makes surveillance-based methods of estimating its disease burden problematic. Cartographic approaches have provided alternative malaria burden estimates, but there remains widespread misunderstanding about their derivation and fidelity. The aims of this study are to present a new cartographic technique and its application for deriving global clinical burden estimates of Plasmodium falciparum malaria for 2007, and to compare these estimates and their likely precision with those derived under existing surveillance-based approaches.In seven of the 87 countries endemic for P. falciparum malaria, the health reporting infrastructure was deemed sufficiently rigorous for case reports to be used verbatim. In the remaining countries, the mapped extent of unstable and stable P. falciparum malaria transmission was first determined. Estimates of the plausible incidence range of clinical cases were then calculated within the spatial limits of unstable transmission. A modelled relationship between clinical incidence and prevalence was used, together with new maps of P. falciparum malaria endemicity, to estimate incidence in areas of stable transmission, and geostatistical joint simulation was used to quantify uncertainty in these estimates at national, regional, and global scales. Combining these estimates for all areas of transmission risk resulted in 451 million (95% credible interval 349-552 million clinical cases of P. falciparum malaria in 2007. Almost all of this burden of morbidity occurred in areas of stable transmission. More than half of all estimated P. falciparum clinical cases and associated uncertainty occurred in India, Nigeria, the Democratic Republic of the Congo (DRC, and Myanmar (Burma, where 1.405 billion people are at risk. Recent surveillance-based methods of burden estimation were then reviewed and discrepancies in national estimates explored. When these cartographically derived national estimates were ranked

A spatial epidemiological analysis of self-rated mental health in the slums of Dhaka

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Müller Daniel

2011-05-01

Full Text Available Abstract Background The deprived physical environments present in slums are well-known to have adverse health effects on their residents. However, little is known about the health effects of the social environments in slums. Moreover, neighbourhood quantitative spatial analyses of the mental health status of slum residents are still rare. The aim of this paper is to study self-rated mental health data in several slums of Dhaka, Bangladesh, by accounting for neighbourhood social and physical associations using spatial statistics. We hypothesised that mental health would show a significant spatial pattern in different population groups, and that the spatial patterns would relate to spatially-correlated health-determining factors (HDF. Methods We applied a spatial epidemiological approach, including non-spatial ANOVA/ANCOVA, as well as global and local univariate and bivariate Moran's I statistics. The WHO-5 Well-being Index was used as a measure of self-rated mental health. Results We found that poor mental health (WHO-5 scores Conclusions Spatial patterns of mental health were detected and could be partly explained by spatially correlated HDF. We thereby showed that the socio-physical neighbourhood was significantly associated with health status, i.e., mental health at one location was spatially dependent on the mental health and HDF prevalent at neighbouring locations. Furthermore, the spatial patterns point to severe health disparities both within and between the slums. In addition to examining health outcomes, the methodology used here is also applicable to residuals of regression models, such as helping to avoid violating the assumption of data independence that underlies many statistical approaches. We assume that similar spatial structures can be found in other studies focussing on neighbourhood effects on health, and therefore argue for a more widespread incorporation of spatial statistics in epidemiological studies.

Naturally acquired immunity to Plasmodium falciparum malaria in Africa

DEFF Research Database (Denmark)

Hviid, Lars

2005-01-01

Infection by Plasmodium falciparum parasites can lead to substantial protective immunity to malaria, and available evidence suggest that acquisition of protection against some severe malaria syndromes can be fairly rapid. Although these facts have raised hopes that the development of effective...... protective immunity to P. falciparum malaria is acquired following natural exposure to the parasites is beginning to emerge, not least thanks to studies that have combined clinical and epidemiological data with basic immunological research. This framework involves IgG with specificity for clonally variant...... antigens on the surface of the infected erythrocytes, can explain some of the difficulties in relating particular immune responses with specificity for well-defined antigenic targets to clinical protection, and suggests a radically new approach to controlling malaria-related morbidity and mortality...

Elimination of Plasmodium falciparum malaria in Tajikistan.

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Kondrashin, Anatoly V; Sharipov, Azizullo S; Kadamov, Dilshod S; Karimov, Saifuddin S; Gasimov, Elkhan; Baranova, Alla M; Morozova, Lola F; Stepanova, Ekaterina V; Turbabina, Natalia A; Maksimova, Maria S; Morozov, Evgeny N

2017-05-30

Malaria was eliminated in Tajikistan by the beginning of the 1960s. However, sporadic introduced cases of malaria occurred subsequently probably as a result of transmission from infected mosquito Anopheles flying over river the Punj from the border areas of Afghanistan. During the 1970s and 1980s local outbreaks of malaria were reported in the southern districts bordering Afghanistan. The malaria situation dramatically changed during the 1990s following armed conflict and civil unrest in the newly independent Tajikistan, which paralyzed health services including the malaria control activities and a large-scale malaria epidemic occurred with more than 400,000 malaria cases. The malaria epidemic was contained by 1999 as a result of considerable financial input from the Government and the international community. Although Plasmodium falciparum constituted only about 5% of total malaria cases, reduction of its incidence was slower than that of Plasmodium vivax. To prevent increase in P. falciparum malaria both in terms of incidence and territory, a P. falciparum elimination programme in the Republic was launched in 200, jointly supported by the Government and the Global Fund for control of AIDS, tuberculosis and malaria. The main activities included the use of pyrethroids for the IRS with determined periodicity, deployment of mosquito nets, impregnated with insecticides, use of larvivorous fishes as a biological larvicide, implementation of small-scale environmental management, and use of personal protection methods by population under malaria risk. The malaria surveillance system was strengthened by the use of ACD, PCD, RCD and selective use of mass blood surveys. All detected cases were timely epidemiologically investigated and treated based on the results of laboratory diagnosis. As a result, by 2009, P. falciparum malaria was eliminated from all of Tajikistan, one year ahead of the originally targeted date. Elimination of P. falciparum also contributed towards

Faktor Risiko Penularan Malaria Di Jawa Barat (Kajian Epidemiologi Tentang Vektor, Parasit Plasmodium, dan Lingkungan Sebagai Faktor Risiko Kesakitan Malaria

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Lukman Hakim

2013-02-01

Full Text Available Abstract. Since the territory is divided with the province of Banten, in West Java there are five regencies that defined as malaria endemie area, there are Ciamis, Tasikmalaya, Garut, Cianjur and Sukabumi. Sufferer, concentrated in southern coastal areas (Indonesian Ocean starting from the beach of Kalipucang at Ciamis up to coast of Cikakak at Sukabumi which borders the province of Banten and also mountain and plantations areas. Malaria morbidity incidence risk factors is differ in each of these endemie areas. In general is the presence of malaria patients without symptoms who can be a source of infection that so difficult to know its existence. Still the number of standing water that can become mosqui­to breeding places of Anopheles spp, such as fish pond, small puddle on the rivers ide, shrimp pond, mangrove forests that potentially at the beginning of the rainy season, the fields during rice that potential when the rice gro wing and the river that potential in the dry season. The existence of high population mobility and also the number of vegetation in the surrounding residential population and the existence of cattle are placed close to settle­ments.Key Words : West Java Province, malaria endemie areas, malaria patients without symp­toms, Anopheles spp.

Factors associated with malaria parasitemia, anemia and serological responses in a spectrum of epidemiological settings in Uganda.

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Adoke Yeka

Full Text Available Understanding the current epidemiology of malaria and the relationship between intervention coverage, transmission intensity, and burden of disease is important to guide control activities. We aimed to determine the prevalence of anemia, parasitemia, and serological responses to P. falciparum antigens, and factors associated with these indicators, in three different epidemiological settings in Uganda.In 2012, cross-sectional surveys were conducted in 200 randomly selected households from each of three sites: Walukuba, Jinja district (peri-urban; Kihihi, Kanungu district (rural; and Nagongera, Tororo district (rural with corresponding estimates of annual entomologic inoculation rates (aEIR of 3.8, 26.6, and 125.0, respectively. Of 2737 participants, laboratory testing was done in 2227 (81.4%, including measurement of hemoglobin, parasitemia using microscopy, and serological responses to P. falciparum apical membrane antigen 1 (AMA-1 and merozoite surface protein 1, 19 kilodalton fragment (MSP-119. Analysis of laboratory results was restricted to 1949 (87.5% participants aged ≤ 40 years. Prevalence of anemia (hemoglobin < 11.0 g/dL was significantly higher in Walukuba (18.9% and Nagongera (17.4% than in Kihihi (13.1%, and was strongly associated with decreasing age for those ≤ 5 years at all sites. Parasite prevalence was significantly higher in Nagongera (48.3% than in Walukuba (12.2% and Kihihi (12.8%, and significantly increased with age to 11 years, and then significantly decreased at all sites. Seropositivity to AMA-1 was 53.3% in Walukuba, 63.0% in Kihihi, and 83.7% in Nagongera and was associated with increasing age at all sites. AMA-1 seroconversion rates strongly correlated with transmission intensity, while serological responses to MSP-119 did not.Anemia was predominant in young children and parasitemia peaked by 11 years across 3 sites with varied transmission intensity. Serological responses to AMA-1 appeared to best reflect

Chronic Plasmodium falciparum infections in an area of low intensity malaria transmission in the Sudan

DEFF Research Database (Denmark)

Hamad, A A; El Hassan, I M; El Khalifa, A A

2000-01-01

Chronic Plasmodium falciparum malaria infections in a Sudanese village, in an area of seasonal and unstable malaria transmission, were monitored and genetically characterized to study the influence of persistent infection on the immunology and epidemiology of low endemicity malaria. During...... the October-December malaria season of 1996, 51 individuals out of a population of 420 had confirmed and treated P. falciparum malaria in the village of Daraweesh in eastern Sudan. In a cross-sectional survey carried out in December 1996, an additional 6 individuals were found to harbour a microscopically...

Current vector control challenges in the fight against malaria.

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Benelli, Giovanni; Beier, John C

2017-10-01

The effective and eco-friendly control of Anopheles vectors plays a key role in any malaria management program. Integrated Vector Management (IVM) suggests making use of the full range of vector control tools available. The strategies for IVM require novel technologies to control outdoor transmission of malaria. Despite the wide number of promising control tools tested against mosquitoes, current strategies for malaria vector control used in most African countries are not sufficient to achieve successful malaria control. The majority of National Malaria Control Programs in Africa still rely on indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). These methods reduce malaria incidence but generally have little impact on malaria prevalence. In addition to outdoor transmission, growing levels of insecticide resistance in targeted vectors threaten the efficacy of LLINs and IRS. Larvicidal treatments can be useful, but are not recommended for rural areas. The research needed to improve the quality and delivery of mosquito vector control should focus on (i) optimization of processes and methods for vector control delivery; (ii) monitoring of vector populations and biting activity with reliable techniques; (iii) the development of effective and eco-friendly tools to reduce the burden or locally eliminate malaria and other mosquito-borne diseases; (iv) the careful evaluation of field suitability and efficacy of new mosquito control tools to prove their epidemiological impact; (v) the continuous monitoring of environmental changes which potentially affect malaria vector populations; (vi) the cooperation among different disciplines, with main emphasis on parasitology, tropical medicine, ecology, entomology, and ecotoxicology. A better understanding of behavioral ecology of malaria vectors is required. Key ecological obstacles that limit the effectiveness of vector control include the variation in mosquito behavior, development of insecticide resistance

Outbreak of human malaria caused by Plasmodium simium in the Atlantic Forest in Rio de Janeiro: a molecular epidemiological investigation.

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Brasil, Patrícia; Zalis, Mariano Gustavo; de Pina-Costa, Anielle; Siqueira, Andre Machado; Júnior, Cesare Bianco; Silva, Sidnei; Areas, André Luiz Lisboa; Pelajo-Machado, Marcelo; de Alvarenga, Denise Anete Madureira; da Silva Santelli, Ana Carolina Faria; Albuquerque, Hermano Gomes; Cravo, Pedro; Santos de Abreu, Filipe Vieira; Peterka, Cassio Leonel; Zanini, Graziela Maria; Suárez Mutis, Martha Cecilia; Pissinatti, Alcides; Lourenço-de-Oliveira, Ricardo; de Brito, Cristiana Ferreira Alves; de Fátima Ferreira-da-Cruz, Maria; Culleton, Richard; Daniel-Ribeiro, Cláudio Tadeu

2017-10-01

Malaria was eliminated from southern and southeastern Brazil over 50 years ago. However, an increasing number of autochthonous episodes attributed to Plasmodium vivax have recently been reported from the Atlantic Forest region of Rio de Janeiro state. As the P vivax-like non-human primate malaria parasite species Plasmodium simium is locally enzootic, we performed a molecular epidemiological investigation to determine whether zoonotic malaria transmission is occurring. We examined blood samples from patients presenting with signs or symptoms suggestive of malaria as well as from local howler monkeys by microscopy and PCR. Samples were included from individuals if they had a history of travel to or resided in areas within the Rio de Janeiro Atlantic Forest, but not if they had malaria prophylaxis, blood transfusion or tissue or organ transplantation, or had travelled to known malaria endemic areas in the preceding year. Additionally, we developed a molecular assay based on sequencing of the parasite mitochondrial genome to distinguish between P vivax and P simium, and applied this assay to 33 cases from outbreaks that occurred in 2015, and 2016. A total of 49 autochthonous malaria cases were reported in 2015-16. Most patients were male, with a mean age of 44 years (SD 14·6), and 82% lived in urban areas of Rio de Janeiro state and had visited the Atlantic Forest for leisure or work-related activities. 33 cases were used for mitochondrial DNA sequencing. The assay was successfully performed for 28 samples, and all were shown to be P simium, indicative of zoonotic transmission of this species to human beings in this region. Sequencing of the whole mitochondrial genome of three of these cases showed that P simium is most closely related to P vivax parasites from South America. The malaria outbreaks in this region were caused by P simium, previously considered to be a monkey-specific malaria parasite, related to but distinct from P vivax, and which has never

MALAREO: a user-driven project

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Michael T. Gebreslasie

2015-11-01

Full Text Available The aim of this study is to assess the capacity gaps and requirements of Earth observation (EO and related technologies for malaria vector control and management in the Lubombo Spatial Development Initiative regions of South Africa, Swaziland and Mozambique. In order to achieve the core objective of this study, available EO data (including main characteristics and resources required to utilize them and their potential applications for malaria epidemiology are reviewed. In addition, a survey was conducted to assess the availability of human and facility resources to operate EO and related technologies for control and management of the malaria control programs in these countries resulting in an analysis of capacity gaps, priorities and requirements. Earth observation in malaria vector control and management has two different applications: i collection of relevant remotely sensed data for epidemiological use; and ii direct support of ongoing malaria vector control activities. All malaria control programs and institutions recognize the significance of EO products to detect mosquito vector habitats, to monitor environmental parameters affecting mosquito vector populations as well as house mapping and distribution of information supporting residual spray planning and monitoring. It was found that only the malaria research unit (MRU of the medical research council (MRC in South Africa and the national malaria control program (MCP in Swaziland currently have a fully functional geographic information systems (GIS, whereas the other surveyed MCPs in South Africa and Mozambique currently do not have this in place. Earth observation skills only exist in MRU of MRC, while spatial epidemiology is scarce in all institutions, which was identified as major gap. The survey has also confirmed that EO and GIS technologies have enormous potential as sources of spatial data and as analytical frameworks for malaria vector control. It is therefore evident that planning

EPIDEMIOLOGY OF MALARIA IN INFANCY AT ENUGU, NIGERIA

African Journals Online (AJOL)

impetigo in 2 patients. The results of investigations, showed the presence of trophozoites of malaria parasites in peripheral blood smears of all the patients. Fifteen infants showed leucocytosis of greater than l0,000/cumm; with a range of I0, 000 to. 15,000/cuinm, only 4 of them were aged more than 6 months while the others ...

A new world malaria map: Plasmodium falciparum endemicity in 2010.

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Gething, Peter W; Patil, Anand P; Smith, David L; Guerra, Carlos A; Elyazar, Iqbal R F; Johnston, Geoffrey L; Tatem, Andrew J; Hay, Simon I

2011-12-20

Transmission intensity affects almost all aspects of malaria epidemiology and the impact of malaria on human populations. Maps of transmission intensity are necessary to identify populations at different levels of risk and to evaluate objectively options for disease control. To remain relevant operationally, such maps must be updated frequently. Following the first global effort to map Plasmodium falciparum malaria endemicity in 2007, this paper describes the generation of a new world map for the year 2010. This analysis is extended to provide the first global estimates of two other metrics of transmission intensity for P. falciparum that underpin contemporary questions in malaria control: the entomological inoculation rate (PfEIR) and the basic reproductive number (PfR). Annual parasite incidence data for 13,449 administrative units in 43 endemic countries were sourced to define the spatial limits of P. falciparum transmission in 2010 and 22,212 P. falciparum parasite rate (PfPR) surveys were used in a model-based geostatistical (MBG) prediction to create a continuous contemporary surface of malaria endemicity within these limits. A suite of transmission models were developed that link PfPR to PfEIR and PfR and these were fitted to field data. These models were combined with the PfPR map to create new global predictions of PfEIR and PfR. All output maps included measured uncertainty. An estimated 1.13 and 1.44 billion people worldwide were at risk of unstable and stable P. falciparum malaria, respectively. The majority of the endemic world was predicted with a median PfEIR of less than one and a median PfRc of less than two. Values of either metric exceeding 10 were almost exclusive to Africa. The uncertainty described in both PfEIR and PfR was substantial in regions of intense transmission. The year 2010 has a particular significance as an evaluation milestone for malaria global health policy. The maps presented here contribute to a rational basis for control and

A new world malaria map: Plasmodium falciparum endemicity in 2010

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Gething Peter W

2011-12-01

Full Text Available Abstract Background Transmission intensity affects almost all aspects of malaria epidemiology and the impact of malaria on human populations. Maps of transmission intensity are necessary to identify populations at different levels of risk and to evaluate objectively options for disease control. To remain relevant operationally, such maps must be updated frequently. Following the first global effort to map Plasmodium falciparum malaria endemicity in 2007, this paper describes the generation of a new world map for the year 2010. This analysis is extended to provide the first global estimates of two other metrics of transmission intensity for P. falciparum that underpin contemporary questions in malaria control: the entomological inoculation rate (PfEIR and the basic reproductive number (PfR. Methods Annual parasite incidence data for 13,449 administrative units in 43 endemic countries were sourced to define the spatial limits of P. falciparum transmission in 2010 and 22,212 P. falciparum parasite rate (PfPR surveys were used in a model-based geostatistical (MBG prediction to create a continuous contemporary surface of malaria endemicity within these limits. A suite of transmission models were developed that link PfPR to PfEIR and PfR and these were fitted to field data. These models were combined with the PfPR map to create new global predictions of PfEIR and PfR. All output maps included measured uncertainty. Results An estimated 1.13 and 1.44 billion people worldwide were at risk of unstable and stable P. falciparum malaria, respectively. The majority of the endemic world was predicted with a median PfEIR of less than one and a median PfRc of less than two. Values of either metric exceeding 10 were almost exclusive to Africa. The uncertainty described in both PfEIR and PfR was substantial in regions of intense transmission. Conclusions The year 2010 has a particular significance as an evaluation milestone for malaria global health policy. The

[Current malaria situation in the Republic of Kazakhstan].

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Bismil'din, F B; Shapieva, Zh Zh; Anpilova, E N

2001-01-01

Republican Health Epidemiology Posts, work is being done on the planning of malaria control measures in Kazakhstan for the period 2001-2003. In 1994 a programme of epidemiological malaria surveillance was introduced, which has enabled us to improve our monitoring of the epidemiological situation of malaria. The number of cases of imported malaria has declined: in 1997, there were 102 cases, in 1998-87 and in 1999-52. There have been occasional local cases in some years, and in 1998 there were four local cases in the south and north-west of the country: two cases in Almaty oblast, one case in Zhambyl oblast and one in West Kazakhstan oblast (see Fig. 1). Most malaria infections are imported from Tajikistan and Azerbaijan, with occasional cases from Pakistan, India, Turkey and Afghanistan. Analysis of the occupational status of patients shows that around 45% are military personnel who have served on the Tajik-Afghan border. The others are refugees, merchants, unemployed people or students. The overall aetiological structure of malaria cases is dominated by P. vivax malaria. For example, in 1999, there were 48 cases of P. vivax malaria (90.5% of the total), one case of tropical malaria (1.9%), two cases of quartan malaria (3.8%) and two cases of P. vivax + P. malariae (3.8%). In order to prevent indigenous malaria occurring within the country, a system of malaria screening has been set up; screening is carried out every year on groups who have visited neighbouring or more distant malaria-endemic countries and for patients with a persistent fever who are suspected of suffering from malaria. The area of water throughout the country within communities or within a 3-5 km radius of them which is susceptible to colonization by the Anopheles mosquito amounts to over 5000 hectares, according to the certification system in force. In addition, approximately 70,000 hectares in three oblasts used for rice cultivation also provide a habitat for Anopheles. The main malaria vector, An

Helminth-infected patients with malaria: a low profile transmission hub?

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Nacher, Mathieu

2012-11-15

Eclipsed by the debates about malaria incidence and severity in individual patients, malaria transmission in helminth-infected persons has so far received very little attention. Studies in humans have shown increased malaria incidence and prevalence, and a trend for a reduction of symptoms in patients with malaria. This suggests that such patients could possibly be less likely to seek treatment thus carrying malaria parasites and their gametocytes for longer durations, therefore, being a greater potential source of transmission. In addition, in humans, a study showed increased gametocyte carriage, and in an animal model of helminth-malaria co-infection, there was increased malaria transmission. These elements converge towards the hypothesis that patients co-infected with worms and malaria may represent a hub of malaria transmission. The test of this hypothesis requires verifying, in different epidemiological settings, that helminth-infected patients have more gametocytes, that they have less symptomatic malaria and longer-lasting infections, and that they are more attractive for the vectors. The negative outcome in one setting of one of the above aspects does not necessarily mean that the other two aspects may suffice to increase transmission. If it is verified that patients co-infected by worms and malaria could be a transmission hub, this would be an interesting piece of strategic information in the context of the spread of anti-malarial resistance and the malaria eradication attempts.

Spatial analysis of land cover determinants of malaria incidence in the Ashanti Region, Ghana.

Science.gov (United States)

Krefis, Anne Caroline; Schwarz, Norbert Georg; Nkrumah, Bernard; Acquah, Samuel; Loag, Wibke; Oldeland, Jens; Sarpong, Nimako; Adu-Sarkodie, Yaw; Ranft, Ulrich; May, Jürgen

2011-03-23

Malaria belongs to the infectious diseases with the highest morbidity and mortality worldwide. As a vector-borne disease malaria distribution is strongly influenced by environmental factors. The aim of this study was to investigate the association between malaria risk and different land cover classes by using high-resolution multispectral Ikonos images and Poisson regression analyses. The association of malaria incidence with land cover around 12 villages in the Ashanti Region, Ghana, was assessed in 1,988 children <15 years of age. The median malaria incidence was 85.7 per 1,000 inhabitants and year (range 28.4-272.7). Swampy areas and banana/plantain production in the proximity of villages were strong predictors of a high malaria incidence. An increase of 10% of swampy area coverage in the 2 km radius around a village led to a 43% higher incidence (relative risk [RR] = 1.43, p<0.001). Each 10% increase of area with banana/plantain production around a village tripled the risk for malaria (RR = 3.25, p<0.001). An increase in forested area of 10% was associated with a 47% decrease of malaria incidence (RR = 0.53, p = 0.029). Distinct cultivation in the proximity of homesteads was associated with childhood malaria in a rural area in Ghana. The analyses demonstrate the usefulness of satellite images for the prediction of malaria endemicity. Thus, planning and monitoring of malaria control measures should be assisted by models based on geographic information systems.

Finding malaria hot-spots in northern Angola: the role of individual, household and environmental factors within a meso-endemic area

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Magalhães Ricardo J

2012-11-01

Full Text Available Abstract Background Identifying and targeting hyper-endemic communities within meso-endemic areas constitutes an important challenge in malaria control in endemic countries such like Angola. Recent national and global predictive maps of malaria allow the identification and quantification of the population at risk of malaria infection in Angola, but their small-scale accuracy is surrounded by large uncertainties. To observe the need to develop higher resolution malaria endemicity maps a predictive risk map of malaria infection for the municipality of Dande (a malaria endemic area in Northern Angola was developed and compared to existing national and global maps, the role of individual, household and environmental risk factors for malaria endemicity was quantified and the spatial variation in the number of children at-risk of malaria was estimated. Methods Bayesian geostatistical models were developed to predict small-scale spatial variation using data collected during a parasitological survey conducted from May to August 2010. Maps of the posterior distributions of predicted prevalence were constructed in a geographical information system. Results Malaria infection was significantly associated with maternal malaria awareness, households with canvas roofing, distance to health care centre and distance to rivers. The predictive map showed remarkable spatial heterogeneity in malaria risk across the Dande municipality in contrast to previous national and global spatial risk models; large high-risk areas of malaria infection (prevalence >50% were found in the northern and most eastern areas of the municipality, in line with the observed prevalence. Conclusions There is remarkable spatial heterogeneity of malaria burden which previous national and global spatial modelling studies failed to identify suggesting that the identification of malaria hot-spots within seemingly mesoendemic areas may require the generation of high resolution malaria maps

Finding malaria hot-spots in northern Angola: the role of individual, household and environmental factors within a meso-endemic area.

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Magalhães, Ricardo J Soares; Langa, Antonio; Sousa-Figueiredo, José Carlos; Clements, Archie C A; Nery, Susana Vaz

2012-11-22

Identifying and targeting hyper-endemic communities within meso-endemic areas constitutes an important challenge in malaria control in endemic countries such like Angola. Recent national and global predictive maps of malaria allow the identification and quantification of the population at risk of malaria infection in Angola, but their small-scale accuracy is surrounded by large uncertainties. To observe the need to develop higher resolution malaria endemicity maps a predictive risk map of malaria infection for the municipality of Dande (a malaria endemic area in Northern Angola) was developed and compared to existing national and global maps, the role of individual, household and environmental risk factors for malaria endemicity was quantified and the spatial variation in the number of children at-risk of malaria was estimated. Bayesian geostatistical models were developed to predict small-scale spatial variation using data collected during a parasitological survey conducted from May to August 2010. Maps of the posterior distributions of predicted prevalence were constructed in a geographical information system. Malaria infection was significantly associated with maternal malaria awareness, households with canvas roofing, distance to health care centre and distance to rivers. The predictive map showed remarkable spatial heterogeneity in malaria risk across the Dande municipality in contrast to previous national and global spatial risk models; large high-risk areas of malaria infection (prevalence >50%) were found in the northern and most eastern areas of the municipality, in line with the observed prevalence. There is remarkable spatial heterogeneity of malaria burden which previous national and global spatial modelling studies failed to identify suggesting that the identification of malaria hot-spots within seemingly mesoendemic areas may require the generation of high resolution malaria maps. Individual, household and hydrological factors play an important role

Imported malaria in pregnancy in Madrid

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Jiménez Beatriz C

2012-04-01

Full Text Available Abstract Background Malaria in pregnancy is associated with maternal and foetal morbidity and mortality in endemic areas, but information on imported cases to non-endemic areas is scarce. The aim of this study was to describe the clinical and epidemiological characteristics of malaria in pregnancy in two general hospitals in Madrid, Spain. Methods Retrospective descriptive study of laboratory-confirmed malaria in pregnant women at the Fuenlabrada University Hospital and the Príncipe de Asturias University Hospital, in Madrid, over a six- and 11-year period, respectively. Relevant epidemiological, clinical and laboratory data was obtained from medical records. Results There were 19 pregnant women among 346 malaria cases (5.4%. The average age was 27 years. The gestational age (trimester was: 53% 3rd, 31% 1st, 16% 2nd. All but one were multigravidae. Three were HIV positive. All were sub-Saharan immigrants: two were recently arrived immigrants and seventeen (89% had visited friends and relatives. None had taken prophylaxis nor seeked pre-travel advice. Presentation: 16 symptomatic patients (fever in fourteen, asthenia in two, three asymptomatic. Median delay in diagnosis: 7.5 days. Laboratory tests: anaemia (cut off Hb level 11 g/dl 78.9% (mild 31.6%, moderate 31.6%, severe 15.8% thrombocytopaenia 73.7%, hypoglycaemia 10.5%. All cases were due to Plasmodium falciparum, one case of hyperparasitaemia. Quinine + clindamycin prescribed in 84%. Outcomes: no severe maternal complications or deaths, two abortions, fifteen term pregnancies, no low-birth-weight newborns, two patients were lost to follow-up. Conclusions Though cases of malaria in pregnancy are uncommon, a most at risk group is clearly defined: young sub-Saharan mothers visiting friends and relatives without pre-travel counselling and recently-arrived immigrants. The most common adverse maternal and foetal effects were anaemia and stillbirth. Given that presentation can be asymptomatic

The Influence of Dams on Malaria Transmission in Sub-Saharan Africa.

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Kibret, Solomon; Wilson, G Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2017-06-01

The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

Plasmodium vivax malaria among pregnant women in Eastern Sudan

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Duria Abdulwhab Rayis

2016-06-01

Full Text Available Objective: To determine the epidemiology of malaria [especially Plasmodium vivax (P. vivax] among pregnant women in Eastern Sudan. Methods: A cross sectional study was conducted in the antenatal care of New Halfa hospital, Eastern Sudan to investigate the prevalence, manifestations and determinants of malaria (especially P. vivax among pregnant women. Results: Out of 2 378 pregnant women, there were 48 (2.0% and 36 (1.5% Plasmodium falciparum (P. falciparum and P. vivax infection, respectively. There was no significant difference in the age, parity, gestational age between women with malaria and healthy controls. The mean ± SD of the temperature was significantly higher in patients with P. vivax than in patient with P. falciparum malaria [(38.6 ± 0.7 °C vs. (38.1 ± 0.6 °C, P = 0.001]. Patients with P. vivax malaria had slightly (not reach statistical significance lower hemoglobin level compared with P. falciparum malaria and healthy controls. The geometric parasite count showed no significant difference between patients with P. vivax and P. falciparum malaria infections (12 189.9 vs. 9 755.1 trophozoite/µL, P = 0.356. Conclusions: P. vivax malaria is an existing health problem in Eastern Sudan. Further research is also needed.

Malaria epidemiology in an area of stable transmission in tribal population of Jharkhand, India.

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Das, Manoj K; Prajapati, Brijesh K; Tiendrebeogo, Régis W; Ranjan, Kumud; Adu, Bright; Srivastava, Amit; Khera, Harvinder K; Chauhan, Narendra; Tevatiya, Sanjay; Kana, Ikhlaq H; Sharma, Surya Kant; Singh, Subhash; Theisen, Michael

2017-05-02

Malaria remains an important health problem in India with approximately 1 million cases in 2014. Of these, 7% occurred in the Jharkhand state mainly in the tribal population. This study was conducted in Dumargarhi, a tribal village about 42 km east of Ranchi city, Jharkhand, from May 2014 to September 2016. Four point prevalence surveys were carried out during consecutive high (October-December) and low (June-August) transmission seasons. Malaria cases were recorded from April 2015 to April 2016 through fortnightly visits to the village. Adult mosquito densities were monitored fortnightly by manual catching using suction tube method. The study area consists of five hamlets inhabited by 945 individuals living in 164 households as recorded through a house-to-house census survey performed at enrollment. The study population consisted predominantly of the Munda (n = 425, 45%) and Oraon (n = 217, 23%) ethnic groups. Study participants were categorized as per their age 0-5, 6-10, 11-15 and >15 years. There were 99 cases of clinical malaria from April 2015 to April 2016 and all malaria cases confirmed by microscopy were attributed to Plasmodium falciparum (94 cases) and Plasmodium vivax (5 cases), respectively. During the high transmission season the mean density of P. falciparum parasitaemia per age group increased to a peak level of 23,601 parasites/μl in the 6-10 years age group and gradually declined in the adult population. Malaria attack rates, parasite prevalence and density levels in the study population showed a gradual decrease with increasing age. This finding is consistent with the phenomenon of naturally acquired immunity against malaria. Three vector species were detected: Anopheles fluviatilis, Anopheles annularis, and Anopheles culicifacies. The incoherence or complete out of phase pattern of the vector density peaks together with a high prevalence of parasite positive individuals in the study population explains the year-round malaria

Mobile phones improve case detection and management of malaria in rural Bangladesh

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2013-01-01

Background The recent introduction of mobile phones into the rural Bandarban district of Bangladesh provided a resource to improve case detection and treatment of patients with malaria. Methods During studies to define the epidemiology of malaria in villages in south-eastern Bangladesh, an area with hypoendemic malaria, the project recorded 986 mobile phone calls from families because of illness suspected to be malaria between June 2010 and June 2012. Results Based on phone calls, field workers visited the homes with ill persons, and collected blood samples for malaria on 1,046 people. 265 (25%) of the patients tested were positive for malaria. Of the 509 symptomatic malaria cases diagnosed during this study period, 265 (52%) were detected because of an initial mobile phone call. Conclusion Mobile phone technology was found to be an efficient and effective method for rapidly detecting and treating patients with malaria in this remote area. This technology, when combined with local knowledge and field support, may be applicable to other hard-to-reach areas to improve malaria control. PMID:23374585

Poverty and malaria in the Yunnan province, China

OpenAIRE

Bi, Yan; Tong, Shilu

2014-01-01

Poverty and malaria appear to have an intertwined link. This paper aims to define the relationship between poverty and malaria in Yunnan, China, and to make recommendations for future research in this important area. Data on malaria prevalence and the population’s income in each county between 2005 and 2010 were obtained from the Yunnan Center for Disease Control and Prevention and the Yunnan Bureau of Statistics, respectively. Geographic mapping shows an apparent spatial convergence of pover...

Application of molecular methods for monitoring transmission stages of malaria parasites

International Nuclear Information System (INIS)

Babiker, Hamza A; Schneider, Petra

2008-01-01

Recent technical advances in malaria research have allowed specific detection of mRNA of genes that are expressed exclusively in sexual stages (gametocytes) of malaria parasites. The specificity and sensitivity of these techniques were validated on cultured laboratory clones of both human malaria parasites (Plasmodium falciparum) and rodent parasites (P. chabaudi). More recently, quantitative molecular techniques have been developed to quantify these sexual stages and used to monitor gametocyte dynamics and their transmission to mosquitoes. Molecular techniques showed that the infectious reservoir for malaria is larger than expected from previous microscopic studies; individual parasite genotypes within an infection can simultaneously produce infectious gametocytes; gametocyte production can be sustained for several months, and is modulated by environmental factors. The above techniques have empowered approaches for in-depth analysis of the biology of the transmission stages of the parasite and epidemiology of malaria transmission

Clinico-epidemiological profile of malaria: Analysis from a primary health centre in Karnataka, Southern India

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Ramachandra Kamath

2012-01-01

Full Text Available Malaria continues to be a major public health problem in India and worldwide. The present study was based on records from a primary health centre in Karnataka. Morbidity patterns and important features of malaria transmission specific to Udupi district were investigated. The incidence of malaria and various morbidity patterns during 2010 and 2011 were compared and analyzed. Factors such as rapid urbanization, increased construction activities and influx of migratory workers were highlighted as the leading causes for the advent of malaria in the area. Recommendations have been provided for implementation in the near future.

Clinico-epidemiological profile of malaria: Analysis from a primary health centre in Karnataka, Southern India

Directory of Open Access Journals (Sweden)

Ramachandra Kamath

2013-01-01

Full Text Available Malaria continues to be a major public health problem in India and worldwide. The present study was based on records from a primary health centre in Karnataka. Morbidity patterns and important features of malaria transmission specific to Udupi district were investigated. The incidence of malaria and various morbidity patterns during 2010 and 2011 were compared and analyzed. Factors such as rapid urbanization, increased construction activities and influx of migratory workers were highlighted as the leading causes for the advent of malaria in the area. Recommendations have been provided for implementation in the near future.

Helminth-infected patients with malaria: a low profile transmission hub?

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Nacher Mathieu

2012-11-01

Full Text Available Abstract Eclipsed by the debates about malaria incidence and severity in individual patients, malaria transmission in helminth-infected persons has so far received very little attention. Studies in humans have shown increased malaria incidence and prevalence, and a trend for a reduction of symptoms in patients with malaria. This suggests that such patients could possibly be less likely to seek treatment thus carrying malaria parasites and their gametocytes for longer durations, therefore, being a greater potential source of transmission. In addition, in humans, a study showed increased gametocyte carriage, and in an animal model of helminth-malaria co-infection, there was increased malaria transmission. These elements converge towards the hypothesis that patients co-infected with worms and malaria may represent a hub of malaria transmission. The test of this hypothesis requires verifying, in different epidemiological settings, that helminth-infected patients have more gametocytes, that they have less symptomatic malaria and longer-lasting infections, and that they are more attractive for the vectors. The negative outcome in one setting of one of the above aspects does not necessarily mean that the other two aspects may suffice to increase transmission. If it is verified that patients co-infected by worms and malaria could be a transmission hub, this would be an interesting piece of strategic information in the context of the spread of anti-malarial resistance and the malaria eradication attempts.

[Malaria in Spain: entomological aspects and future outlook].

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Bueno Marí, Rubén; Jiménez Peydró, Ricardo

2008-01-01

Malaria was officially eradicated in Spain in 1964. However, at the present time, hundreds of imported cases are registered in our country each year. In this context, the study of the vector is seen to be highly significant in order to infer possible transmission scenarios, whether of a sporadic or a regular nature. Although the socio-economic level of the country does not appear to foreshadow the possible re-emergence of the disease in the short and medium term, the presence of well-established populations of anophelini and plasmodium gametocytes circulating in a certain percentage of the human population does appear to warrant the continuation of the current status of epidemiological surveillance. Moreover, the globalisation of markets and the emerging process of climate change could enable the colonisation of our territory by part of the Anopheles species that transmit human plasmodiosis in tropical and subtropical regions. In order to obtain a more thorough knowledge of the range of fauna, spatial distribution and bioecology of the anopheline Culicoides, a number of intensive larval samplings were taken in the Community of Valencia, a region with sufficient surface water heterogeneity and historical data of malaria prevalence to substantiate the decision to choose it for this study. Five species of the Anopheles genus, with varying degrees of impact in the dissemination of the disease, were identified.

The history of the Greek Anti-Malaria League and the influence of the Italian School of Malariology.

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Tsiamis, Costas; Piperaki, Evangelia Theophano; Tsakris, Athanassios

2013-03-01

In 1905, a group of eminent Greek physicians led by Professor of Hygiene and Microbiology Constantinos Savvas and the pediatrician Dr. Ioannis Kardamatis founded the Greek Anti-Malaria League. The League assumed a role that the State would not, and for the next 25 years organized the country's anti-malaria campaign. During its first steps, the Greek Anti-Malaria League adopted the principles of Professor Angelo Celli's Italian Anti-Malaria League. The League's accomplishments include a decrease in malarial prevalence, due to mass treatment with quinine, new legislation ensuring the provision of quinine, State monopoly and the collection of epidemiologic data. However, defeat in the Greek-Turkish War (1922) and the massive influx of one million Greek refugees that ensued, led to a change in malarial epidemiology. In 1928, following a visit to Italy, the Greek League adopted the organization and knowledge of the Italian Malaria Schools in Rome and in Nettuno, and this experience served as the basis of their proposal to the State for the development of the anti-malaria services infrastructure. The State adopted many of Professor Savvas' proposals and modified his plan according to Greek needs. The League's experience, accumulated during its 25 years of struggle against malaria, was its legacy to the campaigns that eventually accomplished the eradication of malaria from Greece after World War II.

The epidemiology of malaria in Rondonia (Western Amazon region, Brazil): study of a riverine population.

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Camargo, L M; Noronha, E; Salcedo, J M; Dutra, A P; Krieger, H; Pereira da Silva, L H; Camargo, E P

1999-01-15

We report on a longitudinal study concerning the incidence of malaria in a riverine population (Portuchuelo) settled on the riverbanks of Rio Madeira, in the State of Rondonia, Brazil. We found the incidence of malaria to be seasonal, prevailing in the dry months of June and July. The Annual Parasite Index (API) was 292/1000 inhabitants, almost three times that of the state of Rondonia for the same period. In contrast with other studied Rondonian populations, malaria in Portuchuelo was more prevalent in youngsters Amazon region where most of its members were born. Due to the permanent presence of malaria among riverine populations, we are proposing that they may act as perennial reserves of malaria and, therefore, as sources of infection for migrants or eventual settlers at their vicinity. To date, the opposite view has been generally held. Anopheles darlingi, the main vector species in the area, is essentially sylvatic, which contributes to make the control of malaria highly problematic. The only hopes for control rest on permanent surveillance and the prompt treatment of patients, which are also problematic considering the vastness of the Amazon region and the remoteness of some of its riverine settlements.

An ecosystem approach to malaria control in an urban setting

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Carrasquilla Gabriel

2001-01-01

Full Text Available We conducted a research project aimed at strengthening local government and the community for a sustainable malaria control strategy. The project began with a baseline diagnosis of malaria prevalence, a KAP survey, entomology, and health services delivery, after which an epidemiological study was performed to identify risk factors associated with malaria, thereafter used to plan intervention measures. A program evaluation was conducted five years later. By using an ecosystem approach to reanalyze data, this paper discusses how malaria arises from a complex interaction of cultural, economic, ecological, social, and individual factors. Intervention measures require an intersectorial and transdisciplinary approach that does not exist at the moment. Health sector leadership is limited, and there is no true community participation. Implications for research, including the use of qualitative and quantitative methods, study design, and complexity of data analysis are discussed. Finally, implications for malaria control are discussed, stressing the differences between the ecosystem and integrated disease control approaches.

[Malaria in Poland in 2010].

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Stepień, Małgorzata

2012-01-01

The objective of this study was to describe the epidemiology of imported malaria in Poland in 2010 in comparison to previous years. The study included malaria cases that were collected and registered by the State Sanitary Inspection in 2010 in Poland. Data reported was verified, processed and published by National Institute of Public Health - National Institute of Hygiene. All cases were laboratory confirmed by blood film, polymerase chain reaction or rapid diagnostic tests outlined by the EU case definition. Differences in the distribution of demographic, parasitological and clinical characteristics, and incidence were analyzed. In 2010, a total of 35 confirmed malaria cases were notified in Poland, 13 more than 2009. All cases were imported, 49% from Africa, including 1 case with relapsing malaria caused by P. vivax and 2 cases of recrudescence falciparum malaria following failure of treatment. The number of cases acquired in Asia (37% of the total), mainly from India and Indonesia, was significantly higher than observed in previous years. Among cases with species-specific diagnosis 19 (63%) were caused by P. falciparum, 9 (30%) by P. vivax, one by P. ovale and one by P. malariae. The median age of all cases was 42 years (range 9 months to 71 years), males comprised 69% of patients, females 31%, three patients were Indian citizens temporarily in Poland. Common reasons for travel to endemic countries were tourism (57%), work-related visits (37%), one person visited family and in one case the reason for travel was unknown. Sixteen travelers took chemoprophylaxis, but only three of them appropriately (adherence to the recommended drug regimen, continuation upon return and use of appropriate medicines). In 2010, there were no deaths due to malaria and clinical course of disease was severe in 7 cases. When compared with 2009, there was a marked increase in the number of imported malaria cases in Poland, however the total number of notified cases remained low. Serious

Role of Activins in Hepcidin Regulation during Malaria.

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Spottiswoode, Natasha; Armitage, Andrew E; Williams, Andrew R; Fyfe, Alex J; Biswas, Sumi; Hodgson, Susanne H; Llewellyn, David; Choudhary, Prateek; Draper, Simon J; Duffy, Patrick E; Drakesmith, Hal

2017-12-01

Epidemiological observations have linked increased host iron with malaria susceptibility, and perturbed iron handling has been hypothesized to contribute to the potentially life-threatening anemia that may accompany blood-stage malaria infection. To improve our understanding of these relationships, we examined the pathways involved in regulation of the master controller of iron metabolism, the hormone hepcidin, in malaria infection. We show that hepcidin upregulation in Plasmodium berghei murine malaria infection was accompanied by changes in expression of bone morphogenetic protein (BMP)/sons of mothers against decapentaplegic (SMAD) pathway target genes, a key pathway involved in hepcidin regulation. We therefore investigated known agonists of the BMP/SMAD pathway and found that Bmp gene expression was not increased in infection. In contrast, activin B, which can signal through the BMP/SMAD pathway and has been associated with increased hepcidin during inflammation, was upregulated in the livers of Plasmodium berghei -infected mice; hepatic activin B was also upregulated at peak parasitemia during infection with Plasmodium chabaudi Concentrations of the closely related protein activin A increased in parallel with hepcidin in serum from malaria-naive volunteers infected in controlled human malaria infection (CHMI) clinical trials. However, antibody-mediated neutralization of activin activity during murine malaria infection did not affect hepcidin expression, suggesting that these proteins do not stimulate hepcidin upregulation directly. In conclusion, we present evidence that the BMP/SMAD signaling pathway is perturbed in malaria infection but that activins, although raised in malaria infection, may not have a critical role in hepcidin upregulation in this setting. Copyright © 2017 Spottiswoode et al.

Application of GIS to predict malaria hotspots based on Anopheles arabiensis habitat suitability in Southern Africa

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Gwitira, Isaiah; Murwira, Amon; Zengeya, Fadzai M.; Shekede, Munyaradzi Davis

2018-02-01

Malaria remains a major public health problem and a principal cause of morbidity and mortality in most developing countries. Although malaria still presents health problems, significant successes have been recorded in reducing deaths resulting from the disease. As malaria transmission continues to decline, control interventions will increasingly depend on the ability to define high-risk areas known as malaria hotspots. Therefore, there is urgent need to use geospatial tools such as geographic information system to detect spatial patterns of malaria and delineate disease hot spots for better planning and management. Thus, accurate mapping and prediction of seasonality of malaria hotspots is an important step towards developing strategies for effective malaria control. In this study, we modelled seasonal malaria hotspots as a function of habitat suitability of Anopheles arabiensis (A. Arabiensis) as a first step towards predicting likely seasonal malaria hotspots that could provide guidance in targeted malaria control. We used Geographical information system (GIS) and spatial statistic methods to identify seasonal hotspots of malaria cases at the country level. In order to achieve this, we first determined the spatial distribution of seasonal malaria hotspots using the Getis Ord Gi* statistic based on confirmed positive malaria cases recorded at health facilities in Zimbabwe over four years (1996-1999). We then used MAXENT technique to model habitat suitability of A. arabiensis from presence data collected from 1990 to 2002 based on bioclimatic variables and altitude. Finally, we used autologistic regression to test the extent to which malaria hotspots can be predicted using A. arabiensis habitat suitability. Our results show that A. arabiensis habitat suitability consistently and significantly (p < 0.05) predicts malaria hotspots from 1996 to 1999. Overall, our results show that malaria hotspots can be predicted using A. arabiensis habitat suitability, suggesting

Mapping malaria risk using geographic information systems and remote sensing: The case of Bahir Dar City, Ethiopia.

Science.gov (United States)

Minale, Amare Sewnet; Alemu, Kalkidan

2018-05-07

The main objective of this study was to develop a malaria risk map for Bahir Dar City, Amhara, which is situated south of Lake Tana on the Ethiopian plateau. Rainfall, temperature, altitude, slope and land use/land cover (LULC), as well as proximity measures to lake, river and health facilities, were investigated using remote sensing and geographical information systems. The LULC variable was derived from a 2012 SPOT satellite image by supervised classification, while 30-m spatial resolution measurements of altitude and slope came from the Shuttle Radar Topography Mission. Metrological data were collected from the National Meteorological Agency, Bahir Dar branch. These separate datasets, represented as layers in the computer, were combined using weighted, multi-criteria evaluations. The outcome shows that rainfall, temperature, slope, elevation, distance from the lake and distance from the river influenced the malaria hazard the study area by 35%, 15%, 10%, 7%, 5% and 3%, respectively, resulting in a map showing five areas with different levels of malaria hazard: very high (11.2%); high (14.5%); moderate (63.3%); low (6%); and none (5%). The malaria risk map, based on this hazard map plus additional information on proximity to health facilities and current LULC conditions, shows that Bahir Dar City has areas with very high (15%); high (65%); moderate (8%); and low (5%) levels of malaria risk, with only 2% of the land completely riskfree. Such risk maps are essential for planning, implementing, monitoring and evaluating disease control as well as for contemplating prevention and elimination of epidemiological hazards from endemic areas.

THE IMPACT OF DDT SPRAYING AND MALARIA TREATMENT ON THE MALARIA TRANSMISSION IN A HYPO-ENDEMIC AREA OF SOUTH KALIMANTAN

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S. Gandahusada

2012-09-01

Full Text Available Dari tahun 1979 sampai dengan 1981 dilaksanakan penelitian epidemiologi malaria disuatu daerah hypo-endemis di Kalimantan Selatan. Sebagian dari penelitian yang dilaporkan di sini, menilai hasil pe­nyemprotan rumah dengan DDT yang dilaksanakan secara rutin oleh Dinas Kesehatan Propinsi serta menilai intervensi yang diadakan atas dasar epidemiologi setempat. Daerah transmigrasi Batutungku di­semprot  secara rutin dan hasilnya dibandingkan dengan Panyipatan, suatu desa yang tidak disemprot. Hasil surveillance menunjukkan bahwa incidence rate tiap tahun selama tiga tahun penelitian di kedua daerah turunnya sama : di Batutungku dari 10,20/00 menjadi 8,70/00 pada tahun 1980 dan 5,30/00 pada tahun 1981, dan di Panyipatan dari 16,60/00 menjadi 14,60/00 pada tahun 1980 dan 7,70/00 pada tahun 1981. Fluktuasi kepadatan An. nigerrimus dan An. peditaeniatus, dua species anopheles yang paling banyak tertangkap di daerah penelitian, juga tidak menunjukkan adanya perbedaan di kedua dae­rah. Dengan incidence rate dan data entomologis ini, dibuktikan bahwa penyemprotan rumah-rumah di Batutungku tidak efektif. Bahwa di kedua daerah incidence rate tiap tahun menurun, disebabkan oleh ''radical treatment' yang dimulai di kedua daerah sejak Oktober 1979. ''Mass treatment "di dua R W di Batutungku di mana incidence malaria per bulan lebih tinggi daripada lain-lain R W, dapat menekan malaria transmisi.

The epidemiology of febrile malaria episodes in an area of unstable and seasonal transmission

DEFF Research Database (Denmark)

Giha, H A; Rosthoj, S; Dodoo, D

2000-01-01

hazard model for recurrent events stratified by family, we have calculated the relative hazard for clinical malaria episodes by age, sex, haemoglobin genotype, blood type and infection in the previous season. The malaria risk was significantly lower in individuals aged 20-88 years than in the 5-19 years...

Malaria situation in an endemic area, southeastern iran.

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Sajjad Fekri

2014-06-01

Full Text Available Malaria is an endemic infectious disease in southeastern parts of Iran. Despite years of efforts and intervention programs against malaria, transmission still occurs in Jask County.The epidemiological perspective of malaria in Jask County was conducted by gathering data from Jask County health center, during 2006-2010. A knowledge, attitude and practice study was also carried out. Data analysis was conducted using SPSS ver. 11.5.A total of 2875 malaria cases were recorded, with highest and lowest numbers in 2007 and 2010, respectively. The number of cases had a decreasing trend from 1022 cases in 2006 to 114 cases in 2010. The main causative parasitic agent was Plasmodium vivax. Blood examination rate and slide positive rate were also decreased from 39.5% and 4.3% in 2006 to 15.6% and 1.4% in 2010, respectively. Most of people interviewed in the KAP study had a good knowledge about malaria transmission and symptoms but their use of the bed net for prevention was low (35%.Malaria incidence had significant reduction during the study years. The main reason for this may be due to changing environmental condition for Anopheline breeding and survival because of drought. Another reason may be integration of vector management by using long lasting insecticide treated bed nets, active case detection and treatment by implementation of mobile teams and increasing in financial sources of malaria control program. Knowledge, attitude and practice of people were good in malaria control and prevention, but needs to do more activities for health education and awareness.

[Malaria's seroepidemiology in a group of migrants in transit (Chiapas, 2008)].

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Betanzos-Reyes, Angel Francisco; González-Cerón, Lilia; Rodríguez, Mario Henry; Torres-Monzón, Jorge Aurelio

2012-10-01

To know the prevalence of malaria and the factors associated with the infection in migrants in the southern border of Mexico, during 2008. In 706 migrants, active malaria infection was investigated using a rapid diagnostic test and PCR and past infection using serology. A questionnaire was applied to investigate the conditions associated to infection. 85.6% originated from Central America, none presented an active infection, although 4.2% were seropositive, most of these came from the countries with the highest malaria incidence in the region. Seropositivity was associated with the number of previous malaria episodes (OR=1.44; IC95% 1.04-2.00), years living in their community of origin (OR=1.03; IC95% 1.00-1.07), and knowledge and self-medication with anti-malaria drugs (OR=3.38; IC95% 1.48-7.67). . The previous exposure of migrants and the difficulties for their detection indicate the need of new strategies for the epidemiological surveillance for these populations.

Malaria vectors in ecologically heterogeneous localities of the Colombian Pacific region.

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Nelson Naranjo-Díaz

Full Text Available The Colombian Pacific region is second nationally in number of malaria cases reported. This zone presents great ecological heterogeneity and Anopheles species diversity. However, little is known about the current spatial and temporal distribution of vector species. This study, conducted in three ecologically different localities of the Pacific region, aimed to evaluate the composition and distribution of Anopheles species and characterize transmission intensity. A total of 4,016 Anopheles mosquitoes were collected representing seven species. The composition and dominant species differed in each locality. Three species were infected with malaria parasites: Anopheles darlingi and An. calderoni were infected with Plasmodium falciparum and An. nuneztovari with Plasmodium vivax VK210 and VK247. Annual EIRs varied from 3.5-7.2 infective bites per year. These results confirm the importance of the primary vector An. nuneztovari in areas disturbed by human interventions, of An. darlingi in deforested margins of humid tropical rainforest and An. albimanus and the suspected vector An. calderoni in areas impacted by urbanization and large-scale palm oil agriculture close to the coast. This constitutes the first report in the Colombia Pacific region of naturally infected An. darlingi, and in Colombia of naturally infected An. calderoni. Further studies should evaluate the epidemiological importance of An. calderoni in the Pacific region.

Bionomics of Anopheline species and malaria transmission dynamics along an altitudinal transect in Western Cameroon

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Toto Jean-Claude

2010-05-01

Full Text Available Abstract Background Highland areas of Africa are mostly malaria hypoendemic, due to climate which is not appropriate for anophelines development and their reproductive fitness. In view of designing a malaria control strategy in Western Cameroon highlands, baseline data on anopheline species bionomics were collected. Methods Longitudinal entomological surveys were conducted in three localities at different altitudinal levels. Mosquitoes were captured when landing on human volunteers and by pyrethrum spray catches. Sampled Anopheles were tested for the presence of Plasmodium circumsporozoite proteins and their blood meal origin with ELISA. Entomological parameters of malaria epidemiology were assessed using Mac Donald's formula. Results Anopheline species diversity and density decreased globally from lowland to highland. The most aggressive species along the altitudinal transect was Anopheles gambiae s.s. of S molecular form, followed in the lowland and on the plateau by An. funestus, but uphill by An. hancocki. An. gambiae and An. ziemanni exhibited similar seasonal biting patterns at the different levels, whereas different features were observed for An. funestus. Only indoor resting species could be captured uphill; it is therefore likely that endophilic behaviour is necessary for anophelines to climb above a certain threshold. Of the ten species collected along the transect, only An. gambiae and An. funestus were responsible for malaria transmission, with entomological inoculation rates (EIR of 90.5, 62.8 and zero infective bites/human/year in the lowland, on the plateau and uphill respectively. The duration of gonotrophic cycle was consistently one day shorter for An. gambiae as compared to An. funestus at equal altitude. Altitudinal climate variations had no effect on the survivorship and the subsequent life expectancy of the adult stage of these malaria vectors, but most probably on aquatic stages. On the contrary increasing altitude

Febrile illness diagnostics and the malaria-industrial complex: a socio-environmental perspective

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Justin Stoler

2016-11-01

Full Text Available Abstract Background Global prioritization of single-disease eradication programs over improvements to basic diagnostic capacity in the Global South have left the world unprepared for epidemics of chikungunya, Ebola, Zika, and whatever lies on the horizon. The medical establishment is slowly realizing that in many parts of sub-Saharan Africa (SSA, particularly urban areas, up to a third of patients suffering from acute fever do not receive a correct diagnosis of their infection. Main body Malaria is the most common diagnosis for febrile patients in low-resource health care settings, and malaria misdiagnosis has soared due to the institutionalization of malaria as the primary febrile illness of SSA by international development organizations and national malaria control programs. This has inadvertently created a “malaria-industrial complex” and historically obstructed our complete understanding of the continent’s complex communicable disease epidemiology, which is currently dominated by a mélange of undiagnosed febrile illnesses. We synthesize interdisciplinary literature from Ghana to highlight the complexity of communicable disease care in SSA from biomedical, social, and environmental perspectives, and suggest a way forward. Conclusion A socio-environmental approach to acute febrile illness etiology, diagnostics, and management would lead to substantial health gains in Africa, including more efficient malaria control. Such an approach would also improve global preparedness for future epidemics of emerging pathogens such as chikungunya, Ebola, and Zika, all of which originated in SSA with limited baseline understanding of their epidemiology despite clinical recognition of these viruses for many decades. Impending ACT resistance, new vaccine delays, and climate change all beckon our attention to proper diagnosis of fevers in order to maximize limited health care resources.

Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

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Magda Magris

2007-06-01

Full Text Available A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS protein. Only An. darlingi (55 was positive for CS proteins of P. falciparum (0.42%, P. malariae (0.25%, and P. vivax-247 (0.1%. The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

Setting research priorities to reduce malaria burden in a post graduate training programme: lessons learnt from the Nigeria field epidemiology and laboratory training programme scientific workshop.

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Fawole, Olufunmilayo I; Ajumobi, Olufemi; Poggensee, Gabriele; Nguku, Patrick

2014-01-01

Although several research groups within institutions in Nigeria have been involved in extensive malaria research, the link between the research community and policy formulation has not been optimal. The workshop aimed to assist post graduate students to identify knowledge gaps and to develop relevant Malaria-related research proposals in line with identified research priorities. A training needs assessment questionnaire was completed by 22 students two week prior to the workshop. Also, a one page concept letter was received from 40 residents. Thirty students were selected based the following six criteria: - answerability and ethics; efficacy and impact; deliverability, affordability; scalability, sustainability; health systems, partnership and community involvement; and equity in achieved disease burden reduction. The workshop was over a three day period. The participants at the workshop were 30 Nigeria Field Epidemiology and Laboratory Training Programme (NFELTP) residents from cohorts 4 and 5. Ten technical papers were presented by the experts from the academia, National Malaria Elimination (NMEP) Programme, NFELTP Faculty and Implementing partners including CDC/PMI. Draft proposals were developed and presented by the residents. The "strongest need" for training was on malaria prevention, followed by malaria diagnosis. Forty seven new research questions were generated, while the 19 developed by the NMEP were shared. Evaluation revealed that all (100%) students either "agreed" that the workshop objectives were met. Full proposals were developed by some of the residents. A debriefing meeting was held with the NMEP coordinator to discuss funding of the projects. Future collaborative partnership has developed as the residents have supported NMEP to develop a research protocol for a national evaluation. Research prioritization workshops are required in most training programmes to ensure that students embark on studies that address the research needs of their country

20 YEARS OF PROGRESS IN MALARIA RESEARCH

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J. Kevin Baird

2012-09-01

Full Text Available U.S. Naval Medical Research Unit No. 2 Detachment (NAMRU, in collaboration with National Institute of Health Research and Development (NIHRD and many other Indonesian government agencies and universities, has conducted studies of malaria throughout Java, Sumatra, Sulawesi, Kalimantan, Flores, Timor, and Irian Jaya. Most studies have characterized the disease epidemiologically by defining the parasitologic distribution of the disease in the population, and by defining the entomologic parameters of local transmission. Studies of patterns of resistance to antimalarials have also been done at many field sites. Several studies on the clinical management of malaria occurred in Rumah Sakit Umum Propinsi in Jayapura. In addition to these studies which impact upon local public health planning policy, immunologic studies routinely occurred in support of the global effort to develop a vaccine against malaria. This report summarizes the progress made in these areas of research during the first 20 years of NAMRU in Indonesia.

Research Challenges and Gaps in Malaria Knowledge in Papua New Guinea

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Kazura, James W.; Siba, Peter M.; Betuela, Inoni; Mueller, Ivo

2011-01-01

Taking into consideration the relative number of people living in Papua New Guinea the burden of malaria in this country is among the highest in Asia and the Pacific region. This article summarizes the research questions and challenges being undertaken by the Southwest Pacific International Center of Excellence for Malaria Research in the context of the epidemiology, transmission and pathogenesis of Plasmodium falciparum and P. vivax at the present time and the recent past. It is hoped that the research accomplished and local infrastructure strengthened by this effort will help inform regional and national policy with regard to the control and ultimately elimination of malaria in this region of the world. PMID:21896268

Malaria control in the African Region: perceptions and viewspoints on proceedings of the Africa Leaders Malaria Alliance (ALMA

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Sambo Luis

2011-06-01

Full Text Available Abstract Background In 2009 a total of 153,408 malaria deaths were reported in Africa. Eleven countries showed a reduction of more than 50% in either confirmed malaria cases or malaria admissions and deaths in recent years. However, many African countries are not on track to achieve the malaria component of the Millennium Development Goal (MDG 6. The African Leaders Malaria Alliance (ALMA working session at the 15th African Union Summit discussed the bottlenecks to achieving MDG 6 (specifically halting and beginning to reverse the incidence of malaria by 2015, success factors, and what countries needed to do to accelerate achievement of the MDG. The purpose of this article is to reflect on the proceedings of the ALMA working session. Methods Working methods of the session included speeches and statements by invited speakers and high-level panel discussions. Discussion The main bottlenecks identified related to the capacity of the health systems to deliver quality care and accessibility issues; need for strong, decentralized malaria-control programmes with linkages with other health and development sectors, the civil society and private sector entities; benefits of co-implementation of malaria control programmes with child survival or other public health interventions; systematic application of integrated promotive, preventive, diagnostic and case management interventions with full community participation; adapting approaches to local political, socio-cultural and administrative environments. The following prerequisites for success were identified: a clear vision and effective leadership of national malaria control programmes; high level political commitment to ensure adequate capacity in expertise, skill mix and number of managers, technicians and service providers; national ownership, intersectoral collaboration and accountability, as well as strong civil society and private sector involvement; functional epidemiological surveillance systems

Malaria Vector Control Still Matters despite Insecticide Resistance.

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Alout, Haoues; Labbé, Pierrick; Chandre, Fabrice; Cohuet, Anna

2017-08-01

Mosquito vectors' resistance to insecticides is usually considered a major threat to the recent progresses in malaria control. However, studies measuring the impact of interventions and insecticide resistance reveal inconsistencies when using entomological versus epidemiological indices. First, evaluation tests that do not reflect the susceptibility of mosquitoes when they are infectious may underestimate insecticide efficacy. Moreover, interactions between insecticide resistance and vectorial capacity reveal nonintuitive outcomes of interventions. Therefore, considering ecological interactions between vector, parasite, and environment highlights that the impact of insecticide resistance on the malaria burden is not straightforward and we suggest that vector control still matters despite insecticide resistance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Short report: entomologic inoculation rates and Plasmodium falciparum malaria prevalence in Africa.

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Beier, J C; Killeen, G F; Githure, J I

1999-07-01

Epidemiologic patterns of malaria infection are governed by environmental parameters that regulate vector populations of Anopheles mosquitoes. The intensity of malaria parasite transmission is normally expressed as the entomologic inoculation rate (EIR), the product of the vector biting rate times the proportion of mosquitoes infected with sporozoite-stage malaria parasites. Malaria transmission intensity in Africa is highly variable with annual EIRs ranging from 1,000 infective bites per person per year. Malaria control programs often seek to reduce morbidity and mortality due to malaria by reducing or eliminating malaria parasite transmission by mosquitoes. This report evaluates data from 31 sites throughout Africa to establish fundamental relationships between annual EIRs and the prevalence of Plasmodium falciparum malaria infection. The majority of sites fitted a linear relationship (r2 = 0.71) between malaria prevalence and the logarithm of the annual EIR. Some sites with EIRs 80%. The basic relationship between EIR and P. falciparum prevalence, which likely holds in east and west Africa, and across different ecologic zones, shows convincingly that substantial reductions in malaria prevalence are likely to be achieved only when EIRs are reduced to levels less than 1 infective bite per person per year. The analysis also highlights that the EIR is a more direct measure of transmission intensity than traditional measures of malaria prevalence or hospital-based measures of infection or disease incidence. As such, malaria field programs need to consider both entomologic and clinical assessments of the efficacy of transmission control measures.

Malaria epidemiology in low-endemicity areas of the northern coast of Ecuador: high prevalence of asymptomatic infections.

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Sáenz, Fabián E; Arévalo-Cortés, Andrea; Valenzuela, Gabriela; Vallejo, Andrés F; Castellanos, Angélica; Poveda-Loayza, Andrea C; Gutierrez, Juan B; Alvarez, Alvaro; Yan, Yi Heng; Benavides, Yoldy; Castro, Luis Enrique; Arévalo-Herrera, Myriam; Herrera, Sócrates

2017-07-26

The recent scale-up in malaria control measures in Latin America has resulted in a significant decrease in the number of reported cases in several countries including Ecuador, where it presented a low malaria incidence in recent years (558 reported cases in 2015) with occasional outbreaks of both Plasmodium falciparum and Plasmodium vivax in the coastal and Amazonian regions. This success in malaria control in recent years has led Ecuador to transition its malaria policy from control to elimination. This study evaluated the general knowledge, attitude and practices (KAP) about malaria, as well as its prevalence in four communities of an endemic area in northwest Ecuador. A total of 258 interviews to assess KAP in the community indicated that most people in the study area have a basic knowledge about the disease but did not use to contribute to its control. Six hundred and forty-eight blood samples were collected and analysed by thick blood smear and real-time PCR. In addition, the distribution of the infections was mapped in the study communities. Although, no parasites were found by microscopy, by PCR the total malaria prevalence was 7.5% (6.9% P. vivax and 0.6% P. falciparum), much higher than expected and comparable to that reported in endemic areas of neighbouring countries with higher malaria transmission. Serology using ELISA and immunofluorescence indicated 27% respondents for P. vivax and 22% respondents for P. falciparum. Results suggest that despite a great malaria reduction in Ecuador, transition from control to elimination would demand further improvement in malaria diagnostics, including active case detection to identify and treat parasite asymptomatic carriers, as well as community participation in its elimination.

Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier.

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Izabel Cristina Dos Reis

Full Text Available Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003-2013 was divided into two phases (epidemic and post-epidemic. Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011-2012 and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39. These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region.

HIV Clustering in Mississippi: Spatial Epidemiological Study to Inform Implementation Science in the Deep South.

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Stopka, Thomas J; Brinkley-Rubinstein, Lauren; Johnson, Kendra; Chan, Philip A; Hutcheson, Marga; Crosby, Richard; Burke, Deirdre; Mena, Leandro; Nunn, Amy

2018-04-03

In recent years, more than half of new HIV infections in the United States occur among African Americans in the Southeastern United States. Spatial epidemiological analyses can inform public health responses in the Deep South by identifying HIV hotspots and community-level factors associated with clustering. The goal of this study was to identify and characterize HIV clusters in Mississippi through analysis of state-level HIV surveillance data. We used a combination of spatial epidemiology and statistical modeling to identify and characterize HIV hotspots in Mississippi census tracts (n=658) from 2008 to 2014. We conducted spatial analyses of all HIV infections, infections among men who have sex with men (MSM), and infections among African Americans. Multivariable logistic regression analyses identified community-level sociodemographic factors associated with HIV hotspots considering all cases. There were HIV hotspots for the entire population, MSM, and African American MSM identified in the Mississippi Delta region, Southern Mississippi, and in greater Jackson, including surrounding rural counties (PHIV cases, HIV hotspots were significantly more likely to include urban census tracts (adjusted odds ratio [AOR] 2.01, 95% CI 1.20-3.37) and census tracts that had a higher proportion of African Americans (AOR 3.85, 95% CI 2.23-6.65). The HIV hotspots were less likely to include census tracts with residents who had less than a high school education (AOR 0.95, 95% CI 0.92-0.98), census tracts with residents belonging to two or more racial/ethnic groups (AOR 0.46, 95% CI 0.30-0.70), and census tracts that had a higher percentage of the population living below the poverty level (AOR 0.51, 95% CI 0.28-0.92). We used spatial epidemiology and statistical modeling to identify and characterize HIV hotspots for the general population, MSM, and African Americans. HIV clusters concentrated in Jackson and the Mississippi Delta. African American race and urban location were

Understanding the population genetics of Plasmodium vivax is essential for malaria control and elimination

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Arnott Alicia

2012-01-01

Full Text Available Abstract Traditionally, infection with Plasmodium vivax was thought to be benign and self-limiting, however, recent evidence has demonstrated that infection with P. vivax can also result in severe illness and death. Research into P. vivax has been relatively neglected and much remains unknown regarding the biology, pathogenesis and epidemiology of this parasite. One of the fundamental factors governing transmission and immunity is parasite diversity. An understanding of parasite population genetic structure is necessary to understand the epidemiology, diversity, distribution and dynamics of natural P. vivax populations. In addition, studying the population structure of genes under immune selection also enables investigation of the dynamic interplay between transmission and immunity, which is crucial for vaccine development. A lack of knowledge regarding the transmission and spread of P. vivax has been particularly highlighted in areas where malaria control and elimination programmes have made progress in reducing the burden of Plasmodium falciparum, yet P. vivax remains as a substantial obstacle. With malaria elimination back on the global agenda, mapping of global and local P. vivax population structure is essential prior to establishing goals for elimination and the roll-out of interventions. A detailed knowledge of the spatial distribution, transmission and clinical burden of P. vivax is required to act as a benchmark against which control targets can be set and measured. This paper presents an overview of what is known and what is yet to be fully understood regarding P. vivax population genetics, as well as the importance and application of P. vivax population genetics studies.

A global map of dominant malaria vectors

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Sinka Marianne E

2012-04-01

Full Text Available Abstract Background Global maps, in particular those based on vector distributions, have long been used to help visualise the global extent of malaria. Few, however, have been created with the support of a comprehensive and extensive evidence-based approach. Methods Here we describe the generation of a global map of the dominant vector species (DVS of malaria that makes use of predicted distribution maps for individual species or species complexes. Results Our global map highlights the spatial variability in the complexity of the vector situation. In Africa, An. gambiae, An. arabiensis and An. funestus are co-dominant across much of the continent, whereas in the Asian-Pacific region there is a highly complex situation with multi-species coexistence and variable species dominance. Conclusions The competence of the mapping methodology to accurately portray DVS distributions is discussed. The comprehensive and contemporary database of species-specific spatial occurrence (currently available on request will be made directly available via the Malaria Atlas Project (MAP website from early 2012.

Determinants of malaria program expenditures during elimination: case study evidence from select provinces in the Philippines.

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Jenny X Liu

Full Text Available ...Even though eliminating malaria from the endemic margins is a part of the Global Malaria Action Plan, little guidance exists on what resources are needed to transition from controlling malaria to eliminating it. Using Philippines as an example, this study aimed to (1 estimate the financial resources used by sub-national malaria programs in different phases during elimination and (2 understand how different environmental and organizational factors may influence expenditure levels and spending proportions. The Philippines provides an opportunity to study variations in sub-national programs because its epidemiological and ecological diversity, devolved health system, and progressive elimination strategy all allow greater flexibility for lower-level governments to direct activities, but also create challenges for coordination and resource mobilization. Through key informant interviews and archival record retrieval in four selected provinces chosen based on eco-epidemiological variation, expenditures associated with provincial malaria programs were collected for selected years (mid-1990s to 2010. Results show that expenditures per person at risk per year decrease as programs progress from a state of controlled low-endemic malaria to elimination to prevention of reintroduction regardless of whether elimination was deliberately planned. However, wide variation across provinces were found: expenditures were generally higher if mainly financed with donor grants, but were moderated by the level of economic development, the level of malaria transmission and receptivity, and the capacity of program staff. Across all provinces, strong leadership appears to be a necessary condition for maintaining progress and is vital in controlling outbreaks. While sampled provinces and years may not be representative of other sub-national malaria programs, these findings suggest that the marginal yearly cost declines with each phase during elimination.

Determinants of malaria program expenditures during elimination: case study evidence from select provinces in the Philippines.

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Liu, Jenny X; Newby, Gretchen; Brackery, Aprielle; Smith Gueye, Cara; Candari, Christine J; Escubil, Luz R; Vestergaard, Lasse S; Baquilod, Mario

2013-01-01

...Even though eliminating malaria from the endemic margins is a part of the Global Malaria Action Plan, little guidance exists on what resources are needed to transition from controlling malaria to eliminating it. Using Philippines as an example, this study aimed to (1) estimate the financial resources used by sub-national malaria programs in different phases during elimination and (2) understand how different environmental and organizational factors may influence expenditure levels and spending proportions. The Philippines provides an opportunity to study variations in sub-national programs because its epidemiological and ecological diversity, devolved health system, and progressive elimination strategy all allow greater flexibility for lower-level governments to direct activities, but also create challenges for coordination and resource mobilization. Through key informant interviews and archival record retrieval in four selected provinces chosen based on eco-epidemiological variation, expenditures associated with provincial malaria programs were collected for selected years (mid-1990s to 2010). Results show that expenditures per person at risk per year decrease as programs progress from a state of controlled low-endemic malaria to elimination to prevention of reintroduction regardless of whether elimination was deliberately planned. However, wide variation across provinces were found: expenditures were generally higher if mainly financed with donor grants, but were moderated by the level of economic development, the level of malaria transmission and receptivity, and the capacity of program staff. Across all provinces, strong leadership appears to be a necessary condition for maintaining progress and is vital in controlling outbreaks. While sampled provinces and years may not be representative of other sub-national malaria programs, these findings suggest that the marginal yearly cost declines with each phase during elimination.

[Analysis of overseas imported malaria situation and implication for control in Jiangsu Province, PR China].

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Liu, Yao-Bao; Cao, Jun; Zhou, Hua-Yun; Wang, Wei-Ming; Cao, Yuan-Yuan; Gao, Qi

2013-02-01

To analyze the epidemiological characteristics of overseas imported malaria in Jiangsu Province and explore the strategies and priorities in prevention and control, so as to provide the evidence for improving the diagnosis, treatment and management of imported malaria. The data of overseas imported malaria as well as the case epidemiological investigation in Jiangsu Province from July 18, 2011 to June 30, 2012 were collected and analyzed descriptively for the species composition, original countries, population distribution, regional distribution, onset time, diagnosis and treatment, channels to go abroad, and counterparts returned together with the patients. A total of 233 overseas imported malaria cases were reported, and 226 cases (97.0%) were imported from African countries. A total of 208 cases (89.3%) were falciparum malaria, and 224 cases (96.1%) were laboratory-confirmed. The imported malaria cases were young adults who were mainly migrant farmer and skilled male workers. There was no significant seasonal variation for onset time. Totally 145 cases (62.2%) got malaria onset in 20 days after returning home. The median time from onset to seeing doctor was two days and the median time from seeing doctor to being diagnosed was one day. The first visit health facilities by the patients were relatively scattered and the diagnostic health facilities were mainly medical institutions and CDC at the county level and above (220 cases, accounting for 94.4%). The ratio of standard treatment after malaria diagnosis was 100%. A total of 205 cases (88.0%) were workers dispatched to abroad as labor export by the company, and 142 cases (60.9%) cases had counterparts returned together. The situation of overseas imported malaria in Jiangsu Province is severe. It is necessary to further strengthen the professional training and multi-sectoral cooperation, establish the collaborative investigation mechanism for high-risk groups, and take effective prevention and control measures

Malaria control in a forest camp in an oil exploration area of Upper Assam.

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Prakash, Anil; Bhattacharyya, D R; Mohapatra, P K; Barua, U; Phukan, Anjan; Mahanta, J

2003-01-01

Assam, in north-east India, is extremely rich in hydrocarbon deposits and the oil industry is the major contributor to its economy. A large number of oil fields and related installations in Assam are located in forest areas or on their fringes where malaria is a serious problem among field staff and security personnel, adversely affecting oil production. We carried out an operational research study for one year in a forest-based industrial security camp of Dibrugarh district and developed an effective malaria control strategy for such areas. The specific strategy was formulated and implemented after taking into account the local epidemiology of malaria, vector's ecology and malaria risk behaviour of the camp inmates. The strategy was based on reducing the man-vector contact, using deltamethrin-treated mosquito nets in conjunction with mosquito repellent cream and weekly chemoprophylaxis with 300 mg chloroquine. The impact of the strategy was monitored entomologically and epidemiologically for one year after implementation. The mean landing rate of Anopheles dirus, the vector mosquito in the camp area, was 5.03 per person per night during the monitoring. In spite of such a high density of the vector, the man-vector contact was effectively checked by the intervention measures adopted. As a result, the incidence of malaria in the camp was reduced by > 90% as compared to previous years and the number of malaria cases came down from 6.7 per 1000 man-nights in 1998-99 to 0.06 in 2000-01. Mortality due to malaria was completely eliminated. Control of malaria should be based on the local determinants of transmission. The use of insecticide-treated mosquito nets in conjunction with a mosquito repellent cream is a good intervention for controlling Anopheles dirus-transmitted malaria in the forests of north-east India. The control module developed on the principle of reducing man-mosquito contact is easy to implement, cost-effective and replicable in similar forest

Characterizing the malaria rural-to-urban transmission interface: The importance of reactive case detection.

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Karen Molina Gómez

2017-07-01

Full Text Available Reported urban malaria cases are increasing in Latin America, however, evidence of such trend remains insufficient. Here, we propose an integrated approach that allows characterizing malaria transmission at the rural-to-urban interface by combining epidemiological, entomological, and parasite genotyping methods.A descriptive study that combines active (ACD, passive (PCD, and reactive (RCD case detection was performed in urban and peri-urban neighborhoods of Quibdó, Colombia. Heads of households were interviewed and epidemiological surveys were conducted to assess malaria prevalence and identify potential risk factors. Sixteen primary cases, eight by ACD and eight by PCD were recruited for RCD. Using the RCD strategy, prevalence of 1% by microscopy (6/604 and 9% by quantitative polymerase chain reaction (qPCR (52/604 were found. A total of 73 houses and 289 volunteers were screened leading to 41 secondary cases, all of them in peri-urban settings (14% prevalence. Most secondary cases were genetically distinct from primary cases indicating that there were independent occurrences. Plasmodium vivax was the predominant species (76.3%, 71/93, most of them being asymptomatic (46/71. Urban and peri-urban neighborhoods had significant sociodemographic differences. Twenty-four potential breeding sites were identified, all in peri-urban areas. The predominant vectors for 1,305 adults were Anopheles nuneztovari (56,2% and An. Darlingi (42,5%. One An. nuneztovari specimen was confirmed naturally infected with P. falciparum by ELISA.This study found no evidence supporting the existence of urban malaria transmission in Quibdó. RCD strategy was more efficient for identifying malaria cases than ACD alone in areas where malaria transmission is variable and unstable. Incorporating parasite genotyping allows discovering hidden patterns of malaria transmission that cannot be detected otherwise. We propose to use the term "focal case" for those primary cases that

Submicroscopic malaria infections in pregnant women from six departments in Haiti.

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Elbadry, Maha A; Tagliamonte, Massimiliano S; Raccurt, Christian P; Lemoine, Jean F; Existe, Alexandre; Boncy, Jacques; Weppelmann, Thomas A; Dame, John B; Okech, Bernard A

2017-08-01

To describe the epidemiology of malaria in pregnancy in Haiti. Cross-sectional study among pregnant women in six departments of Haiti. After obtaining informed consent, whole blood samples and demographic surveys were collected to investigate malaria prevalence, anaemia and socio-behavioural risk factors for infection, respectively. A total of 311 pregnant women were screened for Plasmodium falciparum infection using a rapid diagnostic test (RDT), microscopy and a novel, quantitative reverse transcriptase polymerase chain reaction method (qRT-PCR). Overall, 1.2% (4/311) of pregnant women were tested positive for malaria infection by both microscopy and RDT. However, using the qRT-PCR, 16.4% (51/311) of pregnant women were positive. The prevalence of malaria infection varied with geographical locations ranging between 0% and 46.4%. Additionally, 53% of pregnant women had some form of anaemia; however, no significant association was found between anaemia and submicroscopic malaria infection. The socio-behavioural risk factors identified to be protective of malaria infection were marital status (P < 0.05) and travel within one month prior to screening (P < 0.05). This study is the first to document the high prevalence of submicroscopic malaria infections among pregnant women in Haiti and identify social and behavioural risk factors for disease transmission. © 2017 John Wiley & Sons Ltd.

Spatio-Temporal Dynamics of Asymptomatic Malaria: Bridging the Gap Between Annual Malaria Resurgences in a Sahelian Environment.

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Coulibaly, Drissa; Travassos, Mark A; Tolo, Youssouf; Laurens, Matthew B; Kone, Abdoulaye K; Traore, Karim; Sissoko, Mody; Niangaly, Amadou; Diarra, Issa; Daou, Modibo; Guindo, Boureima; Rebaudet, Stanislas; Kouriba, Bourema; Dessay, Nadine; Piarroux, Renaud; Plowe, Christopher V; Doumbo, Ogobara K; Thera, Mahamadou A; Gaudart, Jean

2017-12-01

In areas of seasonal malaria transmission, the incidence rate of malaria infection is presumed to be near zero at the end of the dry season. Asymptomatic individuals may constitute a major parasite reservoir during this time. We conducted a longitudinal analysis of the spatio-temporal distribution of clinical malaria and asymptomatic parasitemia over time in a Malian town to highlight these malaria transmission dynamics. For a cohort of 300 rural children followed over 2009-2014, periodicity and phase shift between malaria and rainfall were determined by spectral analysis. Spatial risk clusters of clinical episodes or carriage were identified. A nested-case-control study was conducted to assess the parasite carriage factors. Malaria infection persisted over the entire year with seasonal peaks. High transmission periods began 2-3 months after the rains began. A cluster with a low risk of clinical malaria in the town center persisted in high and low transmission periods. Throughout 2009-2014, cluster locations did not vary from year to year. Asymptomatic and gametocyte carriage were persistent, even during low transmission periods. For high transmission periods, the ratio of asymptomatic to clinical cases was approximately 0.5, but was five times higher during low transmission periods. Clinical episodes at previous high transmission periods were a protective factor for asymptomatic carriage, but carrying parasites without symptoms at a previous high transmission period was a risk factor for asymptomatic carriage. Stable malaria transmission was associated with sustained asymptomatic carriage during dry seasons. Control strategies should target persistent low-level parasitemia clusters to interrupt transmission.

Malaria Transmission Risk Factor In West Java (Epidemiology Study About Vector, Plasmodium parasite and Environmental Risk Factors For Malaria Cases

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Lukman Hakim

2010-06-01

Full Text Available Since the territory is divided with the province of Banten, in West Java there are five regencies that defined as malaria endemic area, there are Ciamis, Tasikmalaya, Garut, Cianjur and Sukabumi. Sufferer, concentrated in southern coastal areas (Indonesian Ocean starting from the beach of Kalipucang at Ciamis up to coast of Cikakak at Sukabumi which borders the province of Banten and also mountain and plantations areas. Malaria morbidity incidence risk factors is differ in each of these endemic areas. In general is the presence of malaria patients without symptoms who can be a source of infection that so difficult to know its existence. Still the number of standing water that can become mosqui-to breeding places of Anopheles spp, such as fish pond, small puddle on the riverside, shrimp pond, mangrove forests that potentially at the beginning of the rainy season, the fields during rice that potential when the rice growing and the river that potential in the dry season. The existence of high population mobility and also the number of vegetation in the surrounding residential population and the existence of cattle are placed close to settle-ments.

A systematic review of the application and utility of geographical information systems for exploring disease-disease relationships in paediatric global health research: the case of anaemia and malaria.

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Aimone, Ashley Mariko; Perumal, Nandita; Cole, Donald C

2013-01-10

Malaria and anaemia are important health problems among children globally. Iron deficiency anaemia may offer protection against malaria infection and iron supplementation may increase the risk of malaria-related hospitalization and mortality. The nature and mechanism of these relationships, however, remain largely unresolved, resulting in concern and uncertainty around policies for non-selective iron supplementation in malaria endemic areas. Use of geographical information systems (GIS) to investigate this disease-disease interaction could contribute important new information for developing safe and effective anaemia and malaria interventions. To assess the current state of knowledge we conducted a systematic review of peer-reviewed and grey literature. Our primary objective was to qualitatively assess the application and utility of geographical concepts or spatial analyses in paediatric global health research. The secondary objective was to identify geographical factors that may be associated with anaemia and malaria prevalence or incidence among children 0-5 years of age living in low- and middle-income countries. Evaluation tools for assessing the quality of geographical data could not be found in the peer-reviewed or grey literature, and thus adapted versions of the STROBE (Strengthening The Reporting of Observational Studies in Epidemiology) and GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods were used to create reporting, and overall evidence quality scoring systems. Among the 20 included studies, we found that both malaria and anaemia were more prevalent in rural communities compared to urban areas. Geographical factors associated with malaria prevalence included regional transmission stability, and proximity to a mosquito breeding area. The prevalence of anaemia tended to vary inversely with greater or poorer access to community services such as piped water. Techniques for investigating geographic relationships ranged from

A systematic review of the application and utility of geographical information systems for exploring disease-disease relationships in paediatric global health research: the case of anaemia and malaria

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Aimone Ashley Mariko

2013-01-01

Full Text Available Abstract Malaria and anaemia are important health problems among children globally. Iron deficiency anaemia may offer protection against malaria infection and iron supplementation may increase the risk of malaria-related hospitalization and mortality. The nature and mechanism of these relationships, however, remain largely unresolved, resulting in concern and uncertainty around policies for non-selective iron supplementation in malaria endemic areas. Use of geographical information systems (GIS to investigate this disease-disease interaction could contribute important new information for developing safe and effective anaemia and malaria interventions. To assess the current state of knowledge we conducted a systematic review of peer-reviewed and grey literature. Our primary objective was to qualitatively assess the application and utility of geographical concepts or spatial analyses in paediatric global health research. The secondary objective was to identify geographical factors that may be associated with anaemia and malaria prevalence or incidence among children 0–5 years of age living in low- and middle-income countries. Evaluation tools for assessing the quality of geographical data could not be found in the peer-reviewed or grey literature, and thus adapted versions of the STROBE (Strengthening The Reporting of Observational Studies in Epidemiology and GRADE (Grades of Recommendation, Assessment, Development and Evaluation methods were used to create reporting, and overall evidence quality scoring systems. Among the 20 included studies, we found that both malaria and anaemia were more prevalent in rural communities compared to urban areas. Geographical factors associated with malaria prevalence included regional transmission stability, and proximity to a mosquito breeding area. The prevalence of anaemia tended to vary inversely with greater or poorer access to community services such as piped water. Techniques for investigating geographic

Malaria in Brazil: an overview.

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Oliveira-Ferreira, Joseli; Lacerda, Marcus V G; Brasil, Patrícia; Ladislau, José L B; Tauil, Pedro L; Daniel-Ribeiro, Cláudio Tadeu

2010-04-30

Malaria is still a major public health problem in Brazil, with approximately 306,000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. As a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. From the mid-1960s onwards, Brazil underwent a rapid and disorganized settlement process in the Amazon and this migratory movement led to a progressive increase in the number of reported cases. Although the main mosquito vector (Anopheles darlingi) is present in about 80% of the country, currently the incidence of malaria in Brazil is almost exclusively (99,8% of the cases) restricted to the region of the Amazon Basin, where a number of combined factors favors disease transmission and impair the use of standard control procedures. Plasmodium vivax accounts for 83,7% of registered cases, while Plasmodium falciparum is responsible for 16,3% and Plasmodium malariae is seldom observed. Although vivax malaria is thought to cause little mortality, compared to falciparum malaria, it accounts for much of the morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with P. vivax have been reported in Brazil and this is a matter of concern for Brazilian malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine in some reports needs to be further investigated. In contrast, asymptomatic infection by P. falciparum and P. vivax has been detected in epidemiological studies in the states of Rondonia and Amazonas, indicating probably a pattern of clinical immunity in both autochthonous and migrant populations. Seropidemiological studies investigating the type of immune responses elicited in naturally-exposed populations to several malaria vaccine candidates in

Malaria in Brazil: an overview

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Brasil Patrícia

2010-04-01

Full Text Available Abstract Malaria is still a major public health problem in Brazil, with approximately 306 000 registered cases in 2009, but it is estimated that in the early 1940s, around six million cases of malaria occurred each year. As a result of the fight against the disease, the number of malaria cases decreased over the years and the smallest numbers of cases to-date were recorded in the 1960s. From the mid-1960s onwards, Brazil underwent a rapid and disorganized settlement process in the Amazon and this migratory movement led to a progressive increase in the number of reported cases. Although the main mosquito vector (Anopheles darlingi is present in about 80% of the country, currently the incidence of malaria in Brazil is almost exclusively (99,8% of the cases restricted to the region of the Amazon Basin, where a number of combined factors favors disease transmission and impair the use of standard control procedures. Plasmodium vivax accounts for 83,7% of registered cases, while Plasmodium falciparum is responsible for 16,3% and Plasmodium malariae is seldom observed. Although vivax malaria is thought to cause little mortality, compared to falciparum malaria, it accounts for much of the morbidity and for huge burdens on the prosperity of endemic communities. However, in the last few years a pattern of unusual clinical complications with fatal cases associated with P. vivax have been reported in Brazil and this is a matter of concern for Brazilian malariologists. In addition, the emergence of P. vivax strains resistant to chloroquine in some reports needs to be further investigated. In contrast, asymptomatic infection by P. falciparum and P. vivax has been detected in epidemiological studies in the states of Rondonia and Amazonas, indicating probably a pattern of clinical immunity in both autochthonous and migrant populations. Seropidemiological studies investigating the type of immune responses elicited in naturally-exposed populations to several

Malaria control in Bhutan: case study of a country embarking on elimination

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Yangzom Thinley

2012-01-01

Full Text Available Abstract Background Bhutan has achieved a major reduction in malaria incidence amid multiple challenges. This case study seeks to characterize the Bhutan malaria control programme over the last 10 years. Methods A review of the malaria epidemiology, control strategies, and elimination strategies employed in Bhutan was carried out through a literature review of peer-reviewed and grey national and international literature with the addition of reviewing the surveillance and vector control records of the Bhutan Vector-Borne Disease Control Programme (VDCP. Data triangulation was used to identify trends in epidemiology and key strategies and interventions through analysis of the VDCP surveillance and programme records and the literature review. Enabling and challenging factors were identified through analysis of socio-economic and health indicators, corroborated through a review of national and international reports and peer-review articles. Findings Confirmed malaria cases in Bhutan declined by 98.7% from 1994 to 2010. The majority of indigenous cases were due to Plasmodium vivax (59.9% and adult males are most at-risk of malaria. Imported cases, or those in foreign nationals, varied over the years, reaching 21.8% of all confirmed cases in 2006. Strategies implemented by the VDCP are likely to be related to the decline in cases over the last 10 years. Access to malaria diagnosis in treatment was expanded throughout the country and evidence-based case management, including the introduction of artemisinin-based combination therapy (ACT for P. falciparum, increasing coverage of high risk areas with Indoor Residual Spraying, insecticide-treated bed nets, and long-lasting insecticidal nets are likely to have contributed to the decline alongside enabling factors such as economic development and increasing access to health services. Conclusion Bhutan has made significant strides towards elimination and has adopted a goal of national elimination. A major

Cost analysis of the development and implementation of a spatial decision support system for malaria elimination in Solomon Islands.

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Marston, Luke; Kelly, Gerard C; Hale, Erick; Clements, Archie C A; Hodge, Andrew; Jimenez-Soto, Eliana

2014-08-18

The goal of malaria elimination faces numerous challenges. New tools are required to support the scale up of interventions and improve national malaria programme capacity to conduct detailed surveillance. This study investigates the cost factors influencing the development and implementation of a spatial decision support system (SDSS) for malaria elimination in the two elimination provinces of Isabel and Temotu, Solomon Islands. Financial and economic costs to develop and implement a SDSS were estimated using the Solomon Islands programme's financial records. Using an ingredients approach, verified by stakeholders and operational reports, total costs for each province were quantified. A budget impact sensitivity analysis was conducted to investigate the influence of variations in standard budgetary components on the costs and to identify potential cost savings. A total investment of US$ 96,046 (2012 constant dollars) was required to develop and implement the SDSS in two provinces (Temotu Province US$ 49,806 and Isabel Province US$ 46,240). The single largest expense category was for computerized equipment totalling approximately US$ 30,085. Geographical reconnaissance was the most expensive phase of development and implementation, accounting for approximately 62% of total costs. Sensitivity analysis identified different cost factors between the provinces. Reduced equipment costs would deliver a budget saving of approximately 10% in Isabel Province. Combined travel costs represented the greatest influence on the total budget in the more remote Temotu Province. This study provides the first cost analysis of an operational surveillance tool used specifically for malaria elimination in the South-West Pacific. It is demonstrated that the costs of such a decision support system are driven by specialized equipment and travel expenses. Such factors should be closely scrutinized in future programme budgets to ensure maximum efficiencies are gained and available resources

A spatial epidemiological analysis of nontuberculous mycobacterial infections in Queensland, Australia.

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Chou, Michael P; Clements, Archie C A; Thomson, Rachel M

2014-05-21

The epidemiology of infections with nontuberculous mycobacteria (NTM) has been changing and the incidence has been increasing in some settings. The main route of transmission to humans is considered to be from the environment. We aimed to describe spatial clusters of cases of NTM infections and to identify associated climatic, environmental and socio-economic variables. NTM data were obtained from the Queensland Mycobacterial Reference Laboratory for the period 2001-2011. A Bayesian spatial conditional autoregressive model was constructed at the postcode level, with covariates including soil variables, maximum, mean and minimum rainfall and temperature, income (proportion of population earning Queensland region overlying the Surat sub-division of the Great Artesian Basin, as well as in the lower North Queensland Local Government Area known as the Whitsunday region. Our models estimated an expected increase of 21% per percentage increase of population earning Queensland, and a number of socio-ecological, economic and environmental factors were found to be associated with NTM infection risk.

Rapid urban malaria appraisal (RUMA in sub-Saharan Africa

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Akogbeto Martin

2005-09-01

Full Text Available Abstract Background The rapid urban malaria appraisal (RUMA methodology aims to provide a cost-effective tool to conduct rapid assessments of the malaria situation in urban sub-Saharan Africa and to improve the understanding of urban malaria epidemiology. Methods This work was done in Yopougon municipality (Abidjan, Cotonou, Dar es Salaam and Ouagadougou. The study design consists of six components: 1 a literature review, 2 the collection of available health statistics, 3 a risk mapping, 4 school parasitaemia surveys, 5 health facility-based surveys and 6 a brief description of the health care system. These formed the basis of a multi-country evaluation of RUMA's feasibility, consistency and usefulness. Results A substantial amount of literature (including unpublished theses and statistics was found at each site, providing a good overview of the malaria situation. School and health facility-based surveys provided an overview of local endemicity and the overall malaria burden in different city areas. This helped to identify important problems for in-depth assessment, especially the extent to which malaria is over-diagnosed in health facilities. Mapping health facilities and breeding sites allowed the visualization of the complex interplay between population characteristics, health services and malaria risk. However, the latter task was very time-consuming and required special expertise. RUMA is inexpensive, costing around 8,500–13,000 USD for a six to ten-week period. Conclusion RUMA was successfully implemented in four urban areas with different endemicity and proved to be a cost-effective first approach to study the features of urban malaria and provide an evidence basis for planning control measures.

Border Malaria Associated with Multidrug Resistance on Thailand-Myanmar and Thailand-Cambodia Borders: Transmission Dynamic, Vulnerability, and Surveillance

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Bhumiratana, Adisak; Intarapuk, Apiradee; Sorosjinda-Nunthawarasilp, Prapa; Maneekan, Pannamas; Koyadun, Surachart

2013-01-01

This systematic review elaborates the concepts and impacts of border malaria, particularly on the emergence and spread of Plasmodium falciparum and Plasmodium vivax multidrug resistance (MDR) malaria on Thailand-Myanmar and Thailand-Cambodia borders. Border malaria encompasses any complex epidemiological settings of forest-related and forest fringe-related malaria, both regularly occurring in certain transmission areas and manifesting a trend of increased incidence in transmission prone areas along these borders, as the result of interconnections of human settlements and movement activities, cross-border population migrations, ecological changes, vector population dynamics, and multidrug resistance. For regional and global perspectives, this review analyzes and synthesizes the rationales pertaining to transmission dynamics and the vulnerabilities of border malaria that constrain surveillance and control of the world's most MDR falciparum and vivax malaria on these chaotic borders. PMID:23865048

Multi-step polynomial regression method to model and forecast malaria incidence.

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Chandrajit Chatterjee

Full Text Available Malaria is one of the most severe problems faced by the world even today. Understanding the causative factors such as age, sex, social factors, environmental variability etc. as well as underlying transmission dynamics of the disease is important for epidemiological research on malaria and its eradication. Thus, development of suitable modeling approach and methodology, based on the available data on the incidence of the disease and other related factors is of utmost importance. In this study, we developed a simple non-linear regression methodology in modeling and forecasting malaria incidence in Chennai city, India, and predicted future disease incidence with high confidence level. We considered three types of data to develop the regression methodology: a longer time series data of Slide Positivity Rates (SPR of malaria; a smaller time series data (deaths due to Plasmodium vivax of one year; and spatial data (zonal distribution of P. vivax deaths for the city along with the climatic factors, population and previous incidence of the disease. We performed variable selection by simple correlation study, identification of the initial relationship between variables through non-linear curve fitting and used multi-step methods for induction of variables in the non-linear regression analysis along with applied Gauss-Markov models, and ANOVA for testing the prediction, validity and constructing the confidence intervals. The results execute the applicability of our method for different types of data, the autoregressive nature of forecasting, and show high prediction power for both SPR and P. vivax deaths, where the one-lag SPR values plays an influential role and proves useful for better prediction. Different climatic factors are identified as playing crucial role on shaping the disease curve. Further, disease incidence at zonal level and the effect of causative factors on different zonal clusters indicate the pattern of malaria prevalence in the city

Design of Epidemia - an Ecohealth Informatics System for Integrated Forecasting of Malaria Epidemics

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Wimberly, M. C.; Bayabil, E.; Beyane, B.; Bishaw, M.; Henebry, G. M.; Lemma, A.; Liu, Y.; Merkord, C. L.; Mihretie, A.; Senay, G. B.; Yalew, W.

2014-12-01

Early warning of the timing and locations of malaria epidemics can facilitate the targeting of resources for prevention and emergency response. In response to this need, we are developing the Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system. The system incorporates software for capturing, processing, and integrating environmental and epidemiological data from multiple sources; data assimilation techniques that continually update models and forecasts; and a web-based interface that makes the resulting information available to public health decision makers. This technology will enable forecasts based on lagged responses to environmental risk factors as well as information about recent trends in malaria cases. Environmental driving variables will include a variety of remote-sensed hydrological indicators. EPIDEMIA will be implemented and tested in the Amhara Region of Ethiopia in collaboration with local stakeholders. We conducted an initial co-design workshop in July 2014 that included environmental scientists, software engineers, and participants from the NGO, academic, and public health sectors in Ethiopia. A prototype of the EPIDEMIA web interface was presented and a requirements analysis was conducted to characterize the main use cases for the public health community, identify the critical data requirements for malaria risk modeling, and develop of a list of baseline features for the public health interface. Several critical system features were identified, including a secure web-based interface for uploading and validating surveillance data; a flexible query system to allow retrieval of environmental and epidemiological data summaries as tables, charts, and maps; and an alert system to provide automatic warnings in response to environmental and epidemiological risk factors for malaria. Future system development will involve a cycle of implementation, training, usability testing, and

Can plant biotechnology help break the HIV-malaria link?

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Vamvaka, E; Twyman, R M; Christou, P; Capell, T

2014-01-01

The population of sub-Saharan Africa is at risk from multiple, poverty-related endemic diseases. HIV and malaria are the most prevalent, but they disproportionately affect different groups of people, i.e. HIV predominantly affects sexually-active adults whereas malaria has a greater impact on children and pregnant women. Nevertheless, there is a significant geographical and epidemiological overlap which results in bidirectional and synergistic interactions with important consequences for public health. The immunosuppressive effects of HIV increase the risk of infection when individuals are exposed to malaria parasites and also the severity of malaria symptoms. Similarly, acute malaria can induce a temporary increase in the HIV viral load. HIV is associated with a wide range of opportunistic infections that can be misdiagnosed as malaria, resulting in the wasteful misuse of antimalarial drugs and a failure to address the genuine cause of the disease. There is also a cumulative risk of toxicity when antiretroviral and antimalarial drugs are given to the same patients. Synergistic approaches involving the control of malaria as a strategy to fight HIV/AIDS and vice versa are therefore needed in co-endemic areas. Plant biotechnology has emerged as a promising approach to tackle poverty-related diseases because plant-derived drugs and vaccines can be produced inexpensively in developing countries and may be distributed using agricultural infrastructure without the need for a cold chain. Here we explore some of the potential contributions of plant biotechnology and its integration into broader multidisciplinary public health programs to combat the two diseases in developing countries. Copyright © 2014 Elsevier Inc. All rights reserved.

The association of genetic markers and malaria infection in the Brazilian Western Amazonian region

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B Beiguelman

2003-06-01

Full Text Available Almost all individuals (182 belonging to an Amazonian riverine population (Portuchuelo, RO, Brazil were investigated for ascertaining data on epidemiological aspects of malaria. Thirteen genetic blood polymorphisms were investigated (ABO, MNSs, Rh, Kell, and Duffy systems, haptoglobins, hemoglobins, and the enzymes glucose-6-phosphate dehydrogenase, glyoxalase, phosphoglucomutase, carbonic anhydrase, red cell acid phosphatase, and esterase D. The results indicated that the Duffy system is associated with susceptibility to malaria, as observed in other endemic areas. Moreover, suggestions also arose indicating that the EsD and Rh loci may be significantly associated with resistance to malaria. If statistical type II errors and sample stratification could be ruled out, hypotheses on the existence of a causal mechanism or an unknown closely linked locus involved in susceptibility to malaria infection may explain the present findings.

Fighting malaria in Madhya Pradesh (Central India: Are we loosing the battle?

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Thimasarn Krongthong

2009-05-01

Full Text Available Abstract Malaria control in Madhya Pradesh is complex because of vast tracts of forest with tribal settlement. Fifty four million individuals of various ethnic origins, accounting for 8% of the total population of India, contributed 30% of total malaria cases, 60% of total falciparum cases and 50% of malaria deaths in the country. Ambitious goals to control tribal malaria by launching "Enhanced Malaria Control Project" (EMCP by the National Vector Borne Disease Control Programme (NVBDCP, with the World Bank assistance, became effective in September 1997 in eight north Indian states. Under EMCP, the programme used a broader mix of new interventions, i.e. insecticide-treated bed nets, spraying houses with effective residual insecticides, use of larvivorous fishes, rapid diagnostic tests for prompt diagnosis, treatment of the sick with effective radical treatment and increased public awareness and IEC. However, the challenge is to scale up these services. A retrospective analysis of data on malaria morbidity and associated mortality reported under the existing surveillance system of the Madhya Pradesh (Central India for the years 1996–2007 was carried out to determine the impact of EMCP on malaria morbidity and associated mortality. Analysis revealed that despite the availability of effective intervention tools for the prevention and control of malaria, falciparum malaria remains uncontrolled and deaths due to malaria have increased. Precisely, the aim of this epidemiological analysis is to draw lessons applicable to all international aid efforts, bureaucracy, policy makers and programme managers in assessing its project performance as a new Global Malaria Action Plan is launched with ambitious goal of reducing malaria and its elimination by scaling up the use of existing tools.

Geospatial Technology: A Tool to Aid in the Elimination of Malaria in Bangladesh

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Karen E. Kirk

2014-12-01

Full Text Available Bangladesh is a malaria endemic country. There are 13 districts in the country bordering India and Myanmar that are at risk of malaria. The majority of malaria morbidity and mortality cases are in the Chittagong Hill Tracts, the mountainous southeastern region of Bangladesh. In recent years, malaria burden has declined in the country. In this study, we reviewed and summarized published data (through 2014 on the use of geospatial technologies on malaria epidemiology in Bangladesh and outlined potential contributions of geospatial technologies for eliminating malaria in the country. We completed a literature review using “malaria, Bangladesh” search terms and found 218 articles published in peer-reviewed journals listed in PubMed. After a detailed review, 201 articles were excluded because they did not meet our inclusion criteria, 17 articles were selected for final evaluation. Published studies indicated geospatial technologies tools (Geographic Information System, Global Positioning System, and Remote Sensing were used to determine vector-breeding sites, land cover classification, accessibility to health facility, treatment seeking behaviors, and risk mapping at the household, regional, and national levels in Bangladesh. To achieve the goal of malaria elimination in Bangladesh, we concluded that further research using geospatial technologies should be integrated into the country’s ongoing surveillance system to identify and better assess progress towards malaria elimination.

IgG responses to Anopheles gambiae salivary antigen gSG6 detect variation in exposure to malaria vectors and disease risk

DEFF Research Database (Denmark)

Stone, Will; Bousema, Teun; Jones, Sophie

2012-01-01

as the basis of an immuno-assay determining exposure to Afrotropical malaria vectors. In the present study, IgG responses to gSG6 and 6 malaria antigens (CSP, AMA-1, MSP-1, MSP-3, GLURP R1, and GLURP R2) were compared to Anopheles exposure and malaria incidence in a cohort of children from Korogwe district...... with subsequent malaria incidence (test for trend p¿=¿0.004), comparable to malaria antigens MSP-1 and GLURP R2. Our results show that the gSG6 assay is sensitive to micro-epidemiological variations in exposure to Anopheles mosquitoes, and provides a correlate of malaria risk that is unrelated to immune...

Information Systems to Support Surveillance for Malaria Elimination

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Ohrt, Colin; Roberts, Kathryn W.; Sturrock, Hugh J. W.; Wegbreit, Jennifer; Lee, Bruce Y.; Gosling, Roly D.

2015-01-01

Robust and responsive surveillance systems are critical for malaria elimination. The ideal information system that supports malaria elimination includes: rapid and complete case reporting, incorporation of related data, such as census or health survey information, central data storage and management, automated and expert data analysis, and customized outputs and feedback that lead to timely and targeted responses. Spatial information enhances such a system, ensuring cases are tracked and mapped over time. Data sharing and coordination across borders are vital and new technologies can improve data speed, accuracy, and quality. Parts of this ideal information system exist and are in use, but have yet to be linked together coherently. Malaria elimination programs should support the implementation and refinement of information systems to support surveillance and response and ensure political and financial commitment to maintain the systems and the human resources needed to run them. National malaria programs should strive to improve the access and utility of these information systems and establish cross-border data sharing mechanisms through the use of standard indicators for malaria surveillance. Ultimately, investment in the information technologies that support a timely and targeted surveillance and response system is essential for malaria elimination. PMID:26013378

Age-patterns of malaria vary with severity, transmission intensity and seasonality in sub-Saharan Africa: a systematic review and pooled analysis.

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Ilona Carneiro

Full Text Available BACKGROUND: There is evidence that the age-pattern of Plasmodium falciparum malaria varies with transmission intensity. A better understanding of how this varies with the severity of outcome and across a range of transmission settings could enable locally appropriate targeting of interventions to those most at risk. We have, therefore, undertaken a pooled analysis of existing data from multiple sites to enable a comprehensive overview of the age-patterns of malaria outcomes under different epidemiological conditions in sub-Saharan Africa. METHODOLOGY/PRINCIPAL FINDINGS: A systematic review using PubMed and CAB Abstracts (1980-2005, contacts with experts and searching bibliographies identified epidemiological studies with data on the age distribution of children with P. falciparum clinical malaria, hospital admissions with malaria and malaria-diagnosed mortality. Studies were allocated to a 3x2 matrix of intensity and seasonality of malaria transmission. Maximum likelihood methods were used to fit five continuous probability distributions to the percentage of each outcome by age for each of the six transmission scenarios. The best-fitting distributions are presented graphically, together with the estimated median age for each outcome. Clinical malaria incidence was relatively evenly distributed across the first 10 years of life for all transmission scenarios. Hospital admissions with malaria were more concentrated in younger children, with this effect being even more pronounced for malaria-diagnosed deaths. For all outcomes, the burden of malaria shifted towards younger ages with increasing transmission intensity, although marked seasonality moderated this effect. CONCLUSIONS: The most severe consequences of P. falciparum malaria were concentrated in the youngest age groups across all settings. Despite recently observed declines in malaria transmission in several countries, which will shift the burden of malaria cases towards older children, it

A world malaria map: Plasmodium falciparum endemicity in 2007.

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Simon I Hay

2009-03-01

Full Text Available Efficient allocation of resources to intervene against malaria requires a detailed understanding of the contemporary spatial distribution of malaria risk. It is exactly 40 y since the last global map of malaria endemicity was published. This paper describes the generation of a new world map of Plasmodium falciparum malaria endemicity for the year 2007.A total of 8,938 P. falciparum parasite rate (PfPR surveys were identified using a variety of exhaustive search strategies. Of these, 7,953 passed strict data fidelity tests for inclusion into a global database of PfPR data, age-standardized to 2-10 y for endemicity mapping. A model-based geostatistical procedure was used to create a continuous surface of malaria endemicity within previously defined stable spatial limits of P. falciparum transmission. These procedures were implemented within a Bayesian statistical framework so that the uncertainty of these predictions could be evaluated robustly. The uncertainty was expressed as the probability of predicting correctly one of three endemicity classes; previously stratified to be an informative guide for malaria control. Population at risk estimates, adjusted for the transmission modifying effects of urbanization in Africa, were then derived with reference to human population surfaces in 2007. Of the 1.38 billion people at risk of stable P. falciparum malaria, 0.69 billion were found in Central and South East Asia (CSE Asia, 0.66 billion in Africa, Yemen, and Saudi Arabia (Africa+, and 0.04 billion in the Americas. All those exposed to stable risk in the Americas were in the lowest endemicity class (PfPR2-10 5 to or = 40% areas. High endemicity was widespread in the Africa+ region, where 0.35 billion people are at this level of risk. Most of the rest live at intermediate risk (0.20 billion, with a smaller number (0.11 billion at low stable risk.High levels of P. falciparum malaria endemicity are common in Africa. Uniformly low endemic levels are

A world malaria map: Plasmodium falciparum endemicity in 2007.

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Hay, Simon I; Guerra, Carlos A; Gething, Peter W; Patil, Anand P; Tatem, Andrew J; Noor, Abdisalan M; Kabaria, Caroline W; Manh, Bui H; Elyazar, Iqbal R F; Brooker, Simon; Smith, David L; Moyeed, Rana A; Snow, Robert W

2009-03-24

Efficient allocation of resources to intervene against malaria requires a detailed understanding of the contemporary spatial distribution of malaria risk. It is exactly 40 y since the last global map of malaria endemicity was published. This paper describes the generation of a new world map of Plasmodium falciparum malaria endemicity for the year 2007. A total of 8,938 P. falciparum parasite rate (PfPR) surveys were identified using a variety of exhaustive search strategies. Of these, 7,953 passed strict data fidelity tests for inclusion into a global database of PfPR data, age-standardized to 2-10 y for endemicity mapping. A model-based geostatistical procedure was used to create a continuous surface of malaria endemicity within previously defined stable spatial limits of P. falciparum transmission. These procedures were implemented within a Bayesian statistical framework so that the uncertainty of these predictions could be evaluated robustly. The uncertainty was expressed as the probability of predicting correctly one of three endemicity classes; previously stratified to be an informative guide for malaria control. Population at risk estimates, adjusted for the transmission modifying effects of urbanization in Africa, were then derived with reference to human population surfaces in 2007. Of the 1.38 billion people at risk of stable P. falciparum malaria, 0.69 billion were found in Central and South East Asia (CSE Asia), 0.66 billion in Africa, Yemen, and Saudi Arabia (Africa+), and 0.04 billion in the Americas. All those exposed to stable risk in the Americas were in the lowest endemicity class (PfPR2-10 5 to or = 40%) areas. High endemicity was widespread in the Africa+ region, where 0.35 billion people are at this level of risk. Most of the rest live at intermediate risk (0.20 billion), with a smaller number (0.11 billion) at low stable risk. High levels of P. falciparum malaria endemicity are common in Africa. Uniformly low endemic levels are found in the

A multi-criteria decision analysis approach to assessing malaria risk in northern South America

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Temitope O. Alimi

2016-03-01

Full Text Available Abstract Background Malaria control in South America has vastly improved in the past decade, leading to a decrease in the malaria burden. Despite the progress, large parts of the continent continue to be at risk of malaria transmission, especially in northern South America. The objectives of this study were to assess the risk of malaria transmission and vector exposure in northern South America using multi-criteria decision analysis. Methods The risk of malaria transmission and vector exposure in northern South America was assessed using multi-criteria decision analysis, in which expert opinions were taken on the key environmental and population risk factors. Results Results from our risk maps indicated areas of moderate-to-high risk along rivers in the Amazon basin, along the coasts of the Guianas, the Pacific coast of Colombia and northern Colombia, in parts of Peru and Bolivia and within the Brazilian Amazon. When validated with occurrence records for malaria, An. darlingi, An. albimanus and An. nuneztovari s.l., t-test results indicated that risk scores at occurrence locations were significantly higher (p < 0.0001 than a control group of geographically random points. Conclusion In this study, we produced risk maps based on expert opinion on the spatial representation of risk of potential vector exposure and malaria transmission. The findings provide information to the public health decision maker/policy makers to give additional attention to the spatial planning of effective vector control measures. Therefore, as the region tackles the challenge of malaria elimination, prioritizing areas for interventions by using spatially accurate, high-resolution (1 km or less risk maps may guide targeted control and help reduce the disease burden in the region.

Application of geographically-weighted regression analysis to assess risk factors for malaria hotspots in Keur Soce health and demographic surveillance site.

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Ndiath, Mansour M; Cisse, Badara; Ndiaye, Jean Louis; Gomis, Jules F; Bathiery, Ousmane; Dia, Anta Tal; Gaye, Oumar; Faye, Babacar

2015-11-18

In Senegal, considerable efforts have been made to reduce malaria morbidity and mortality during the last decade. This resulted in a marked decrease of malaria cases. With the decline of malaria cases, transmission has become sparse in most Senegalese health districts. This study investigated malaria hotspots in Keur Soce sites by using geographically-weighted regression. Because of the occurrence of hotspots, spatial modelling of malaria cases could have a considerable effect in disease surveillance. This study explored and analysed the spatial relationships between malaria occurrence and socio-economic and environmental factors in small communities in Keur Soce, Senegal, using 6 months passive surveillance. Geographically-weighted regression was used to explore the spatial variability of relationships between malaria incidence or persistence and the selected socio-economic, and human predictors. A model comparison of between ordinary least square and geographically-weighted regression was also explored. Vector dataset (spatial) of the study area by village levels and statistical data (non-spatial) on malaria confirmed cases, socio-economic status (bed net use), population data (size of the household) and environmental factors (temperature, rain fall) were used in this exploratory analysis. ArcMap 10.2 and Stata 11 were used to perform malaria hotspots analysis. From Jun to December, a total of 408 confirmed malaria cases were notified. The explanatory variables-household size, housing materials, sleeping rooms, sheep and distance to breeding site returned significant t values of -0.25, 2.3, 4.39, 1.25 and 2.36, respectively. The OLS global model revealed that it explained about 70 % (adjusted R(2) = 0.70) of the variation in malaria occurrence with AIC = 756.23. The geographically-weighted regression of malaria hotspots resulted in coefficient intercept ranging from 1.89 to 6.22 with a median of 3.5. Large positive values are distributed mainly in the southeast

Malaria case clinical profiles and Plasmodium falciparum parasite genetic diversity: a cross sectional survey at two sites of different malaria transmission intensities in Rwanda.

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Kateera, Fredrick; Nsobya, Sam L; Tukwasibwe, Stephen; Mens, Petra F; Hakizimana, Emmanuel; Grobusch, Martin P; Mutesa, Leon; Kumar, Nirbhay; van Vugt, Michele

2016-04-26

Malaria remains a public health challenge in sub-Saharan Africa with Plasmodium falciparum being the principal cause of malaria disease morbidity and mortality. Plasmodium falciparum virulence is attributed, in part, to its population-level genetic diversity-a characteristic that has yet to be studied in Rwanda. Characterizing P. falciparum molecular epidemiology in an area is needed for a better understand of malaria transmission and to inform choice of malaria control strategies. In this health-facility based survey, malaria case clinical profiles and parasite densities as well as parasite genetic diversity were compared among P. falciparum-infected patients identified at two sites of different malaria transmission intensities in Rwanda. Data on demographics and clinical features and finger-prick blood samples for microscopy and parasite genotyping were collected(.) Nested PCR was used to genotype msp-2 alleles of FC27 and 3D7. Patients' variables of age group, sex, fever (both by patient report and by measured tympanic temperatures), parasite density, and bed net use were found differentially distributed between the higher endemic (Ruhuha) and lower endemic (Mubuga) sites. Overall multiplicity of P. falciparum infection (MOI) was 1.73 but with mean MOI found to vary significantly between 2.13 at Ruhuha and 1.29 at Mubuga (p < 0.0001). At Ruhuha, expected heterozygosity (EH) for FC27 and 3D7 alleles were 0.62 and 0.49, respectively, whilst at Mubuga, EH for FC27 and 3D7 were 0.26 and 0.28, respectively. In this study, a higher geometrical mean parasite counts, more polyclonal infections, higher MOI, and higher allelic frequency were observed at the higher malaria-endemic (Ruhuha) compared to the lower malaria-endemic (Mubuga) area. These differences in malaria risk and MOI should be considered when choosing setting-specific malaria control strategies, assessing p. falciparum associated parameters such as drug resistance, immunity and impact of used

Community knowledge, attitudes and practices (KAP on malaria in Swaziland: A country earmarked for malaria elimination

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Govender Dayanandan

2009-02-01

Full Text Available Abstract Background The potential contribution of knowledge, attitudes and practices (KAP studies to malaria research and control has not received much attention in most southern African countries. This study investigated the local communities' understanding of malaria transmission, recognition of signs and symptoms, perceptions of cause, treatment-seeking patterns, preventive measures and practices in order to inform the country's proposed malaria elimination programme in Swaziland. Methods A descriptive cross-sectional survey was undertaken in four Lubombo Spatial Development Initiative (LSDI sentinel sites in Swaziland. These sentinel sites share borders with Mozambique. A structured questionnaire was administered to 320 randomly selected households. Only one adult person was interviewed per household. The interviewees were the heads of households and in the absence of the heads of households responsible adults above 18 years were interviewed. Results A substantial number of research participants showed reasonable knowledge of malaria, including correct association between malaria and mosquito bites, its potential fatal consequences and correct treatment practices. Almost 90% (n = 320 of the respondents stated that they would seek treatment within 24 hours of onset of malaria symptoms, with health facilities as their first treatment option. Most people (78% perceived clinics and vector control practices as central to treating and preventing malaria disease. Indoor residual spraying (IRS coverage and bed net ownership were 87.2% and 38.8%, respectively. IRS coverage was in agreement with the World Health Organization's (WHO recommendation of more than 80% within the targeted communities. Conclusion Despite fair knowledge of malaria in Swaziland, there is a need for improving the availability of information through the preferred community channels, such as tinkhundlas (districts, as well as professional health routes. This recommendation

Shifting suitability for malaria vectors across Africa with warming climates

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Peterson A Townsend

2009-05-01

Full Text Available Abstract Background Climates are changing rapidly, producing warm climate conditions globally not previously observed in modern history. Malaria is of great concern as a cause of human mortality and morbidity, particularly across Africa, thanks in large part to the presence there of a particularly competent suite of mosquito vector species. Methods I derive spatially explicit estimates of human populations living in regions newly suitable climatically for populations of two key Anopheles gambiae vector complex species in Africa over the coming 50 years, based on ecological niche model projections over two global climate models, two scenarios of climate change, and detailed spatial summaries of human population distributions. Results For both species, under all scenarios, given the changing spatial distribution of appropriate conditions and the current population distribution, the models predict a reduction of 11.3–30.2% in the percentage of the overall population living in areas climatically suitable for these vector species in coming decades, but reductions and increases are focused in different regions: malaria vector suitability is likely to decrease in West Africa, but increase in eastern and southern Africa. Conclusion Climate change effects on African malaria vectors shift their distributional potential from west to east and south, which has implications for overall numbers of people exposed to these vector species. Although the total is reduced, malaria is likely to pose novel public health problems in areas where it has not previously been common.

Border Malaria Associated with Multidrug Resistance on Thailand-Myanmar and Thailand-Cambodia Borders: Transmission Dynamic, Vulnerability, and Surveillance

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Adisak Bhumiratana

2013-01-01

Full Text Available This systematic review elaborates the concepts and impacts of border malaria, particularly on the emergence and spread of Plasmodium falciparum and Plasmodium vivax multidrug resistance (MDR malaria on Thailand-Myanmar and Thailand-Cambodia borders. Border malaria encompasses any complex epidemiological settings of forest-related and forest fringe-related malaria, both regularly occurring in certain transmission areas and manifesting a trend of increased incidence in transmission prone areas along these borders, as the result of interconnections of human settlements and movement activities, cross-border population migrations, ecological changes, vector population dynamics, and multidrug resistance. For regional and global perspectives, this review analyzes and synthesizes the rationales pertaining to transmission dynamics and the vulnerabilities of border malaria that constrain surveillance and control of the world’s most MDR falciparum and vivax malaria on these chaotic borders.

WHO policy development processes for a new vaccine: case study of malaria vaccines

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Cheyne James

2010-06-01

Full Text Available Abstract Background Recommendations from the World Health Organization (WHO are crucial to inform developing country decisions to use, or not, a new intervention. This article analysed the WHO policy development process to predict its course for a malaria vaccine. Methods The decision-making processes for one malaria intervention and four vaccines were classified through (1 consultations with staff and expert advisors to WHO's Global Malaria Programme (GMP and Immunization, Vaccines and Biologicals Department (IVB; (2 analysis of the procedures and recommendations of the major policy-making bodies of these groups; (3 interviews with staff of partnerships working toward new vaccine availability; and (4 review and analyses of evidence informing key policy decisions. Case description WHO policy formulation related to use of intermittent preventive treatment in infancy (IPTi and the following vaccine interventions: Haemophilus influenzae type b conjugate vaccine (Hib, pneumococcal conjugate vaccine (PCV, rotavirus vaccine (RV, and human papillomavirus vaccine (HPV, five interventions which had relatively recently been through systematic WHO policy development processes as currently constituted, was analysed. Required information was categorized in three areas defined by a recent WHO publication on development of guidelines: safety and efficacy in relevant populations, implications for costs and population health, and localization of data to specific epidemiological situations. Discussion and evaluation Data needs for a malaria vaccine include safety; the demonstration of efficacy in a range of epidemiological settings in the context of other malaria prevention interventions; and information on potential rebound in which disease increases subsequent to the intervention. In addition, a malaria vaccine would require attention to additional factors, such as costs and cost-effectiveness, supply and demand, impact of use on other interventions, and

Assessing the social vulnerability to malaria in Rwanda.

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Bizimana, Jean-Pierre; Twarabamenye, Emmanuel; Kienberger, Stefan

2015-01-07

indicates which indicators need to be addressed and in which districts. The results from this study are salient for public health policy- and decision makers in malaria control in Rwanda and timely support the national integrated malaria initiative. Future research development should focus on spatial explicit vulnerability assessment by combining environmental and social drivers to achieve an integrated and complete assessment of vulnerability to malaria.

[Important vector-borne infectious diseases among humans in Germany. Epidemiological aspects].

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Frank, C; Faber, M; Hellenbrand, W; Wilking, H; Stark, K

2014-05-01

Vector-borne infections pathogenic to humans play an important role in Germany. The relevant zoonotic pathogens are either endemic throughout Germany (e.g. Borrelia burgdorferi sensu latu) or only in specific regions, e.g. tick-borne encephalitis (TBE) virus and hantavirus. They cause a substantial burden of disease. Prevention and control largely rely on public advice and the application of personal protective measures (e.g. TBE virus vaccination and protection against vectors). High quality surveillance and targeted epidemiological studies are fundamental for the evaluation of temporal and spatial risks of infection and the effectiveness of preventive measures. Aside from endemic pathogens, vector-borne infections acquired abroad, mostly transmitted by mosquitoes, have to be systematically and intensively monitored as well, to assess the risk of infection for German residents traveling abroad and to adequately evaluate the risk of autochthonous transmission. Related issues, such as invasive species of mosquitoes in Germany and climate change, have to be taken into consideration. Such pathogens include West Nile, dengue and chikungunya viruses, as well as malaria parasites (Plasmodium species). The article presents an overview of the epidemiological situation of selected relevant vector-borne infections in Germany.

Spatial modelling of malaria risk factors in Ruhuha sector in the east of Rwanda

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Tuyishimire, J.; Kateera, F.; Mugisha, J.; Amer, S.; Mens, P.

2017-01-01

Malaria is a vector borne disease posing a severe health risk to the population of Sub Saharan Africa and particularly in the East African Rift-Valley Region. The fact that malaria is still killing hundreds of thousands of people annually is due to insufficient researchers about its causing factors

Spatial analysis for the epidemiological study of cardiovascular diseases: A systematic literature search.

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Mena, Carlos; Sepúlveda, Cesar; Fuentes, Eduardo; Ormazábal, Yony; Palomo, Iván

2018-05-07

Cardiovascular diseases (CVDs) are the primary cause of death and disability in de world, and the detection of populations at risk as well as localization of vulnerable areas is essential for adequate epidemiological management. Techniques developed for spatial analysis, among them geographical information systems and spatial statistics, such as cluster detection and spatial correlation, are useful for the study of the distribution of the CVDs. These techniques, enabling recognition of events at different geographical levels of study (e.g., rural, deprived neighbourhoods, etc.), make it possible to relate CVDs to factors present in the immediate environment. The systemic literature presented here shows that this group of diseases is clustered with regard to incidence, mortality and hospitalization as well as obesity, smoking, increased glycated haemoglobin levels, hypertension physical activity and age. In addition, acquired variables such as income, residency (rural or urban) and education, contribute to CVD clustering. Both local cluster detection and spatial regression techniques give statistical weight to the findings providing valuable information that can influence response mechanisms in the health services by indicating locations in need of intervention and assignment of available resources.

Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria.

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Freya M Shearer

2016-08-01

Full Text Available Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated.A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines.We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified.

A study on the epidemiological characteristics and infectious forecast model of malaria at Guangzhou Airport among Chinese returnees from Africa.

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Wu, Hui-Ming; Fang, Zhi-Qiang; Zhao, Dang; Chen, Yan-Ling; Liu, Chuan-Ge; Liang, Xi

2017-07-04

Cross-border malaria transmission in China is a major component of Chinese imported malaria cases. Such cases mostly are travellers returning from malaria endemic countries in Africa. By investigating malaria infectious status among Chinese worker in Africa, this study analysed the malaria risk factors, in order to establish infectious forecast model. Chinese returnees data from Africa were collected at Guangzhou Baiyun International Airport, Guangzhou, China between August 2015 and March 2016 and were included in the cross-sectional and retrospective survey. A total of 1492 respondents were included in the study with the majority consisting of junior middle school educated male. Most of them are manual and technical workers hired by companies, with average of 37.04 years of age. Overall malaria incidence rate of the population was 8.98% (134/1492), and there were no significant differences regarding age, gender, occupation, or team. Forecast model was developed on the basis of malaria risk factors including working country, local ecological environment type, work duration and intensity of mosquito bite prevention. The survey suggested that malaria incidence was high among Chinese travellers who had worked in Africa countries of heavy malaria burden. Further research on the frequency and severity of clinical episodes among Chinese travellers having worked in Africa is needed.

Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes.

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Samson S Kiware

Full Text Available BACKGROUND: High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as "very zoophagic," meaning they feed occasionally (<10% of blood meals upon humans, so personal protection interventions have negligible impact upon their survival. METHODS AND FINDINGS: We extended a published malaria transmission model to examine the relationship between transmission, control, and the baseline proportion of bloodmeals obtained from humans (human blood index. The lower limit of the human blood index enables derivation of simplified models for zoophagic vectors that (1 Rely on only three field-measurable parameters. (2 Predict immediate and delayed (with and without assuming reduced human infectivity, respectively impacts of personal protection measures upon transmission. (3 Illustrate how appreciable indirect communal-level protection for non-users can be accrued through direct personal protection of users. (4 Suggest the coverage and efficacy thresholds required to attain epidemiological impact. The findings suggest that immediate, indirect, community-wide protection of users and non-users alike may linearly relate to the efficacy of a user's direct personal protection, regardless of whether that is achieved by killing or repelling mosquitoes. High protective coverage and efficacy (≥80% are important to achieve epidemiologically meaningful impact. Non-users are indirectly protected because the two most common species of human malaria are strict anthroponoses. Therefore, the small proportion of mosquitoes that are killed or diverted while attacking humans can represent a large proportion of those actually transmitting malaria. CONCLUSIONS: Simplified models of malaria transmission by very zoophagic vectors may be used by control practitioners to predict intervention impact

A decade of malaria during pregnancy in Brazil: what has been done concerning prevention and management

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Paola Marchesini

2014-08-01

Full Text Available In Brazil, malaria remains a disease of major epidemiological importance because of the high number of cases in the Amazonian Region. Plasmodium spp infections during pregnancy are a significant public health problem with substantial risks for the pregnant woman, the foetus and the newborn child. In Brazil, the control of malaria during pregnancy is primarily achieved by prompt and effective treatment of the acute episodes. Thus, to assure rapid diagnosis and treatment for pregnant women with malaria, one of the recommended strategy for low transmission areas by World Health Organization and as part of a strategy by the Ministry of Health, the National Malaria Control Program has focused on integrative measures with woman and reproductive health. Here, we discuss the approach for the prevention and management of malaria during pregnancy in Brazil over the last 10 years (2003-2012 using morbidity data from Malaria Health Information System. Improving the efficiency and quality of healthcare and education and the consolidation of prevention programmes will be challenges in the control of malaria during pregnancy in the next decade.

The role of age, ethnicity and environmental factors in modulating malaria risk in Rajasthali, Bangladesh

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Haque Ubydul

2011-12-01

Full Text Available Abstract Background Malaria is endemic in the Rajasthali region of the Chittagong Hill Tracts in Bangladesh and the Rajasthali region is the most endemic area of Bangladesh. Quantifying the role of environmental and socio-economic factors in the local spatial patterns of malaria endemicity can contribute to successful malaria control and elimination. This study aimed to investigate the role of environmental factors on malaria risk in Rajasthali and to quantify the geographical clustering in malaria risk unaccounted by these factors. Method A total of 4,200 (78.9%; N = 5,322 households were targeted in Rajasthali in July, 2009, and 1,400 individuals were screened using a rapid diagnostic test (Falci-vax. These data were linked to environmental and socio-economic data in a geographical information system. To describe the association between environmental factors and malaria risk, a generalized linear mixed model approach was utilized. The study investigated the role of environmental factors on malaria risk by calculating their population-attributable fractions (PAF, and used residual semivariograms to quantify the geographical clustering in malaria risk unaccounted by these factors. Results Overall malaria prevalence was 11.7%. Out of 5,322 households, 44.12% households were living in areas with malaria prevalence of ≥ 10%. The results from statistical analysis showed that age, ethnicity, proximity to forest, household density, and elevation were significantly and positively correlated with the malaria risk and PAF estimation. The highest PAF of malaria prevalence was 47.7% for third tertile (n = 467 of forest cover, 17.6% for second tertile (n = 467 of forest cover and 19.9% for household density >1,000. Conclusion Targeting of malaria health interventions at small spatial scales in Bangladesh should consider the social and socio-economic risk factors identified as well as alternative methods for improving equity of access to interventions

Epidemiological characterization of Plasmodium falciparum in the Republic of Cabo Verde: implications for potential large-scale re-emergence of malaria

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Alves, Joana; Roque, Ana Luísa; Cravo, Pedro; Valdez, Tomás; Jelinek, Tomas; do Rosário, Virgílio E; Arez, Ana Paula

2006-01-01

Background Malaria has come near eradication at archipelago of Cabo Verde in 1970. Infections are now only observed in Santiago, where outbreaks occur. In these islands, malaria is considered by the international community as being of limited risk and, therefore, no prophylaxis is recommended. Since the understanding of factors that determine malaria outbreaks are crucial for controlling the disease, the present study aimed to investigate if the malaria infections observed in Santiago Island are maintained in isolated foci and in asymptomatic individuals. Methods The occurrence of asymptomatic carriers in villages with history of malaria as well as the level of exposure of these populations were investigated using PCR and serological analyses. Results Results indicate that malaria is maintained as asymptomatic and sub-patent infections and that the majority of the circulating parasite populations harbour chloroquine-resistant mutations. Conclusion These observations highlight the alarming prospect of malaria to become a serious public health problem and underscore the need for a tighter surveillance. PMID:16630349

Spatio-Temporal Analysis to Predict Environmental Influence on Malaria

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Baig, S.; Sarfraz, M. S.

2018-05-01

Malaria is a vector borne disease which is a major cause of morbidity and mortality. It is one of the major diseases in the category of infectious diseases. The survival and bionomics of malaria is affected by environmental factors such as climatic, demographic and land-use/land-cover etc. Currently, a very few under developing countries are using Geo-informatics approaches to control this disease. Gujrat a district of Pakistan, is still under threat of malaria disease. Current research is carried on malaria incidents obtained from District Executive Officer of Health Gujrat. The objective of this study was to explore the spatio-temporal patterns of malaria in district Gujrat and to identify the areas being affected by Malaria. Furthermore, it has been also analyzed the relationship between malaria incident and environmental factors in highly favorable zones. Data is analyzed based on spatial and temporal patterns using (Moran's I). Moreover cluster and hot spots analysis were performed on the incident data. This study shows positive correlation with rainfall, vegetation index, population density and water bodies; while it shows positive and negative correlation with temperature in different seasons. However, variation between amount of vegetation and water bodies were observed. Finding of this research can help the decision makers to take preventive measures and reduce the morbidity and mortality related with malaria in Gujrat, Pakistan.

[Descriptive study of malaria cases in a general hospital in Madrid between 1996 and 2011].

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Paredes, P; Pérez, E; Guizar, M; Penín, M; Gómez Carrasco, J A

2014-11-01

Malaria causes around 863,000 deaths per year, mostly of them in children under 5 years old. We have reviewed the epidemiological data of malaria cases in a pediatric department in a Hospital in the Community of Madrid, in the period 1996-2011. In the period reviewed, 103 cases of malaria were diagnosed in children under 14 years old. Sixty percent were males and the average age was 4.5 years. In most cases, the infection arose during a visit to relatives in the country of origin. The vast majority did not have malaria prophylaxis. Twenty-five percent of the cases were diagnosed as complicated malaria, the main criteria being hyperparasitemia, of which 80% of the patients did not present any other complications A high level of suspicion must be maintained in any patient who comes from a malaria endemic area. The key factor responsible for the infection was the lack of chemoprophylaxis. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Recent Advances of Malaria Parasites Detection Systems Based on Mathematical Morphology

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Andrea Loddo

2018-02-01

Full Text Available Malaria is an epidemic health disease and a rapid, accurate diagnosis is necessary for proper intervention. Generally, pathologists visually examine blood stained slides for malaria diagnosis. Nevertheless, this kind of visual inspection is subjective, error-prone and time-consuming. In order to overcome the issues, numerous methods of automatic malaria diagnosis have been proposed so far. In particular, many researchers have used mathematical morphology as a powerful tool for computer aided malaria detection and classification. Mathematical morphology is not only a theory for the analysis of spatial structures, but also a very powerful technique widely used for image processing purposes and employed successfully in biomedical image analysis, especially in preprocessing and segmentation tasks. Microscopic image analysis and particularly malaria detection and classification can greatly benefit from the use of morphological operators. The aim of this paper is to present a review of recent mathematical morphology based methods for malaria parasite detection and identification in stained blood smears images.

Recent Advances of Malaria Parasites Detection Systems Based on Mathematical Morphology.

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Loddo, Andrea; Di Ruberto, Cecilia; Kocher, Michel

2018-02-08

Malaria is an epidemic health disease and a rapid, accurate diagnosis is necessary for proper intervention. Generally, pathologists visually examine blood stained slides for malaria diagnosis. Nevertheless, this kind of visual inspection is subjective, error-prone and time-consuming. In order to overcome the issues, numerous methods of automatic malaria diagnosis have been proposed so far. In particular, many researchers have used mathematical morphology as a powerful tool for computer aided malaria detection and classification. Mathematical morphology is not only a theory for the analysis of spatial structures, but also a very powerful technique widely used for image processing purposes and employed successfully in biomedical image analysis, especially in preprocessing and segmentation tasks. Microscopic image analysis and particularly malaria detection and classification can greatly benefit from the use of morphological operators. The aim of this paper is to present a review of recent mathematical morphology based methods for malaria parasite detection and identification in stained blood smears images.

Temperature suitability for malaria climbing the Ethiopian Highlands

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Lyon, Bradfield; Dinku, Tufa; Raman, Anita; Thomson, Madeleine C.

2017-06-01

While the effect of climate change on the prevalence of malaria in the highlands of Eastern Africa has been the topic of protracted debate, temperature is widely accepted as a fundamentally important environmental factor constraining its transmission. Air temperatures below approximately 18 °C and 15 °C, respectively, prohibit the development of the Plasmodium falciparum and P. vivax parasites responsible for the majority of malaria cases in Ethiopia. Low temperatures also impede the development rates of the Anopheles mosquito vectors. While locations of sufficiently high elevation have temperatures below these transmission thresholds, a fundamental question is how such temperature ‘threshold elevations’ are changing with time. A lack of high quality, high spatial resolution climate data has previously prohibited a rigorous investigation. Using a newly developed national temperature dataset for Ethiopia that combines numerous in-situ surface observations with downscaled reanalysis data, we here identify statistically significant increases in elevation for both the 18 °C and 15 °C thresholds in highland areas between 1981-2014. Substantial interannual and spatial variations in threshold elevations are identified, the former associated with the El Niño Southern-Oscillation and the latter with the complex climate of the region. The estimated population in locations with an upward trend in the 15 °C threshold elevation is approximately 6.5 million people (2.2 million for 18 °C). While not a direct prediction of the additional population made vulnerable to malaria through a shift to higher temperature, our results underscore a newly acquired ability to investigate climate variability and trends at fine spatial scales across Ethiopia, including changes in a fundamental constraint on malaria transmission in the Ethiopian Highlands.

Information systems to support surveillance for malaria elimination.

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Ohrt, Colin; Roberts, Kathryn W; Sturrock, Hugh J W; Wegbreit, Jennifer; Lee, Bruce Y; Gosling, Roly D

2015-07-01

Robust and responsive surveillance systems are critical for malaria elimination. The ideal information system that supports malaria elimination includes: rapid and complete case reporting, incorporation of related data, such as census or health survey information, central data storage and management, automated and expert data analysis, and customized outputs and feedback that lead to timely and targeted responses. Spatial information enhances such a system, ensuring cases are tracked and mapped over time. Data sharing and coordination across borders are vital and new technologies can improve data speed, accuracy, and quality. Parts of this ideal information system exist and are in use, but have yet to be linked together coherently. Malaria elimination programs should support the implementation and refinement of information systems to support surveillance and response and ensure political and financial commitment to maintain the systems and the human resources needed to run them. National malaria programs should strive to improve the access and utility of these information systems and establish cross-border data sharing mechanisms through the use of standard indicators for malaria surveillance. Ultimately, investment in the information technologies that support a timely and targeted surveillance and response system is essential for malaria elimination. © The American Society of Tropical Medicine and Hygiene.

International travel increase and malaria importation in Romania, 2008-2009.

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Neghina, Raul; Neghina, Adriana M; Marincu, Iosif; Iacobiciu, Ioan

2011-09-01

This report aims to assess the epidemiological characteristics of imported malaria in Romania in the context of international travel increase, and to compare them with the data reported by other European countries. Data on malaria cases were provided by the National Centre for Surveillance and Control of the Communicable Disease, whereas the data regarding international travels to and from Romania were retrieved from the Romanian Statistical Yearbook. The number of Romanian citizens who traveled to Africa in 2007 increased by over 600% as compared to the previous year. During the years 2008-2009, 25 cases of imported malaria were registered in Romania, with no fatalities. All patients were male and most of them (84%) acquired the infection in Africa. Plasmodium falciparum was involved in 68% of cases. The majority of the affected patients (41%) were aged 31 to 40 years. Labor was the main reason for traveling (72%), and 92% of cases took either partial or no chemoprophylaxis. The continuous growth of professional and leisure voyages to malaria-endemic regions may lead to a dramatic increase of imported cases, especially if prophylactic measures are not strictly followed.

The London School of Hygiene and Tropical Medicine: a new century of malaria research

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Riley Eleanor M

2000-01-01

Full Text Available The global malaria situation has scarcely improved in the last 100 years, despite major advances in our knowledge of the basic biology, epidemiology and clinical basis of the disease. Effective malaria control, leading to a significant decrease in the morbidity and mortality attributable to malaria, will require a multidisciplinary approach. New tools - drugs, vaccine and insecticides - are needed but there is also much to be gained by better use of existing tools: using drugs in combination in order to slow the development of drug resistance; targeting resources to areas of greatest need; using geographic information systems to map the populations at risk and more sophisticated marketing techniques to distribute bed nets and insecticides. Sustainable malaria control may require the deployment of a highly effective vaccine, but there is much that can be done in the meantime to reduce the burden of disease.

Optimizing malarial epidemiological studies in areas of low transmission

DEFF Research Database (Denmark)

Amerasinghe, Priyanie H; Alifrangis, Michael; van der Hoek, Wim

2005-01-01

risk factor in this area was the location of houses relative to confirmed vector breeding sites. At the peak of the transmission season, the results pointed in the same direction, irrespective of the diagnostic method used. However, the importance of distance from the breeding site......Malaria risk factor studies have traditionally used microscopy readings of blood slides as the measure of malaria infection in humans, although alternatives are available. There is the need for an assessment of how the use of these alternative diagnostic approaches will influence the efficiency...... and significance of epidemiological studies. In an area of Sri Lanka with known risk factors for malaria, two cross-sectional surveys were done at the start and at the peak of transmission season. Microscopy was compared with enzyme-linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR). The major...

Epidemiological features and risk factors associated with the spatial and temporal distribution of human brucellosis in China

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2013-01-01

Background Human brucellosis incidence in China has been increasing dramatically since 1999. However, epidemiological features and potential factors underlying the re-emergence of the disease remain less understood. Methods Data on human and animal brucellosis cases at the county scale were collected for the year 2004 to 2010. Also collected were environmental and socioeconomic variables. Epidemiological features including spatial and temporal patterns of the disease were characterized, and the potential factors related to the spatial heterogeneity and the temporal trend of were analysed using Poisson regression analysis, Granger causality analysis, and autoregressive distributed lag (ADL) models, respectively. Results The epidemic showed a significantly higher spatial correlation with the number of sheep and goats than swine and cattle. The disease was most prevalent in grassland areas with elevation between 800–1,600 meters. The ADL models revealed that local epidemics were correlated with comparatively lower temperatures and less sunshine in winter and spring, with a 1–7 month lag before the epidemic peak in May. Conclusions Our findings indicate that human brucellosis tended to occur most commonly in grasslands at moderate elevation where sheep and goats were the predominant livestock, and in years with cooler winter and spring or less sunshine. PMID:24238301

Malaria in Brazil: what happens outside the Amazonian endemic region.

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de Pina-Costa, Anielle; Brasil, Patrícia; Di Santi, Sílvia Maria; de Araujo, Mariana Pereira; Suárez-Mutis, Martha Cecilia; Santelli, Ana Carolina Faria e Silva; Oliveira-Ferreira, Joseli; Lourenço-de-Oliveira, Ricardo; Daniel-Ribeiro, Cláudio Tadeu

2014-08-01

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation's territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation's malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or

Malaria in Brazil: what happens outside the Amazonian endemic region

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Anielle de Pina-Costa

2014-08-01

Full Text Available Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation’s territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation’s malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013. The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex. The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites

The demographics of human and malaria movement and migration patterns in East Africa.

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Pindolia, Deepa K; Garcia, Andres J; Huang, Zhuojie; Smith, David L; Alegana, Victor A; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

2013-11-05

The quantification of parasite movements can provide valuable information for control strategy planning across all transmission intensities. Mobile parasite carrying individuals can instigate transmission in receptive areas, spread drug resistant strains and reduce the effectiveness of control strategies. The identification of mobile demographic groups, their routes of travel and how these movements connect differing transmission zones, potentially enables limited resources for interventions to be efficiently targeted over space, time and populations. National population censuses and household surveys provide individual-level migration, travel, and other data relevant for understanding malaria movement patterns. Together with existing spatially referenced malaria data and mathematical models, network analysis techniques were used to quantify the demographics of human and malaria movement patterns in Kenya, Uganda and Tanzania. Movement networks were developed based on connectivity and magnitudes of flow within each country and compared to assess relative differences between regions and demographic groups. Additional malaria-relevant characteristics, such as short-term travel and bed net use, were also examined. Patterns of human and malaria movements varied between demographic groups, within country regions and between countries. Migration rates were highest in 20-30 year olds in all three countries, but when accounting for malaria prevalence, movements in the 10-20 year age group became more important. Different age and sex groups also exhibited substantial variations in terms of the most likely sources, sinks and routes of migration and malaria movement, as well as risk factors for infection, such as short-term travel and bed net use. Census and survey data, together with spatially referenced malaria data, GIS and network analysis tools, can be valuable for identifying, mapping and quantifying regional connectivities and the mobility of different demographic

[Control of malaria transmission in a gold-mining area in Amapá State, Brazil, with participation by private enterprise].

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Couto AA; Calvosa, V S; Lacerda, R; Castro, F; Santa Rosa, E; Nascimento, J M

2001-01-01

This paper reports on the epidemiological characterization of malaria following implementation of a program to control the endemic in a gold-mining area in northern Amapá State. The study focuses on total malaria cases in Amapá and the impact of the disease on the population, as represented by the Mineração Novo Astro S/A company and its employees as well as the community of Vila de Lourenço in the municipality of Calçoene, and adjacent gold miners. The effect of control measures in the program area is indicated by a significant reduction in malaria incidence and malaria-related morbidity and mortality. The importance of participation by private enterprise is emphasized, particularly in large projects for the control of endemic diseases (notably malaria) in the Amazon Region.

Time trends and changes in the distribution of malaria cases in the Brazilian Amazon Region, 2004-2013

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Isac da SF Lima

Full Text Available Recent efforts to reduce malaria incidence have had some successes. Nevertheless, malaria persists as a significant public health problem in the Brazilian Amazon. The objective of this study was to describe changes in malaria case characteristics and to identify trends in malaria incidence in the Brazilian Amazon. This study used data from the Malaria Epidemiological Surveillance and Case Notification Information System from 2004 to 2013. The annual parasite incidence (API was calculated and joinpoint regression was used to assess the trends in API over time. There was a sharp increase in API in the state of Acre, followed by two periods of decrease. Pará also presented inconsistent decreases over the study period. Amapá, Amazonas, Rondônia, and Roraima showed statistically significant decreases over the period. The sharpest decrease occurred in Rondônia, with a reduction of 21.7% in the average annual percent change (AAPC (AAPC: -21.7%; 95% confidence interval: -25.4%, -17.8%; p < 0.05. This panorama of malaria incidence highlights the importance of integrating evidence-based malaria surveillance and control. Malaria is highly preventable, and eliminating its transmission should be a goal in coming decades.

SPECIES COMPOSITION OF MALARIAL MOSQUITOES KHARKIV REGION. NATURAL FACTORS OF MALARIA TRANSMISSION

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Gazzawi - Rogozinа L. V.

2015-05-01

Full Text Available Introduction. This article describes the species composition of the dominant Anopheles mosquitoes in the Kharkiv region, the season of their possible effective infection, as well as ongoing anti-malaria activities . Key words: malaria , mosquitoes, p . Anopheles, epidemiology, census, hydraulic events. Material & methods. The analysis of entomological and meteorological situation in Ukraine and in the Kharkiv region according to data of the Ukrainian Center of control and monitoring of diseases of the Ministry of Health of Ukraine and Kharkiv regional laboratory center. Collection of material (imaginal and larval was carried out on the territory of natural and artificial water bodies of Kharkiv region in the period 2013 - 2014. When collecting the material used conventional accounting methods mosquito populations. On the territory of the region under study, we have found 30 species of mosquitoes three genera: Anopheles, Culex, Aedes. Results & discussion. Epidemiological role of each species of mosquitoes depends on several conditions. Dangerous vector species can only be found in large numbers, a significant percentage of individuals in a population that feeds on the blood of man, having a sufficiently long season activity and a sufficient number of females surviving to age possible maturation of sporozoites in their body. In Ukraine, the major carriers - Anopheles maculipennis, An. m. messeae, An. m. atroparvus, An. claviger, An. plumbeus, An. hyrcanus. Mosquito species registered in the territory of the Kharkiv region are susceptible to currently known types of human malaria parasites . Moreover, the dominant species in terms of urban landscapes are An.maculipennis and An.messeae . These species possess all the qualities necessary to be considered dangerous malaria vector control. They are well infected with the three main types of human parasites. In the study area , in terms of urban landscapes, gonoaktivnye females occurs within 3

Malaria hotspots defined by clinical malaria, asymptomatic carriage, PCR and vector numbers in a low transmission area on the Kenyan Coast.

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Kangoye, David Tiga; Noor, Abdisalan; Midega, Janet; Mwongeli, Joyce; Mkabili, Dora; Mogeni, Polycarp; Kerubo, Christine; Akoo, Pauline; Mwangangi, Joseph; Drakeley, Chris; Marsh, Kevin; Bejon, Philip; Njuguna, Patricia

2016-04-14

Targeted malaria control interventions are expected to be cost-effective. Clinical, parasitological and serological markers of malaria transmission have been used to detect malaria transmission hotspots, but few studies have examined the relationship between the different potential markers in low transmission areas. The present study reports on the relationships between clinical, parasitological, serological and entomological markers of malaria transmission in an area of low transmission intensity in Coastal Kenya. Longitudinal data collected from 831 children aged 5-17 months, cross-sectional survey data from 800 older children and adults, and entomological survey data collected in Ganze on the Kenyan Coast were used in the present study. The spatial scan statistic test used to detect malaria transmission hotspots was based on incidence of clinical malaria episodes, prevalence of asymptomatic asexual parasites carriage detected by microscopy and polymerase chain reaction (PCR), seroprevalence of antibodies to two Plasmodium falciparum merozoite antigens (AMA1 and MSP1-19) and densities of Anopheles mosquitoes in CDC light-trap catches. There was considerable overlapping of hotspots by these different markers, but only weak to moderate correlation between parasitological and serological markers. PCR prevalence and seroprevalence of antibodies to AMA1 or MSP1-19 appeared to be more sensitive markers of hotspots at very low transmission intensity. These findings may support the choice of either serology or PCR as markers in the detection of malaria transmission hotspots for targeted interventions.

Non-Genetic Determinants of Mosquito Competence for Malaria Parasites

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Lefèvre, Thierry; Vantaux, Amélie; Dabiré, Kounbobr R.; Mouline, Karine; Cohuet, Anna

2013-01-01

Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies. PMID:23818841

Non-genetic determinants of mosquito competence for malaria parasites.

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Thierry Lefèvre

Full Text Available Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control. Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence. Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects. However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions. Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions. We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies. Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies.

Complicated malaria in children and adults from three settings of the Colombian Pacific Coast: A prospective study.

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Myriam Arévalo-Herrera

Full Text Available Complicated malaria remains an important public health problem, particularly in endemic settings where access to health services is limited and consequently malaria fatal outcomes occur. Few publications describing the clinical course and outcomes of complicated malaria in Latin America are found in the literature. This prospective study approached the clinical and laboratory characteristics of hospitalized patients with complicated malaria in different endemic areas of the Colombian Pacific Coast with the aim to provide epidemiological knowledge and guide to further reducing malaria severity and mortality.A prospective, descriptive hospital-based study was conducted in 323 complicated malaria patients (median age 20 years enrolled in Quibdó, Tumaco and Cali between 2014 and 2016. Clinical evaluation was performed and laboratory parameters were assessed during hospitalization. Plasmodium falciparum was the most common parasite species (70%, followed by P. vivax (28%, and mixed malaria (Pf/Pv; 1.9%. Overall, predominant laboratory complications were severe thrombocytopenia (43%, hepatic dysfunction (40%, and severe anaemia (34%. Severe thrombocytopenia was more common in adults (52% regardless of parasite species. Severe anaemia was the most frequent complication in children ≤10 years (72% and was most commonly related to P. vivax infection (p < 0.001; whereas liver dysfunction was more frequent in older patients (54% with P. falciparum (p < 0.001. Two deaths due to P. vivax and P. falciparum each were registered. Treatment provision before recruitment hindered qPCR confirmation of parasite species in some cases.The study identified a high prevalence of complicated malaria in the Pacific Coast, together with more frequent severe anaemia in children infected by P. vivax and hepatic dysfunction in adults with P. falciparum. Results indicated the need for earlier diagnosis and treatment to prevent complications development as well as more

A systematic review of transfusion-transmitted malaria in non-endemic areas.

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Verra, Federica; Angheben, Andrea; Martello, Elisa; Giorli, Giovanni; Perandin, Francesca; Bisoffi, Zeno

2018-01-16

Transfusion-transmitted malaria (TTM) is an accidental Plasmodium infection caused by whole blood or a blood component transfusion from a malaria infected donor to a recipient. Infected blood transfusions directly release malaria parasites in the recipient's bloodstream triggering the development of high risk complications, and potentially leading to a fatal outcome especially in individuals with no previous exposure to malaria or in immuno-compromised patients. A systematic review was conducted on TTM case reports in non-endemic areas to describe the epidemiological characteristics of blood donors and recipients. Relevant articles were retrieved from Pubmed, EMBASE, Scopus, and LILACS. From each selected study the following data were extracted: study area, gender and age of blood donor and recipient, blood component associated with TTM, Plasmodium species, malaria diagnostic method employed, blood donor screening method, incubation period between the infected transfusion and the onset of clinical symptoms in the recipient, time elapsed between the clinical symptoms and the diagnosis of malaria, infection outcome, country of origin of the blood donor and time of the last potential malaria exposure. Plasmodium species were detected in 100 TTM case reports with a different frequency: 45% Plasmodium falciparum, 30% Plasmodium malariae, 16% Plasmodium vivax, 4% Plasmodium ovale, 2% Plasmodium knowlesi, 1% mixed infection P. falciparum/P. malariae. The majority of fatal outcomes (11/45) was caused by P. falciparum whilst the other fatalities occurred in individuals infected by P. malariae (2/30) and P. ovale (1/4). However, non P. falciparum fatalities were not attributed directly to malaria. The incubation time for all Plasmodium species TTM case reports was longer than what expected in natural infections. This difference was statistically significant for P. malariae (p = 0.006). A longer incubation time in the recipient together with a chronic infection at low

Outbreak of Plague in a High Malaria Endemic Region - Nyimba District, Zambia, March-May 2015.

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Sinyange, Nyambe; Kumar, Ramya; Inambao, Akatama; Moonde, Loveness; Chama, Jonathan; Banda, Mapopa; Tembo, Elliot; Nsonga, Beron; Mwaba, John; Fwoloshi, Sombo; Musokotwane, Kebby; Chizema, Elizabeth; Kapin'a, Muzala; Hang'ombe, Benard Mudenda; Baggett, Henry C; Hachaambwa, Lottie

2016-08-12

Outbreaks of plague have been recognized in Zambia since 1917 (1). On April 10, 2015, Zambia's Ministry of Health was notified by the Eastern Provincial Medical Office of possible bubonic plague cases in Nyimba District. Eleven patients with acute fever and cervical lymphadenopathy had been evaluated at two rural health centers during March 28-April 9, 2015; three patients died. To confirm the outbreak and develop control measures, the Zambia Ministry of Health's Field Epidemiology Training Program (ZFETP) conducted epidemiologic and laboratory investigations in partnership with the University of Zambia's schools of Medicine and Veterinary Medicine and the provincial and district medical offices. Twenty-one patients with clinically compatible plague were identified, with symptom onset during March 26-May 5, 2015. The median age was 8 years, and all patients were from the same village. Blood specimens or lymph node aspirates from six (29%) patients tested positive for Yersinia pestis by polymerase chain reaction (PCR). There is an urgent need to improve early identification and treatment of plague cases. PCR is a potential complementary tool for identifying plague, especially in areas with limited microbiologic capacity. Twelve (57%) patients, including all six with PCR-positive plague and all three who died, also tested positive for malaria by rapid diagnostic test (RDT). Plague patients coinfected with malaria might be misdiagnosed as solely having malaria, and appropriate antibacterial treatment to combat plague might not be given, increasing risk for mortality. Because patients with malaria might be coinfected with other pathogens, broad spectrum antibiotic treatment to cover other pathogens is recommended for all children with severe malaria, until a bacterial infection is excluded.

The trial detection of malaria sporozoit in field-collected mosquito by immunoradiometric assay in Thailand

International Nuclear Information System (INIS)

Kasemsuth, R.; Asavanich, A.; Sucharit, S.; Vutikes, S.; Vutikes, M.; Patamatum, S.

1988-01-01

The sporozoite rate, species of parasite and vector are important in the epidemiology of malaria. The investigation of sporozoite by dissection and examination under a microscope is time-consuming and it could be done only on freshly killed mosquitoes. Immunoradiometric assay (IRMA) that can detect, identify and quantify malaria sporozoite (Zavala et al., 1982) was therefore applied to detect sporozoite in laboratory-maintained Anopheles dirus and wild-caught mosquitoes. Study on P. falciparum-infected An. dirus showed that the circumsporozoite (CS) antigen was first found in the abdomen on the 10th day post-infection, whilst the sporozoites were examined in salivary glands from day 15 onwards. The malaria infection in wild-caught mosquitoes were investigated in Anopheles spp collected by human baites from three endemic areas in Thailand. Since the sporozoite rate refers to the presence of sporozoite in the salivary gland, then only head-thorax part of the specimens were detected by IRMA to prevent an exaggeration over the true results. It was found that none of mosquitoes collected from Phrae was positive for malaria. Four out of 1243 An. dirus among eight species collected from Chantaburi were positive for P. falciparum with sporozoites ranged from 270 to 3875. Of all ten species collected from Kanchanaburi, two and one out of 3123 An. minimus were positive for P. falciparum and P. vivax with sporozoites found in head-thorax portions were 1880, 2380 and 1026 respectively. It is evident that the IRMA is suitable for the investigation of malaria sporozoites in this region. The application of this technique in the further epidemiological study is in progress

Malaria prophylaxis in the French armed forces: evolution of concepts.

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Touze, J E; Paule, P; Baudon, D; Boutin, J P

2001-01-01

Malaria is still a serious public health problem in the world and control remains a major priority for the approximately 25.000 French troops deployed, mostly on permanent assignment, in malaria transmission regions. Epidemiological surveillance of malaria provides data necessary to assess morbidity, monitor changing patterns of Plasmodium falciparum drug-sensitivity, and evaluate the efficacy of malaria control measures. About 540 cases were observed in 1999 for an incidence of 4.1 p. 100 men. year. Since 1991, strong emphasis has been placed on prophylaxis. In addition to vector control measures and individual protection against mosquito bites (impregnated bednets, protective clothing, application of repellents, and indoor insecticide spraying), drug prophylaxis has been recommended using a combination of 100 mg of chloroquine and 200 mg of proguanil chlorhydrate (CQ + PG) in a single capsule manufactured by the French Health Army Service. Initially this policy led to a significant decrease in malaria cases among French soldiers. However the incidence of malaria rose in 1995 and 1996. This recrudescence was attributed to poor compliance with chemoprophylaxis and to the declining efficacy of the CQ + PG combination. In response to these problems, a new policy was implemented especially in countries where cycloguanil-resistant Plasmodium falciparum incidence rate is increasing. The new chemoprophylactic regimen calls for a personal prescription of mefloquine. Doxycycline monohydrate is used in case of mefloquine contra-indication or intolerance. Combination of CQ + PG delivered in a single capsule remains a suitable chemoprophylactic regimen in Sahel countries as well as Horn of Africa.

Malaria elimination in Haiti by the year 2020: an achievable goal?

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Boncy, Paul Jacques; Adrien, Paul; Lemoine, Jean Frantz; Existe, Alexandre; Henry, Patricia Jean; Raccurt, Christian; Brasseur, Philippe; Fenelon, Natael; Dame, John B; Okech, Bernard A; Kaljee, Linda; Baxa, Dwayne; Prieur, Eric; El Badry, Maha A; Tagliamonte, Massimiliano S; Mulligan, Connie J; Carter, Tamar E; Beau de Rochars, V Madsen; Lutz, Chelsea; Parke, Dana M; Zervos, Marcus J

2015-06-05

Haiti and the Dominican Republic, which share the island of Hispaniola, are the last locations in the Caribbean where malaria still persists. Malaria is an important public health concern in Haiti with 17,094 reported cases in 2014. Further, on January 12, 2010, a record earthquake devastated densely populated areas in Haiti including many healthcare and laboratory facilities. Weakened infrastructure provided fertile reservoirs for uncontrolled transmission of infectious pathogens. This situation results in unique challenges for malaria epidemiology and elimination efforts. To help Haiti achieve its malaria elimination goals by year 2020, the Laboratoire National de Santé Publique and Henry Ford Health System, in close collaboration with the Direction d'Épidémiologie, de Laboratoire et de Recherches and the Programme National de Contrôle de la Malaria, hosted a scientific meeting on "Elimination Strategies for Malaria in Haiti" on January 29-30, 2015 at the National Laboratory in Port-au-Prince, Haiti. The meeting brought together laboratory personnel, researchers, clinicians, academics, public health professionals, and other stakeholders to discuss main stakes and perspectives on malaria elimination. Several themes and recommendations emerged during discussions at this meeting. First, more information and research on malaria transmission in Haiti are needed including information from active surveillance of cases and vectors. Second, many healthcare personnel need additional training and critical resources on how to properly identify malaria cases so as to improve accurate and timely case reporting. Third, it is necessary to continue studies genotyping strains of Plasmodium falciparum in different sites with active transmission to evaluate for drug resistance and impacts on health. Fourth, elimination strategies outlined in this report will continue to incorporate use of primaquine in addition to chloroquine and active surveillance of cases. Elimination of

Change of strategy is required for malaria elimination: a case study in Purworejo District, Central Java Province, Indonesia.

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Murhandarwati, E Elsa Herdiana; Fuad, Anis; Sulistyawati; Wijayanti, Mahardika Agus; Bia, Michael Badi; Widartono, Barandi Sapta; Kuswantoro; Lobo, Neil F; Supargiyono; Hawley, William A

2015-08-16

Malaria has been targeted for elimination from Indonesia by 2030, with varying timelines for specific geographical areas based on disease endemicity. The regional deadline for malaria elimination for Java island, given the steady decrease of malaria cases, was the end of 2015. Purworejo District, a malaria-endemic area in Java with an annual parasite incidence (API) of 0.05 per 1,000 population in 2009, aims to enter this elimination stage. This study documents factors that affect incidence and spatial distribution of malaria in Purworejo, such as geomorphology, topography, health system issues, and identifies potential constraints and challenges to achieve the elimination stage, such as inter-districts coordination, decentralization policy and allocation of financial resources for the programme. Historical malaria data from 2007 to 2011 were collected through secondary data, in-depth interviews and focus group discussions during study year (2010-2011). Malaria cases were mapped using the village-centroid shape file to visualize its distribution with geomorphologic characteristics overlay and spatial distribution of malaria. API in each village in Purworejo and its surrounding districts from 2007 to 2011 was stratified into high, middle or low case incidence to show the spatiotemporal mapping pattern. The spatiotemporal pattern of malaria cases in Purworejo and the adjacent districts demonstrate repeated concentrated occurrences of malaria in specific areas from 2007 to 2011. District health system issues, i.e., suboptimal coordination between primary care and referral systems, suboptimal inter-district collaboration for malaria surveillance, decentralization policy and the lack of resources, especially district budget allocations for the malaria programme, were major constraints for programme sustainability. A new malaria elimination approach that fits the local disease transmission, intervention and political system is required. These changes include timely

Role of Anopheles (Kerteszia bellator as malaria vector in Southeastern Brazil (Diptera: Culicidae

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Oswaldo Paulo Forattini

1999-11-01

Full Text Available New research concerning Anopheles bellator in the southeast of the State of São Paulo, Brazil, are reported. Adult females of this mosquito showed remarkable endophily and endophagy which was even greater than An. cruzii. The epidemiological role of this anopheline as a malaria vector is discussed.

The geography of malaria genetics in the Democratic Republic of Congo: A complex and fragmented landscape

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Carrel, Margaret; Patel, Jaymin; Taylor, Steve M.; Janko, Mark; Mwandagalirwa, Melchior Kashamuka; Tshefu, Antoinette K.; Escalante, Ananias A.; McCollum, Andrea; Alam, Md Tauqeer; Udhayakumar, Venkatachalam; Meshnick, Steven; Emch, Michael

2014-01-01

Understanding how malaria parasites move between populations is important, particularly given the potential for malaria to be reintroduced into areas where it was previously eliminated. We examine the distribution of malaria genetics across seven sites within the Democratic Republic of Congo (DRC) and two nearby countries, Ghana and Kenya, in order to understand how the relatedness of malaria parasites varies across space, and whether there are barriers to the flow of malaria parasites within the DRC or across borders. Parasite DNA was retrieved from dried blood spots from 7 Demographic and Health Survey sample clusters in the DRC. Malaria genetic characteristics of parasites from Ghana and Kenya were also obtained. For each of 9 geographic sites (7 DRC, 1 Ghana and 1 Kenya), a pair-wise RST statistic was calculated, indicating the genetic distance between malaria parasites found in those locations. Mapping genetics across the spatial extent of the study area indicates a complex genetic landscape, where relatedness between two proximal sites may be relatively high (RST > 0.64) or low (RST < 0.05), and where distal sites also exhibit both high and low genetic similarity. Mantel’s tests suggest that malaria genetics differ as geographic distances increase. Principal Coordinate Analysis suggests that genetically related samples are not co-located. Barrier analysis reveals no significant barriers to gene flow between locations. Malaria genetics in the DRC have a complex and fragmented landscape. Limited exchange of genes across space is reflected in greater genetic distance between malaria parasites isolated at greater geographic distances. There is, however, evidence for close genetic ties between distally located sample locations, indicating that movement of malaria parasites and flow of genes is being driven by factors other than distance decay. This research demonstrates the contributions that spatial disease ecology and landscape genetics can make to

Malaria prevalence defined by microscopy, antigen detection, DNA amplification and total nucleic acid amplification in a malaria-endemic region during the peak malaria transmission season.

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Waitumbi, John N; Gerlach, Jay; Afonina, Irina; Anyona, Samuel B; Koros, Joseph N; Siangla, Joram; Ankoudinova, Irina; Singhal, Mitra; Watts, Kate; Polhemus, Mark E; Vermeulen, Nicolaas M; Mahoney, Walt; Steele, Matt; Domingo, Gonzalo J

2011-07-01

To determine the malaria prevalence by microscopy, antigen detection and nucleic acid detection in a defined subpopulation in a Plasmodium falciparum-endemic region during the peak transmission season. Blood specimens were collected in a cross-sectional study involving children aged 5-10 years (n = 195) presenting with acute fever to two clinics in Western Kenya. All specimens underwent microscopy, HRP2 and aldolase antigen detection by enzyme immunoassay (EIA), parasite-specific DNA and total nucleic acid (RNA and DNA) by real-time PCR (qPCR) and reverse-transcriptase PCR (qRT-PCR). Microscopy detected 65/195 cases of malaria infection [95% confidence interval (CI) 52-78]. HRP2 and aldolase EIA had similar sensitivity levels detecting antigen in 65/195 (95% CI, 52-78) and 57/195 (95% CI, 45-70) cases. Discordants in antigen detection vs. microscopy occurred at Detection of total nucleic acid allowed a 3 log lower limit of detection than just DNA detection by real-time PCR in vitro. In clinical specimens, 114/195 (95% CI, 100-127) were qPCR positive (DNA), and 187/195 (95% CI, 179-191) were qRT-PCR positive (DNA plus RNA). The prevalence of submicroscopic malaria infection was significantly higher when detecting total nucleic acid than just DNA in this outpatient population during the high transmission season. Defining standards for submicroscopic infection will be important for control programmes, diagnostics development efforts and molecular epidemiology studies. © 2011 Blackwell Publishing Ltd.

Utility of health facility-based malaria data for malaria surveillance.

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Yaw A Afrane

Full Text Available Currently, intensive malaria control programs are being implemented in Africa to reduce the malaria burden. Clinical malaria data from hospitals are valuable for monitoring trends in malaria morbidity and for evaluating the impacts of these interventions. However, the reliability of hospital-based data for true malaria incidence is often questioned because of diagnosis accuracy issues and variation in access to healthcare facilities among sub-groups of the population. This study investigated how diagnosis and treatment practices of malaria cases in hospitals affect reliability of hospital malaria data.The study was undertaken in health facilities in western Kenya. A total of 3,569 blood smears were analyzed after being collected from patients who were requested by clinicians to go to the hospital's laboratory for malaria testing. We applied several quality control measures for clinical malaria diagnosis. We compared our slide reading results with those from the hospital technicians. Among the 3,390 patients whose diagnoses were analyzed, only 36% had clinical malaria defined as presence of any level of parasitaemia and fever. Sensitivity and specificity of clinicians' diagnoses were 60.1% (95% CI: 61.1-67.5 and 75.0% (95% CI: 30.8-35.7, respectively. Among the 980 patients presumptively treated with an anti-malarial by the clinicians without laboratory diagnosis, only 47% had clinical malaria.These findings revealed substantial over-prescription of anti-malarials and misdiagnosis of clinical malaria. More than half of the febrile cases were not truly clinical malaria, but were wrongly diagnosed and treated as such. Deficiency in malaria diagnosis makes health facility data unreliable for monitoring trends in malaria morbidity and for evaluating impacts of malaria interventions. Improving malaria diagnosis should be a top priority in rural African health centers.

ANALISIS SPASIAL PADA KEJADIAN LUAR BIASA (KLB MALARIA DI DESA PANUSUPAN KECAMATAN REMBANG DAN DESA SIDAREJA KECAMATAN KALIGONDANG KABUPATEN PURBALINGGA

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Widiarti Widiarti

2015-01-01

Full Text Available AbstrakMalaria seringkali muncul pada kejadian luar biasa (KLB maupun peningkatan kasus baik di Jawa maupun di luar Jawa. Dilaporkannya peningkatan kasus atau KLB malaria di Kabupaten Purbalingga menimbulkan pemikiran faktor-faktor apa yang mempengaruhi terjadinya KLB malaria. Tujuan penelitian adalah analisis spasial kasus malaria, konfirmasi vektor yang berperan dalam penularan malaria dan bioekologi nyamuk tersangka vektor. Lokasi penelitian di Desa Panusupan Kecamatan Rembang dan Desa Sidareja Kecamatan Kaligondang Kabupaten Purbalingga Jawa Tengah. Konfirmasi vektor dilakukan dengan elisa sporozoit dari semua nyamuk Anopheles sp yang diperoleh. Analisis kasus malaria digunakan metoda GIS dan dilanjutkan uji spatially weighted regression (spatial error model dengan GeoDa. Survei entomologi dilakukan sesuai standart penangkapan nyamuk oleh WHO. Hasil penelitian diperoleh informasi bahwa berdasarkan  elisa  sporozoit,  vektor  yang  berperan  di  Desa  Panusupan  Kecamatan  Rembang  adalah Anopheles maculatus hasil penangkapan hinggap pada manusia diluar rumah pada jam 18.00. Kejadian luar biasa malaria di Kabupaten Purbalingga, semula kasus import namun karena keberadaan vektor (daerah reseptif, sehingga terjadi penularan lokal. Analisis spasial kasus malaria di kedua desa mengelompok dan berdekatan dengan habitat perkembangbiakan An. maculatus yaitu ditepi aliran sungai. Mencermati vektor yang berperan di daerah KLB adalah An. maculatus dengan aktivitas sore sampai malam hari, maka perlu diinformasikan kepada masyarakat agar menjaga tidak kontak dengan nyamuk dan melindungi masyarakat dengan kelambu berinsektisida yang mempunyai daya lindung lama (LLIN sehingga dapat mengurangi terjadinya penularan.Kata Kunci : analisis spasial, KLB, Anopheles maculatus dan malariaAbstractMalaria outbreak or increase cases has came up very often inside or outside of Java Island. The increase malaria cases from Purbalingga Regency is reported

Adaptive geostatistical sampling enables efficient identification of malaria hotspots in repeated cross-sectional surveys in rural Malawi.

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Alinune N Kabaghe

Full Text Available In the context of malaria elimination, interventions will need to target high burden areas to further reduce transmission. Current tools to monitor and report disease burden lack the capacity to continuously detect fine-scale spatial and temporal variations of disease distribution exhibited by malaria. These tools use random sampling techniques that are inefficient for capturing underlying heterogeneity while health facility data in resource-limited settings are inaccurate. Continuous community surveys of malaria burden provide real-time results of local spatio-temporal variation. Adaptive geostatistical design (AGD improves prediction of outcome of interest compared to current random sampling techniques. We present findings of continuous malaria prevalence surveys using an adaptive sampling design.We conducted repeated cross sectional surveys guided by an adaptive sampling design to monitor the prevalence of malaria parasitaemia and anaemia in children below five years old in the communities living around Majete Wildlife Reserve in Chikwawa district, Southern Malawi. AGD sampling uses previously collected data to sample new locations of high prediction variance or, where prediction exceeds a set threshold. We fitted a geostatistical model to predict malaria prevalence in the area.We conducted five rounds of sampling, and tested 876 children aged 6-59 months from 1377 households over a 12-month period. Malaria prevalence prediction maps showed spatial heterogeneity and presence of hotspots-where predicted malaria prevalence was above 30%; predictors of malaria included age, socio-economic status and ownership of insecticide-treated mosquito nets.Continuous malaria prevalence surveys using adaptive sampling increased malaria prevalence prediction accuracy. Results from the surveys were readily available after data collection. The tool can assist local managers to target malaria control interventions in areas with the greatest health impact and is

EFFECTS OF ECONOMIC BEHAVIOUR AND PEIPLE MIGRANTION ON THE EPIDEMIOLOGY OF MALARIA : A MODEL BASED STUDY

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Sajal Bhattacharya

2006-11-01

Full Text Available The objective of the paper is to study the socio economic behaviour of migrant labourers in the context of the control of the diseases like malaria. The paper, therefore, makes a model and survey based study in the city of Kolkata, India to drive home the point that low income of people particularly of the migrant workers can be a major hurdle in the malaria control programme. The paper first looks at the economic behaviour pattern theoretically from neo-classical optimization exercise and the tries to test the theoetical result empirically from primary survey. The theoritical model gives the result that low income people is likely to take less rest and discontinue medical tratment. Since migrant workers of less developed counties are usually low-income people, pur model suggests that migrant workers will have incomplete treatment and their migration even before complete recovery may contribute to spread of the disease. We hage empirically tested the model econometrically by a logit model, and derived the result that migrat workers do take less rest and discontinue treatment becouse of economic compulsion. Thus the data support the result of the theoretical model and refeals a behafiour pattern, conducive to spread of malaria infection. The paper drives some policy prescriptions on the basis of these studies like infurance support, health survillance of migrant population as a part of integrated malaria control programme.

Hari Malaria Sedunia 2013 Investasi Di Masa Depan. Taklukkan Malaria

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Hotnida Sitorus

2017-02-01

Full Text Available Abstract Malaria is still the global health problems, World Health Organization estimates that malaria causes death of approximately 660.000 in 2010, most of the age of the children in the region of sub-Saharan Africa. World Malaria Day 2013 assigned the theme “Invest in the future. Defeat malaria”. It takes political will and collective action to jointly combat malaria through malaria elimination. Needed more new donors to be involved in global partnerships against malaria. These partnerships exist, one of which is support of funding or facility for malaria endemic countries which do not have sufficient resources to control malaria. A lot of effort has been done or is still in the development stage. The use of long-lasting insecticidal nets appropriately can reduce malaria cases. The use of rapid diagnostic test, especially in remote areas and health facility with no microscopy, is very beneficial for patients to get prompt treatment. The control of malaria through integrated vector management is a rational decision making process to optimize the use of resources in the control of vector. Sterile insect technique has a promising prospect and expected to replace the role of chemical insecticides that have negative impact both on the environment and target vector (resistance. Keywords: Malaria, long-lasting insecticidal nets, rapid diagnostic test Abstrak Malaria masih menjadi masalah kesehatan dunia, Organisasi Kesehatan Dunia (WHO memperkirakan malaria menyebabkan kurang lebih 660.000 kematian pada tahun 2010, kebanyakan usia anak-anak di wilayah Sub-Sahara Afrika. Pada peringatan hari malaria dunia tahun 2013 ditetapkan tema “Investasi di masa depan. Taklukkan malaria”. Dibutuhkan kemauan politik dan tindakan kolektif untuk bersama-sama memerangi malaria melalui gerakan eliminasi malaria. Diperlukan lebih banyak donor baru untuk turut terlibat dalam kemitraan global melawan malaria. Wujud kemitraan tersebut salah satunya adalah

[Vectors of malaria: biology, diversity, prevention, and individual protection].

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Pages, F; Orlandi-Pradines, E; Corbel, V

2007-03-01

Only the Anopheles mosquitoes are implicated in the transmission of malaria. Among the numerous species of anopheles, around fifty are currently involved in the transmission. 20 are responsible for most of the transmission in the world. The diversity of behavior between species and in a single species of anopheles as well as climatic and geographical conditions along with the action of man on the environment condition the man vector contact level and the various epidemiological aspects of malaria. The anopheles are primarily rural mosquitoes and are less likely to be found in city surroundings in theory. But actually, the adaptation of some species to urban surroundings and the common habit of market gardening in big cities or in the suburbs is responsible for the de persistence of Anopheles populations in town. Except for South-East Asia, urban malaria has become a reality. The transmission risk of malaria is heterogeneous and varies with time. There is a great variation of risk within a same country, a same zone, and even within a few kilometers. The transmission varies in time according to seasons but also according to years and to the level of climatic events. For the traveler, prevention at any time relies on the strict application of individual protection, as well in rural than in urban surroundings.

Plasmodium vivax congenital malaria in an area of very low endemicity in Guatemala: implications for clinical and epidemiological surveillance in a malaria elimination context

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Castellanos María Eugenia

2012-12-01

Full Text Available Abstract This is a report of the first Plasmodium vivax congenital malaria case in Guatemala and the first case in Latin America with genotypical, histological and clinical characterization. The findings show that maternal P. vivax infection still occurs in areas that are in the pathway towards malaria elimination, and can be associated with detrimental health effects for the neonate. It also highlights the need in very low transmission areas of not only maintaining, but increasing awareness of the problem and developing surveillance strategies, based on population risk, to detect the infection especially in this vulnerable group of the population.

Emerging vector-borne zoonoses: eco-epidemiology and public health implications in India.

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Dhiman, Ramesh C

2014-01-01

The diseases originating from animals or associated with man and animals are remerging and have resulted in considerable morbidity and mortality. The present review highlights the re-emergence of emerging mainly zoonotic diseases like chikungunya, scrub typhus, and extension of spatial distribution of cutaneous leishmaniasis from western Rajasthan to Himachal Pradesh, Kerala, and Haryana states; West Nile virus to Assam, and non-endemic areas of Japanese encephalitis (JE) like Maharashtra and JE to Delhi; Crimean-Congo hemorrhagic fever making inroads in Ahmedabad; and reporting fifth parasite of human malaria with possibility of zoonosis have been highlighted, which necessitates further studies for prevention and control. Emphasis has been given on understanding the ecology of reservoir hosts of pathogen, micro niche of vector species, climatic, socioeconomic risk factors, etc. Development of facilities for diagnosis of virus from insects, reservoirs, and human beings (like BSL4, which has been established in NIV, Pune), awareness about symptoms of new emerging viral and other zoonotic diseases, differential diagnosis, risk factors (climatic, ecological, and socioeconomic) and mapping of disease-specific vulnerable areas, and mathematical modeling for projecting epidemiological scenario is needed for preparedness of public health institutes. It is high time to understand the ecological link of zoonotic or anthroponotic diseases for updated risk maps and epidemiological knowledge for effective preventive and control measures. The public health stakeholders in India as well as in Southeast Asia should emphasize on understanding the eco-epidemiology of the discussed zoonotic diseases for taking preventive actions.

Challenges for modelling spatio-temporal variations of malaria risk in Malawi

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Lowe, R.; Chirombo, J.; Tompkins, A. M.

2012-04-01

the unobserved confounding factors that influence malaria, which are not accounted for using measured covariates, a negative binomial generalised linear mixed model (GLMM) is adopted, which includes structured and unstructured spatial and temporal random effects. The parameters in this spatio-temporal Bayesian hierarchical model are estimated using Markov Chain Monte Carlo (MCMC). This allows posterior predictive distributions for disease risk to be derived for each spatial location and time period. A novel visualisation technique is then used to display seasonal probabilistic forecasts of malaria risk, derived from the developed model using pre-defined risk category thresholds, on a map. This technique allows decision makers to identify areas where the model predicts with certainty a particular malaria risk category (high, medium or low); in order to effectively target limited resources to those districts most at risk for a given season.

A threshold concentration of anti-merozoite antibodies is required for protection from clinical episodes of malaria

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Murungi, Linda M; Kamuyu, Gathoni; Lowe, Brett

2013-01-01

Antibodies to selected Plasmodium falciparum merozoite antigens are often reported to be associated with protection from malaria in one epidemiological cohort, but not in another. Here, we sought to understand this paradox by exploring the hypothesis that a threshold concentration of antibodies i...

Serologic markers for detecting malaria in areas of low endemicity, Somalia, 2008.

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Bousema, Teun; Youssef, Randa M; Cook, Jackie; Cox, Jonathan; Alegana, Victor A; Amran, Jamal; Noor, Abdisalan M; Snow, Robert W; Drakeley, Chris

2010-03-01

Areas in which malaria is not highly endemic are suitable for malaria elimination, but assessing transmission is difficult because of lack of sensitivity of commonly used methods. We evaluated serologic markers for detecting variation in malaria exposure in Somalia. Plasmodium falciparum or P. vivax was not detected by microscopy in cross-sectional surveys of samples from persons during the dry (0/1,178) and wet (0/1,128) seasons. Antibody responses against P. falciparum or P. vivax were detected in 17.9% (179/1,001) and 19.3% (202/1,044) of persons tested. Reactivity against P. falciparum was significantly different between 3 villages (p<0.001); clusters of seroreactivity were present. Distance to the nearest seasonal river was negatively associated with P. falciparum (p = 0.028) and P. vivax seroreactivity (p = 0.016). Serologic markers are a promising tool for detecting spatial variation in malaria exposure and evaluating malaria control efforts in areas where transmission has decreased to levels below the detection limit of microscopy.

Population hemoglobin mean and anemia prevalence in Papua New Guinea: new metrics for defining malaria endemicity?

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Nicolas Senn

Full Text Available BACKGROUND: The hypothesis is that hemoglobin-based metrics are useful tools for estimating malaria endemicity and for monitoring malaria control strategies. The aim of this study is to compare population hemoglobin mean and anemia prevalence to established indicators of malaria endemicity, including parasite rates, rates of enlarged spleens in children, and records of (presumptive malaria diagnosis among populations living with different levels of malaria transmission. METHODOLOGY/PRINCIPAL FINDINGS: Convenience sample, multisite cross-sectional household surveys conducted in Papua New Guinea. Correlations (r(2 between population Hb mean and anemia prevalence and altitude, parasite rate, and spleen rate were investigated in children ages 2 to 10 years, and in the general population; 21,664 individuals from 156 different communities were surveyed. Altitude ranged from 5 to 2120 meters. In young children, correlations between altitude and parasite rate, population Hb mean, anemia prevalence, and spleen rate were high (r(2: -0.77, 0.73, -0.81, and -0.68; p1500 m (p<0.001. CONCLUSIONS/SIGNIFICANCE: In PNG, where Plasmodium vivax accounts for an important part of all malaria infections, population hemoglobin mean and anemia prevalence correlate well with altitude, parasite, and spleen rates. Hb measurement is simple and affordable, and may be a useful new tool, alone or in association with other metrics, for estimating malaria endemicity and monitoring effectiveness of malaria control programs. Further prospective studies in areas with different malaria epidemiology and different factors contributing to the burden of anemia are warranted to investigate the usefulness of Hb metrics in monitoring malaria transmission intensity.

Simulating the spread of malaria using a generic transmission model for mosquito-borne infectious diseases

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Kon, Cynthia Mui Lian; Labadin, Jane

2016-06-01

Malaria is a critical infection caused by parasites which are spread to humans through mosquito bites. Approximately half of the world's population is in peril of getting infected by malaria. Mosquito-borne diseases have a standard behavior where they are transmitted in the same manner, only through vector mosquito. Taking this into account, a generic spatial-temporal model for transmission of multiple mosquito-borne diseases had been formulated. Our interest is to reproduce the actual cases of different mosquito-borne diseases using the generic model and then predict future cases so as to improve control and target measures competently. In this paper, we utilize notified weekly malaria cases in four districts in Sarawak, Malaysia, namely Kapit, Song, Belaga and Marudi. The actual cases for 36 weeks, which is from week 39 in 2012 to week 22 in 2013, are compared with simulations of the generic spatial-temporal transmission mosquito-borne diseases model. We observe that the simulation results display corresponding result to the actual malaria cases in the four districts.

Systemic Modeling for the diagnosis of the interaction climate-malaria in Colombia, application during El Nino 1997-1998 and La Nina 1998-2000

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Ruiz, Daniel; Poveda, German; Quinonez, Martha Lucia; Velez Ivan, Dario; Rojas, William; Zuluaga, Juan Santiago

2002-01-01

A vector-borne disease model has been developed to represent the entomological, epidemiological and climatic interactions of malaria transmission conductive to disease outbreaks in Nuqui prone-region, Choco province, along the pacific Colombian coast. Considering breeding place availability model and several predator-prey-food models allow us to represent the vectorial densities fluctuations observed during the field's campaigns. The comprehensive model has been applied to represent malaria incidence during the period Nov/1997-Feb/2001 (1200 days simulation period), when both El Nino and la Nina events strongly affected the hydro-climatology of Colombia. The model has been run for observed climatic patterns such as mean daily temperatures, total daily precipitation records, and mean daily relative humidities gathered by a nearby climatological station. Diverse temperature scenarios have been considered to deepen the understanding of the entomological-climatic linkages conductive to malaria outbreaks. Sensitivity analysis and instabilities cases have been also studied during the experimentation-validation processes. Obtained results allow us to conclude that the model constitutes a promising tool to deepen the understanding of the ecological, entomological, and epidemiological linkages conductive to malaria outbreaks

Change in composition of the Anopheles gambiae complex and its possible implications for the transmission of malaria and lymphatic filariasis in north-eastern Tanzania

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Derua, Yahya A; Alifrangis, Michael; Hosea, Kenneth M

2012-01-01

ABSTRACT: BACKGROUND: A dramatic decline in the incidence of malaria due to Plasmodium falciparum infection in coastal East Africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control. ...... to differences in biology and vectorial capacity of the An. gambiae s.l. complex the change in sibling species composition will have important implications for the epidemiology and control of malaria and lymphatic filariasis in the study area.......ABSTRACT: BACKGROUND: A dramatic decline in the incidence of malaria due to Plasmodium falciparum infection in coastal East Africa has recently been reported to be paralleled (or even preceded) by an equally dramatic decline in malaria vector density, despite absence of organized vector control...

Malaria.

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Dupasquier, Isabelle

1989-01-01

Malaria, the greatest pandemia in the world, claims an estimated one million lives each year in Africa alone. While it may still be said that for the most part malaria is found in what is known as the world's poverty belt, cases are now frequently diagnosed in western countries. Due to resistant strains of malaria which have developed because of…

Tissue-specific features of the X chromosome and nucleolus spatial dynamics in a malaria mosquito, Anopheles atroparvus.

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Bondarenko, Semen M; Artemov, Gleb N; Sharakhov, Igor V; Stegniy, Vladimir N

2017-01-01

Spatial organization of chromosome territories is important for maintenance of genomic stability and regulation of gene expression. Recent studies have shown tissue-specific features of chromosome attachments to the nuclear envelope in various organisms including malaria mosquitoes. However, other spatial characteristics of nucleus organization, like volume and shape of chromosome territories, have not been studied in Anopheles. We conducted a thorough analysis of tissue-specific features of the X chromosome and nucleolus volume and shape in follicular epithelium and nurse cells of the Anopheles atroparvus ovaries using a modern open-source software. DNA of the polytene X chromosome from ovarian nurse cells was obtained by microdissection and was used as a template for amplification with degenerate oligo primers. A fluorescently labeled X chromosome painting probe was hybridized with formaldehyde-fixed ovaries of mosquitoes using a 3D-FISH method. The nucleolus was stained by immunostaining with an anti-fibrillarin antibody. The analysis was conducted with TANGO-a software for a chromosome spatial organization analysis. We show that the volume and position of the X chromosome have tissue-specific characteristics. Unlike nurse cell nuclei, the growth of follicular epithelium nuclei is not accompanied with the proportional growth of the X chromosome. However, the shape of the X chromosome does not differ between the tissues. The dynamics of the X chromosome attachment regions location is tissue-specific and it is correlated with the process of nucleus growth in follicular epithelium and nurse cells.

Achievement of malaria pre-elimination in Cape Verde according to the data collected from 2010 to 2016.

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DePina, Adilson José; Niang, El Hadji Amadou; Barbosa Andrade, Alex Jailson; Dia, Abdoulaye Kane; Moreira, Antonio; Faye, Ousmane; Seck, Ibrahima

2018-06-19

Malaria, despite being preventable and treatable, continues to be a major public health problem worldwide. The archipelago nation of Cape Verde is in a malaria pre-elimination phase with the highest potential to achieve the target goal of elimination in 2020. Nationwide malaria epidemiological data were obtained from the Cape Verde health information system that includes the individual malaria case notification system from all of the country's health structures. Each case is reported to the surveillance service then to the National Malaria Control Programme, which allowed for compilation in the national malaria case database. The database was analysed to assess the origin of the malaria cases, and incidence was calculated from 2010 to 2016 by sex and age. The health centre, health district and month of diagnosis were evaluated, as well as the sex and the age of the patients, allowing a direct descriptive analysis of national data to provide an up-to-date malaria epidemiological profile of the country. Malaria cases were classified as imported or indigenous, and then, geographical analyses were performed using a unique Geographical National Code with Quantum Geographic Information System 2.16.2 software to map the cases by municipalities. The overall temporal evolution of cases was analysed to assess their monthly and yearly variations from 2010 to 2016. Malaria is unstable in Cape Verde, with inter-annual variation and the majority of infections occurring in adult males (> 20 years). The indigenous cases are restricted to Santiago (96%) and Boavista (4%), while imported cases were recorded in all the nine inhabited islands, originating from neighbouring countries with ongoing malaria transmission; from Lusophone countries (25% from Angola, 25% from Guinea-Bissau), followed by the Republic of Senegal (12%) and Equatorial Guinea (10%). In 2010-2012, more imported (93 cases) than indigenous cases (26 cases) were observed; conversely, in 2013 and 2014, more

Elevated dry-season malaria prevalence associated with fine-scale spatial patterns of environmental risk: a case-control study of children in rural Malawi.

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Townes, Lindsay R; Mwandama, Dyson; Mathanga, Don P; Wilson, Mark L

2013-11-11

Understanding the role of local environmental risk factors for malaria in holo-endemic, poverty-stricken settings will be critical to more effectively implement- interventions aimed at eventual elimination. Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children Authority (TA) regions dominated by small-scale agriculture. Ten villages were randomly selected from TA Sitola (n = 6) and Nsamala (n = 4). Within each village, during June to August 2011, a census was conducted of all households with children under-five and recorded their locations with a geographic position system (GPS) device. At each participating house, a nurse administered a malaria rapid diagnostic test (RDT) to children under five years of age, and a questionnaire to parents. Environmental data were collected for each house, including land cover within 50-m radius. Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models, including multivariate logistic regression (MLR) and multi-level multivariate logistic regression (MLLR). Spatial clustering of RDT status, environmental factors, and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi* statistic. Of 390 children enrolled from six villages in Sitola (n = 162) and four villages in Nsamala (n = 228), 45.6% tested positive (n = 178) for Plasmodium infection by RDT. The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture ( 2.58, p < 0.01) predominantly within TA Sitola, while residuals from MLLR showed no such clustering. This study provides evidence for significant, dry-season heterogeneity of malaria prevalence strongly linked to peridomestic land use, and particularly of elevated risk associated with nearby crop production.

The use of insecticide-treated nets for reducing malaria morbidity among children aged 6-59 months, in an area of high malaria transmission in central Côte d'Ivoire

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Nsanzabana Christian

2010-09-01

Full Text Available Abstract Background Long-lasting insecticidal nets (LLINs are an important tool for controlling malaria. Much attention has been devoted to determine both the effect of LLINs on the reduction of Plasmodium infection rate and on clinically-confirmed malaria cases in sub-Saharan Africa. We carried out an epidemiological study to investigate whether LLINs impact on Plasmodium prevalence rate and the proportion of clinically-confirmed malaria cases, in five villages in the district of Toumodi, central Côte d'Ivoire. Methods From April 2007 to November 2008, a community-based malaria control programme was implemented in the study villages, which involved large-scale distribution of LLINs, and training and sensitization activities within the community. We determined the effect of this programme on Plasmodium prevalence rate, clinically-confirmed malaria cases and proportion of high parasitaemia rates in children aged 6-59 months through a series of cross-sectional surveys starting in April 2007 and repeated once every 6 months. Results We observed a significant decrease in the mean P. falciparum prevalence rate from April 2007 to April 2008 (p = 0.029. An opposite trend was observed from November 2007 to November 2008 when P. falciparum prevalence rate increased significantly (p = 0.003. Highly significant decreases in the proportions of clinical malaria cases were observed between April 2007 and April 2008 (p Conclusions Large-scale distribution of LLINs, accompanied by training and sensitization activities, significantly reduced Plasmodium prevalence rates among young children in the first year of the project, whereas overall clinical malaria rates dropped over the entire 18-month project period. A decrease in community motivation to sleep under bed nets, perhaps along with changing patterns of malaria transmission, might explain the observed increase in the Plasmodium prevalence rate between November 2007 and November 2008.

Cost Effectiveness Analysis of Optimal Malaria Control Strategies in Kenya

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Gabriel Otieno

2016-03-01

which produces health improvements in the most cost effective way for different epidemiological zones. This offers the good value for money for the public health programs and can guide in the allocation of malaria control resources for the post-2015 malaria eradication strategies and the achievement of the Sustainable Development Goals.

A refined estimate of the malaria burden in Niger

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Doudou Maimouna

2012-03-01

malaria cases by biological diagnosis methods, to increase the accuracy of the malaria indicators used in monitoring and evaluation processes and to improve patient care in the more remote areas of Niger. This country extends over a large range of latitudes, resulting in the existence of three major bioclimatic zones determining vector distribution and endemicity. Conclusion This survey showed that the number of cases of presumed malaria reported in health centres in Niger is largely overestimated. The results highlight inadequacies in the description of the malaria situation and disease risk in Niger, due to the over-diagnosis of malaria in patients with simple febrile illness. They point out the necessity of confirming all cases of suspected malaria by biological diagnosis methods and the need to take geographic constraints into account more effectively, to improve malaria control and to adapt the choice of diagnostic method to the epidemiological situation in the area concerned. Case confirmation will thus also require a change in behaviour, through the training of healthcare staff, the introduction of quality control, greater supervision of the integrated health centres, the implementation of good clinical practice and a general optimization of the use of available diagnostic methods.

Malaria vector species in Colombia: a review

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James Montoya-Lerma

2011-08-01

Full Text Available Here we present a comprehensive review of the literature on the vectorial importance of the major Anopheles malaria vectors in Colombia. We provide basic information on the geographical distribution, altitudinal range, immature habitats, adult behaviour, feeding preferences and anthropophily, endophily and infectivity rates. We additionally review information on the life cycle, longevity and population fluctuation of Colombian Anopheles species. Emphasis was placed on the primary vectors that have been epidemiologically incriminated in malaria transmission: Anopheles darlingi, Anopheles albimanus and Anopheles nuneztovari. The role of a selection of local, regional or secondary vectors (e.g., Anopheles pseudopunctipennis and Anopheles neivai is also discussed. We highlight the importance of combining biological, morphological and molecular data for the correct taxonomical determination of a given species, particularly for members of the species complexes. We likewise emphasise the importance of studying the bionomics of primary and secondary vectors along with an examination of the local conditions affecting the transmission of malaria. The presence and spread of the major vectors and the emergence of secondary species capable of transmitting human Plasmodia are of great interest. When selecting control measures, the anopheline diversity in the region must be considered. Variation in macroclimate conditions over a species' geographical range must be well understood and targeted to plan effective control measures based on the population dynamics of the local Anopheles species.

Emerging Vector borne zoonoses: eco-­epidemiology and public health implications in India

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Ramesh C Dhiman

2014-09-01

Full Text Available The diseases originating from animals or associated with man and animals are remerging and have resulted in considerable morbidity and mortality. The present review highlights the re-emergence of emerging mainly zoonotic diseases like chikungunya, scrub typhus, extension of spatial distribution of cutaneous leishmaniasis from Western Rajasthan to Himachal Pradesh, Kerala, and Haryana states; West Nile virus to Assam, and non- endemic areas of JE like Maharashtra and JE to Delhi; Crimean Congo Hemorrhagic Fever making inroads in Ahmedabad; reporting fifth parasite of human malaria with possibility of zoonosis have been highlighted which necessitates further studies for prevention and control. Emphasis has been given on understanding the ecology of reservoir hosts of pathogen, micro niche of vector species, climatic, socioeconomic risk factors etc. Development of facilities for diagnosis of virus from insects, reservoirs and human beings (like BSL4 which has been established in NIV, Pune, awareness about symptoms of new emerging viral and other zoonotic diseases, differential diagnosis, risk factors (Climatic, ecological and socioeconomic and mapping of disease specific vulnerable areas, mathematical modeling for projecting epidemiological scenario, are needed for preparedness of public health institutes. It is high time to understand the ecological link of zoonotic or anthroponotic diseases for updated risk maps and epidemiological knowledge for effective preventive and control measures. The public health stakeholders in India as well as in south East Asia should emphasize on understanding the eco-epidemiology of the discussed zoonotic diseases for taking preventive actions.

About Malaria

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... Emergency Consultations, and General Public. Contact Us About Malaria Recommend on Facebook Tweet Share Compartir Malaria is ... from sub-Saharan Africa and South Asia. About Malaria Topics FAQs Frequently Asked Question, Incubation period, uncomplicated & ...

A regional-scale, high resolution dynamical malaria model that accounts for population density, climate and surface hydrology.

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Tompkins, Adrian M; Ermert, Volker

2013-02-18

The relative roles of climate variability and population related effects in malaria transmission could be better understood if regional-scale dynamical malaria models could account for these factors. A new dynamical community malaria model is introduced that accounts for the temperature and rainfall influences on the parasite and vector life cycles which are finely resolved in order to correctly represent the delay between the rains and the malaria season. The rainfall drives a simple but physically based representation of the surface hydrology. The model accounts for the population density in the calculation of daily biting rates. Model simulations of entomological inoculation rate and circumsporozoite protein rate compare well to data from field studies from a wide range of locations in West Africa that encompass both seasonal endemic and epidemic fringe areas. A focus on Bobo-Dioulasso shows the ability of the model to represent the differences in transmission rates between rural and peri-urban areas in addition to the seasonality of malaria. Fine spatial resolution regional integrations for Eastern Africa reproduce the malaria atlas project (MAP) spatial distribution of the parasite ratio, and integrations for West and Eastern Africa show that the model grossly reproduces the reduction in parasite ratio as a function of population density observed in a large number of field surveys, although it underestimates malaria prevalence at high densities probably due to the neglect of population migration. A new dynamical community malaria model is publicly available that accounts for climate and population density to simulate malaria transmission on a regional scale. The model structure facilitates future development to incorporate migration, immunity and interventions.

Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal

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Ibrahima Diouf

2017-09-01

Full Text Available The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM, driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be

Comparison of Malaria Simulations Driven by Meteorological Observations and Reanalysis Products in Senegal.

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Diouf, Ibrahima; Rodriguez-Fonseca, Belen; Deme, Abdoulaye; Caminade, Cyril; Morse, Andrew P; Cisse, Moustapha; Sy, Ibrahima; Dia, Ibrahima; Ermert, Volker; Ndione, Jacques-André; Gaye, Amadou Thierno

2017-09-25

The analysis of the spatial and temporal variability of climate parameters is crucial to study the impact of climate-sensitive vector-borne diseases such as malaria. The use of malaria models is an alternative way of producing potential malaria historical data for Senegal due to the lack of reliable observations for malaria outbreaks over a long time period. Consequently, here we use the Liverpool Malaria Model (LMM), driven by different climatic datasets, in order to study and validate simulated malaria parameters over Senegal. The findings confirm that the risk of malaria transmission is mainly linked to climate variables such as rainfall and temperature as well as specific landscape characteristics. For the whole of Senegal, a lag of two months is generally observed between the peak of rainfall in August and the maximum number of reported malaria cases in October. The malaria transmission season usually takes place from September to November, corresponding to the second peak of temperature occurring in October. Observed malaria data from the Programme National de Lutte contre le Paludisme (PNLP, National Malaria control Programme in Senegal) and outputs from the meteorological data used in this study were compared. The malaria model outputs present some consistencies with observed malaria dynamics over Senegal, and further allow the exploration of simulations performed with reanalysis data sets over a longer time period. The simulated malaria risk significantly decreased during the 1970s and 1980s over Senegal. This result is consistent with the observed decrease of malaria vectors and malaria cases reported by field entomologists and clinicians in the literature. The main differences between model outputs and observations regard amplitude, but can be related not only to reanalysis deficiencies but also to other environmental and socio-economic factors that are not included in this mechanistic malaria model framework. The present study can be considered as a

Attacking the mosquito on multiple fronts: Insights from the Vector Control Optimization Model (VCOM for malaria elimination.

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Samson S Kiware

elimination.The Vector Control Optimization Model (VCOM is a computational tool to predict the impact of combined vector control interventions at the mosquito population level in a range of eco-epidemiological settings. The model predicts specific combinations of vector control tools to achieve local malaria elimination in a range of eco-epidemiological settings and can assist researchers and program decision-makers on the design of experimental or operational research to test vector control interventions. A corresponding graphical user interface is available for national malaria control programs and other end users.

Malaria training for community health workers in the setting of elimination: a qualitative study from China.

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Lu, Guangyu; Liu, Yaobao; Wang, Jinsong; Li, Xiangming; Liu, Xing; Beiersmann, Claudia; Feng, Yu; Cao, Jun; Müller, Olaf

2018-02-23

Continuous training of health workers is a key intervention to maintain their good performance and keep their vigilance during malaria elimination programmes. However, countries progressing toward malaria elimination have a largely decreased malaria disease burden, less frequent exposure of health workers to malaria patients, and new challenges in the epidemiology of the remaining malaria cases. Moreover, competing health priorities and usually a decline in resources and in political commitment also pose challenges to the elimination programme. As a consequence, the acceptability, sustainability, and impact of malaria training and education programmes face challenges. However, little is known of the perceptions and expectations of malaria training and education programmes of health workers being engaged in countries with malaria elimination programmes. This qualitative study provides information on perceptions and expectations of health workers of malaria training programmes from China, which aims to malaria elimination by the year 2020. This study was embedded into a larger study on the challenges and lessons learned during the malaria surveillance strategy in China, involving 42 interviews with malaria experts, health staff, laboratory practitioners, and village doctors at the provincial, city, county, township, and village levels from Gansu province (northwestern China) and Jiangsu province (southeastern China). In the context of an increasing number of imported malaria cases in China, the majority of respondents emphasized the necessity and importance of such programmes and complained about a decreasing frequency of training courses. Moreover, they called for innovative strategies to improve the implementation and sustainability of the malaria training programmes until the elimination goal has been achieved. Perceptions and expectations of health workers from different health centres were quite different. Health workers from higher-level facilities were more

Malaria epidemiology in an area of stable transmission in tribal population of Jharkhand, India

DEFF Research Database (Denmark)

Das, Manoj K; Prajapati, Brijesh K; Tiendrebeogo, Régis W

2017-01-01

and density levels in the study population showed a gradual decrease with increasing age. This finding is consistent with the phenomenon of naturally acquired immunity against malaria. Three vector species were detected: Anopheles fluviatilis, Anopheles annularis, and Anopheles culicifacies. The incoherence...

Potency assay design for adjuvanted recombinant proteins as malaria vaccines.

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Giersing, Birgitte K; Dubovsky, Filip; Saul, Allan; Denamur, Francoise; Minor, Philip; Meade, Bruce

2006-05-15

Many licensed vaccines are composed of live, attenuated or inactivated whole-cell microorganisms, or they comprise purified components from whole-cell extracts or culture supernatants. For some diseases, pathology is fairly well understood, and there may be known correlates of protection that provide obvious parameters for assessment of vaccine potency. However, this is not always the case, and some effective vaccines are routinely used even though the mechanisms or correlates of protection are unknown. Some more modern vaccine approaches employ purified recombinant proteins, based on molecules that appear on the surface of the pathogen. This is one of the strategies that has been adopted in the quest to develop a malaria vaccine. Use of these parasite antigens as vaccine candidates is supported by substantial epidemiological data, and some have demonstrated the ability to elicit protective responses in animal models of malaria infection. However, there is as yet no immunological correlate of protection and no functional assays or animal models that have demonstrated the ability to predict efficacy in humans. There is little precedence for the most appropriate and practical method for assessing potency of vaccines based on these recombinant molecules for malaria vaccines. This is likely because the majority of malaria vaccine candidates have only recently entered clinical evaluation. The PATH Malaria Vaccine Initiative (MVI) convened a panel with expertise in potency assay design from industry, governmental institutions, and regulatory bodies to discuss and review the rationale, available methods, and best approaches for assessing the potency of recombinant proteins, specifically for their use as malarial vaccines. The aim of this meeting was to produce a discussion document on the practical potency assessment of recombinant protein malaria vaccines, focusing on early phase potency assay development.

Antibody reactivities to glutamate-rich peptides of Plasmodium falciparum parasites in humans from areas of different malaria endemicity

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Jakobsen, P.H.; Theander, T.G.; Hvid, L

1996-01-01

Synthetic P. falciparum peptides were evaluated as tools in epidemiological investigations of malaria. Plasma IgM and IgG antibody reactivities against synthetic peptides covering sequences of glutamate-rich protein (GLURP) and acidic-basic repeat antigen (ABRA) were measured by ELISA...

A seroprevalence and descriptive epidemiological study of malaria among Indian tribes of the Amazon basin of Brazil.

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de Arruda, M E; Aragaki, C; Gagliardi, F; Haile, R W

1996-04-01

Data on the seroprevalences of Plasmodium falciparum, P. vivax, and P. malariae in four isolated Indian tribes of the Amazon basin in Brazil, as determined by IFAT, were re-analysed. Age-, sex- and tribe-specific geometric mean antibody titres and externally standardized prevalence ratios were calculated for each parasite species. Correlation coefficients and prevalence odds ratios were also calculated for multiple infections with different combinations of the three Plasmodium species. Titres of all but one of the antibodies studied were similar in males and females; titres of antibodies to the blood stages of P. malariae were slightly higher in females than in males. Titres of antibodies to all three Plasmodium species increased with subject age, and this age effect was not confounded by sex or tribal differences. There were striking differences between tribes, with the Parakana tribe having relatively low titres of antibodies against P. falciparum and P. malariae; these tribal effects were not confounded by sex or age differences between tribes. The results indicate that conditions conductive to the transmission of P. malariae exist in this region of the Amazon. The potential for zoonotic transmission of P. brasilianum, a parasite of monkeys which is morphologically similar to P. malarie, and the generally high rates of seropositivity to all three species of Plasmodium indicate that control measures which are adequate and applicable to the region studied need to be developed.

Content Analysis of Primary and Secondary School Textbooks Regarding Malaria Control: A Multi-Country Study

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Nonaka, Daisuke; Jimba, Masamine; Mizoue, Tetsuya; Kobayashi, Jun; Yasuoka, Junko; Ayi, Irene; Jayatilleke, Achini C.; Shrestha, Sabina; Kikuchi, Kimiyo; Haque, Syed E.; Yi, Siyan

2012-01-01

Background In tropical settings, malaria education at school is potentially useful, but textbook content related to malaria education has so far received little attention. This study aimed to examine whether school textbooks contain sufficient knowledge and skills to help children in primary and lower secondary schools and their family members to cope with malaria. Methodology/Principal Findings This was a descriptive, cross-country study. We collected textbooks that were used by children in grades one to nine from nine countries endemic for malaria: Laos, Cambodia, Nepal, Bangladesh, Sri Lanka, Zambia, Niger, Benin, and Ghana. Two reviewers per country identified descriptions about malaria by seeking the term “malaria” or a local word that corresponds to malaria in languages other than English. The authors categorized the identified descriptions according to the content of the descriptions. Additionally, the authors examined whether the identified contents addressed life skill messages. Of a total of 474 textbooks collected, 35 contained descriptions about malaria. The most commonly included content was transmission mode/vector (77.1%), followed by preventive measures (60.0%), epidemiology (57.1%), cause/agent (54.3%), signs/symptoms (37.1%) and treatment (22.9%). Treatment-related content was not included in any textbooks from four countries and textbooks failed to recommend the use of insecticide-treated bed nets in five countries. Very few textbooks included content that facilitated prompt treatment, protection of risk groups, and use of recommended therapy. Conclusion/Significance Textbooks rarely included knowledge and skills that are crucial to protect schoolchildren and their families from malaria. This study identified the need for improvement to textbook contents regarding malaria. PMID:22574203

STATUS HEMATOLOGI PENDERITA MALARIA SEREBRAL

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Nurhayati Nurhayati

2009-05-01

Full Text Available AbstrakMalaria masih merupakan masalah kesehatan masyarakat dunia. Berdasarkan klasifikasi klinis, malaria dibedakan atas malaria berat dan malaria tanpa komplikasi. Malaria serebral merupakan komplikasi terberat dari malaria falsiparum.Telah dilakukan penelitian seksi silang terhadap penderita malaria falciparum yang dirawat inap di Bangsal Penyakit Dalam RS. Perjan. Dr. M. Djamil Padang dari bulan Juni 2002 sampai Juni 2006. Pada penelitian ini didapatkan jumlah sampel sebanyak 60 orang, terdiri dari 16 orang penderita malaria serebral dan 44 orang penderita malaria tanpa komplikasi.Data penelitian menunjukan terdapat perbedaan bermakna nilai hematokrit (p<0,05 dan jumlah leukosit (p<0,05 antara penderita malaria serebral dengan penderita malaria tanpa komplikasi. Dan terdapat korelasi positif antara nilai hemoglobin dengan hematokrit (r=0,864; p<0,05 pada penderita malaria falsiparum.Kata kunci: malaria serebral, malaria tanpa komplikasi, malaria falsiparumAbstract Malaria is still a problem of health of world society. Based on the clinical classification, are distinguished on severe malaria and uncomplicated malaria. Cerebral malaria is the worst complication of falciparum malaria. Cross section of the research done at the Hospital Dr. M. Djamil Padang againts medical record of malaria patients who are hospitalized in the Internal Medicine from June 2002 until June 2004. In this study, a total sample of 60 people, consisting of 16 cerebral malaria and 44 uncomplicated malaria. Data showed there were significant differences for hematocrit values (p <0.05 and total leukocytes values (p <0.05 between cerebral malaria and uncomplicated malaria patients. There is a positive correlation between hemoglobin with hematocrit values (r = 0.864; p <0.05 of falciparum malaria patients. Keywords: cerebral malaria, uncomplicated malaria, falciparum malaria

Genetic characterization of an epidemic of Plasmodium falciparum malaria among Yanomami Amerindians.

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Laserson, K F; Petralanda, I; Almera, R; Barker, R H; Spielman, A; Maguire, J H; Wirth, D F

1999-12-01

Malaria parasites are genetically diverse at all levels of endemicity. In contrast, the merozoite surface protein (MSP) alleles in samples from 2 isolated populations of Yanomami Amerindians during an epidemic of Plasmodium falciparum were identical. The nonvariable restriction fragment length polymorphism patterns further suggested that the sequential outbreak comprised only a single P. falciparum genotype. By examination of serial samples from single human infections, the MSP characteristics were found to remain constant throughout the course of infection. An apparent clonal population structure of parasites seemed to cause outbreaks in small isolated villages. The use of standard molecular epidemiologic methods to measure genetic diversity in malaria revealed the occurrence of a genetically monomorphic population of P. falciparum within a human community.

Invasive Salmonella Infections in Areas of High and Low Malaria Transmission Intensity in Tanzania

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Biggs, Holly M.; Lester, Rebecca; Nadjm, Behzad; Mtove, George; Todd, Jim E.; Kinabo, Grace D.; Philemon, Rune; Amos, Ben; Morrissey, Anne B.; Reyburn, Hugh; Crump, John A.

2014-01-01

Background. The epidemiology of Salmonella Typhi and invasive nontyphoidal Salmonella (NTS) differs, and prevalence of these pathogens among children in sub-Saharan Africa may vary in relation to malaria transmission intensity. Methods. We compared the prevalence of bacteremia among febrile pediatric inpatients aged 2 months to 13 years recruited at sites of high and low malaria endemicity in Tanzania. Enrollment at Teule Hospital, the high malaria transmission site, was from June 2006 through May 2007, and at Kilimanjaro Christian Medical Centre (KCMC), the low malaria transmission site, from September 2007 through August 2008. Automated blood culture, malaria microscopy with Giemsa-stained blood films, and human immunodeficiency virus testing were performed. Results. At Teule, 3639 children were enrolled compared to 467 at KCMC. Smear-positive malaria was detected in 2195 of 3639 (60.3%) children at Teule and 11 of 460 (2.4%) at KCMC (P < .001). Bacteremia was present in 336 of 3639 (9.2%) children at Teule and 20 of 463 (4.3%) at KCMC (P < .001). NTS was isolated in 162 of 3639 (4.5%) children at Teule and 1 of 463 (0.2%) at KCMC (P < .001). Salmonella Typhi was isolated from 11 (0.3%) children at Teule and 6 (1.3%) at KCMC (P = .008). With NTS excluded, the prevalence of bacteremia at Teule was 5.0% and at KCMC 4.1% (P = .391). Conclusions. Where malaria transmission was intense, invasive NTS was common and Salmonella Typhi was uncommon, whereas the inverse was observed at a low malaria transmission site. The relationship between these pathogens, the environment, and the host is a compelling area for further research. PMID:24336909

Mapping malaria risk using environmental and anthropic variables Mapeamento do risco de malaria utilizando variáveis ambientais e antrópicas

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Mauricio Edilberto Rincón-Romero

2009-09-01

Full Text Available Despite much research in the identification of areas with malaria, it is urgent to further investigate mapping techniques to achieve better approaches in strategies to prevent, mitigate, and eradicate the mosquito and the illness eventually. By using spatial distributed modeling techniques with Geographical Information Systems (GIS, the study proposes methodology to map malaria risk zoning for the municipality of Buenaventura in Colombia. The model proposed by Craig et al.¹ using climatic information was adapted to the conditions of the study area regarding scale and spatial resolution. Geomorphologic and anthropic variables were added to improve spatial allocation of areas with higher risk of contracting the illness, refining zoning. Then, they were contrasted with the locations reported by health entities², taking into account spatial distribution. The comparison of results shows a decrease in the area obtained initially using the Craig et al. model¹ (1999, from 5,422.4 km² (89.1% of the municipality's territory to 624.3km² (approximately 10% of the municipality's area, yielding a total reduction of 78.8% when environmental and anthropic variables were included in the model. Data show that of the 9,863 cases reported during 2001 to 2005 for 20 selected towns as basis for the amount of surveyed malaria cases², 1,132 were located in the very high-risk areas, 7,662 were in the areas of moderate risk, and 1,066 cases in low-risk areas, showing that 89% of the cases reported fell into the areas with higher risk for malaria.A pesar de muchas investigaciones en la identificación de las zonas con presencia de malaria, es urgente profundizar las técnicas de su mapeo para lograr mejores aproximaciones, para ayudar a focalizar los esfuerzos y recursos en prevención, mitigación y estrategias de erradicación del mosquito y eventualmente de la enfermedad. Usando modelación espacial distribuida con herramientas de Sistemas de Información Geogr

Relationship between the entomologic inoculation rate and the force of infection for Plasmodium falciparum malaria.

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Smith, Thomas; Maire, Nicolas; Dietz, Klaus; Killeen, Gerry F; Vounatsou, Penelope; Molineaux, Louis; Tanner, Marcel

2006-08-01

We propose a stochastic model for the relationship between the entomologic inoculation rate (EIR) for Plasmodium falciparum malaria and the force of infection in endemic areas. The model incorporates effects of increased exposure to mosquito bites as a result of the growth in body surface area with the age of the host, naturally acquired pre-erythrocytic immunity, and the reduction in the proportion of entomologically assessed inoculations leading to infection, as the EIR increases. It is fitted to multiple datasets from field studies of the relationship between malaria infection and the EIR. We propose that this model can account for non-monotonic relationships between the age of the host and the parasite prevalence and incidence of disease. It provides a parsimonious explanation for the faster acquisition of natural immunity in adults than in children exposed to high EIRs. This forms one component of a new stochastic model for the entire transmission cycle of P. falciparum that we have derived to estimate the potential epidemiologic impact of malaria vaccines and other malaria control interventions.

Maternal environment shapes the life history and susceptibility to malaria of Anopheles gambiae mosquitoes

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Lorenz Lena M

2011-12-01

Full Text Available Abstract Background It is becoming generally recognized that an individual's phenotype can be shaped not only by its own genotype and environmental experience, but also by its mother's environment and condition. Maternal environmental factors can influence mosquitoes' population dynamics and susceptibility to malaria, and therefore directly and indirectly the epidemiology of malaria. Methods In a full factorial experiment, the effects of two environmental stressors - food availability and infection with the microsporidian parasite Vavraia culicis - of female mosquitoes (Anopheles gambiae sensu stricto on their offspring's development, survival and susceptibility to malaria were studied. Results The offspring of A. gambiae s.s. mothers infected with V. culicis developed into adults more slowly than those of uninfected mothers. This effect was exacerbated when mothers were reared on low food. Maternal food availability had no effect on the survival of their offspring up to emergence, and microsporidian infection decreased survival only slightly. Low food availability for mothers increased and V. culicis-infection of mothers decreased the likelihood that the offspring fed on malaria-infected blood harboured malaria parasites (but neither maternal treatment influenced their survival up to dissection. Conclusions Resource availability and infection with V. culicis of A. gambiae s.s. mosquitoes not only acted as direct environmental stimuli for changes in the success of one generation, but could also lead to maternal effects. Maternal V. culicis infection could make offspring more resistant and less likely to transmit malaria, thus enhancing the efficacy of the microsporidian for the biological control of malaria.

Kajian Manajemen Lingkungan Terhadap Kejadian Malaria di Daerah Endemis, Kecamatan Kakuluk Mesak, Kabupaten Belu

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Antonius Tae Asa

2015-12-01

Full Text Available ABSTRACT Background : Malaria is still endemic disease  in Indonesia, especially in Belu district. Many measures had been implemented to reduce malaria cases , but its rate is still quite high in any areas . The fluctuation of malaria cases were influenced by epidemiological and environmental factors. Prevention of malaria had been conducted simultaneously through clinical and environmental intervention. However, such intervention had no more impact, especially the environmental intervention. Such failure may be associated with the location of this area closed to the highest malaria rate (AMI area in Belu District for four years later, namely : AMI 416/1000 population for year 2000, 527/1000 population for year 2001, 418/1000 population for year 2002, 468/1000 population for year 2003, and  it rose tobe  493/1000 population for the year of 2004. Based on this fact, this study was conducted to study  the environmental management related to the occurrence of malaria  in endemic areas in working area of  Atapupu Health Centre, Belu District. Furthermore, the study would  also analyze the impact  of vector and its larva. Method : This was a qualitative research using secondary data of the environmental management measure. The subject of this research was the malaria programmer and health worker who responsible for malaria program.  They were the Head of Public Health Centre, laboratory technician, Co-assistant of entomologist. The program measures would be studied in this research focusing on planning of malaria program, the malaria control measure, collecting and reporting of data, and monitoring – evaluation. Result : Measures had been conducted for reducing malaria cases in Atapupu Health Center through fogging,  mosquito netting by medical officials without involving related sector. Monitoring and evaluating have been conducted just through data collection and reporting the rate of cases which was found  in Passive Case Detection

Targeting indoor residual spraying for malaria using epidemiological data: a case study of the Zambia experience.

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Pinchoff, Jessie; Larsen, David A; Renn, Silvia; Pollard, Derek; Fornadel, Christen; Maire, Mark; Sikaala, Chadwick; Sinyangwe, Chomba; Winters, Benjamin; Bridges, Daniel J; Winters, Anna M

2016-01-06

In Zambia and other sub-Saharan African countries affected by ongoing malaria transmission, indoor residual spraying (IRS) for malaria prevention has typically been implemented over large areas, e.g., district-wide, and targeted to peri-urban areas. However, there is a recent shift in some countries, including Zambia, towards the adoption of a more strategic and targeted IRS approach, in coordination with increased emphasis on universal coverage of long-lasting insecticidal nets (LLINs) and effective insecticide resistance management. A true targeted approach would deliver IRS to sub-district areas identified as high-risk, with the goal of maximizing the prevention of malaria cases and deaths. Together with the Government of the Republic of Zambia, a new methodology was developed applying geographic information systems and satellite imagery to support a targeted IRS campaign during the 2014 spray season using health management information system data. This case study focuses on the developed methodology while also highlighting the significant research gaps which must be filled to guide countries on the most effective strategy for IRS targeting in the context of universal LLIN coverage and evolving insecticide resistance.

Malaria hotspots drive hypoendemic transmission in the Chittagong Hill Districts of Bangladesh.

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Sabeena Ahmed

Full Text Available Malaria is endemic in 13 of 64 districts of Bangladesh, representing a population at risk of about 27 million people. The highest rates of malaria in Bangladesh occur in the Chittagong Hill Districts, and Plasmodium falciparum (predominately chloroquine resistant is the most prevalent species.The objective of this research was to describe the epidemiology of symptomatic P. falciparum malaria in an area of Bangladesh following the introduction of a national malaria control program. We carried out surveillance for symptomatic malaria due to P. falciparum in two demographically defined unions of the Chittagong Hill Districts in Bangladesh, bordering western Myanmar, between October 2009 and May 2012. The association between sociodemographics and temporal and climate factors with symptomatic P. falciparum infection over two years of surveillance data was assessed. Risk factors for infection were determined using a multivariate regression model.472 cases of symptomatic P. falciparum malaria cases were identified among 23,372 residents during the study period. Greater than 85% of cases occurred during the rainy season from May to October, and cases were highly clustered geographically within these two unions with more than 80% of infections occurring in areas that contain approximately one-third of the total population. Risk factors statistically associated with infection in a multivariate logistic regression model were living in the areas of high incidence, young age, and having an occupation including jhum cultivation and/or daily labor. Use of long lasting insecticide-treated bed nets was high (89.3%, but its use was not associated with decreased incidence of infection.Here we show that P. falciparum malaria continues to be hypoendemic in the Chittagong Hill Districts of Bangladesh, is highly seasonal, and is much more common in certain geographically limited hot spots and among certain occupations.

Avances más recientes en el desarrollo de vacunas contra la malaria The most recent advances in developing vaccines against malaria

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Lázara Rojas Rivero

2005-02-01

Full Text Available According to reports of the Pan American Health Organization, malaria transmission continues to occur in 21 countries of the Americas. Of the 835 million inhabitants of the Region of the Americas, 293 million live in areas with some possibility of transmission of the disease. The most advanced of the candidate vaccines that have been designed based on the sequences of the circumsporozoite protein, is one based on the RTS,S/AS02A polypeptides of Plasmodium falciparum. A test of that vaccine was conducted in Mozambique with children from 1 to 4 years old. The test proved the vaccine to be safe, well tolerated, and immunogenic, but the level of protection reached was still low. However, the advantages that the RTS,S/AS02A vaccine offers to people who live in malaria-endemic areas justifies its being tested in the Americas in order to evaluate its effectiveness in the clinical and epidemiological conditions specific to the Region.

Malaria og graviditet

DEFF Research Database (Denmark)

Hoffmann, A L; Rønn, A M; Langhoff-Roos, J

1992-01-01

In regions where malaria is endemism, the disease is a recognised cause of complications of pregnancy such as spontaneous abortion, premature delivery, intrauterine growth retardation and foetal death. Malaria is seldom seen in pregnant women in Denmark but, during the past two years, the authors...... the patients but also their practitioners were unaware that malaria can occur several years after exposure. Three out of the four patients had employed malaria prophylaxis. As resistance to malarial prophylactics in current use is increasing steadily, chemoprophylaxis should be supplemented by mechanical...... protection against malaria and insect repellents. As a rule, malaria is treated with chloroquine. In cases of Falciparum malaria in whom chloroquine resistance is suspected, treatment with mefloquine may be employed although this should only be employed in cases of dire necessity in pregnant patients during...

Evolución de la malaria en la región Loreto

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Juan Celis S

2003-12-01

Full Text Available OBJETIVOS: Describir la evolución de la malaria en la región Loreto, tanto para malaria vivax como para falciparum, su relación con el total de casos para el Perú y los cambios de políticas en medicamentos. MATERIAL Y MÉTODOS: Estudio observacional, descriptivo. La fuente de información fue la Oficina General de Epidemiología del Ministerio de Salud. RESULTADOS: La incidencia de malaria en Loreto (vivax y falciparum aumenta desde el año 2000 luego de una disminución de 40%. El año 2001 se reporta un incremento de 24% con respecto al 2000 y el 2002, de 52% respecto al 2001. Como porcentaje del total casos en Perú, Loreto aportó 29%, 31%, 44%, 47% y 57% los años 1998 al 2002, respectivamente. Loreto está en alto riesgo desde 1995. En la semana epidemiológica 46 (09 al 15 de noviembre 2003 Loreto (IPA 45 y San Martin (IPA 10 se presentan en condición de riesgo alto. En total, 60,4% de los casos totales procede de Loreto. CONCLUSIONES: La incidencia de la malaria en la región Loreto ha ido en aumento en los últimos 3 años. En los últimos años, los casos de Malaria en el Perú se concentran en la región Loreto.

Declines in Malaria Burden and All-Cause Child Mortality following Increases in Control Interventions in Senegal, 2005-2010.

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Thwing, Julie; Eckert, Erin; Dione, Demba Anta; Tine, Roger; Faye, Adama; Yé, Yazoume; Ndiop, Medoune; Cisse, Moustapha; Ndione, Jacques Andre; Diouf, Mame Birame; Ba, Mady

2017-09-01

Malaria is endemic in Senegal. The national malaria control strategy focuses on achieving universal coverage for major interventions, with a goal of reaching preelimination status by 2018. Senegal began distribution of insecticide-treated nets (ITNs) and introduced artemisinin-based combination therapy in 2006, then introduced rapid diagnostic tests in 2007. We evaluated the impact of these efforts using a plausibility design based on malaria's contribution to all-cause under-five mortality (ACCM) and considering other contextual factors which may influence ACCM. Between 2005 and 2010, household ownership of ITNs increased from 20% to 63%, and the proportion of people sleeping under an ITN the night prior to the survey increased from 6% to 29%. Malaria parasite prevalence declined from 6% to 3% from 2008 to 2010 among children under five. Some nonmalaria indicators of child health improved, for example, increase of complete vaccination coverage from 58% to 64%; however, nutritional indicators deteriorated, with an increase in stunting from 16% to 26%. Although economic indicators improved, environmental conditions favored an increase in malaria transmission. ACCM decreased 40% between 2005 and 2010, from 121 (95% confidence interval [CI] 113-129) to 72 (95% CI 66-77) per 1,000, and declines were greater among age groups, epidemiologic zones, and wealth quintiles most at risk for malaria. After considering coverage of malaria interventions, trends in malaria morbidity, effects of contextual factors, and trends in ACCM, it is plausible that malaria control interventions contributed to a reduction in malaria mortality and to the impressive gains in child survival in Senegal.

Assessing the effects of air temperature and rainfall on malaria incidence: an epidemiological study across Rwanda and Uganda

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Felipe J. Colón-González

2016-03-01

Full Text Available We investigate the short-term effects of air temperature, rainfall, and socioeconomic indicators on malaria incidence across Rwanda and Uganda from 2002 to 2011. Delayed and nonlinear effects of temperature and rainfall data are estimated using generalised additive mixed models with a distributed lag nonlinear specification. A time series cross-validation algorithm is implemented to select the best subset of socioeconomic predictors and to define the degree of smoothing of the weather variables. Our findings show that trends in malaria incidence agree well with variations in both temperature and rainfall in both countries, although factors other than climate seem to play an important role too. The estimated short-term effects of air temperature and precipitation are nonlinear, in agreement with previous research and the ecology of the disease. These effects are robust to the effects of temporal correlation. The effects of socioeconomic data are difficult to ascertain and require further evaluation with longer time series. Climate-informed models had lower error estimates compared to models with no climatic information in 77 and 60% of the districts in Rwanda and Uganda, respectively. Our results highlight the importance of using climatic information in the analysis of malaria surveillance data, and show potential for the development of climateinformed malaria early warning systems.

Epidemiologia de la malaria falciparum complicada: estudio de casos y controles en Tumaco y Turbo, Colombia, 2003 The epidemiology of complicated falciparum malaria: case and controls study in Tumaco and Turbo, Colombia, 2003

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Alberto Tobón C.

2006-09-01

Full Text Available OBJETIVOS: Identificar aspectos del hospedero, del parásito y del ambiente asociados con ocurrencia de malaria por Plasmodium falciparum complicada. MÉTODOS: Estudio de casos y controles en pacientes de Tumaco y Turbo (Colombia aplicando los criterios de complicación de la Organización Mundial de la Salud. RESULTADOS: Entre noviembre 2002 y julio 2003 se captaron 64 casos (malaria complicada y 135 controles (malaria no complicada. Las complicaciones fueron: hiperparasitemia (40%, falla hepática (36%, síndrome dificultad respiratoria aguda (7%, falla renal (4%, trombocitopenia grave (3%, anemia grave (2%, malaria cerebral (2% e hipoglicemia grave (1%. Se encontraron como factores de riesgo para malaria falciparum complicada: a Los antecedentes de malaria falciparum durante el último año fueron menores en los casos (OR= 7.0 (1.2-43.6 P=0.019; b Mayor uso previo de antimaláricos en los casos (OR=2.2 (1.1-4.4 P=0.031 y c mayor uso de cloroquina en los casos (OR=7.4 (1.1-7.8 P=0.017. Se hallaron los alelos MAD-20 y K1 del gen msp1 y FC-27 e IC-1 del gen msp2, cuya distribución de frecuencias fue similar entre casos y controles, aunque el alelo K1 mostró una variación importante entre grupos (casos: 9.4%, controles: 3.5%. La frecuencia de "signos de peligro" fue significativamente mayor en los casos (OR= 3.3, (1.5-7.4 P=0.001. Los criterios de complicación malárica de la Organización Mundial de la Salud se comparan con otros y se discuten algunas implicaciones. CONCLUSIÓN: Se identificaron como factores de riesgo para malaria falciparum complicada, la ausencia de antecedentes de malaria falciparum en el último año y el uso de antimaláricos antes de llegar al hospital.OBJECTIVES: Aimed at identifying host and parasite aspects associated to the presence of Plasmodium falciparum complicated malaria. METHODS: Case and controls study in patients from Tumaco and Turbo (Colombia. We used the World Health Organization criteria to assess the

Human population, urban settlement patterns and their impact on Plasmodium falciparum malaria endemicity

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Kabaria Caroline W

2008-10-01

significant differences between author-defined 'urban' and 'rural' designations in Africa, but not for the remainder of the malaria endemic world. The Global Rural Urban Mapping Project (GRUMP urban extent mask proved most accurate for mapping these author-defined rural and urban locations, and further sub-divisions of urban extents into urban and peri-urban classes enabled the effects of high population densities on malaria transmission to be mapped and quantified. Conclusion The availability of detailed, contemporary census and urban extent data for the construction of coherent and accurate global spatial population databases is often poor. These known sources of uncertainty in population surfaces and urban maps have the potential to be incorporated into future malaria burden estimates. Currently, insufficient spatial information exists globally to identify areas accurately where population density is low enough to impact upon transmission. Medical intelligence does however exist to reliably identify malaria free cities. Moreover, in Africa, urban areas that have a significant effect on malaria transmission can be mapped.

The Historical Distribution of Main Malaria Foci in Spain as Related to Water Bodies

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Arturo Sousa

2014-08-01

Full Text Available The possible connectivity between the spatial distribution of water bodies suitable for vectors of malaria and endemic malaria foci in Southern Europe is still not well known. Spain was one of the last countries in Western Europe to be declared free of malaria by the World Health Organization (WHO in 1964. This study combines, by means of a spatial-temporal analysis, the historical data of patients and deceased with the distribution of water bodies where the disease-transmitting mosquitos proliferate. Therefore, data from historical archives with a Geographic Information System (GIS, using the Inverse Distance Weighted (IDW interpolation method, was analyzed with the aim of identifying regional differences in the distribution of malaria in Spain. The reasons, why the risk of transmission is concentrated in specific regions, are related to worse socioeconomic conditions (Extremadura, the presence of another vector (Anopheles labranchiae besides A. atroparvus (Levante or large areas of water bodies in conditions to reproduce theses vectors (La Mancha and Western Andalusia. In the particular case of Western Andalusia, in 1913, the relatively high percentage of 4.73% of the surface, equal to 202362 ha, corresponds to wetlands and other unhealthy water bodies. These wetlands have been reduced as a result of desiccation policies and climate change such as the Little Ice Age and Global Climate Change. The comprehension of the main factors of these wetland changes in the past can help us interpret accurately the future risk of malaria re-emergence in temperate latitudes, since it reveals the crucial role of unhealthy water bodies on the distribution, endemicity and eradication of malaria in southern Europe.

Avian malaria: a new lease of life for an old experimental model to study the evolutionary ecology of Plasmodium.

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Pigeault, Romain; Vézilier, Julien; Cornet, Stéphane; Zélé, Flore; Nicot, Antoine; Perret, Philippe; Gandon, Sylvain; Rivero, Ana

2015-08-19

Avian malaria has historically played an important role as a model in the study of human malaria, being a stimulus for the development of medical parasitology. Avian malaria has recently come back to the research scene as a unique animal model to understand the ecology and evolution of the disease, both in the field and in the laboratory. Avian malaria is highly prevalent in birds and mosquitoes around the world and is amenable to laboratory experimentation at each stage of the parasite's life cycle. Here, we take stock of 5 years of experimental laboratory research carried out using Plasmodium relictum SGS1, the most prevalent avian malaria lineage in Europe, and its natural vector, the mosquito Culex pipiens. For this purpose, we compile and analyse data obtained in our laboratory in 14 different experiments. We provide statistical relationships between different infection-related parameters, including parasitaemia, gametocytaemia, host morbidity (anaemia) and transmission rates to mosquitoes. This analysis provides a wide-ranging picture of the within-host and between-host parameters that may bear on malaria transmission and epidemiology. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Spatial and temporal epidemiology of Mycobacterium leprae infection among leprosy patients and household contacts of an endemic region in Southeast Brazil.

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Nicchio, Mariana V C; Araujo, Sergio; Martins, Lorraine C; Pinheiro, Andressa V; Pereira, Daniela C; Borges, Angélica; Antunes, Douglas E; Barreto, Josafá G; Goulart, Isabela Maria B

2016-11-01

Leprosy is a chronic infectious disease that remains a public health problem in low- and middle-income countries. Household contacts of leprosy patients (HHCs) have increased risk of developing disease and are important links in the chain of transmission of Mycobacterium leprae. Based on epidemiological and operational factors, the global elimination strategy depends on the geographic stratification of endemic areas to intensify control activities. The purpose of the study was to integrate epidemiological indicators and serology into the spatial and temporal analysis of M. leprae infection, in order to understanding of the dynamics of transmission, essential information for the control of leprosy. Using location-based technologies and epidemiological data obtained from leprosy cases (N=371) and HHCs (N=53), during a 11year period (2004-2014), we explored the spatial and temporal distribution of diagnosed cases: stratified according their disease manifestation; and of subclinical infection among HHCs: determined by serology (anti-PGL-I ELISA and anti-NDO-LID rapid lateral-flow test); in order to assess the distribution pattern of the disease and the areas of greatest risk of illness, in a highly endemic municipality (Ituiutaba, MG) in the southeast region of Brazil. Seropositivity among HHCs was: 17% (9/53) for anti-PGL-I ELISA; and 42% for the NDO-LID rapid lateral-flow test. Forty-nine percent of the contacts were seropositive to at least one of the immunological tests. We observed substantial spatial heterogeneity of cases throughout the urban perimeter. Even so, four main clusters of patients and three main clusters of subclinical infection were identified. Spatio-temporal epidemiology associated to serological assessment can identify high-risk areas imbedded within the overall epidemic municipality, to prioritize active search of new cases as well support prevention strategies in these locations of greater disease burden and transmission. Such techniques should

Dynamics of forest malaria transmission in Balaghat district, Madhya Pradesh, India.

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Neeru Singh

Full Text Available BACKGROUND: An epidemiological and entomological study was carried out in Balaghat district, Madhya Pradesh, India to understand the dynamics of forest malaria transmission in a difficult and hard to reach area where indoor residual spray and insecticide treated nets were used for vector control. METHODS: This community based cross-sectional study was undertaken from January 2010 to December 2012 in Baihar and Birsa Community Health Centres of district Balaghat for screening malaria cases. Entomological surveillance included indoor resting collections, pyrethrum spray catches and light trap catches. Anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite protein. FINDINGS: Plasmodium falciparum infection accounted for >80% of all infections. P. vivax 16.5%, P. malariae 0.75% and remaining were mixed infections of P. falciparum, P. vivax and P. malariae. More than, 30% infections were found in infants under 6 months of age. Overall, an increasing trend in malaria positivity was observed from 2010 to 2012 (chi-square for trend  =  663.55; P<0.0001. Twenty five Anopheles culicifacies (sibling species C, D and E were positive for circumsporozoite protein of P. falciparum (44% and P. vivax (56%. Additionally, 2 An. fluviatilis, were found positive for P. falciparum and 1 for P. vivax (sibling species S and T. An. fluviatilis sibling species T was found as vector in forest villages for the first time in India. CONCLUSION: These results showed that the study villages are experiencing almost perennial malaria transmission inspite of indoor residual spray and insecticide treated nets. Therefore, there is a need for new indoor residual insecticides which has longer residual life or complete coverage of population with long lasting insecticide treated nets or both indoor residual spray and long lasting bed nets for effective vector control. There is a need to undertake a well designed case control study to evaluate the efficacy

Spatial prediction of Plasmodium falciparum prevalence in Somalia.

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Noor, Abdisalan M; Clements, Archie C A; Gething, Peter W; Moloney, Grainne; Borle, Mohammed; Shewchuk, Tanya; Hay, Simon I; Snow, Robert W

2008-08-21

Maps of malaria distribution are vital for optimal allocation of resources for anti-malarial activities. There is a lack of reliable contemporary malaria maps in endemic countries in sub-Saharan Africa. This problem is particularly acute in low malaria transmission countries such as those located in the horn of Africa. Data from a national malaria cluster sample survey in 2005 and routine cluster surveys in 2007 were assembled for Somalia. Rapid diagnostic tests were used to examine the presence of Plasmodium falciparum parasites in finger-prick blood samples obtained from individuals across all age-groups. Bayesian geostatistical models, with environmental and survey covariates, were used to predict continuous maps of malaria prevalence across Somalia and to define the uncertainty associated with the predictions. For analyses the country was divided into north and south. In the north, the month of survey, distance to water, precipitation and temperature had no significant association with P. falciparum prevalence when spatial correlation was taken into account. In contrast, all the covariates, except distance to water, were significantly associated with parasite prevalence in the south. The inclusion of covariates improved model fit for the south but not for the north. Model precision was highest in the south. The majority of the country had a predicted prevalence of or = 5% prevalence were predominantly in the south. The maps showed that malaria transmission in Somalia varied from hypo- to meso-endemic. However, even after including the selected covariates in the model, there still remained a considerable amount of unexplained spatial variation in parasite prevalence, indicating effects of other factors not captured in the study. Nonetheless the maps presented here provide the best contemporary information on malaria prevalence in Somalia.

Spatial prediction of Plasmodium falciparum prevalence in Somalia

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Shewchuk Tanya

2008-08-01

Full Text Available Abstract Background Maps of malaria distribution are vital for optimal allocation of resources for anti-malarial activities. There is a lack of reliable contemporary malaria maps in endemic countries in sub-Saharan Africa. This problem is particularly acute in low malaria transmission countries such as those located in the horn of Africa. Methods Data from a national malaria cluster sample survey in 2005 and routine cluster surveys in 2007 were assembled for Somalia. Rapid diagnostic tests were used to examine the presence of Plasmodium falciparum parasites in finger-prick blood samples obtained from individuals across all age-groups. Bayesian geostatistical models, with environmental and survey covariates, were used to predict continuous maps of malaria prevalence across Somalia and to define the uncertainty associated with the predictions. Results For analyses the country was divided into north and south. In the north, the month of survey, distance to water, precipitation and temperature had no significant association with P. falciparum prevalence when spatial correlation was taken into account. In contrast, all the covariates, except distance to water, were significantly associated with parasite prevalence in the south. The inclusion of covariates improved model fit for the south but not for the north. Model precision was highest in the south. The majority of the country had a predicted prevalence of Conclusion The maps showed that malaria transmission in Somalia varied from hypo- to meso-endemic. However, even after including the selected covariates in the model, there still remained a considerable amount of unexplained spatial variation in parasite prevalence, indicating effects of other factors not captured in the study. Nonetheless the maps presented here provide the best contemporary information on malaria prevalence in Somalia.

Coexistence of Malaria and Thalassemia in Malaria Endemic Areas of Thailand

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Kuesap, Jiraporn; Chaijaroenkul, W.; Rungsihirunrat, K.; Pongjantharasatien, K.; Na-Bangchang, Kesara

2015-01-01

Hemoglobinopathy and malaria are commonly found worldwide particularly in malaria endemic areas. Thalassemia, the alteration of globin chain synthesis, has been reported to confer resistance against malaria. The prevalence of thalassemia was investigated in 101 malaria patients with Plasmodium falciparum and Plasmodium vivax along the Thai-Myanmar border to examine protective effect of thalassemia against severe malaria. Hemoglobin typing was performed using low pressure liquid chromatography (LPLC) and α-thalassemia was confirmed by multiplex PCR. Five types of thalassemia were observed in malaria patients. The 2 major types of thalassemia were Hb E (18.8%) and α-thalassemia-2 (11.9%). There was no association between thalassemia hemoglobinopathy and malaria parasitemia, an indicator of malaria disease severity. Thalassemia had no significant association with P. vivax infection, but the parasitemia in patients with coexistence of P. vivax and thalassemia was about 2-3 times lower than those with coexistence of P. falciparum and thalassemia and malaria without thalassemia. Furthermore, the parasitemia of P. vivax in patients with coexistence of Hb E showed lower value than coexistence with other types of thalassemia and malaria without coexistence. Parasitemia, hemoglobin, and hematocrit values in patients with coexistence of thalassemia other than Hb E were significantly lower than those without coexistence of thalassemia. Furthermore, parasitemia with coexistence of Hb E were 2 times lower than those with coexistence of thalassemia other than Hb E. In conclusion, the results may, at least in part, support the protective effect of thalassemia on the development of hyperparasitemia and severe anemia in malaria patients. PMID:26174819

The importance of an entomo-epidemiological monitoring in the construction of pipelines at the Amazon

Energy Technology Data Exchange (ETDEWEB)

Cruz, Elidianne da S.; Valgas, Luciana L.; Batista, Rita de Cassia G.; Agostini, Lucimara de; Pereira, Andreia Labrea; Freitas, Wanderleia Isabel P. de; Frade, Amadeu Farage [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2009-12-19

This work has as objective to evidence one of the consequences of most satisfactory results, talking about attendance to the legal requirements of health on a pipeline undertake at the Amazon: a positive result of index zero of malaria cases until the present days. This work, in its peak, reached the contingent of eight thousand workers lodged in rafts, boats, carps and jungle camps. To reach this index, a methodology of prevention through an entomo epidemiological control was adopted, recommended for the World-wide Organization of Health, as basic activity for malaria control in endemic areas, as in Amazon. The activities had consisted to identify the epidemiologic profile of each area, to elaborate procedures of vectorial control, to implant laboratories for analysis of malaria blades, to enable staff to accomplishment of vectorial control, to realize thermo nebulization and domestic spread and to sensitize the workers of prevention and control measures. Therefore, by means of accomplishment of these basic actions, it was possible to assure an integral, equitable and qualitative attendance providing a critical and conscientious vision of involved and the success of the procedures adopted by PETROBRAS, represented by ENGENHARIA/IENOR (Northern Undertake Implementation), unit responsible for the pipeline Urucu-Manaus Construction. (author)

Plasmodium vivax hospitalizations in a monoendemic malaria region: severe vivax malaria?

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Quispe, Antonio M; Pozo, Edwar; Guerrero, Edith; Durand, Salomón; Baldeviano, G Christian; Edgel, Kimberly A; Graf, Paul C F; Lescano, Andres G

2014-07-01

Severe malaria caused by Plasmodium vivax is no longer considered rare. To describe its clinical features, we performed a retrospective case control study in the subregion of Luciano Castillo Colonna, Piura, Peru, an area with nearly exclusive vivax malaria transmission. Severe cases and the subset of critically ill cases were compared with a random set of uncomplicated malaria cases (1:4). Between 2008 and 2009, 6,502 malaria cases were reported, including 106 hospitalized cases, 81 of which fit the World Health Organization definition for severe malaria. Of these 81 individuals, 28 individuals were critically ill (0.4%, 95% confidence interval = 0.2-0.6%) with severe anemia (57%), shock (25%), lung injury (21%), acute renal failure (14%), or cerebral malaria (11%). Two potentially malaria-related deaths occurred. Compared with uncomplicated cases, individuals critically ill were older (38 versus 26 years old, P < 0.001), but similar in other regards. Severe vivax malaria monoinfection with critical illness is more common than previously thought. © The American Society of Tropical Medicine and Hygiene.

Malaria overdiagnosis and subsequent overconsumption of antimalarial drugs in Angola: Consequences and effects on human health.

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Manguin, Sylvie; Foumane, Vincent; Besnard, Patrick; Fortes, Filomeno; Carnevale, Pierre

2017-07-01

Microscopic blood smear examinations done in health centers of Angola demonstrated a large overdiagnosis of malaria cases with an average rate of errors as high as 85%. Overall 83% of patients who received Coartem ® had an inappropriate treatment. Overestimated malaria diagnosis was noticed even when specific symptoms were part of the clinical observation, antimalarial treatments being subsequently given. Then, malaria overdiagnosis has three main consequences, (i) the lack of data reliability is of great concern, impeding epidemiological records and evaluation of the actual influence of operations as scheduled by the National Malaria Control Programme; (ii) the large misuse of antimalarial drug can increase the selective pressure for resistant strain and can make a false consideration of drug resistant P. falciparum crisis; and (iii) the need of strengthening national health centers in term of human, with training in microscopy, and equipment resources to improve malaria diagnosis with a large scale use of rapid diagnostic tests associated with thick blood smears, backed up by a "quality control" developed by the national health authorities. Monitoring of malaria cases was done in three Angolan health centers of Alto Liro (Lobito town) and neighbor villages of Cambambi and Asseque (Benguéla Province) to evaluate the real burden of malaria. Carriers of Plasmodium among patients of newly-borne to 14 years old, with or without fever, were analyzed and compared to presumptive malaria cases diagnosed in these health centers. Presumptive malaria cases were diagnosed six times more than the positive thick blood smears done on the same children. In Alto Liro health center, the percentage of diagnosis error reached 98%, while in Cambambi and Asseque it was of 79% and 78% respectively. The percentage of confirmed malaria cases was significantly higher during the dry (20.2%) than the rainy (13.2%) season. These observations in three peripheral health centers confirmed what

Malaria in Brazil, Colombia, Peru and Venezuela: current challenges in malaria control and elimination.

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Recht, Judith; Siqueira, André M; Monteiro, Wuelton M; Herrera, Sonia M; Herrera, Sócrates; Lacerda, Marcus V G

2017-07-04

In spite of significant progress towards malaria control and elimination achieved in South America in the 2000s, this mosquito-transmitted tropical disease remains an important public health concern in the region. Most malaria cases in South America come from Amazon rain forest areas in northern countries, where more than half of malaria is caused by Plasmodium vivax, while Plasmodium falciparum malaria incidence has decreased in recent years. This review discusses current malaria data, policies and challenges in four South American Amazon countries: Brazil, Colombia, Peru and the Bolivarian Republic of Venezuela. Challenges to continuing efforts to further decrease malaria incidence in this region include: a significant increase in malaria cases in recent years in Venezuela, evidence of submicroscopic and asymptomatic infections, peri-urban malaria, gold mining-related malaria, malaria in pregnancy, glucose-6-phosphate dehydrogenase (G6PD) deficiency and primaquine use, and possible under-detection of Plasmodium malariae. Some of these challenges underscore the need to implement appropriate tools and procedures in specific regions, such as a field-compatible molecular malaria test, a P. malariae-specific test, malaria diagnosis and appropriate treatment as part of regular antenatal care visits, G6PD test before primaquine administration for P. vivax cases (with weekly primaquine regimen for G6PD deficient individuals), single low dose of primaquine for P. falciparum malaria in Colombia, and national and regional efforts to contain malaria spread in Venezuela urgently needed especially in mining areas. Joint efforts and commitment towards malaria control and elimination should be strategized based on examples of successful regional malaria fighting initiatives, such as PAMAFRO and RAVREDA/AMI.

Nested PCR detection of Plasmodium malariae from microscopy confirmed P. falciparum samples in endemic area of NE India.

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Dhiman, Sunil; Goswami, Diganta; Kumar, Dinesh; Rabha, Bipul; Sharma, Dhirendra Kumar; Bhola, Rakesh Kumar; Baruah, Indra; Veer, Vijay

2013-11-01

The present study evaluates the performance of OptiMAL-IT test and nested PCR assay in detection of malaria parasites. A total of 76 randomly selected blood samples collected from two malaria endemic areas were tested for malaria parasites using microscopy and OptiMAL-IT test in the field. PCR assays were performed in the laboratory using DNA extracted from blood spots of the same samples collected on the FTA classic cards. Of the total of 61 field confirmed malaria positive samples, only 58 (95%) were detected positive using microscopy in the laboratory. Sensitivity, specificity, positive predictive value, negative predictive value and false discovery rate of OptiMal-IT in comparison to the microscopy were 93%, 83%, 95%, 79% and 5%, respectively. On the other hand, the sensitivity and specificity of PCR assay were 97% and 100%, respectively, whereas positive predictive value, negative predictive value and false discovery rate were 100%, 90% and 0%, respectively. The overall performance of OptiMal-IT and PCR assays for malaria diagnosis was 76% and 97%, respectively. PCR assay enabled the identification of infection with Plasmodium malariae Laveran, 1881 in four samples misidentified by microscopy and Plasmodium-specific antigen (PAN) identified by the OptiMAL-IT test. In addition to the standard methods, such PCR assay could be useful to obtain the real incidence of each malaria parasite species for epidemiological perspectives.

Sub-microscopic malaria cases and mixed malaria infection in a remote area of high malaria endemicity in Rattanakiri province, Cambodia: implication for malaria elimination

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Socheat Duong

2010-04-01

Full Text Available Abstract Background Malaria microscopy and rapid diagnostic tests are insensitive for very low-density parasitaemia. This insensitivity may lead to missed asymptomatic sub-microscopic parasitaemia, a potential reservoir for infection. Similarly, mixed infections and interactions between Plasmodium species may be missed. The objectives were first to develop a rapid and sensitive PCR-based diagnostic method to detect low parasitaemia and mixed infections, and then to investigate the epidemiological importance of sub-microscopic and mixed infections in Rattanakiri Province, Cambodia. Methods A new malaria diagnostic method, using restriction fragment length polymorphism analysis of the cytochrome b genes of the four human Plasmodium species and denaturing high performance liquid chromatography, has been developed. The results of this RFLP-dHPLC method have been compared to 1 traditional nested PCR amplification of the 18S rRNA gene, 2 sequencing of the amplified fragments of the cytochrome b gene and 3 microscopy. Blood spots on filter paper and Giemsa-stained blood thick smears collected in 2001 from 1,356 inhabitants of eight villages of Rattanakiri Province have been analysed by the RFLP-dHPLC method and microscopy to assess the prevalence of sub-microscopic and mixed infections. Results The sensitivity and specificity of the new RFLP-dHPLC was similar to that of the other molecular methods. The RFLP-dHPLC method was more sensitive and specific than microscopy, particularly for detecting low-level parasitaemia and mixed infections. In Rattanakiri Province, the prevalences of Plasmodium falciparum and Plasmodium vivax were approximately two-fold and three-fold higher, respectively, by RFLP-dHPLC (59% and 15%, respectively than by microscopy (28% and 5%, respectively. In addition, Plasmodium ovale and Plasmodium malariae were never detected by microscopy, while they were detected by RFLP-dHPLC, in 11.2% and 1.3% of the blood samples, respectively

Increase in cases of malaria in Mozambique, 2014: epidemic or new endemic pattern?

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Arroz, Jorge Alexandre Harrison

2016-01-01

To describe the increase in cases of malaria in Mozambique. Cross-sectional study conducted in 2014, in Mozambique with national weekly epidemiological bulletin data. I analyzed the number of recorded cases in the 2009-2013 period, which led to the creation of an endemic channel using the quartile and C-Sum methods. Monthly incidence rates were calculated for the first half of 2014, making it possible to determine the pattern of endemicity. Months in which the incidence rates exceeded the third quartile or line C-sum were declared as epidemic months. The provinces of Nampula, Zambezia, Sofala, and Inhambane accounted for 52.7% of all cases in the first half of 2014. Also during this period, the provinces of Nampula, Sofala and Tete were responsible for 54.9% of the deaths from malaria. The incidence rates of malaria in children, and in all ages, have showed patterns in the epidemic zone. For all ages, the incidence rate has peaked in April (2,573 cases/100,000 inhabitants). The results suggest the occurrence of an epidemic pattern of malaria in the first half of 2014 in Mozambique. It is strategic to have a more accurate surveillance at all levels (central, provincial and district) to target prevention and control interventions in a timely manner.

Spatial variation and socio-economic determinants of Plasmodium falciparum infection in northeastern Tanzania

DEFF Research Database (Denmark)

Mmbando, Bruno P; Kamugisha, Mathias L; Lusingu, John P

2011-01-01

system (GPS) unit. The effects of risk factors were determined using generalized estimating equation and spatial risk of P. falciparum infection was modelled using a kernel (non-parametric) method. RESULTS: There was a significant spatial variation of P. falciparum infection, and urban areas were......ABSTRACT: BACKGROUND: Malaria due to Plasmodium falciparum is the leading cause of morbidity and mortality in Tanzania. According to health statistics, malaria accounts for about 30% and 15% of hospital admissions and deaths, respectively. The risk of P. falciparum infection varies across...... the country. This study describes the spatial variation and socio-economic determinants of P. falciparum infection in northeastern Tanzania. METHODS: The study was conducted in 14 villages located in highland, lowland and urban areas of Korogwe district. Four cross-sectional malaria surveys involving...

Predictors of knowledge towards malaria of rural tribal communities in Dhalai District of Tripura, India.

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Kumar, S; Debbarma, A

2013-10-01

Reduction of malarial morbidity and mortality is one of the top public health priorities in Tripura and the Country. To achieve these targets it is imperative to have active community participation to control malaria. Community participation in turn depends on people's knowledge and attitude towards the disease. This study was conducted to examine the factors that predict the knowledge of rural tribal communities in Dhalai district of Tripura towards malaria. This community based epidemiological cross-sectional descriptive study was carried out in Dhalai district of Tripura. A pre-tested structured questionnaire collecting socio-demographic and malaria-related KAP information was administered to the 216 adult respondents from a representative sample of households. As a whole, there were 147(68.1%) illiterate respondents. Out of them, 89(41.2%) persons were male and 58(26.9%) were female. Correct knowledge about the cause of malaria was 2.77 times higher in males than females and 11.53 times higher in literate tribal people than in illiterate. Correct knowledge about the symptoms fever, chills, and rigors of malaria were also higher in male sex and in literate tribal people. Use of smoke as preventive measure was very high among the respondents. Common predictors of correct knowledge about etiology and clinical features of malaria were in male Tripuri and Reang community. Use of smoke for killing of adult mosquito was predicted by illiteracy. Promotion of literacy and participation in health education are vital component in terms of knowledge and practice.

Environmental data analysis and remote sensing for early detection of dengue and malaria

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Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Rosy, Dilara A.

2014-06-01

Malaria and dengue fever are the two most common mosquito-transmitted diseases, leading to millions of serious illnesses and deaths each year. Because the mosquito vectors are sensitive to environmental conditions such as temperature, precipitation, and humidity, it is possible to map areas currently or imminently at high risk for disease outbreaks using satellite remote sensing. In this paper we propose the development of an operational geospatial system for malaria and dengue fever early warning; this can be done by bringing together geographic information system (GIS) tools, artificial neural networks (ANN) for efficient pattern recognition, the best available ground-based epidemiological and vector ecology data, and current satellite remote sensing capabilities. We use Vegetation Health Indices (VHI) derived from visible and infrared radiances measured by satellite-mounted Advanced Very High Resolution Radiometers (AVHRR) and available weekly at 4-km resolution as one predictor of malaria and dengue fever risk in Bangladesh. As a study area, we focus on Bangladesh where malaria and dengue fever are serious public health threats. The technology developed will, however, be largely portable to other countries in the world and applicable to other disease threats. A malaria and dengue fever early warning system will be a boon to international public health, enabling resources to be focused where they will do the most good for stopping pandemics, and will be an invaluable decision support tool for national security assessment and potential troop deployment in regions susceptible to disease outbreaks.

[Malaria and hematological aspects among residents to be impacted by reservoirs for the Santo Antônio and Jirau Hydroelectric Power Stations, Rondônia State, Brazil].

Science.gov (United States)

Katsuragawa, Tony Hiroshi; Cunha, Roberto Penna de Almeida; de Souza, Daniele Cristina Apoluceno; Gil, Luiz Herman Soares; Cruz, Rafael Bastos; Silva, Alexandre de Almeida E; Tada, Mauro Shugiro; da Silva, Luiz Hildebrando Pereira

2009-07-01

In Rondônia State, Brazil, two new hydroelectric plants, Santo Antônio and Jirau, are scheduled for construction on the Madeira River, upriver from the State capital, Porto Velho. The current study analyzes malaria prevalence before the construction and provides information on the possible impacts of malaria burden related to the influx of thousands of persons attracted by direct and indirect employment opportunities. According to the findings, malaria is present throughout the region, with varying prevalence rates. The existence of potential asymptomatic malaria carriers among the local population may be epidemiologically relevant and should be considered in the malaria control programs organized by public authorities and companies responsible for building the power plants, aimed at early diagnosis and treatment, vector control, water supply, and infrastructure in the urban areas.

Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data

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Jorge Alberto Achcar

2011-12-01

Full Text Available INTRODUCTION: Malaria is a serious problem in the Brazilian Amazon region, and the detection of possible risk factors could be of great interest for public health authorities. The objective of this article was to investigate the association between environmental variables and the yearly registers of malaria in the Amazon region using Bayesian spatiotemporal methods. METHODS: We used Poisson spatiotemporal regression models to analyze the Brazilian Amazon forest malaria count for the period from 1999 to 2008. In this study, we included some covariates that could be important in the yearly prediction of malaria, such as deforestation rate. We obtained the inferences using a Bayesian approach and Markov Chain Monte Carlo (MCMC methods to simulate samples for the joint posterior distribution of interest. The discrimination of different models was also discussed. RESULTS: The model proposed here suggests that deforestation rate, the number of inhabitants per km², and the human development index (HDI are important in the prediction of malaria cases. CONCLUSIONS: It is possible to conclude that human development, population growth, deforestation, and their associated ecological alterations are conducive to increasing malaria risk. We conclude that the use of Poisson regression models that capture the spatial and temporal effects under the Bayesian paradigm is a good strategy for modeling malaria counts.

Use of Poisson spatiotemporal regression models for the Brazilian Amazon Forest: malaria count data.

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Achcar, Jorge Alberto; Martinez, Edson Zangiacomi; Souza, Aparecida Doniseti Pires de; Tachibana, Vilma Mayumi; Flores, Edilson Ferreira

2011-01-01

Malaria is a serious problem in the Brazilian Amazon region, and the detection of possible risk factors could be of great interest for public health authorities. The objective of this article was to investigate the association between environmental variables and the yearly registers of malaria in the Amazon region using bayesian spatiotemporal methods. We used Poisson spatiotemporal regression models to analyze the Brazilian Amazon forest malaria count for the period from 1999 to 2008. In this study, we included some covariates that could be important in the yearly prediction of malaria, such as deforestation rate. We obtained the inferences using a bayesian approach and Markov Chain Monte Carlo (MCMC) methods to simulate samples for the joint posterior distribution of interest. The discrimination of different models was also discussed. The model proposed here suggests that deforestation rate, the number of inhabitants per km², and the human development index (HDI) are important in the prediction of malaria cases. It is possible to conclude that human development, population growth, deforestation, and their associated ecological alterations are conducive to increasing malaria risk. We conclude that the use of Poisson regression models that capture the spatial and temporal effects under the bayesian paradigm is a good strategy for modeling malaria counts.

Congenital malaria in China.

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Zhi-Yong Tao

2014-03-01

Full Text Available BACKGROUND: Congenital malaria, in which infants are directly infected with malaria parasites from their mother prior to or during birth, is a potentially life-threatening condition that occurs at relatively low rates in malaria-endemic regions. It is recognized as a serious problem in Plasmodium falciparum-endemic sub-Saharan Africa, where recent data suggests that it is more common than previously believed. In such regions where malaria transmission is high, neonates may be protected from disease caused by congenital malaria through the transfer of maternal antibodies against the parasite. However, in low P. vivax-endemic regions, immunity to vivax malaria is low; thus, there is the likelihood that congenital vivax malaria poses a more significant threat to newborn health. Malaria had previously been a major parasitic disease in China, and congenital malaria case reports in Chinese offer valuable information for understanding the risks posed by congenital malaria to neonatal health. As most of the literature documenting congenital malaria cases in China are written in Chinese and therefore are not easily accessible to the global malaria research community, we have undertaken an extensive review of the Chinese literature on this subject. METHODS/PRINCIPAL FINDINGS: Here, we reviewed congenital malaria cases from three major searchable Chinese journal databases, concentrating on data from 1915 through 2011. Following extensive screening, a total of 104 cases of congenital malaria were identified. These cases were distributed mainly in the eastern, central, and southern regions of China, as well as in the low-lying region of southwest China. The dominant species was P. vivax (92.50%, reflecting the malaria parasite species distribution in China. The leading clinical presentation was fever, and other clinical presentations were anaemia, jaundice, paleness, diarrhoea, vomiting, and general weakness. With the exception of two cases, all patients

Assessing the risk of self-diagnosed malaria in urban informal settlements of Nairobi using self-reported morbidity survey

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Mugisha Frederick

2007-05-01

Full Text Available Abstract Background Because of the belief that Nairobi is a low risk zone for malaria, little empirical data exists on malaria risk in the area. The aim of this study was to explore the risk of perceived malaria and some associated factors in Nairobi informal settlements using self-reported morbidity survey. Methods The survey was conducted from May to August 2004 on 7,288 individuals in two informal settlements of Nairobi. Participants were asked to report illnesses they experienced in the past 14 days. Logistic regression was used to estimate the odds of perceived-malaria. The model included variables such as site of residence, age, ethnicity and number of reported symptoms. Results Participants reported 165 illnesses among which malaria was the leading cause (28.1%. The risk of perceived-malaria was significantly higher in Viwandani compared to Korogocho (OR 1.61, 95%CI: 1.10–2.26. Participants in age group 25–39 years had significantly higher odds of perceived-malaria compared to those under-five years (OR 2.07, 95%CI: 1.43–2.98. The Kikuyu had reduced odds of perceived-malaria compared to other ethnic groups. Individuals with five and more symptoms had higher odds compared to those with no symptoms (OR 23.69, 95%CI: 12.98–43.23. Conclusion Malaria was the leading cause of illness as perceived by the residents in the two informal settlements. This was rational as the number of reported symptoms was highly associated with the risk of reporting the illness. These results highlight the need for a more comprehensive assessment of malaria epidemiology in Nairobi to be able to offer evidence-based guidance to policy on malaria in Kenya and particularly in Nairobi.

Study of the malaria situation in forested foothill and nearby plain areas of Myanmar.

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Myint, L; Ye, H

1991-12-01

A longitudinal demographic-parasitological survey on malaria was conducted at 10 weekly intervals starting from September in one foothill village with the population of 1,095 and one epidemiologically comparable plain village with the population of 962 in Kyauktaga township, Bago division, 120 miles north of Yangon. The objective was to describe and analyse the current malaria situation in a forested foothill area and an adjacent plain area. Ten weekly blood film collections for malaria parasite examination, six monthly sera collections on filter paper for serological examination from the whole study population and ten weekly splenic measurements from 2-9 year children were done. The malaria parasite rate in the foothill area was invariably higher than that in the plain area in all age groups throughout the study period. Moreover, the parasite rate decreased with the increase in distance from the forested foothill area indicating that the deep forest malaria may have some influence on the foothill villages. The total age specific parasite rate in foothill villages was found to be highest in the 5-8 year age group and decreased as the age advanced which may be due to the increasing immunity. The study revealed the presence of local transmission in the foothill village. From these data it is evident that new village sites should be chosen at least 5 miles away from the forest fringe and the malaria control measures in the plain area should utilize chemoprophylaxis and effective chemotherapy focusing on the people who travel into the forest.

Avian malaria Plasmodium relictum in native Hawaiian forest birds: epizootiology and demographic impacts on ‵apapane Himatione sanguinea

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Atkinson, Carter T.; Samuel, Michael D.

2010-01-01

The role of introduced avian malaria Plasmodium relictum in the decline and extinction of native Hawaiian forest birds has become a classic example of the potential effect of invasive diseases on biological diversity of naïve populations. However, empirical evidence describing the impact of avian malaria on fitness of Hawai‵i's endemic forest birds is limited, making it difficult to determine the importance of disease among the suite of potential limiting factors affecting the distribution and abundance of this threatened avifauna. We combined epidemiological force-of-infection with multistate capture––recapture models to evaluate a 7-year longitudinal study of avian malaria in ‵apapane, a relatively common native honeycreeper within mid-elevation Hawaiian forests. We found that malaria transmission was seasonal in this mid-elevation forest; transmission peaked during fall and during some years produced epizootic mortality events. Estimated annual mortality of hatch-year birds typically exceeded 50% and mortality of adults exceeded 25% during epizootics. The substantial impact of avian malaria on this relatively common native species demonstrates the key role this disease has played in the decline and extinction of Hawaiian forest birds.

Assessment of climate-driven variations in malaria incidence in Swaziland: toward malaria elimination.

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Chuang, Ting-Wu; Soble, Adam; Ntshalintshali, Nyasatu; Mkhonta, Nomcebo; Seyama, Eric; Mthethwa, Steven; Pindolia, Deepa; Kunene, Simon

2017-06-01

Swaziland aims to eliminate malaria by 2020. However, imported cases from neighbouring endemic countries continue to sustain local parasite reservoirs and initiate transmission. As certain weather and climatic conditions may trigger or intensify malaria outbreaks, identification of areas prone to these conditions may aid decision-makers in deploying targeted malaria interventions more effectively. Malaria case-surveillance data for Swaziland were provided by Swaziland's National Malaria Control Programme. Climate data were derived from local weather stations and remote sensing images. Climate parameters and malaria cases between 2001 and 2015 were then analysed using seasonal autoregressive integrated moving average models and distributed lag non-linear models (DLNM). The incidence of malaria in Swaziland increased between 2005 and 2010, especially in the Lubombo and Hhohho regions. A time-series analysis indicated that warmer temperatures and higher precipitation in the Lubombo and Hhohho administrative regions are conducive to malaria transmission. DLNM showed that the risk of malaria increased in Lubombo when the maximum temperature was above 30 °C or monthly precipitation was above 5 in. In Hhohho, the minimum temperature remaining above 15 °C or precipitation being greater than 10 in. might be associated with malaria transmission. This study provides a preliminary assessment of the impact of short-term climate variations on malaria transmission in Swaziland. The geographic separation of imported and locally acquired malaria, as well as population behaviour, highlight the varying modes of transmission, part of which may be relevant to climate conditions. Thus, the impact of changing climate conditions should be noted as Swaziland moves toward malaria elimination.

Social and environmental malaria risk factors in urban areas of Ouagadougou, Burkina Faso

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Ouedraogo Herman

2009-01-01

Full Text Available Abstract Background Despite low endemicity, malaria remains a major health problem in urban areas where a high proportion of fevers are presumptively treated using anti-malarial drugs. Low acquired malaria immunity, behaviour of city-dwellers, access to health care and preventive interventions, and heterogenic suitability of urban ecosystems for malaria transmission contribute to the complexity of the malaria epidemiology in urban areas. Methods The study was designed to identify the determinants of malaria transmission estimated by the prevalence of anti-circumsporozoite (CSP antibodies, the prevalence and density of Plasmodium falciparum infection, and the prevalence of malarial disease in areas of Ouagadougou, Burkina-Faso. Thick blood smears, dried blood spots and clinical status have been collected from 3,354 randomly chosen children aged 6 months to 12 years using two cross-sectional surveys (during the dry and rainy seasons in eight areas from four ecological strata defined according to building density and land tenure (regular versus irregular. Demographic characteristics, socio-economic information, and sanitary and environmental data concerning the children or their households were simultaneously collected. Dependent variables were analysed using mixed multivariable models with random effects, taking into account the clustering of participants within compounds and areas. Results Overall prevalences of CSP-antibodies and P. falciparum infections were 7.7% and 16.6% during the dry season, and 12.4% and 26.1% during the rainy season, respectively, with significant differences according to ecological strata. Malaria risk was significantly higher among children who i lived in households with lower economic or education levels, iii near the hydrographic network, iv in sparsely built-up areas, v in irregularly built areas, vi who did not use a bed net, vii were sampled during the rainy season or ii had traveled outside of Ouagadougou

Malaria – a major health problem within an oil palm plantation around Popondetta, Papua New Guinea

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King Graham

2009-04-01

Full Text Available Abstract Background For companies operating in malaria endemic countries, malaria represents a substantial risk to workers and their dependants, and can lead to significantly reduced worker productivity. This study provides an overview of the malaria epidemiology within an oil palm plantation in Popondetta, south-eastern Papua New Guinea, its implication for the company with its employees and their families and the potential for control. Methods In 2006, we carried out a cross-sectional study within six company villages, which included the determination of parasite rates by conventional microscopy, interviews and haemoglobin measurements. Passive surveillance data were collected from the 13 company aid posts for the years 2005 and 2006. Results Malaria prevalence was found to be high: all-age prevalence was 33.5% (95% CI 30.1–37.0 in 723 individuals. Plasmodium falciparum was the dominant species, followed by Plasmodium vivax and Plasmodium malariae. Children between five and nine years of age were most affected (40.3%, 95% CI 0.32–0.49. Haemoglobin levels were found to be low; 11.0 g/dl (95% CI 10.8–11.1 for men and 10.4 g/dl (95% CI 10.3–10.5 for women, respectively. Plasmodium falciparum infections were significantly associated with anaemia (Hb Conclusion Malaria was found to be a major health burden in the Higaturu Oil Palm plantation, posing a high risk for company staff and their relatives, including expatriates and other non-immune workers. Reducing the malaria risk is a highly recommended investment for the company.

Intermittent preventive treatment with sulphadoxine-pyrimethamine is effective in preventing maternal and placental malaria in Ibadan, south-western Nigeria

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Mokuolu Olugbenga A

2007-07-01

Full Text Available Abstract Background Intermittent preventive treatment with sulphadoxine-pyrimethamine (IPT-SP is currently the recommended regimen for prevention of malaria in pregnancy in endemic areas. This study sets out to evaluate the effectiveness of IPT-SP in the prevention of maternal and placental malaria in parturient mothers in Ibadan, Nigeria, where the risk of malaria is present all year round. Method During a larger study evaluating the epidemiology of congenital malaria, the effect of malaria prophylaxis was examined in 983 parturient mothers. Five hundred and ninety eight mothers (60.8% received IPT-SP, 214 (21.8% received pyrimethamine (PYR and 171 (17.4% did not take any chemoprophylactic agent (NC. Results The prevalence of maternal parasitaemia in the IPT-SP, PYR and NC groups was 10.4%, 15.9% and 17% respectively (p = 0.021. The prevalence of placental parasitaemia was 10.5% in the IPT-SP, 16.8% PYR and 17% NC groups, respectively (p = 0.015. The prevalence of maternal anaemia (haematocrit Conclusion IPT-SP is effective in preventing maternal and placental malaria as well as improving pregnancy outcomes among parturient women in Ibadan, Nigeria. The implementation of the recently adopted IPT-SP strategy should be pursued with vigour as it holds great promise for reducing the burden of malaria in pregnancy in Nigeria.

Molecular Investigation into a Malaria Outbreak in Cusco, Peru: Plasmodium falciparum BV1 Lineage is Linked to a Second Outbreak in Recent Times

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Okoth, Sheila Akinyi; Chenet, Stella M.; Arrospide, Nancy; Gutierrez, Sonia; Cabezas, Cesar; Matta, Jose Antonio; Udhayakumar, Venkatachalam

2016-01-01

In November 2013, a Plasmodium falciparum malaria outbreak of 11 cases occurred in Cusco, southern Peru, where falciparum malaria had not been reported since 1946. Although initial microscopic diagnosis reported only Plasmodium vivax infection in each of the specimens, subsequent examination by the national reference laboratory confirmed P. falciparum infection in all samples. Molecular typing of four available isolates revealed identity as the B-variant (BV1) strain that was responsible for a malaria outbreak in Tumbes, northern Peru, between 2010 and 2012. The P. falciparum BV1 strain is multidrug resistant, can escape detection by PfHRP2-based rapid diagnostic tests, and has contributed to two malaria outbreaks in Peru. This investigation highlights the importance of accurate species diagnosis given the potential for P. falciparum to be reintroduced to regions where it may have been absent. Similar molecular epidemiological investigations can track the probable source(s) of outbreak parasite strains for malaria surveillance and control purposes. PMID:26483121

Climatic Variables and Malaria Morbidity in Mutale Local Municipality, South Africa: A 19-Year Data Analysis.

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Adeola, Abiodun M; Botai, Joel O; Rautenbach, Hannes; Adisa, Omolola M; Ncongwane, Katlego P; Botai, Christina M; Adebayo-Ojo, Temitope C

2017-11-08

The north-eastern parts of South Africa, comprising the Limpopo Province, have recorded a sudden rise in the rate of malaria morbidity and mortality in the 2017 malaria season. The epidemiological profiles of malaria, as well as other vector-borne diseases, are strongly associated with climate and environmental conditions. A retrospective understanding of the relationship between climate and the occurrence of malaria may provide insight into the dynamics of the disease's transmission and its persistence in the north-eastern region. In this paper, the association between climatic variables and the occurrence of malaria was studied in the Mutale local municipality in South Africa over a period of 19-year. Time series analysis was conducted on monthly climatic variables and monthly malaria cases in the Mutale municipality for the period of 1998-2017. Spearman correlation analysis was performed and the Seasonal Autoregressive Integrated Moving Average (SARIMA) model was developed. Microsoft Excel was used for data cleaning, and statistical software R was used to analyse the data and develop the model. Results show that both climatic variables' and malaria cases' time series exhibited seasonal patterns, showing a number of peaks and fluctuations. Spearman correlation analysis indicated that monthly total rainfall, mean minimum temperature, mean maximum temperature, mean average temperature, and mean relative humidity were significantly and positively correlated with monthly malaria cases in the study area. Regression analysis showed that monthly total rainfall and monthly mean minimum temperature ( R ² = 0.65), at a two-month lagged effect, are the most significant climatic predictors of malaria transmission in Mutale local municipality. A SARIMA (2,1,2) (1,1,1) model fitted with only malaria cases has a prediction performance of about 51%, and the SARIMAX (2,1,2) (1,1,1) model with climatic variables as exogenous factors has a prediction performance of about 72% in

The epidemiology and small-scale spatial heterogeneity of urinary schistosomiasis in Lusaka province, Zambia

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Christopher Simoonga

2008-11-01

Full Text Available In line with the aims of the “National Bilharzia Control Programme” and the “School Health and Nutrition Programme” in Zambia, a study on urinary schistosomiasis was conducted in 20 primary schools of Lusaka province to further our understanding of the epidemiology of the infection, and to enhance spatial targeting of control. We investigated risk factors associated with urinary schistosomiasis, and examined small-scale spatial heterogeneity in prevalence, using data collected from 1,912 schoolchildren, 6 to 15-year-old, recruited from 20 schools in Kafue and Luangwa districts. The risk factors identified included geographical location, altitude, normalized difference vegetation index (NDVI, maximum temperature, age, sex of the child and intermediate host snail abundance. Three logistic regression models were fitted assuming different random effects to allow for spatial structuring. The mean prevalence rate was 9.6%, with significance difference between young and older children (odds ratio (OR = 0.71; 95% confidence interval (CI = 0.51-0.96. The risk of infection was related to intermediate host snail abundance (OR = 1.03; 95% CI = 1.00-1.05 and vegetation cover (OR = 1.04; 95% CI = 1.00-1.07. Schools located either on the plateau and the valley also differed in prevalence and intensity of infection for moderate infection to none (OR = 1.64; 95% CI = 1.36- 1.96. The overall predictive performance of the spatial random effects model was higher than the ordinary logistic regression. In addition, evidence of heterogeneity of the infection risk was found at the micro-geographical level. A sound understanding of small-scale heterogeneity, caused by spatial aggregation of schoolchildren, is important to inform health planners for implementing control schistosomiasis interventions.

Malaria and the mobile and migrant population in Cambodia: a population movement framework to inform strategies for malaria control and elimination.

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Guyant, Philippe; Canavati, Sara E; Chea, Nguon; Ly, Po; Whittaker, Maxine Anne; Roca-Feltrer, Arantxa; Yeung, Shunmay

2015-06-20

The relationships between human population movement (HPM) and health are a concern at global level. In the case of malaria, those links are crucial in relation to the spread of drug resistant parasites and to the elimination of malaria in the Greater Mekong sub-Region (GMS) and beyond. The mobile and migrant populations (MMP) who are involved in forest related activities are both at high risk of being infected with malaria and at risk of receiving late and sub-standard treatment due to poor access to health services. In Cambodia, in 2012, the National Malaria Control Programme (NMCP) identified, as a key objective, the development of a specific strategy for MMPs in order to address these challenges. A population movement framework (PMF) for malaria was developed and operationalized in order to contribute to this strategy. A review of the published and unpublished literature was conducted. Based on a synthesis of the results, information was presented and discussed with experienced researchers and programme managers in the Cambodian NMCP and led to the development and refinement of a PMF for malaria. The framework was "tested" for face and content validity with national experts through a workshop approach. In the literature, HPM has been described using various spatial and temporal dimensions both in the context of the spread of anti-malarial drug resistance, and in the context of malaria elimination and previous classifications have categorized MMPs in Cambodia and the GMS through using a number of different criteria. Building on these previous models, the PMF was developed and then refined and populated with in-depth information relevant to Cambodia collected from social science research and field experiences in Cambodia. The framework comprises of the PMF itself, MMP activity profiles and a Malaria Risk Index which is a summation of three related indices: a vulnerability index, an exposure index and an access index which allow a qualitative ranking of malaria

Thalassemia and malaria: new insights into an old problem.

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Clegg, J B; Weatherall, D J

1999-01-01

The hemoglobinopathies are probably the world's most common genetic diseases: The World Health Organization has estimated that at least 5% of the population are carriers for one or other of the most serious forms, the alpha- and beta-thalassemias and the structural variant hemoglobins S, C, and E, which are found at polymorphic frequencies in many countries. All these hemoglobinopathies are believed to provide protection against malaria, and it is thought that, in malarial regions of the world, natural selection has been responsible for elevating and maintaining their gene frequencies, an idea first proposed 50 years ago by J.B.S. Haldane. Epidemiological studies undertaken in the 1950s on hemoglobin S in Africa provided support for the "malaria hypothesis," but until recently it has proved extremely difficult to verify it for the thalassemias. The application of molecular methods has, however, provided new opportunities to address this old question. Population and molecular genetic analysis of thalassemia variants, and microepidemiological studies of the relationship between alpha-thalassemia and malaria in the southwest Pacific, have provided unequivocal evidence for protection. Surprisingly, some of this protection appears to derive from enhanced susceptibility in very young thalassemic children to both Plasmodium falciparum and, especially, P. vivax, and this early exposure appears to provide the basis for better protection in later life.

Ranking malaria risk factors to guide malaria control efforts in African highlands.

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Protopopoff, Natacha; Van Bortel, Wim; Speybroeck, Niko; Van Geertruyden, Jean-Pierre; Baza, Dismas; D'Alessandro, Umberto; Coosemans, Marc

2009-11-25

Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Knowledge of malaria and practice of home management of malaria ...

African Journals Online (AJOL)

Background: Malaria is a preventable and treatable disease associated with high morbidity and mortality. It is the 3rd leading cause of death for children under five years worldwide. Home-based management of malaria may go a long way in reducing the attending morbidity and mortality associated with malaria in this group ...

An analysis of the spatial distribution of Plasmodium sporozoites and effects of climatic correlates on malaria infection in Anyigba town, Nigeria.

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Ifatimehin, Olarewaju Oluseyi; Falola, O O; Odogbo, E V

2013-10-27

The infectivity of sporozoites on both mosquitoes and human is the major cause of malaria infection on its host, Man. Malaria infection had continued to blossom despite measures to curb it. Clinically diagnosed malaria data for 3 years, capture of mosquitoes for laboratory analysis to determining the infectivity of sporozoites, responses from the population on the number of episode of malaria in the last 60 days were all collected and generated, and also subjected to various analysis using methods accepted tools and methods. A fifteen weeks climatic data was also collected. It was discovered that malaria incidence of 467.2853/1000 persons is very high. This high rate is possible as out of every 10 mosquitoes in Anyigba, 4 are infected by sporozoites and can possibly transmit these sporozoites during blood feeding on the population. This is affirmed by the prevalence of malaria by 54.75% among Anyigba's population. At p>001 (0.829), climatic variables and sporozoites rate showed a strong affinity with the prevalence of malaria. The risk map showed that the university community and the surrounding students' lodges are areas of very high risk. Therefore, the populace is strongly advised to employed practicable measures such as regular environmental sanitation and the use of Insecticidal Treated Nets (ITN) in order to drastically address this epidemic.

Pre-elimination of malaria on the island of Príncipe

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do Rosario Virgilio E

2010-01-01

Full Text Available Abstract Background Plasmodium falciparum is the major species responsible for malaria transmission on the island of Príncipe, in the Republic of São Tomé and Príncipe (STP. Indoor residual spraying (IRS has been intensively deployed on the island, since 2003. Other measures included intermittent preventive therapy (IPT, since 2004, as well as artemisinin-based therapy (ACT and long-lasting insecticidal nets (LLINs from 2005. The work was coordinated by the Ministry of Health of STP through their Centro Nacional de Endemias (CNE and the impact of such an integrated control programme on the prevalence and epidemiology of malaria in Príncipe was evaluated. Methods The scaling-up of preventive strategies included IRS, LLINs, IPT for pregnant women, as well as early diagnosis and prompt treatment with ACT. Regular implementation of an island-wide IRS programme was carried out yearly in 2003-2005, and later in 2008. Malaria incidence and prevalence were estimated based on passive case detection and active case detection, respectively. Slide positivity rate (SPR was used as an indicator of any increase of malaria cases during and after the control programme was initiated. Results Regular IRS achieved a coverage of 85-90% for each of the four annual cycles (2003-2005, annually and one spraying in 2008 while usage of LLINs was never superior to 50% from 2006-2009. Coverage of IPT steadily increased from 50% in 2004 to 80% in 2008. Since 2006, over 90% of uncomplicated malaria patients received ACT treatment. Severe malaria cases were hospitalized and treated with quinine. Monthly trends of SPR were constantly over 50% in 2003, but steadily decreased below 10% in 2006. SPR has been below 5% since 2007, but an increase to up to 15% was noted in June 2009 when 16 imported cases were detected. A steep decline by 99% of malaria incidence was observed between 2003 and 2008, with an incidence risk of the population of five per thousand, in 2008. No

[Congenital malaria due to Plasmodium falciparum and Plasmodium malariae].

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Zenz, W; Trop, M; Kollaritsch, H; Reinthaler, F

2000-05-19

Increasing tourism and growing numbers of immigrants from malaria-endemic countries are leading to a higher importation rate of rare tropical disorders in European countries. We describe, to the best of our knowledge, the first case of connatal malaria in Austria. The patient is the first child of a 24 year old mother who was born in Ghana and immigrated to Austria one and a half years before delivery. She did not stay in an endemic region during this period and did not show fever or any other signs of malaria. The boy was healthy for the first six weeks of his life. In the 8th week of life he was admitted to our hospital due to persistent fever of unknown origin. On physical examination he showed only mild splenomegaly. Routine laboratory testing revealed mild hemolytic anemia with a hemoglobin value of 8.3 g/l. In the blood smear Plasmodium falciparum and Plasmodium malariae were detected. Oral therapy with quinine hydrochloride was successful and blood smears became negative for Plasmodia within 6 days. This case shows that congenital malaria can occur in children of clinically healthy women who were born in malaria-endemic areas even one and a half year after they have immigrated to non-endemic regions.

Spatio-temporal distribution of mosquitoes and risk of malaria infection in Rwanda

NARCIS (Netherlands)

Hakizimana, Emmanuel; Karema, Corine; Munyakanage, Dunia; Githure, John; Mazarati, Jean Baptiste; Tongren, Jon Eric; Takken, Willem; Binagwaho, Agnes; Koenraadt, Constantianus J.M.

2018-01-01

To date, the Republic of Rwanda has not systematically reported on distribution, diversity and malaria infectivity rate of mosquito species throughout the country. Therefore, we assessed the spatial and temporal variation of mosquitoes in the domestic environment, as well as the nocturnal biting

The US President's Malaria Initiative, Plasmodium falciparum transmission and mortality: A modelling study.

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Winskill, Peter; Slater, Hannah C; Griffin, Jamie T; Ghani, Azra C; Walker, Patrick G T

2017-11-01

Although significant progress has been made in reducing malaria transmission globally in recent years, a large number of people remain at risk and hence the gains made are fragile. Funding lags well behind amounts needed to protect all those at risk and ongoing contributions from major donors, such as the President's Malaria Initiative (PMI), are vital to maintain progress and pursue further reductions in burden. We use a mathematical modelling approach to estimate the impact of PMI investments to date in reducing malaria burden and to explore the potential negative impact on malaria burden should a proposed 44% reduction in PMI funding occur. We combined an established mathematical model of Plasmodium falciparum transmission dynamics with epidemiological, intervention, and PMI-financing data to estimate the contribution PMI has made to malaria control via funding for long-lasting insecticide treated nets (LLINs), indoor residual spraying (IRS), and artemisinin combination therapies (ACTs). We estimate that PMI has prevented 185 million (95% CrI: 138 million, 230 million) malaria cases and saved 940,049 (95% CrI: 545,228, 1.4 million) lives since 2005. If funding is maintained, PMI-funded interventions are estimated to avert a further 162 million (95% CrI: 116 million, 194 million) cases, saving a further 692,589 (95% CrI: 392,694, 955,653) lives between 2017 and 2020. With an estimate of US$94 (95% CrI: US$51, US$166) per Disability Adjusted Life Year (DALY) averted, PMI-funded interventions are highly cost-effective. We also demonstrate the further impact of this investment by reducing caseloads on health systems. If a 44% reduction in PMI funding were to occur, we predict that this loss of direct aid could result in an additional 67 million (95% CrI: 49 million, 82 million) cases and 290,649 (95% CrI: 167,208, 395,263) deaths between 2017 and 2020. We have not modelled indirect impacts of PMI funding (such as health systems strengthening) in this analysis. Our

Mapping Malaria Transmission Risk in Northern Morocco Using Entomological and Environmental Data

Directory of Open Access Journals (Sweden)

E. Adlaoui

2011-01-01

Full Text Available Malaria resurgence risk in Morocco depends, among other factors, on environmental changes as well as the introduction of parasite carriers. The aim of this paper is to analyze the receptivity of the Loukkos area, large wetlands in Northern Morocco, to quantify and to map malaria transmission risk in this region using biological and environmental data. This risk was assessed on entomological risk basis and was mapped using environmental markers derived from satellite imagery. Maps showing spatial and temporal variations of entomological risk for Plasmodium vivax and P. falciparum were produced. Results showed this risk to be highly seasonal and much higher in rice fields than in swamps. This risk is lower for Afrotropical P. falciparum strains because of the low infectivity of Anopheles labranchiae, principal malaria vector in Morocco. However, it is very high for P. vivax mainly during summer corresponding to the rice cultivation period. Although the entomological risk is high in Loukkos region, malaria resurgence risk remains very low, because of the low vulnerability of the area.

Ranking malaria risk factors to guide malaria control efforts in African highlands.

Directory of Open Access Journals (Sweden)

Natacha Protopopoff

Full Text Available INTRODUCTION: Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. METHODS AND FINDINGS: A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. CONCLUSIONS: In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Surveillance and Control of Malaria Transmission in Thailand using Remotely Sensed Meteorological and Environmental Parameters

Science.gov (United States)

Kiang, Richard K.; Adimi, Farida; Soika, Valerii; Nigro, Joseph

2007-01-01

These slides address the use of remote sensing in a public health application. Specifically, this discussion focuses on the of remote sensing to detect larval habitats to predict current and future endemicity and identify key factors that sustain or promote transmission of malaria in a targeted geographic area (Thailand). In the Malaria Modeling and Surveillance Project, which is part of the NASA Applied Sciences Public Health Applications Program, we have been developing techniques to enhance public health's decision capability for malaria risk assessments and controls. The main objectives are: 1) identification of the potential breeding sites for major vector species; 2) implementation of a risk algorithm to predict the occurrence of malaria and its transmission intensity; 3) implementation of a dynamic transmission model to identify the key factors that sustain or intensify malaria transmission. The potential benefits are: 1) increased warning time for public health organizations to respond to malaria outbreaks; 2) optimized utilization of pesticide and chemoprophylaxis; 3) reduced likelihood of pesticide and drug resistance; and 4) reduced damage to environment. !> Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. The NASA Earth science data sets that have been used for malaria surveillance and risk assessment include AVHRR Pathfinder, TRMM, MODIS, NSIPP, and SIESIP. Textural-contextual classifications are used to identify small larval habitats. Neural network methods are used to model malaria cases as a function of the remotely sensed parameters. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records. Discrete event simulations are used for modeling the detailed interactions among the vector life cycle, sporogonic cycle and human infection cycle, under the explicit influences of selected extrinsic and intrinsic factors