Assessing respiratory pathogen communities in bighorn sheep populations: Sampling realities, challenges, and improvements.

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Carson J Butler

Full Text Available Respiratory disease has been a persistent problem for the recovery of bighorn sheep (Ovis canadensis, but has uncertain etiology. The disease has been attributed to several bacterial pathogens including Mycoplasma ovipneumoniae and Pasteurellaceae pathogens belonging to the Mannheimia, Bibersteinia, and Pasteurella genera. We estimated detection probability for these pathogens using protocols with diagnostic tests offered by a fee-for-service laboratory and not offered by a fee-for-service laboratory. We conducted 2861 diagnostic tests on swab samples collected from 476 bighorn sheep captured across Montana and Wyoming to gain inferences regarding detection probability, pathogen prevalence, and the power of different sampling methodologies to detect pathogens in bighorn sheep populations. Estimated detection probability using fee-for-service protocols was less than 0.50 for all Pasteurellaceae and 0.73 for Mycoplasma ovipneumoniae. Non-fee-for-service Pasteurellaceae protocols had higher detection probabilities, but no single protocol increased detection probability of all Pasteurellaceae pathogens to greater than 0.50. At least one protocol resulted in an estimated detection probability of 0.80 for each pathogen except Mannheimia haemolytica, for which the highest detection probability was 0.45. In general, the power to detect Pasteurellaceae pathogens at low prevalence in populations was low unless many animals were sampled or replicate samples were collected per animal. Imperfect detection also resulted in low precision when estimating prevalence for any pathogen. Low and variable detection probabilities for respiratory pathogens using live-sampling protocols may lead to inaccurate conclusions regarding pathogen community dynamics and causes of bighorn sheep respiratory disease epizootics. We recommend that agencies collect multiples samples per animal for Pasteurellaceae detection, and one sample for Mycoplasma ovipneumoniae detection from

The Tick Microbiome: Why Non-pathogenic Microorganisms Matter in Tick Biology and Pathogen Transmission

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Sarah I. Bonnet

2017-06-01

Full Text Available Ticks are among the most important vectors of pathogens affecting humans and other animals worldwide. They do not only carry pathogens however, as a diverse group of commensal and symbiotic microorganisms are also present in ticks. Unlike pathogens, their biology and their effect on ticks remain largely unexplored, and are in fact often neglected. Nonetheless, they can confer multiple detrimental, neutral, or beneficial effects to their tick hosts, and can play various roles in fitness, nutritional adaptation, development, reproduction, defense against environmental stress, and immunity. Non-pathogenic microorganisms may also play a role in driving transmission of tick-borne pathogens (TBP, with many potential implications for both human and animal health. In addition, the genetic proximity of some pathogens to mutualistic symbionts hosted by ticks is evident when studying phylogenies of several bacterial genera. The best examples are found within members of the Rickettsia, Francisella, and Coxiella genera: while in medical and veterinary research these bacteria are traditionally recognized as highly virulent vertebrate pathogens, it is now clear to evolutionary ecologists that many (if not most Coxiella, Francisella, and Rickettsia bacteria are actually non-pathogenic microorganisms exhibiting alternative lifestyles as mutualistic ticks symbionts. Consequently, ticks represent a compelling yet challenging system in which to study microbiomes and microbial interactions, and to investigate the composition, functional, and ecological implications of bacterial communities. Ultimately, deciphering the relationships between tick microorganisms as well as tick symbiont interactions will garner invaluable information, which may aid in the future development of arthropod pest and vector-borne pathogen transmission control strategies.

Molecular surveillance of traditional and emerging pathogens associated with canine infectious respiratory disease.

Science.gov (United States)

Decaro, Nicola; Mari, Viviana; Larocca, Vittorio; Losurdo, Michele; Lanave, Gianvito; Lucente, Maria Stella; Corrente, Marialaura; Catella, Cristiana; Bo, Stefano; Elia, Gabriella; Torre, Giorgio; Grandolfo, Erika; Martella, Vito; Buonavoglia, Canio

2016-08-30

A molecular survey for traditional and emerging pathogens associated with canine infectious respiratory disease (CIRD) was conducted in Italy between 2011 and 2013 on a total of 138 dogs, including 78 early acute clinically ill CIRD animals, 22 non-clinical but exposed to clinically ill CIRD dogs and 38 CIRD convalescent dogs. The results showed that canine parainfluenza virus (CPIV) was the most commonly detected CIRD pathogen, followed by canine respiratory coronavirus (CRCoV), Bordetella bronchiseptica, Mycoplasma cynos, Mycoplasma canis and canine pneumovirus (CnPnV). Some classical CIRD agents, such as canine adenoviruses, canine distemper virus and canid herpesvirus 1, were not detected at all, as were not other emerging respiratory viruses (canine influenza virus, canine hepacivirus) and bacteria (Streptococcus equi subsp. zooepidemicus). Most severe forms of respiratory disease were observed in the presence of CPIV, CRCoV and M. cynos alone or in combination with other pathogens, whereas single CnPnV or M. canis infections were detected in dogs with no or very mild respiratory signs. Interestingly, only the association of M. cynos (alone or in combination with either CRCoV or M. canis) with severe clinical forms was statistically significant. The study, while confirming CPIV as the main responsible for CIRD occurrence, highlights the increasing role of recently discovered viruses, such as CRCoV and CnPnV, for which effective vaccines are not available in the market. Copyright © 2016 Elsevier B.V. All rights reserved.

Implementing hospital-based surveillance for severe acute respiratory infections caused by influenza and other respiratory pathogens in New Zealand

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Q Sue Huang

2014-05-01

Full Text Available Background: Recent experience with pandemic influenza A(H1N1pdm09 highlighted the importance of global surveillance for severe respiratory disease to support pandemic preparedness and seasonal influenza control. Improved surveillance in the southern hemisphere is needed to provide critical data on influenza epidemiology, disease burden, circulating strains and effectiveness of influenza prevention and control measures. Hospital-based surveillance for severe acute respiratory infection (SARI cases was established in New Zealand on 30 April 2012. The aims were to measure incidence, prevalence, risk factors, clinical spectrum and outcomes for SARI and associated influenza and other respiratory pathogen cases as well as to understand influenza contribution to patients not meeting SARI case definition. Methods/Design: All inpatients with suspected respiratory infections who were admitted overnight to the study hospitals were screened daily. If a patient met the World Health Organization’s SARI case definition, a respiratory specimen was tested for influenza and other respiratory pathogens. A case report form captured demographics, history of presenting illness, co-morbidities, disease course and outcome and risk factors. These data were supplemented from electronic clinical records and other linked data sources. Discussion: Hospital-based SARI surveillance has been implemented and is fully functioning in New Zealand. Active, prospective, continuous, hospital-based SARI surveillance is useful in supporting pandemic preparedness for emerging influenza A(H7N9 virus infections and seasonal influenza prevention and control.

Comparison between nasopharyngeal swab and nasal wash, using culture and PCR, in the detection of potential respiratory pathogens.

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Gritzfeld, Jenna F; Roberts, Paul; Roche, Lorna; El Batrawy, Sherouk; Gordon, Stephen B

2011-04-13

Nasopharyngeal carriage of potential pathogens is important as it is both the major source of transmission and the prerequisite of invasive disease. New methods for detecting carriage could improve comfort, accuracy and laboratory utility. The aims of this study were to compare the sensitivities of a nasopharyngeal swab (NPS) and a nasal wash (NW) in detecting potential respiratory pathogens in healthy adults using microbiological culture and PCR. Healthy volunteers attended for nasal washing and brushing of the posterior nasopharynx. Conventional and real-time PCR were used to detect pneumococcus and meningococcus. Statistical differences between the two nasal sampling methods were determined using a nonparametric Mann-Whitney U test; differences between culture and PCR methods were determined using the McNemar test.Nasal washing was more comfortable for volunteers than swabbing (n = 24). In detection by culture, the NW was significantly more likely to detect pathogens than the NPS (p < 0.00001). Overall, there was a low carriage rate of pathogens in this sample; no significant difference was seen in the detection of bacteria between culture and PCR methods. Nasal washing and PCR may provide effective alternatives to nasopharyngeal swabbing and classical microbiology, respectively.

Comparison between nasopharyngeal swab and nasal wash, using culture and PCR, in the detection of potential respiratory pathogens

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El Batrawy Sherouk

2011-04-01

Full Text Available Abstract Background Nasopharyngeal carriage of potential pathogens is important as it is both the major source of transmission and the prerequisite of invasive disease. New methods for detecting carriage could improve comfort, accuracy and laboratory utility. The aims of this study were to compare the sensitivities of a nasopharyngeal swab (NPS and a nasal wash (NW in detecting potential respiratory pathogens in healthy adults using microbiological culture and PCR. Results Healthy volunteers attended for nasal washing and brushing of the posterior nasopharynx. Conventional and real-time PCR were used to detect pneumococcus and meningococcus. Statistical differences between the two nasal sampling methods were determined using a nonparametric Mann-Whitney U test; differences between culture and PCR methods were determined using the McNemar test. Nasal washing was more comfortable for volunteers than swabbing (n = 24. In detection by culture, the NW was significantly more likely to detect pathogens than the NPS (p Conclusions Nasal washing and PCR may provide effective alternatives to nasopharyngeal swabbing and classical microbiology, respectively.

Early immune response patterns to pathogenic bacteria are associated to increased risk of lower respiratory infections in children

DEFF Research Database (Denmark)

Vissing, N. H.; Larsen, Jeppe Madura; Rasmussen, Mette Annelie

2014-01-01

Neonatal colonisation of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood (1). Therefore, we hypothesized that children developing LRI have an abnormal immune response to pathogenic bacteria in infancy. We aimed...... to characterise the systemic immune response to pathogenic bacteria at the age of 6 months and study the association with incidence of LRI during the first 3 years of life....

Infection prevention and control measures for acute respiratory infections in healthcare settings: an update.

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Seto, W H; Conly, J M; Pessoa-Silva, C L; Malik, M; Eremin, S

2013-01-01

Viruses account for the majority of the acute respiratory tract infections (ARIs) globally with a mortality exceeding 4 million deaths per year. The most commonly encountered viruses, in order of frequency, include influenza, respiratory syncytial virus, parainfluenza and adenovirus. Current evidence suggests that the major mode of transmission of ARls is through large droplets, but transmission through contact (including hand contamination with subsequent self-inoculation) and infectious respiratory aerosols of various sizes and at short range (coined as "opportunistic" airborne transmission) may also occur for some pathogens. Opportunistic airborne transmission may occur when conducting highrisk aerosol generating procedures and airborne precautions will be required in this setting. General infection control measures effective for all respiratory viral infections are reviewed and followed by discussion on some of the common viruses, including severe acute respiratory syndrome (SARS) coronavirus and the recently discovered novel coronavirus.

Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review

Science.gov (United States)

Warren‐Gash, Charlotte; Fragaszy, Ellen; Hayward, Andrew C.

2012-01-01

Please cite this paper as: Warren‐Gash et al. (2012) Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12015. Hand hygiene may be associated with modest protection against some acute respiratory tract infections, but its specific role in influenza transmission in different settings is unclear. We aimed to review evidence that improving hand hygiene reduces primary and secondary transmission of (i) influenza and (ii) acute respiratory tract infections in community settings. We searched Medline, Embase, Global Health and Cochrane databases up to 13 February 2012 for reports in any language of original research investigating the effect of hand hygiene on influenza or acute respiratory tract infection where aetiology was unspecified in community settings including institutions such as schools, and domestic residences. Data were presented and quality rated across outcomes according to the Grading of Recommendations Assessment, Development and Evaluation system. Sixteen articles met inclusion criteria. There was moderate to low‐quality evidence of a reduction in both influenza and respiratory tract infection with hand hygiene interventions in schools, greatest in a lower–middle‐income setting. There was high‐quality evidence of a small reduction in respiratory infection in childcare settings. There was high‐quality evidence for a large reduction in respiratory infection with a hand hygiene intervention in squatter settlements in a low‐income setting. There was moderate‐ to high‐quality evidence of no effect on secondary transmission of influenza in households that had already experienced an index case. While hand hygiene interventions have potential to reduce transmission of influenza and acute respiratory tract infections, their effectiveness varies depending on setting, context and compliance. PMID:23043518

Detection of respiratory bacterial pathogens causing atypical pneumonia by multiplex Lightmix® RT-PCR.

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Wagner, Karoline; Springer, Burkard; Imkamp, Frank; Opota, Onya; Greub, Gilbert; Keller, Peter M

2018-04-01

Pneumonia is a severe infectious disease. In addition to common viruses and bacterial pathogens (e.g. Streptococcus pneumoniae), fastidious respiratory pathogens like Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp. can cause severe atypical pneumonia. They do not respond to penicillin derivatives, which may cause failure of antibiotic empirical therapy. The same applies for infections with B. pertussis and B. parapertussis, the cause of pertussis disease, that may present atypically and need to be treated with macrolides. Moreover, these fastidious bacteria are difficult to identify by culture or serology, and therefore often remain undetected. Thus, rapid and accurate identification of bacterial pathogens causing atypical pneumonia is crucial. We performed a retrospective method evaluation study to evaluate the diagnostic performance of the new, commercially available Lightmix ® multiplex RT-PCR assay that detects these fastidious bacterial pathogens causing atypical pneumonia. In this retrospective study, 368 clinical respiratory specimens, obtained from patients suffering from atypical pneumonia that have been tested negative for the presence of common agents of pneumonia by culture and viral PCR, were investigated. These clinical specimens have been previously characterized by singleplex RT-PCR assays in our diagnostic laboratory and were used to evaluate the diagnostic performance of the respiratory multiplex Lightmix ® RT-PCR. The multiplex RT-PCR displayed a limit of detection between 5 and 10 DNA copies for different in-panel organisms and showed identical performance characteristics with respect to specificity and sensitivity as in-house singleplex RT-PCRs for pathogen detection. The Lightmix ® multiplex RT-PCR assay represents a low-cost, time-saving and accurate diagnostic tool with high throughput potential. The time-to-result using an automated DNA extraction device for respiratory specimens followed by multiplex RT-PCR detection was

Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review.

OpenAIRE

Warren-Gash, C; Fragaszy, E; Hayward, AC

2012-01-01

: Please cite this paper as: Warren-Gash et al. (2012) Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12015. Hand hygiene may be associated with modest protection against some acute respiratory tract infections, but its specific role in influenza transmission in different settings is unclear. We aimed to review evidence that improving hand hygiene reduces primary an...

The detection and differentiation of canine respiratory pathogens using oligonucleotide microarrays.

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Wang, Lih-Chiann; Kuo, Ya-Ting; Chueh, Ling-Ling; Huang, Dean; Lin, Jiunn-Horng

2017-05-01

Canine respiratory diseases are commonly seen in dogs along with co-infections with multiple respiratory pathogens, including viruses and bacteria. Virus infections in even vaccinated dogs were also reported. The clinical signs caused by different respiratory etiological agents are similar, which makes differential diagnosis imperative. An oligonucleotide microarray system was developed in this study. The wild type and vaccine strains of canine distemper virus (CDV), influenza virus, canine herpesvirus (CHV), Bordetella bronchiseptica and Mycoplasma cynos were detected and differentiated simultaneously on a microarray chip. The detection limit is 10, 10, 100, 50 and 50 copy numbers for CDV, influenza virus, CHV, B. bronchiseptica and M. cynos, respectively. The clinical test results of nasal swab samples showed that the microarray had remarkably better efficacy than the multiplex PCR-agarose gel method. The positive detection rate of microarray and agarose gel was 59.0% (n=33) and 41.1% (n=23) among the 56 samples, respectively. CDV vaccine strain and pathogen co-infections were further demonstrated by the microarray but not by the multiplex PCR-agarose gel. The oligonucleotide microarray provides a highly efficient diagnosis alternative that could be applied to clinical usage, greatly assisting in disease therapy and control. Copyright © 2017 Elsevier B.V. All rights reserved.

Probiotic bacteria inhibit the bovine respiratory pathogen Mannheimia haemolytica serotype 1 in vitro.

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Amat, S; Subramanian, S; Timsit, E; Alexander, T W

2017-05-01

This study evaluated the potential of probiotic bacteria to inhibit growth and cell adhesion of the bovine respiratory pathogen Mannheimia haemoltyica serotype 1. The inhibitory effects of nine probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis, Streptococcus thermophilus and two Paenibacillus polymyxa strains) against M. haemolytica were evaluated using a spot-on-lawn method. Probiotic strains were then tested for their adherence to bovine bronchial epithelial (BBE) cells and the ability to displace and compete against M. haemolytica on BBE. Except for S. thermophilus, all probiotic strains inhibited the growth of M. haemolytica, with zones of inhibition ranging between 12 and 19 mm. Lactobacillus strains and Lactococcus lactis displayed greater (P probiotics (probiotics. The results of this study suggest that probiotics may have the potential to colonize the bovine respiratory tract, and exert antagonistic effects against M. haemolytica serotype 1. A common method to control bovine respiratory disease (BRD) in feedlots is through mass medication with antibiotics upon cattle entry (i.e. metaphylaxis). Increasingly, antimicrobial resistance in BRD bacterial pathogens has been observed in feedlots, which may have important implications for cattle health. In this study, probiotic strains were shown to adhere to bovine respiratory cells and inhibit the BRD pathogen M. haemolytica serotype 1 through competition and displacement. Probiotics may therefore offer a mitigation strategy to reduce BRD bacterial pathogens, in place of metaphylactic antimicrobials. © 2017 Her Majesty the Queen in Right of Canada Letters in Applied Microbiology © 2017 The Society for Applied Microbiology Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.

New Epidemiological and Clinical Signatures of 18 Pathogens from Respiratory Tract Infections Based on a 5-Year Study.

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Xiaohong Liao

Full Text Available Respiratory tract infections (RTIs are a heavy burden on society. However, due to the complex etiology of RTIs, the clinical diagnosis, treatment, and prevention of these infections remain challenging, especially in developing countries.To determine the epidemiological and clinical characteristics of 18 respiratory pathogens, we analyzed 12,502 patients with acute respiratory infections (ARIs by performing polymerase chain reaction (PCR on patient pharyngeal swabs.Samples positive for at least 1 pathogen were obtained from 48.42% of the total patients. Of these pathogen-positive patients, 17.99% were infected with more than 1 pathogen. Of the 18 pathogens analyzed, four were detected with a positive detection rate (PDR > 5%: influenza A virus (IAV > respiratory syncytial virus (RSV >Mycoplasma pneumoniae (MP > human coronavirus (HCoV. The pathogens with the 4 highest co-infection rates (CIRs were as follows: HCoV > human bocavirus (HBoV > enterovirus (EV > parainfluenza virus (PIV. The overall positive detection rate (PDR varied significantly according to patient age, the season and year of detection, and the disease subgroup, but not according to patient sex. The individual PDRs of the pathogens followed 3 types of distributions for patient sex, 4 types of distributions for patient age, 4 types of seasonal distributions, 2 types of seasonal epidemic trends, 4 types of yearly epidemic trends, and different susceptibility distributions in the disease subgroups. Additionally, the overall CIR showed significantly different distributions according to patient sex, patient age, and the disease subgroup, whereas the CIRs of individual pathogens suggested significant preference characteristics.IAV remains the most common pathogen among the pathogens analyzed. More effort should be directed toward the prevention and control of pathogens that show a trend of increasing incidence such as HCoV, human adenovirus (ADV, and RSV. Although clinically

Probable transmission of coxsackie B3 virus from human to chimpanzee, Denmark

DEFF Research Database (Denmark)

Nielsen, Sandra Cathrine Abel; Mourier, Tobias; Baandrup, Ulrik

2012-01-01

In 2010, a chimpanzee died at Copenhagen Zoo following an outbreak of respiratory disease among chimpanzees in the zoo. Identification of coxsackie B3 virus, a common human pathogen, as the causative agent, and its severe manifestation, raise questions about pathogenicity and transmissibility among...

Simultaneous Detection of 13 Key Bacterial Respiratory Pathogens by Combination of Multiplex PCR and Capillary Electrophoresis.

Science.gov (United States)

Jiang, Lu Xi; Ren, Hong Yu; Zhou, Hai Jian; Zhao, Si Hong; Hou, Bo Yan; Yan, Jian Ping; Qin, Tian; Chen, Yu

2017-08-01

Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction (PCR) and capillary electrophoresis (MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebacterium diphtheriae, and Streptococcus pyogenes. Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 152 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. This study revealed that the MPCE assay is a rapid, reliable, and high-throughput method with high specificity and sensitivity. This assay has great potential in the molecular epidemiological survey of respiratory pathogens. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review.

Science.gov (United States)

Warren-Gash, Charlotte; Fragaszy, Ellen; Hayward, Andrew C

2013-09-01

Hand hygiene may be associated with modest protection against some acute respiratory tract infections, but its specific role in influenza transmission in different settings is unclear. We aimed to review evidence that improving hand hygiene reduces primary and secondary transmission of (i) influenza and (ii) acute respiratory tract infections in community settings. We searched Medline, Embase, Global Health and Cochrane databases up to 13 February 2012 for reports in any language of original research investigating the effect of hand hygiene on influenza or acute respiratory tract infection where aetiology was unspecified in community settings including institutions such as schools, and domestic residences. Data were presented and quality rated across outcomes according to the Grading of Recommendations Assessment, Development and Evaluation system. Sixteen articles met inclusion criteria. There was moderate to low-quality evidence of a reduction in both influenza and respiratory tract infection with hand hygiene interventions in schools, greatest in a lower-middle-income setting. There was high-quality evidence of a small reduction in respiratory infection in childcare settings. There was high-quality evidence for a large reduction in respiratory infection with a hand hygiene intervention in squatter settlements in a low-income setting. There was moderate- to high-quality evidence of no effect on secondary transmission of influenza in households that had already experienced an index case. While hand hygiene interventions have potential to reduce transmission of influenza and acute respiratory tract infections, their effectiveness varies depending on setting, context and compliance. © 2012 John Wiley & Sons Ltd.

Equivalence of self- and staff-collected nasal swabs for the detection of viral respiratory pathogens.

Directory of Open Access Journals (Sweden)

Manas K Akmatov

Full Text Available BACKGROUND: The need for the timely collection of diagnostic biosamples during symptomatic episodes represents a major obstacle to large-scale studies on acute respiratory infection (ARI epidemiology. This may be circumvented by having the participants collect their own nasal swabs. We compared self- and staff-collected swabs in terms of swabbing quality and detection of viral respiratory pathogens. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a prospective study among employees of our institution during the ARI season 2010/2011 (December-March. Weekly emails were sent to the participants (n = 84, reminding them to come to the study center in case of new symptoms. The participants self-collected an anterior nasal swab from one nostril, and trained study personnel collected one from the other nostril. The participants self-collected another two swabs (one from each nostril on a subsequent day. Human β-actin DNA concentration was determined in the swabs as a quality control. Viral respiratory pathogens were detected by multiplex RT-PCR (Seeplex RV15 kit, Seegene, Eschborn, Germany. Of 84 participants, 56 (67% reported at least one ARI episode, 18 participants two, and one participant three. Self-swabbing was highly accepted by the participants. The amount of β-actin DNA per swab was higher in the self- than in the staff-collected swabs (p = 0.008. β-actin concentration was lower in the self-swabs collected on day 1 than in those collected on a subsequent day (p<0.0001. A respiratory viral pathogen was detected in 31% (23/75 of staff- and in 35% (26/75 of self-collected swabs (p = 0.36. With both approaches, the most frequently identified pathogens were human rhinoviruses A/B/C (12/75 swabs, 16% and human coronavirus OC43 (4/75 swabs, 5%. There was almost perfect agreement between self- and staff-collected swabs in terms of pathogen detection (agreement = 93%, kappa = 0.85, p<0.0001. CONCLUSIONS/SIGNIFICANCE: Nasal self

Transmission of human respiratory syncytial virus in the immunocompromised ferret model

NARCIS (Netherlands)

de Waal, L. (Leon); S.L. Smits (Saskia); E.J.B. Veldhuis Kroeze (Edwin); G. van Amerongen (Geert); Pohl, M.O. (Marie O.); Osterhaus, A.D.M.E. (Albert D. M. E.); K.J. Stittelaar (Koert)

2018-01-01

textabstractHuman respiratory syncytial virus (HRSV) causes substantial morbidity and mortality in vulnerable patients, such as the very young, the elderly, and immunocompromised individuals of any age. Nosocomial transmission of HRSV remains a serious challenge in hospital settings, with

Public perceptions of non-pharmaceutical interventions for reducing transmission of respiratory infection: systematic review and synthesis of qualitative studies.

Science.gov (United States)

Teasdale, Emma; Santer, Miriam; Geraghty, Adam W A; Little, Paul; Yardley, Lucy

2014-06-11

Non-pharmaceutical public health interventions may provide simple, low-cost, effective ways of minimising the transmission and impact of acute respiratory infections in pandemic and non-pandemic contexts. Understanding what influences the uptake of non-pharmaceutical interventions such as hand and respiratory hygiene, mask wearing and social distancing could help to inform the development of effective public health advice messages. The aim of this synthesis was to explore public perceptions of non-pharmaceutical interventions that aim to reduce the transmission of acute respiratory infections. Five online databases (MEDLINE, PsycINFO, CINAHL, EMBASE and Web of Science) were systematically searched. Reference lists of articles were also examined. We selected papers that used a qualitative research design to explore perceptions and beliefs about non-pharmaceutical interventions to reduce transmission of acute respiratory infections. We excluded papers that only explored how health professionals or children viewed non-pharmaceutical respiratory infection control. Three authors performed data extraction and assessment of study quality. Thematic analysis and components of meta-ethnography were adopted to synthesise findings. Seventeen articles from 16 studies in 9 countries were identified and reviewed. Seven key themes were identified: perceived benefits of non-pharmaceutical interventions, perceived disadvantages of non-pharmaceutical interventions, personal and cultural beliefs about infection transmission, diagnostic uncertainty in emerging respiratory infections, perceived vulnerability to infection, anxiety about emerging respiratory infections and communications about emerging respiratory infections. The synthesis showed that some aspects of non-pharmaceutical respiratory infection control (particularly hand and respiratory hygiene) were viewed as familiar and socially responsible actions to take. There was ambivalence about adopting isolation and personal

Transient virulence of emerging pathogens.

Science.gov (United States)

Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

2010-05-06

Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

Influenza A virus transmission via respiratory aerosols or droplets as it relates to pandemic potential

Science.gov (United States)

Richard, Mathilde; Fouchier, Ron A.M.

2015-01-01

Many respiratory viruses of humans originate from animals. For instance, there are now eight paramyxoviruses, four coronaviruses and four orthomxoviruses that cause recurrent epidemics in humans but were once confined to other hosts. In the last decade, several members of the same virus families have jumped the species barrier from animals to humans. Fortunately, these viruses have not become established in humans, because they lacked the ability of sustained transmission between humans. However, these outbreaks highlighted the lack of understanding of what makes a virus transmissible. In part triggered by the relatively high frequency of occurrence of influenza A virus zoonoses and pandemics, the influenza research community has started to investigate the viral genetic and biological traits that drive virus transmission via aerosols or respiratory droplets between mammals. Here we summarize recent discoveries on the genetic and phenotypic traits required for airborne transmission of zoonotic influenza viruses of subtypes H5, H7 and H9 and pandemic viruses of subtypes H1, H2 and H3. Increased understanding of the determinants and mechanisms of respiratory virus transmission is not only key from a basic scientific perspective, but may also aid in assessing the risks posed by zoonotic viruses to human health, and preparedness for such risks. PMID:26385895

Developing cryotherapy to eliminate graft-transmissible pathogens in citrus

Science.gov (United States)

This article summarizes research being conducted as part of a project funded by the California Citrus Research Board to develop cryotherapy (freezing buds in liquid nitrogen, and then recovering them) as a viable method for elimination of graft transmissible pathogens from Citrus. There are current...

Bayesian evidence and epidemiological implications of environmental contamination from acute respiratory infection in long-term care facilities.

Science.gov (United States)

Diaz-Decaro, J D; Launer, B; Mckinnell, J A; Singh, R; Dutciuc, T D; Green, N M; Bolaris, M; Huang, S S; Miller, L G

2018-05-01

Skilled nursing home facilities (SNFs) house a vulnerable population frequently exposed to respiratory pathogens. Our study aims to gain a better understanding of the transmission of nursing home-acquired viral respiratory infections in non-epidemic settings. Symptomatic surveillance was performed in three SNFs for residents exhibiting acute respiratory symptoms. Environmental surveillance of five high-touch areas was performed to assess possible transmission. All resident and environmental samples were screened using a commercial multiplex polymerase chain reaction platform. Bayesian methods were used to evaluate environmental contamination. Among nursing home residents with respiratory symptoms, 19% had a detectable viral pathogen (parainfluenza-3, rhinovirus/enterovirus, RSV, or influenza B). Environmental contamination was found in 20% of total room surface swabs of symptomatic residents. Environmental and resident results were all concordant. Target period prevalence among symptomatic residents ranged from 5.5 to 13.3% depending on target. Bayesian analysis quantifies the probability of environmental shedding due to parainfluenza-3 as 92.4% (95% CI: 86.8-95.8%) and due to rhinovirus/enterovirus as 65.6% (95% CI: 57.9-72.5%). Our findings confirm that non-epidemic viral infections are common among SNF residents exhibiting acute respiratory symptoms and that environmental contamination may facilitate further spread with considerable epidemiological implications. Findings further emphasise the importance of environmental infection control for viral respiratory pathogens in long-term care facilities.

Climate Change and Respiratory Infections.

Science.gov (United States)

Mirsaeidi, Mehdi; Motahari, Hooman; Taghizadeh Khamesi, Mojdeh; Sharifi, Arash; Campos, Michael; Schraufnagel, Dean E

2016-08-01

The rate of global warming has accelerated over the past 50 years. Increasing surface temperature is melting glaciers and raising the sea level. More flooding, droughts, hurricanes, and heat waves are being reported. Accelerated changes in climate are already affecting human health, in part by altering the epidemiology of climate-sensitive pathogens. In particular, climate change may alter the incidence and severity of respiratory infections by affecting vectors and host immune responses. Certain respiratory infections, such as avian influenza and coccidioidomycosis, are occurring in locations previously unaffected, apparently because of global warming. Young children and older adults appear to be particularly vulnerable to rapid fluctuations in ambient temperature. For example, an increase in the incidence in childhood pneumonia in Australia has been associated with sharp temperature drops from one day to the next. Extreme weather events, such as heat waves, floods, major storms, drought, and wildfires, are also believed to change the incidence of respiratory infections. An outbreak of aspergillosis among Japanese survivors of the 2011 tsunami is one such well-documented example. Changes in temperature, precipitation, relative humidity, and air pollution influence viral activity and transmission. For example, in early 2000, an outbreak of Hantavirus respiratory disease was linked to a local increase in the rodent population, which in turn was attributed to a two- to threefold increase in rainfall before the outbreak. Climate-sensitive respiratory pathogens present challenges to respiratory health that may be far greater in the foreseeable future.

Apoptosis, Toll-like, RIG-I-like and NOD-like Receptors Are Pathways Jointly Induced by Diverse Respiratory Bacterial and Viral Pathogens

Science.gov (United States)

Martínez, Isidoro; Oliveros, Juan C.; Cuesta, Isabel; de la Barrera, Jorge; Ausina, Vicente; Casals, Cristina; de Lorenzo, Alba; García, Ernesto; García-Fojeda, Belén; Garmendia, Junkal; González-Nicolau, Mar; Lacoma, Alicia; Menéndez, Margarita; Moranta, David; Nieto, Amelia; Ortín, Juan; Pérez-González, Alicia; Prat, Cristina; Ramos-Sevillano, Elisa; Regueiro, Verónica; Rodriguez-Frandsen, Ariel; Solís, Dolores; Yuste, José; Bengoechea, José A.; Melero, José A.

2017-01-01

Lower respiratory tract infections are among the top five leading causes of human death. Fighting these infections is therefore a world health priority. Searching for induced alterations in host gene expression shared by several relevant respiratory pathogens represents an alternative to identify new targets for wide-range host-oriented therapeutics. With this aim, alveolar macrophages were independently infected with three unrelated bacterial (Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus aureus) and two dissimilar viral (respiratory syncytial virus and influenza A virus) respiratory pathogens, all of them highly relevant for human health. Cells were also activated with bacterial lipopolysaccharide (LPS) as a prototypical pathogen-associated molecular pattern. Patterns of differentially expressed cellular genes shared by the indicated pathogens were searched by microarray analysis. Most of the commonly up-regulated host genes were related to the innate immune response and/or apoptosis, with Toll-like, RIG-I-like and NOD-like receptors among the top 10 signaling pathways with over-expressed genes. These results identify new potential broad-spectrum targets to fight the important human infections caused by the bacteria and viruses studied here. PMID:28298903

Disposable gendine antimicrobial gloves for preventing transmission of pathogens in health care settings.

Science.gov (United States)

Reitzel, Ruth; Rosenblatt, Joel; Jiang, Ying; Hachem, Ray; Raad, Issam

2014-01-01

Transmission of organisms by contact of gloves with surfaces following contact with a pathogen source has been recognized as an important vector for pathogenesis of health care-associated infections. In these cases, the gloves protect the wearer from contact with the pathogenic organisms; however, this personal protection can facilitate the wearer unwittingly becoming a carrier of the pathogens from one location to another. A novel gendine (combination of chlorhexidine and gentian violet) antiseptic coating for the external surface of the glove was developed as a potential intervention to prevent this mode of transmission. We characterized the ability of the coating to rapidly kill bacterial and fungal pathogens within 1 minute of contact with the glove surface. The International Organization of Standardization 22196 concentrated inoculum contact testing methodology was followed. The gendine-coated gloves were able to fully eradicate multidrug-resistant organisms included methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterocci, multidrug-resistant Pseudomonas aeruginosa, and Klebsiella pneumoniae carbapenemase producing. In addition, Candida albicans, Candida glabarata, and 2 pathogenic Escherichia coli strains commonly associated with invasive gastroenteritis were also fully eradicated within 1 minute of contact. The gendine coating did not adversely impact the finish or integrity of the disposable gloves. The highly efficacious gendine-coated antimicrobial gloves potentially provide an additional means of protection against horizontal transmission of common pathogens in a hospital setting. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Bighorn sheep (Ovis canadensis) sinus tumors are associated with coinfections by potentially pathogenic bacteria in the upper respiratory tract.

Science.gov (United States)

Fox, Karen A; Rouse, Natalie M; Huyvaert, Kathryn P; Griffin, Karen A; Killion, Halcyon J; Jennings-Gaines, Jessica; Edwards, William H; Quackenbush, Sandra L; Miller, Michael W

2015-01-01

Bighorn sheep (Ovis canadensis) sinus tumors are hyperplastic to neoplastic, predominantly stromal masses of the paranasal sinuses that expand the sinus lining and obstruct the sinus cavities. Obstruction of the sinus cavities and disruption of normal sinus lining anatomy may interfere with clearance of bacterial pathogens from the upper respiratory tract. To examine this possibility, we explored whether the presence of sinus tumor features (tumor score) affected the likelihood of detecting potentially pathogenic bacteria from upper respiratory sinus lining tissues in bighorn sheep. We developed or used existing PCR assays for the detection of leukotoxigenic Pasteurellaceae and Mycoplasma ovipneumoniae in sinus lining tissues collected from 97 bighorn sheep in Colorado, US from 2009 to 2012. With the use of logistic regression analyses we found that tumor score was a good predictor of the probability of detecting potentially pathogenic bacteria in sinus lining tissues; we were more likely to detect potentially pathogenic bacteria from samples with high tumor scores. These findings add to our understanding of possible mechanisms for the maintenance and shedding of bacterial agents from the upper respiratory tracts of bighorn sheep.

Apparent competition in canopy trees determined by pathogen transmission rather than susceptibility.

Science.gov (United States)

Richard Cobb; Ross Meentemeyer; David Rizzo

2010-01-01

Epidemiological theory predicts that asymmetric transmission, susceptibility, and mortality within a community will drive pathogen and disease dynamics. These epidemiological asymmetries can result in apparent competition, where a highly infectious host reduces the abundance of less infectious or more susceptible members in a community via a shared pathogen. We show...

Transmission of highly pathogenic avian influenza H7 virus

NARCIS (Netherlands)

Bos, M.E.H.

2009-01-01

Knowledge of the transmission of highly pathogenic avian influenza (HPAI) virus still has gaps, complicating epidemic control. A model was developed to back-calculate the day HPAI virus was introduced into a flock, based on within-flock mortality data of the Dutch HPAI H7N7 epidemic (2003). The

Immune response in the lungs following oral immunization with bacterial lysates of respiratory pathogens.

OpenAIRE

Ruedl, C; Frühwirth, M; Wick, G; Wolf, H

1994-01-01

We have investigated the local immune response of the BALB/c mouse respiratory tract after oral immunization with a bacterial lysate of seven common respiratory pathogens. After two immunization on five consecutive days, we examined the immunoglobulin (immunoglobulin G [IgG], IgM, and IgA) secretion rates of cells isolated from the lungs and compared them with those of spleen cells of orally immunized and nonimmunized animals by using a new test system based on time-resolved fluorescence. The...

An evaluation of indices for quantifying tuberculosis transmission using genotypes of pathogen isolates

Directory of Open Access Journals (Sweden)

Phong Renault

2006-06-01

Full Text Available Abstract Background Infectious diseases are often studied by characterising the population structure of the pathogen using genetic markers. An unresolved problem is the effective quantification of the extent of transmission using genetic variation data from such pathogen isolates. Methods It is important that transmission indices reflect the growth of the infectious population as well as account for the mutation rate of the marker and the effects of sampling. That is, while responding to this growth rate, indices should be unresponsive to the sample size and the mutation rate. We use simulation methods taking into account both the mutation and sampling processes to evaluate indices designed to quantify transmission of tuberculosis. Results Previously proposed indices generally perform inadequately according to the above criteria, with the partial exception of the recently proposed Transmission-Mutation Index. Conclusion Any transmission index needs to take into account mutation of the marker and the effects of sampling. Simple indices are unlikely to capture the full complexity of the underlying processes.

Acquisition and automated 3-D segmentation of respiratory/cardiac-gated PET transmission images

International Nuclear Information System (INIS)

Reutter, B.W.; Klein, G.J.; Brennan, K.M.; Huesman, R.H.

1996-01-01

To evaluate the impact of respiratory motion on attenuation correction of cardiac PET data, we acquired and automatically segmented gated transmission data for a dog breathing on its own under gas anesthesia. Data were acquired for 20 min on a CTI/Siemens ECAT EXACT HR (47-slice) scanner configured for 12 gates in a static study, Two respiratory gates were obtained using data from a pneumatic bellows placed around the dog's chest, in conjunction with 6 cardiac gates from standard EKG gating. Both signals were directed to a LabVIEW-controlled Macintosh, which translated them into one of 12 gate addresses. The respiratory gating threshold was placed near end-expiration to acquire 6 cardiac-gated datasets at end-expiration and 6 cardiac-gated datasets during breaths. Breaths occurred about once every 10 sec and lasted about 1-1.5 sec. For each respiratory gate, data were summed over cardiac gates and torso and lung surfaces were segmented automatically using a differential 3-D edge detection algorithm. Three-dimensional visualizations showed that lung surfaces adjacent to the heart translated 9 mm inferiorly during breaths. Our results suggest that respiration-compensated attenuation correction is feasible with a modest amount of gated transmission data and is necessary for accurate quantitation of high-resolution gated cardiac PET data

Transmission Bottleneck Size Estimation from Pathogen Deep-Sequencing Data, with an Application to Human Influenza A Virus.

Science.gov (United States)

Sobel Leonard, Ashley; Weissman, Daniel B; Greenbaum, Benjamin; Ghedin, Elodie; Koelle, Katia

2017-07-15

The bottleneck governing infectious disease transmission describes the size of the pathogen population transferred from the donor to the recipient host. Accurate quantification of the bottleneck size is particularly important for rapidly evolving pathogens such as influenza virus, as narrow bottlenecks reduce the amount of transferred viral genetic diversity and, thus, may decrease the rate of viral adaptation. Previous studies have estimated bottleneck sizes governing viral transmission by using statistical analyses of variants identified in pathogen sequencing data. These analyses, however, did not account for variant calling thresholds and stochastic viral replication dynamics within recipient hosts. Because these factors can skew bottleneck size estimates, we introduce a new method for inferring bottleneck sizes that accounts for these factors. Through the use of a simulated data set, we first show that our method, based on beta-binomial sampling, accurately recovers transmission bottleneck sizes, whereas other methods fail to do so. We then apply our method to a data set of influenza A virus (IAV) infections for which viral deep-sequencing data from transmission pairs are available. We find that the IAV transmission bottleneck size estimates in this study are highly variable across transmission pairs, while the mean bottleneck size of 196 virions is consistent with a previous estimate for this data set. Furthermore, regression analysis shows a positive association between estimated bottleneck size and donor infection severity, as measured by temperature. These results support findings from experimental transmission studies showing that bottleneck sizes across transmission events can be variable and influenced in part by epidemiological factors. IMPORTANCE The transmission bottleneck size describes the size of the pathogen population transferred from the donor to the recipient host and may affect the rate of pathogen adaptation within host populations. Recent

Disease management mitigates risk of pathogen transmission from maricultured salmonids

DEFF Research Database (Denmark)

Jones, Simon R. M.; Bruno, David W.; Madsen, Lone

2015-01-01

that increased risk of exposure to neighbouring farms is inversely related to distance from and directly related to biomass at the source of infection. Epidemiological techniques integrating data from oceanography, diagnostics and pathogen shedding rates and viability contribute to improved understanding...... management thresholds. For wild populations, risk of pathogen spillback is estimated from farm-based epidemiological data; however, validation, particularly for ISAV and SAV, is required using direct surveillance....... of pathogen transmission pathways among farms and permit the designation of areas of risk associated with sources of infection. Occupation of an area of risk may increase the likelihood of exposure, infection and disease among susceptible fish. Disease mitigation in mariculture occurs at 2 scales: area...

Identifying the Achilles heel of multi-host pathogens: the concept of keystone ‘host’ species illustrated by Mycobacterium ulcerans transmission

International Nuclear Information System (INIS)

Roche, Benjamin; Eric Benbow, M; Merritt, Richard; Kimbirauskas, Ryan; McIntosh, Mollie; Small, Pamela L C; Williamson, Heather; Guégan, Jean-François

2013-01-01

Pathogens that use multiple host species are an increasing public health issue due to their complex transmission, which makes them difficult to mitigate. Here, we explore the possibility of using networks of ecological interactions among potential host species to identify the particular disease-source species to target to break down transmission of such pathogens. We fit a mathematical model on prevalence data of Mycobacterium ulcerans in western Africa and we show that removing the most abundant taxa for this category of pathogen is not an optimal strategy to decrease the transmission of the mycobacterium within aquatic ecosystems. On the contrary, we reveal that the removal of some taxa, especially Oligochaeta worms, can clearly reduce rates of pathogen transmission, and these should be considered as keystone organisms for its transmission because they lead to a substantial reduction in pathogen prevalence regardless of the network topology. Besides their potential application for the understanding of M. ulcerans ecology, we discuss how networks of species interactions can modulate transmission of multi-host pathogens. (letter)

Comparison of direct-plating and broth-enrichment culture methods for detection of potential bacterial pathogens in respiratory secretions.

Science.gov (United States)

Kaur, Ravinder; Wischmeyer, Jareth; Morris, Matthew; Pichichero, Michael E

2017-11-01

We compared the recovery of potential respiratory bacterial pathogens and normal flora from nasopharyngeal specimens collected from children during health and at the onset of acute otitis media (AOM) by selective direct-plating and overnight broth-enrichment. Overall, 3442 nasal wash (NW) samples collected from young children were analysed from a 10-year prospective study. NWs were cultured by (1) direct-plating to TSAII/5 % sheep blood agar and chocolate agar plates and (2) overnight broth-enrichment in BacT/ALERT SA-broth followed by plating. Standard microbiology techniques were applied to identify three dominant respiratory bacterial pathogens: Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hflu) and Moraxella catarrhalis (Mcat) as well as two common nasal flora, Staphylococcus aureus (SA) and alpha-haemolytic Streptococci (AHS).Results/Key findings. Direct-plating of NW resulted in isolation of Spn from 37.8 %, Hflu from 13.6 % and Mcat from 33.2 % of samples. In comparison, overnight broth-enrichment isolated fewer Spn (30.1 %), Hflu (6.2 %) and Mcat (16.2 %) (Penrichment resulted in significant increased isolation of SA (6.0 %) and AHS (30.1 %) (Penrichment when samples were collected from healthy children but not during AOM. In middle ear fluids (MEF) at the onset of AOM, broth-enrichment resulted in higher recovery of Spn (+10.4 %, Penrichment significantly reduces the accurate detection of bacterial respiratory pathogens and increases identification of SA and AHS in NW. Broth-enrichment improves detection of bacterial respiratory pathogens in MEF samples.

Infectivity, transmission and pathogenicity of avian influenza viruses for domestic and wild birds

Science.gov (United States)

Individual avian influenza (AI) virus strains vary in their ability to infect, transmit and cause disease and death in different bird species. Low pathogenicity AI (LPAI) viruses are maintained in wild birds, and must be adapted to pass to domestic poultry, where they replicate in respiratory and in...

Feeder use predicts both acquisition and transmission of a contagious pathogen in a North American songbird.

Science.gov (United States)

Adelman, James S; Moyers, Sahnzi C; Farine, Damien R; Hawley, Dana M

2015-09-22

Individual heterogeneity can influence the dynamics of infectious diseases in wildlife and humans alike. Thus, recent work has sought to identify behavioural characteristics that contribute disproportionately to individual variation in pathogen acquisition (super-receiving) or transmission (super-spreading). However, it remains unknown whether the same behaviours enhance both acquisition and transmission, a scenario likely to result in explosive epidemics. Here, we examined this possibility in an ecologically relevant host-pathogen system: house finches and their bacterial pathogen, Mycoplasma gallisepticum, which causes severe conjunctivitis. We examined behaviours likely to influence disease acquisition (feeder use, aggression, social network affiliations) in an observational field study, finding that the time an individual spends on bird feeders best predicted the risk of conjunctivitis. To test whether this behaviour also influences the likelihood of transmitting M. gallisepticum, we experimentally inoculated individuals based on feeding behaviour and tracked epidemics within captive flocks. As predicted, transmission was fastest when birds that spent the most time on feeders initiated the epidemic. Our results suggest that the same behaviour underlies both pathogen acquisition and transmission in this system and potentially others. Identifying individuals that exhibit such behaviours is critical for disease management. © 2015 The Author(s).

Transmission of Human Respiratory Syncytial Virus in the Immunocompromised Ferret Model

Science.gov (United States)

de Waal, Leon; Smits, Saskia L.; Veldhuis Kroeze, Edwin J. B.; van Amerongen, Geert; Pohl, Marie O.; Osterhaus, Albert D. M. E.; Stittelaar, Koert J.

2018-01-01

Human respiratory syncytial virus (HRSV) causes substantial morbidity and mortality in vulnerable patients, such as the very young, the elderly, and immunocompromised individuals of any age. Nosocomial transmission of HRSV remains a serious challenge in hospital settings, with intervention strategies largely limited to infection control measures, including isolation of cases, high standards of hand hygiene, cohort nursing, and use of personal protective equipment. No vaccines against HRSV are currently available, and treatment options are largely supportive care and expensive monoclonal antibody or antiviral therapy. The limitations of current animal models for HRSV infection impede the development of new preventive and therapeutic agents, and the assessment of their potential for limiting HRSV transmission, in particular in nosocomial settings. Here, we demonstrate the efficient transmission of HRSV from immunocompromised ferrets to both immunocompromised and immunocompetent contact ferrets, with pathological findings reproducing HRSV pathology in humans. The immunocompromised ferret-HRSV model represents a novel tool for the evaluation of intervention strategies against nosocomial transmission of HRSV. PMID:29301313

Mobile phones: Reservoirs for the transmission of nosocomial pathogens.

Science.gov (United States)

Pal, Shekhar; Juyal, Deepak; Adekhandi, Shamanth; Sharma, Munesh; Prakash, Rajat; Sharma, Neelam; Rana, Amit; Parihar, Ashwin

2015-01-01

Global burden of hospital-associated infection (HAI) is on the rise and contributes significantly to morbidity and mortality of the patients. Mobile phones are indispensible part of communication among doctors and other health care workers (HCWs) in hospitals. Hands of HCWs play an important role in transmission of HAI and mobile phones which are seldom cleaned and often touched during or after the examination of patients without hand washing can act as a reservoir for transmission of potent pathogens. This study aimed to investigate the rate of bacterial contamination of mobile phones among HCWs in our tertiary care hospital and to compare it with personal mobile phones of non-HCWs (control group). The mobile phones and dominant hands of 386 participants were sampled from four different groups, hospital doctors and staff (132), college faculty and staff (54), medical students (100) and control group (100). Informed consent and questionnaire was duly signed by all the participants. Samples were processed according to standard guidelines. 316 mobile phones (81.8%) and 309 hand swab samples (80%) showed growth of bacterial pathogens. The most predominant isolates were Coagulase-negative Staphylococcus, Staphylococcus aureus, Acinetobacter species, Escherichia coli, Klebsiella pneumoniae, Pseudomonas species and Enterococcus species. Hundred percent contamination was found in mobile phones and hands of HCWs indicating mobile phones can be the potential source of nosocomial pathogens. Our study results suggest that use of mobile phones in health care setup should be restricted only for emergency calls. Strict adherence to infection control policies such as proper hand hygiene practices should be followed.

How Respiratory Pathogens Contribute to Lamb Mortality in a Poorly Performing Bighorn Sheep ( Ovis canadensis ) Herd.

Science.gov (United States)

Wood, Mary E; Fox, Karen A; Jennings-Gaines, Jessica; Killion, Halcyon J; Amundson, Sierra; Miller, Michael W; Edwards, William H

2017-01-01

We evaluated bighorn sheep ( Ovis canadensis ) ewes and their lambs in captivity to examine the sources and roles of respiratory pathogens causing lamb mortality in a poorly performing herd. After seven consecutive years of observed December recruitments of sheep from the remnant Gribbles Park herd in Colorado, US were captured and transported to the Thorne-Williams Wildlife Research Center in Wyoming in March 2013. Ewes were sampled repeatedly over 16 mo. In April 2014, ewes were separated into individual pens prior to lambing. Upon death, lambs were necropsied and tested for respiratory pathogens. Six lambs developed clinical respiratory disease and one lamb was abandoned. Pathology from an additional six lambs born in 2013 was also evaluated. Mycoplasma ovipneumoniae , leukotoxigenic Mannheimia spp., leukotoxigenic Bibersteinia trehalosi , and Pasteurella multocida all contributed to lamb pneumonia. Histopathology suggested a continuum of disease, with lesions typical of pasteurellosis predominating in younger lambs and lesions typical of mycoplasmosis predominating in older lambs. Mixed pathology was observed in lambs dying between these timeframes. We suspected that all the ewes in our study were persistently infected and chronically shedding the bacteria that contributed to summer lamb mortality.

A multiplexed reverse transcriptase PCR assay for identification of viral respiratory pathogens at point-of-care

Energy Technology Data Exchange (ETDEWEB)

Letant, S E; .Ortiz, J I; Tammero, L; Birch, J M; Derlet, R W; Cohen, S; Manning, D; McBride, M T

2007-04-11

We have developed a nucleic acid-based assay that is rapid, sensitive, specific, and can be used for the simultaneous detection of 5 common human respiratory pathogens including influenza A, influenza B, parainfluenza type 1 and 3, respiratory syncytial virus, and adenovirus group B, C, and E. Typically, diagnosis on an un-extracted clinical sample can be provided in less than 3 hours, including sample collection, preparation, and processing, as well as data analysis. Such a multiplexed panel would enable rapid broad-spectrum pathogen testing on nasal swabs, and therefore allow implementation of infection control measures, and timely administration of antiviral therapies. This article presents a summary of the assay performance in terms of sensitivity and specificity. Limits of detection are provided for each targeted respiratory pathogen, and result comparisons are performed on clinical samples, our goal being to compare the sensitivity and specificity of the multiplexed assay to the combination of immunofluorescence and shell vial culture currently implemented at the UCDMC hospital. Overall, the use of the multiplexed RT-PCR assay reduced the rate of false negatives by 4% and reduced the rate of false positives by up to 10%. The assay correctly identified 99.3% of the clinical negatives, 97% of adenovirus, 95% of RSV, 92% of influenza B, and 77% of influenza A without any extraction performed on the clinical samples. The data also showed that extraction will be needed for parainfluenza virus, which was only identified correctly 24% of the time on un-extracted samples.

Intervention methods to control the transmission of noroviruses and other enteric and respiratory viruses

NARCIS (Netherlands)

Tuladhar, E.

2014-01-01

Intervention methods to control the transmission of noroviruses and other enteric and respiratory viruses

Era Tuladhar

Abstract

Human noroviruses are the leading cause of acute and outbreak associated gastroenteritis worldwide. The outbreaks

Respiratory transmission of an avian H3N8 influenza virus isolated from a harbour seal

Science.gov (United States)

Karlsson, Erik A.; Ip, Hon S.; Hall, Jeffrey S.; Yoon, Sun W.; Johnson, Jordan; Beck, Melinda A.; Webby, Richard J.; Schultz-Cherry, Stacey

2014-01-01

The ongoing human H7N9 influenza infections highlight the threat of emerging avian influenza viruses. In 2011, an avian H3N8 influenza virus isolated from moribund New England harbour seals was shown to have naturally acquired mutations known to increase the transmissibility of highly pathogenic H5N1 influenza viruses. To elucidate the potential human health threat, here we evaluate a panel of avian H3N8 viruses and find that the harbour seal virus displays increased affinity for mammalian receptors, transmits via respiratory droplets in ferrets and replicates in human lung cells. Analysis of a panel of human sera for H3N8 neutralizing antibodies suggests that there is no population-wide immunity to these viruses. The prevalence of H3N8 viruses in birds and multiple mammalian species including recent isolations from pigs and evidence that it was a past human pandemic virus make the need for surveillance and risk analysis of these viruses of public health importance.

Infections by pathogens with different transmission modes in feral cats from urban and rural areas of Korea.

Science.gov (United States)

Hwang, Jusun; Gottdenker, Nicole; Oh, Dae-Hyun; Lee, Hang; Chun, Myung-Sun

2017-12-31

In this study, we examine prevalences of three infectious pathogens with different transmission modes ( Bartonella henselae , hemoplasma, and Toxoplasma gondii ) in feral cats from urban and rural habitats. Infection status of the three pathogens in blood samples (n = 117) was determined through molecular or serological diagnostic methods. Overall prevalence of hemoplasma, Toxoplasma gondii , and Bartonella henselae was 47.9%, 50%, and 35.7%, respectively. Comparing the two habitats, only seroprevalence of Bartonella henselae was significantly higher in urban cats. Based on the results, we discuss how pathogens with distinct transmission modes may show different prevalence between urban and rural habitat types.

Pharmacodynamic evaluation of commonly prescribed oral antibiotics against respiratory bacterial pathogens

Directory of Open Access Journals (Sweden)

Pignatari Antonio CC

2011-10-01

Full Text Available Abstract Background Upper and lower respiratory tract infections (RTIs account for a substantial portion of outpatient antibiotic utilization. However, the pharmacodynamic activity of commonly used oral antibiotic regimens has not been studied against clinically relevant pathogens. The objective of this study was to assess the probability of achieving the requisite pharmacodynamic exposure for oral antibacterial regimens commonly prescribed for RTIs in adults against bacterial isolates frequently involved in these processes (S. pneumoniae, H. influenzae, and M. catharralis. Methods Using a 5000-subject Monte Carlo simulation, the cumulative fractions of response (CFR, (i.e., probabilities of achieving requisite pharmacodynamic targets for the most commonly prescribed oral antibiotic regimens, as determined by a structured survey of medical prescription patterns, were assessed against local respiratory bacterial isolates from adults in São Paulo collected during the same time period. Minimal inhibitory concentration (MIC of 230 isolates of Streptococcus pneumoniae (103, Haemophilus influenzae (98, and Moraxella catharralis (29 from a previous local surveillance were used. Results The most commonly prescribed antibiotic regimens were azithromycin 500 mg QD, amoxicillin 500 mg TID, and levofloxacin 500 mg QD, accounting for 58% of the prescriptions. Varied doses of these agents, plus gatifloxacin, amoxicillin-clavulanate, moxifloxacin, and cefaclor made up the remaining regimens. Utilizing aggressive pharmacodynamic exposure targets, the only regimens to achieve greater than 90% CFR against all three pathogens were amoxicillin/amoxicillin-clavulanate 500 mg TID (> 91%, gatifloxacin 400 mg QD (100%, and moxifloxacin 400 mg QD (100%. Considering S. pneumoniae isolates alone, azithromycin 1000 mg QD also achieved greater than 90% CFR (91.3%. Conclusions The only regimens to achieve high CFR against all three pathogen populations in both scenarios

European surveillance of emerging pathogens associated with canine infectious respiratory disease.

Science.gov (United States)

Mitchell, Judy A; Cardwell, Jacqueline M; Leach, Heather; Walker, Caray A; Le Poder, Sophie; Decaro, Nicola; Rusvai, Miklos; Egberink, Herman; Rottier, Peter; Fernandez, Mireia; Fragkiadaki, Eirini; Shields, Shelly; Brownlie, Joe

2017-12-01

Canine infectious respiratory disease (CIRD) is a major cause of morbidity in dogs worldwide, and is associated with a number of new and emerging pathogens. In a large multi-centre European study the prevalences of four key emerging CIRD pathogens; canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), influenza A, and Mycoplasma cynos (M. cynos); were estimated, and risk factors for exposure, infection and clinical disease were investigated. CIRD affected 66% (381/572) of the dogs studied, including both pet and kennelled dogs. Disease occurrence and severity were significantly reduced in dogs vaccinated against classic CIRD agents, canine distemper virus (CDV), canine adenovirus 2 (CAV-2) and canine parainfluenza virus (CPIV), but substantial proportions (65.7%; 201/306) of vaccinated dogs remained affected. CRCoV and CnPnV were highly prevalent across the different dog populations, with overall seropositivity and detection rates of 47% and 7.7% for CRCoV, and 41.7% and 23.4% for CnPnV, respectively, and their presence was associated with increased occurrence and severity of clinical disease. Antibodies to CRCoV had a protective effect against CRCoV infection and more severe clinical signs of CIRD but antibodies to CnPnV did not. Involvement of M. cynos and influenza A in CIRD was less apparent. Despite 45% of dogs being seropositive for M. cynos, only 0.9% were PCR positive for M. cynos. Only 2.7% of dogs were seropositive for Influenza A, and none were positive by PCR. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative analytical evaluation of the respiratory TaqMan Array Card with real-time PCR and commercial multi-pathogen assays.

Science.gov (United States)

Harvey, John J; Chester, Stephanie; Burke, Stephen A; Ansbro, Marisela; Aden, Tricia; Gose, Remedios; Sciulli, Rebecca; Bai, Jing; DesJardin, Lucy; Benfer, Jeffrey L; Hall, Joshua; Smole, Sandra; Doan, Kimberly; Popowich, Michael D; St George, Kirsten; Quinlan, Tammy; Halse, Tanya A; Li, Zhen; Pérez-Osorio, Ailyn C; Glover, William A; Russell, Denny; Reisdorf, Erik; Whyte, Thomas; Whitaker, Brett; Hatcher, Cynthia; Srinivasan, Velusamy; Tatti, Kathleen; Tondella, Maria Lucia; Wang, Xin; Winchell, Jonas M; Mayer, Leonard W; Jernigan, Daniel; Mawle, Alison C

2016-02-01

In this study, a multicenter evaluation of the Life Technologies TaqMan(®) Array Card (TAC) with 21 custom viral and bacterial respiratory assays was performed on the Applied Biosystems ViiA™ 7 Real-Time PCR System. The goal of the study was to demonstrate the analytical performance of this platform when compared to identical individual pathogen specific laboratory developed tests (LDTs) designed at the Centers for Disease Control and Prevention (CDC), equivalent LDTs provided by state public health laboratories, or to three different commercial multi-respiratory panels. CDC and Association of Public Health Laboratories (APHL) LDTs had similar analytical sensitivities for viral pathogens, while several of the bacterial pathogen APHL LDTs demonstrated sensitivities one log higher than the corresponding CDC LDT. When compared to CDC LDTs, TAC assays were generally one to two logs less sensitive depending on the site performing the analysis. Finally, TAC assays were generally more sensitive than their counterparts in three different commercial multi-respiratory panels. TAC technology allows users to spot customized assays and design TAC layout, simplify assay setup, conserve specimen, dramatically reduce contamination potential, and as demonstrated in this study, analyze multiple samples in parallel with good reproducibility between instruments and operators. Copyright © 2015 Elsevier B.V. All rights reserved.

Parasites and Pathogens of the Honeybee (Apis mellifera and Their Influence on Inter-Colonial Transmission.

Directory of Open Access Journals (Sweden)

Nadège Forfert

Full Text Available Pathogens and parasites may facilitate their transmission by manipulating host behavior. Honeybee pathogens and pests need to be transferred from one colony to another if they are to maintain themselves in a host population. Inter-colony transmission occurs typically through honeybee workers not returning to their home colony but entering a foreign colony ("drifting". Pathogens might enhance drifting to enhance transmission to new colonies. We here report on the effects infection by ten honeybee viruses and Nosema spp., and Varroa mite infestation on honeybee drifting. Genotyping of workers collected from colonies allowed us to identify genuine drifted workers as well as source colonies sending out drifters in addition to sink colonies accepting them. We then used network analysis to determine patterns of drifting. Distance between colonies in the apiary was the major factor explaining 79% of drifting. None of the tested viruses or Nosema spp. were associated with the frequency of drifting. Only colony infestation with Varroa was associated with significantly enhanced drifting. More specifically, colonies with high Varroa infestation had a significantly enhanced acceptance of drifters, although they did not send out more drifting workers. Since Varroa-infested colonies show an enhanced attraction of drifting workers, and not only those infected with Varroa and its associated pathogens, infestation by Varroa may also facilitate the uptake of other pests and parasites.

Susceptibility to Lower Respiratory Infections in Childhood is Associated with Perturbation of the Cytokine Response to Pathogenic Airway Bacteria.

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Vissing, Nadja Hawwa; Larsen, Jeppe Madura; Rasmussen, Morten Arendt; Chawes, Bo Lund Krogsgaard; Thysen, Anna Hammerich; Bønnelykke, Klaus; Brix, Susanne; Bisgaard, Hans

2016-05-01

Neonatal colonization of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood. Therefore, we hypothesized that children developing LRI have an aberrant immune response to pathogenic bacteria in infancy. The objective was to characterize in vitro the early life systemic immune response to pathogenic bacteria and study the possible association with incidence of LRI during the first 3 years of life. The Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) is a clinical birth cohort study of 411 children born of mothers with asthma. LRI incidence was prospectively captured from 6-monthly planned visits and visits at acute respiratory episodes. The in vitro systemic immune response to Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae was characterized by the production of TNF-α, IFN-γ, IL-2, IL-5, IL-10, IL-13 and IL-17 in peripheral blood mononuclear cells isolated at age 6 months from 291 infants. Data were analyzed by Poisson regression against incidence of LRI in infancy. A multivariable model including all cytokine responses from the 3 different bacterial stimulations significantly identified children at risk of LRI (P = 0.006). The immune response pattern associated with LRI was characterized by perturbed production of several cytokines rather than production of one specific cytokine, and was independent of concurrent asthma. TNF-α and IL-5 were key drivers but did not explain the entire variation in LRI susceptibility. Children at risk of future LRI present a perturbed systemic immune response upon exposure to common airway pathogens in early life.

Porcine semen as a vector for transmission of viral pathogens.

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Maes, Dominiek; Van Soom, Ann; Appeltant, Ruth; Arsenakis, Ioannis; Nauwynck, Hans

2016-01-01

Different viruses have been detected in porcine semen. Some of them are on the list of the World Organization for Animal Health (OIE), and consequently, these pathogens are of socioeconomic and/or public health importance and are of major importance in the international trade of animals and animal products. Artificial insemination (AI) is one of the most commonly used assisted reproductive technologies in pig production worldwide. This extensive use has enabled pig producers to benefit from superior genetics at a lower cost compared to natural breeding. However, the broad distribution of processed semen doses for field AI has increased the risk of widespread transmission of swine viral pathogens. Contamination of semen can be due to infections of the boar or can occur during semen collection, processing, and storage. It can result in reduced semen quality, embryonic mortality, endometritis, and systemic infection and/or disease in the recipient female. The presence of viral pathogens in semen can be assessed by demonstration of viable virus, nucleic acid of virus, or indirectly by measuring serum antibodies in the boar. The best way to prevent disease transmission via the semen is to assure that the boars in AI centers are free from the disease, to enforce very strict biosecurity protocols, and to perform routine health monitoring of boars. Prevention of viral semen contamination should be the primary focus because it is easier to prevent contamination than to eliminate viruses once present in semen. Nevertheless, research and development of novel semen processing treatments such as single-layer centrifugation is ongoing and may allow in the future to decontaminate semen. Copyright © 2016 Elsevier Inc. All rights reserved.

Transmission dynamics of Bacillus thuringiensis infecting Plodia interpunctella: a test of the mass action assumption with an insect pathogen.

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Knell, R J; Begon, M; Thompson, D J

1996-01-22

Central to theoretical studies of host-pathogen population dynamics is a term describing transmission of the pathogen. This usually assumes that transmission is proportional to the density of infectious hosts or particles and of susceptible individuals. We tested this assumption with the bacterial pathogen Bacillus thuringiensis infecting larvae of Plodia interpunctella, the Indian meal moth. Transmission was found to increase in a more than linear way with host density in fourth and fifth instar P. interpunctella, and to decrease with the density of infectious cadavers in the case of fifth instar larvae. Food availability was shown to play an important part in this process. Therefore, on a number of counts, the usual assumption was found not to apply in our experimental system.

The association between oral health status and respiratory pathogen colonization with pneumonia risk in institutionalized adults.

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Hong, Chl; Aung, M M; Kanagasabai, K; Lim, C A; Liang, S; Tan, K S

2018-05-01

This study aimed to assess the oral health and the prevalence of pre-existing oral colonization with respiratory pathogens in dependent elderly, and whether these factors influence pneumonia development. Participants residing in a long-term care facility received bedside oral examinations, and information on their oral health (caries status, calculus index and debris index) was obtained. Samples from the tongue and teeth were collected at baseline and at time of pneumonia development. Sputum was collected at the time of pneumonia diagnosis. Samples were assessed for Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae by polymerase chain reaction. This was a 1-year longitudinal study of 60 dependent elderly (mean age: 64.2 ± 14.1 years). Seventeen patients (28.3%) developed pneumonia. The mean Decayed, Missing and Filled Teeth and Simplified Oral Hygiene Index were 22.8 ± 9.2 and 4.0 ± 1.0, respectively. At baseline, 48.3% were orally colonized with ≥1 respiratory pathogens. The presence of H. influenzae (P = .002) and P. aeruginosa (P = .049) in the sputum was significantly associated with their colonization on the tongue at baseline. In the bivariate analyses, pneumonia development was associated with naso-gastric feeding tube (P = .0001), H. influenzae (P = .015) and P. aeruginosa (P = .003) tongue colonization at baseline and calculus index (P = .002). Multivariate analyses revealed that calculus index (P = .09) and the presence of tracheostomy (P = .037) were associated with pneumonia. The calculus amount and tongue colonization with respiratory pathogens are risk factors for pneumonia development. Oral hygiene measures to remove tongue biofilm and calculus may reduce pneumonia development. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Recasting the theory of mosquito-borne pathogen transmission dynamics and control

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Smith, David L.; Perkins, T. Alex; Reiner, Robert C.; Barker, Christopher M.; Niu, Tianchan; Chaves, Luis Fernando; Ellis, Alicia M.; George, Dylan B.; Le Menach, Arnaud; Pulliam, Juliet R. C.; Bisanzio, Donal; Buckee, Caroline; Chiyaka, Christinah; Cummings, Derek A. T.; Garcia, Andres J.; Gatton, Michelle L.; Gething, Peter W.; Hartley, David M.; Johnston, Geoffrey; Klein, Eili Y.; Michael, Edwin; Lloyd, Alun L.; Pigott, David M.; Reisen, William K.; Ruktanonchai, Nick; Singh, Brajendra K.; Stoller, Jeremy; Tatem, Andrew J.; Kitron, Uriel; Godfray, H. Charles J.; Cohen, Justin M.; Hay, Simon I.; Scott, Thomas W.

2014-01-01

Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of the world. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald's formula for R0 and its entomological derivative, vectorial capacity, are now used to study dynamics and design interventions for many mosquito-borne diseases. A systematic review of 388 models published between 1970 and 2010 found that the vast majority adopted the Ross–Macdonald assumption of homogeneous transmission in a well-mixed population. Studies comparing models and data question these assumptions and point to the capacity to model heterogeneous, focal transmission as the most important but relatively unexplored component in current theory. Fine-scale heterogeneity causes transmission dynamics to be nonlinear, and poses problems for modeling, epidemiology and measurement. Novel mathematical approaches show how heterogeneity arises from the biology and the landscape on which the processes of mosquito biting and pathogen transmission unfold. Emerging theory focuses attention on the ecological and social context for mosquito blood feeding, the movement of both hosts and mosquitoes, and the relevant spatial scales for measuring transmission and for modeling dynamics and control. PMID:24591453

Recasting the theory of mosquito-borne pathogen transmission dynamics and control.

Science.gov (United States)

Smith, David L; Perkins, T Alex; Reiner, Robert C; Barker, Christopher M; Niu, Tianchan; Chaves, Luis Fernando; Ellis, Alicia M; George, Dylan B; Le Menach, Arnaud; Pulliam, Juliet R C; Bisanzio, Donal; Buckee, Caroline; Chiyaka, Christinah; Cummings, Derek A T; Garcia, Andres J; Gatton, Michelle L; Gething, Peter W; Hartley, David M; Johnston, Geoffrey; Klein, Eili Y; Michael, Edwin; Lloyd, Alun L; Pigott, David M; Reisen, William K; Ruktanonchai, Nick; Singh, Brajendra K; Stoller, Jeremy; Tatem, Andrew J; Kitron, Uriel; Godfray, H Charles J; Cohen, Justin M; Hay, Simon I; Scott, Thomas W

2014-04-01

Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of the world. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald's formula for R0 and its entomological derivative, vectorial capacity, are now used to study dynamics and design interventions for many mosquito-borne diseases. A systematic review of 388 models published between 1970 and 2010 found that the vast majority adopted the Ross-Macdonald assumption of homogeneous transmission in a well-mixed population. Studies comparing models and data question these assumptions and point to the capacity to model heterogeneous, focal transmission as the most important but relatively unexplored component in current theory. Fine-scale heterogeneity causes transmission dynamics to be nonlinear, and poses problems for modeling, epidemiology and measurement. Novel mathematical approaches show how heterogeneity arises from the biology and the landscape on which the processes of mosquito biting and pathogen transmission unfold. Emerging theory focuses attention on the ecological and social context for mosquito blood feeding, the movement of both hosts and mosquitoes, and the relevant spatial scales for measuring transmission and for modeling dynamics and control.

Dembo polymerase chain reaction technique for detection of bovine abortion, diarrhea, and respiratory disease complex infectious agents in potential vectors and reservoirs.

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Rahpaya, Sayed Samim; Tsuchiaka, Shinobu; Kishimoto, Mai; Oba, Mami; Katayama, Yukie; Nunomura, Yuka; Kokawa, Saki; Kimura, Takashi; Kobayashi, Atsushi; Kirino, Yumi; Okabayashi, Tamaki; Nonaka, Nariaki; Mekata, Hirohisa; Aoki, Hiroshi; Shiokawa, Mai; Umetsu, Moeko; Morita, Tatsushi; Hasebe, Ayako; Otsu, Keiko; Asai, Tetsuo; Yamaguchi, Tomohiro; Makino, Shinji; Murata, Yoshiteru; Abi, Ahmad Jan; Omatsu, Tsutomu; Mizutani, Tetsuya

2018-05-31

Bovine abortion, diarrhea, and respiratory disease complexes, caused by infectious agents, result in high and significant economic losses for the cattle industry. These pathogens are likely transmitted by various vectors and reservoirs including insects, birds, and rodents. However, experimental data supporting this possibility are scarce. We collected 117 samples and screened them for 44 bovine abortive, diarrheal, and respiratory disease complex pathogens by using Dembo polymerase chain reaction (PCR), which is based on TaqMan real-time PCR. Fifty-seven samples were positive for at least one pathogen, including bovine viral diarrhea virus, bovine enterovirus, Salmonella enterica ser. Dublin, Salmonella enterica ser. Typhimurium, and Neospora caninum ; some samples were positive for multiple pathogens. Bovine viral diarrhea virus and bovine enterovirus were the most frequently detected pathogens, especially in flies, suggesting an important role of flies in the transmission of these viruses. Additionally, we detected the N. caninum genome from a cockroach sample for the first time. Our data suggest that insects (particularly flies), birds, and rodents are potential vectors and reservoirs of abortion, diarrhea, and respiratory infectious agents, and that they may transmit more than one pathogen at the same time.

[Uncommon non-fermenting Gram-negative rods as pathogens of lower respiratory tract infection].

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Juhász, Emese; Iván, Miklós; Pongrácz, Júlia; Kristóf, Katalin

2018-01-01

Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet. The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options. Lower respiratory tract samples of 3589 patients collected in a four-year period (2013-2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method. Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also. Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23-30.

Associations between pathogens in the upper respiratory tract of young children: interplay between viruses and bacteria.

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Menno R van den Bergh

Full Text Available High rates of potentially pathogenic bacteria and respiratory viruses can be detected in the upper respiratory tract of healthy children. Investigating presence of and associations between these pathogens in healthy individuals is still a rather unexplored field of research, but may have implications for interpreting findings during disease.We selected 986 nasopharyngeal samples from 433 6- to 24-month-old healthy children that had participated in a randomized controlled trial. We determined the presence of 20 common respiratory viruses using real-time PCR. Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus were identified by conventional culture methods. Information on risk factors was obtained by questionnaires. We performed multivariate logistic regression analyses followed by partial correlation analysis to identify the overall pattern of associations. S. pneumoniae colonization was positively associated with the presence of H. influenzae (adjusted odds ratio 1.60, 95% confidence interval 1.18-2.16, M. catarrhalis (1.78, 1.29-2.47, human rhinoviruses (1.63, 1.19-2.22 and enteroviruses (1.97, 1.26-3.10, and negatively associated with S. aureus presence (0.59, 0.35-0.98. H. influenzae was positively associated with human rhinoviruses (1.63, 1.22-2.18 and respiratory syncytial viruses (2.78, 1.06-7.28. M. catarrhalis colonization was positively associated with coronaviruses (1.99, 1.01-3.93 and adenoviruses (3.69, 1.29-10.56, and negatively with S. aureus carriage (0.42, 0.25-0.69. We observed a strong positive association between S. aureus and influenza viruses (4.87, 1.59-14.89. In addition, human rhinoviruses and enteroviruses were positively correlated (2.40, 1.66-3.47, as were enteroviruses and human bocavirus, WU polyomavirus, parainfluenza viruses, and human parechovirus. A negative association was observed between human rhinoviruses and coronaviruses.Our data revealed high viral and

Influence of contact definitions in assessment of the relative importance of social settings in disease transmission risk.

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Kirsty J Bolton

Full Text Available BACKGROUND: Realistic models of disease transmission incorporating complex population heterogeneities require input from quantitative population mixing studies. We use contact diaries to assess the relative importance of social settings in respiratory pathogen spread using three measures of person contact hours (PCH as proxies for transmission risk with an aim to inform bipartite network models of respiratory pathogen transmission. METHODS AND FINDINGS: Our survey examines the contact behaviour for a convenience sample of 65 adults, with each encounter classified as occurring in a work, retail, home, social, travel or "other" setting. The diary design allows for extraction of PCH-interaction (cumulative time in face-face conversational or touch interaction with contacts--analogous to the contact measure used in several existing surveys--as well as PCH-setting (product of time spent in setting and number of people present and PCH-reach (product of time spent in setting and number of people in close proximity. Heterogeneities in day-dependent distribution of risk across settings are analysed using partitioning and cluster analyses and compared between days and contact measures. Although home is typically the highest-risk setting when PCH measures isolate two-way interactions, its relative importance compared to social and work settings may reduce when adopting a more inclusive contact measure that considers the number and duration of potential exposure events. CONCLUSIONS: Heterogeneities in location-dependent contact behaviour as measured by contact diary studies depend on the adopted contact definition. We find that contact measures isolating face-face conversational or touch interactions suggest that contact in the home dominates, whereas more inclusive contact measures indicate that home and work settings may be of higher importance. In the absence of definitive knowledge of the contact required to facilitate transmission of various

The Characteristics of Middle Eastern Respiratory Syndrome Coronavirus Transmission Dynamics in South Korea.

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Kim, Yunhwan; Lee, Sunmi; Chu, Chaeshin; Choe, Seoyun; Hong, Saeme; Shin, Youngseo

2016-02-01

The outbreak of Middle Eastern respiratory syndrome coronavirus (MERS-CoV) was one of the major events in South Korea in 2015. In particular, this study pays attention to formulating a mathematical model for MERS transmission dynamics and estimating transmission rates. Incidence data of MERS-CoV from the government authority was analyzed for the first aim and a mathematical model was built and analyzed for the second aim of the study. A mathematical model for MERS-CoV transmission dynamics is used to estimate the transmission rates in two periods due to the implementation of intensive interventions. Using the estimates of the transmission rates, the basic reproduction number was estimated in two periods. Due to the superspreader, the basic reproduction number was very large in the first period; however, the basic reproduction number of the second period has reduced significantly after intensive interventions. It turned out to be the intensive isolation and quarantine interventions that were the most critical factors that prevented the spread of the MERS outbreak. The results are expected to be useful to devise more efficient intervention strategies in the future.

Occupational blood exposures in health care workers: incidence, characteristics, and transmission of bloodborne pathogens in South Korea

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Ju Hyun Lee

2017-10-01

Full Text Available Abstract Background Health care workers (HCWs are at high risk for occupational blood exposures (OBEs and transmission of bloodborne pathogens. This study elucidated the incidence rate and epidemiological characteristics of OBEs among HCWs and investigated the pathogen transmission rate for hepatitis B virus (HBV, hepatitis C virus (HCV, and human immunodeficiency virus (HIV. Methods Self-reported OBEs from January 1, 2011 to December 31, 2015 were obtained from the electronic recording system. OBE incidence densities per 100 person-years and per 100 bed-years were calculated with a 5-year trend analysis. OBE characteristics and pathogen transmission rates were evaluated. Results Among 10,452 HCWs and 1072 average yearly beds, 1076 OBEs were reported. OBE incidence rate was 5.6 cases per 100 person (full-time equivalent-years and 20.3 per 100 bed-years. Incidence rate decreased and was significantly associated with a decrease of beds served per HCW. Housekeeping showed the highest OBE rate (14.8% followed by doctors (8.5% and nurses (6.2%. OBEs occurred in wards, emergency rooms, and operating rooms (38.1%, 13.3% and 12.2%, respectively via percutaneous (86.7% and mucocutaneous exposures (13.2%. Of OBEs associated with HBV (n = 133, HCV (n = 126, and HIV (n = 25, only one led to an infection (HCV; transmission rate of 0.8%. Neither HBV nor HIV infection occurred. Conclusions OBE incidence rate in a Korean university hospital was 5.6 cases per 100 person-years and 20.3 per 100 bed-years and was related to HCW workload and work proficiency. Though the actual bloodborne pathogen transmission rate was low, efforts to prevent OBE should be made for hospital safety.

Quantifying Transmission.

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Woolhouse, Mark

2017-07-01

Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

A Network Integration Approach to Predict Conserved Regulators Related to Pathogenicity of Influenza and SARS-CoV Respiratory Viruses

Energy Technology Data Exchange (ETDEWEB)

Mitchell, Hugh D.; Eisfeld, Amie J.; Sims, Amy; McDermott, Jason E.; Matzke, Melissa M.; Webb-Robertson, Bobbie-Jo M.; Tilton, Susan C.; Tchitchek, Nicholas; Josset, Laurence; Li, Chengjun; Ellis, Amy L.; Chang, Jean H.; Heegel, Robert A.; Luna, Maria L.; Schepmoes, Athena A.; Shukla, Anil K.; Metz, Thomas O.; Neumann, Gabriele; Benecke, Arndt; Smith, Richard D.; Baric, Ralph; Kawaoka, Yoshihiro; Katze, Michael G.; Waters, Katrina M.

2013-07-25

Respiratory infections stemming from influenza viruses and the Severe Acute Respiratory Syndrome corona virus (SARS-CoV) represent a serious public health threat as emerging pandemics. Despite efforts to identify the critical interactions of these viruses with host machinery, the key regulatory events that lead to disease pathology remain poorly targeted with therapeutics. Here we implement an integrated network interrogation approach, in which proteome and transcriptome datasets from infection of both viruses in human lung epithelial cells are utilized to predict regulatory genes involved in the host response. We take advantage of a novel “crowd-based” approach to identify and combine ranking metrics that isolate genes/proteins likely related to the pathogenicity of SARS-CoV and influenza virus. Subsequently, a multivariate regression model is used to compare predicted lung epithelial regulatory influences with data derived from other respiratory virus infection models. We predicted a small set of regulatory factors with conserved behavior for consideration as important components of viral pathogenesis that might also serve as therapeutic targets for intervention. Our results demonstrate the utility of integrating diverse ‘omic datasets to predict and prioritize regulatory features conserved across multiple pathogen infection models.

Electrical coupling and excitatory synaptic transmission between rhythmogenic respiratory neurons in the preBötzinger complex

DEFF Research Database (Denmark)

Rekling, J C; Shao, X M; Feldman, J L

2000-01-01

Breathing pattern is postulated to be generated by brainstem neurons. However, determination of the underlying cellular mechanisms, and in particular the synaptic interactions between respiratory neurons, has been difficult. Here we used dual recordings from two distinct populations of brainstem...... respiratory neurons, hypoglossal (XII) motoneurons, and rhythmogenic (type-1) neurons in the preBötzinger complex (preBötC), the hypothesized site for respiratory rhythm generation, to determine whether electrical and chemical transmission is present. Using an in vitro brainstem slice preparation from newborn...... mice, we found that intracellularly recorded pairs of XII motoneurons and pairs of preBötC inspiratory type-1 neurons showed bidirectional electrical coupling. Coupling strength was low (neurons was heavily filtered (corner frequency,

Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses.

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Zhou, S Steve; Lukula, Salimatu; Chiossone, Cory; Nims, Raymond W; Suchmann, Donna B; Ijaz, M Khalid

2018-03-01

Prevention of infection with airborne pathogens and exposure to airborne particulates and aerosols (environmental pollutants and allergens) can be facilitated through use of disposable face masks. The effectiveness of such masks for excluding pathogens and pollutants is dependent on the intrinsic ability of the masks to resist penetration by airborne contaminants. This study evaluated the relative contributions of a mask, valve, and Micro Ventilator on aerosol filtration efficiency of a new N95 respiratory face mask. The test mask was challenged, using standardized methods, with influenza A and rhinovirus type 14, bacteriophage ΦΧ174, Staphylococcus aureus ( S . aureus ), and model pollutants. The statistical significance of results obtained for different challenge microbial agents and for different mask configurations (masks with operational or nonoperational ventilation fans and masks with sealed Smart Valves) was assessed. The results demonstrate >99.7% efficiency of each test mask configuration for exclusion of influenza A virus, rhinovirus 14, and S . aureus and >99.3% efficiency for paraffin oil and sodium chloride (surrogates for PM 2.5 ). Statistically significant differences in effectiveness of the different mask configurations were not identified. The efficiencies of the masks for excluding smaller-size (i.e., rhinovirus and bacteriophage ΦΧ174) vs. larger-size microbial agents (influenza virus, S . aureus ) were not significantly different. The masks, with or without features intended for enhancing comfort, provide protection against both small- and large-size pathogens. Importantly, the mask appears to be highly efficient for filtration of pathogens, including influenza and rhinoviruses, as well as the fine particulates (PM 2.5 ) present in aerosols that represent a greater challenge for many types of dental and surgical masks. This renders this individual-use N95 respiratory mask an improvement over the former types of masks for protection against

A scoping review of the role of wildlife in the transmission of bacterial pathogens and antimicrobial resistance to the food Chain.

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Greig, J; Rajić, A; Young, I; Mascarenhas, M; Waddell, L; LeJeune, J

2015-06-01

Wildlife can contribute to environmental contamination with bacterial pathogens and their transfer to the human food chain. Global usage and frequent misuse of antimicrobials contribute to emergence of new antimicrobial resistant (AMR) strains of foodborne pathogens. We conducted a scoping review of published research to identify and characterize the evidence on wildlife's role in transmission of AMR and/or bacterial pathogens to the food chain. An advisory group (AG) of 13 North American experts from diverse disciplines was surveyed to solicit insight in the review scope, priority topics and research characteristics. A pre-tested search strategy was implemented in seven bibliographic databases (1990 to January 2013). Citations were relevance screened, and key characteristics on priority topics extracted independently by two reviewers. Analysis identified topic areas with solid evidence and main knowledge gaps. North America reported 30% of 866 relevant articles. The prevalence of five targeted bacterial pathogens and/or AMR in any pathogen in wildlife was reported in 582 articles. Transmission risk factors for selected bacteria or AMR in any bacteria were reported in 300. Interventions to control transmission were discussed in 124 articles and formally evaluated in 50. The majority of primary research investigated birds, cervids, rodents, feral pigs, opossums, E. coli (n = 329), Salmonella (n = 293) and Campylobacter (n = 124). An association between wildlife and transmission of bacterial pathogens and/or AMR to the food chain was supported in 122 studies. The scoping review identified a significant body of research on the role of wild birds in the prevalence and transmission of E. coli, Salmonella and Campylobacter. There was little research employing molecular methods contributing to the evidence concerning the importance and direction of transmission of wildlife/pathogen combinations. Given the advancements of these methods, future research should focus in this

Increased pathogenicity of European porcine reproductive and respiratory syndrome virus is associated with enhanced adaptive responses and viral clearance

NARCIS (Netherlands)

Morgan, S.B.; Graham, S.P.; Salguero, F.J.; Sánchez Cordón, P.J.; Mokhtar, H.; Rebel, J.M.J.; Weesendorp, E.; Bodman-Smith, K.B.; Steinbach, F.; Frossard, J.P.

2013-01-01

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases of swine worldwide. Since its first emergence in 1987 the PRRS virus (PRRSV) has become particularly divergent with highly pathogenic strains appearing in both Europe and Asia. However, the

Methods for air cleaning and protection of building occupants from airborne pathogens

DEFF Research Database (Denmark)

Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor

2009-01-01

germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification from pathogens are analyzed with respect to currently used air distribution principles. The importance of indoor air characteristics, such as temperature, relative...... of transmission, i.e. the generation of pathogen laden droplets originating in the respiratory tract of an infected individual, the survivability of the pathogens, their dispersal indoors and their transfer to a healthy person are reviewed. The advantages and the drawbacks of air dilution, filtration, ultraviolet...... humidity and velocity for the efficiency of each method is analyzed, taking into consideration the nature of the pathogens themselves. The applicability of the methods to the different types of total volume air distribution used at present indoors, i.e. mixing, displacement and underfloor ventilation...

Review of economic evaluations of mask and respirator use for protection against respiratory infection transmission.

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Mukerji, Shohini; MacIntyre, C Raina; Newall, Anthony T

2015-10-13

There has been increasing debate surrounding mask and respirator interventions to control respiratory infection transmission in both healthcare and community settings. As decision makers are considering the recommendations they should evaluate how to provide the most efficient protection strategies with minimum costs. The aim of this review is to identify and evaluate the existing economic evaluation literature in this area and to offer advice on how future evaluations on this topic should be conducted. We searched the Scopus database for all literature on economic evaluation of mask or respirator use to control respiratory infection transmission. Reference lists from the identified studies were also manually searched. Seven studies met our inclusion criteria from the initial 806 studies identified by the search strategy and our manual search. Five studies considered interventions for seasonal and/or pandemic influenza, with one also considering SARS (Severe Acute Respiratory Syndrome). The other two studies focussed on tuberculosis transmission control interventions. The settings and methodologies of the studies varied greatly. No low-middle income settings were identified. Only one of the reviewed studies cited clinical evidence to inform their mask/respirator intervention effectiveness parameters. Mask and respirator interventions were generally reported by the study authors to be cost saving or cost-effective when compared to no intervention or other control measures, however the evaluations had important limitations. Given the large cost differential between masks and respirators, there is a need for more comprehensive economic evaluations to compare the relative costs and benefits of these interventions in situations and settings where alternative options are potentially applicable. There are at present insufficient well conducted cost-effectiveness studies to inform decision-makers on the value for money of alternative mask/respirator options.

Evaluation of respiratory route as a viable portal of entry for Salmonella in poultry

Directory of Open Access Journals (Sweden)

Kallapura G

2014-08-01

Full Text Available Gopala Kallapura,1 Xochitl Hernandez-Velasco,2 Neil R Pumford,1 Lisa R Bielke,1 Billy M Hargis,1 Guillermo Tellez1 1Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA; 2College of Veterinary Medicine and Animal Husbandry, The National Autonomous University of Mexico, Mexico Abstract: With increasing reports of Salmonella infection, we are forced to question whether the fecal–oral route is the major route of infection and consider the possibility that airborne Salmonella infections might have a major unappreciated role. Today's large-scale poultry production, with densely stocked and enclosed production buildings, is often accompanied by very high concentrations of airborne microorganisms. Considering that the upper and lower respiratory lymphoid tissue requires up to 6 weeks to be fully developed, these immune structures seem to have a very minor role in preventing pathogen infection. In addition, the avian respiratory system in commercial poultry has anatomic and physiologic properties that present no challenge to the highly adapted Salmonella. The present review evaluates the hypothesis that transmission by the fecal–respiratory route may theoretically be a viable portal of entry for Salmonella in poultry. First, we update the current knowledge on generation of Salmonella bioaerosols, and the transport and fate of Salmonella at various stages of commercial poultry production. Further, emphasis is placed on survivability of Salmonella in these bioaerosols, as a means to assess the transport and subsequent risk of exposure and infection of poultry. Additionally, the main anatomic structures, physiologic functions, and immunologic defense in the avian respiratory system are discussed to understand the potential entry points inherent in each component that could potentially lead to infection and subsequent systemic infection of poultry by Salmonella. In this context, we also evaluate the role of the mucosal immune

A model of the transmission of micro-organisms in a public setting and its correlation to pathogen infection risks.

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Gerhardts, A; Hammer, T R; Balluff, C; Mucha, H; Hoefer, D

2012-03-01

Gastro-intestinal infections are widespread in the community and have considerable economic consequences. In this study, we followed chains of infection from a public toilet scenario, looking at infection risks by correlating the transmission of bacteria, fungi and viruses to our current knowledge of infectious doses. Transmission of Escherichia coli, Bacillus atrophaeus spores, Candida albicans and bacteriophage MS2 from hands to surfaces was examined in a transmission model, that is toilet brush, door handle to water tap. The load of viable pathogens was significantly reduced during transfer from hands to objects. Nevertheless, it was shown that pathogens were successfully transferred to other people in contagious doses by contact with contaminated surfaces. Our results suggest that infection risks are mainly dependent on current infectious doses of pathogens. For enteritic viruses or bacteria, for example Norovirus or EHEC, only a few particles or cells are sufficient for infection in public lavatories, thus bearing a high risk of infection for other persons. However, there seems to be only a low probability of becoming infected with pathogens that have a high infectious dose whilst sharing the same bathroom. The transmission model for micro-organisms enables a risk assessment of gastro-intestinal infections on the basis of a practical approach. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Three pathogens in sympatric populations of pumas, bobcats, and domestic cats: implications for infectious disease transmission.

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Sarah N Bevins

Full Text Available Anthropogenic landscape change can lead to increased opportunities for pathogen transmission between domestic and non-domestic animals. Pumas, bobcats, and domestic cats are sympatric in many areas of North America and share many of the same pathogens, some of which are zoonotic. We analyzed bobcat, puma, and feral domestic cat samples collected from targeted geographic areas. We examined exposure to three pathogens that are taxonomically diverse (bacterial, protozoal, viral, that incorporate multiple transmission strategies (vector-borne, environmental exposure/ingestion, and direct contact, and that vary in species-specificity. Bartonella spp., Feline Immunodeficiency Virus (FIV, and Toxoplasma gondii IgG were detected in all three species with mean respective prevalence as follows: puma 16%, 41% and 75%; bobcat 31%, 22% and 43%; domestic cat 45%, 10% and 1%. Bartonella spp. were highly prevalent among domestic cats in Southern California compared to other cohort groups. Feline Immunodeficiency Virus exposure was primarily associated with species and age, and was not influenced by geographic location. Pumas were more likely to be infected with FIV than bobcats, with domestic cats having the lowest infection rate. Toxoplasma gondii seroprevalence was high in both pumas and bobcats across all sites; in contrast, few domestic cats were seropositive, despite the fact that feral, free ranging domestic cats were targeted in this study. Interestingly, a directly transmitted species-specific disease (FIV was not associated with geographic location, while exposure to indirectly transmitted diseases--vector-borne for Bartonella spp. and ingestion of oocysts via infected prey or environmental exposure for T. gondii--varied significantly by site. Pathogens transmitted by direct contact may be more dependent upon individual behaviors and intra-specific encounters. Future studies will integrate host density, as well as landscape features, to better

Cage size, movement in and out of housing during daily care, and other environmental and population health risk factors for feline upper respiratory disease in nine North American animal shelters.

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Denae C Wagner

Full Text Available Upper respiratory infection (URI is not an inevitable consequence of sheltering homeless cats. This study documents variation in risk of URI between nine North American shelters; determines whether this reflects variation in pathogen frequency on intake or differences in transmission and expression of disease; and identifies modifiable environmental and group health factors linked to risk for URI. This study demonstrated that although periodic introduction of pathogens into shelter populations may be inevitable, disease resulting from those pathogens is not. Housing and care of cats, particularly during their first week of stay in an animal shelter environment, significantly affects the rate of upper respiratory infection.

Cage size, movement in and out of housing during daily care, and other environmental and population health risk factors for feline upper respiratory disease in nine North American animal shelters.

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Wagner, Denae C; Kass, Philip H; Hurley, Kate F

2018-01-01

Upper respiratory infection (URI) is not an inevitable consequence of sheltering homeless cats. This study documents variation in risk of URI between nine North American shelters; determines whether this reflects variation in pathogen frequency on intake or differences in transmission and expression of disease; and identifies modifiable environmental and group health factors linked to risk for URI. This study demonstrated that although periodic introduction of pathogens into shelter populations may be inevitable, disease resulting from those pathogens is not. Housing and care of cats, particularly during their first week of stay in an animal shelter environment, significantly affects the rate of upper respiratory infection.

Diversity and role of cave-dwelling hematophagous insects in pathogen transmission in the Afrotropical region.

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Obame-Nkoghe, Judicaël; Leroy, Eric-Maurice; Paupy, Christophe

2017-04-12

The progressive anthropization of caves for food resources or economic purposes increases human exposure to pathogens that naturally infect cave-dwelling animals. The presence of wild or domestic animals in the immediate surroundings of caves also may contribute to increasing the risk of emergence of such pathogens. Some zoonotic pathogens are transmitted through direct contact, but many others require arthropod vectors, such as blood-feeding insects. In Africa, hematophagous insects often play a key role in the epidemiology of many pathogens; however, their ecology in cave habitats remains poorly known. During the last decades, several investigations carried out in Afrotropical caves suggested the medical and veterinary importance particularly of insect taxa of the Diptera order. Therefore, the role of some of these insects as vectors of pathogens that infect cave-dwelling vertebrates has been studied. The present review summarizes these findings, brings insights into the diversity of cave-dwelling hematophagous Diptera and their involvement in pathogen transmission, and finally discusses new challenges and future research directions.

Burden of Disease Attributed to Waterborne Transmission of Selected Enteric Pathogens, Australia, 2010.

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Gibney, Katherine B; O'Toole, Joanne; Sinclair, Martha; Leder, Karin

2017-06-01

AbstractUniversal access to safe drinking water is a global priority. To estimate the annual disease burden of campylobacteriosis, nontyphoidal salmonellosis, cryptosporidiosis, giardiasis, and norovirus attributable to waterborne transmission in Australia, we multiplied regional World Health Organization (WHO) estimates of the proportion of cases attributable to waterborne transmission by estimates of all-source disease burden for each study pathogen. Norovirus was attributed as causing the most waterborne disease cases (479,632; 95% uncertainty interval [UI]: 0-1,111,874) followed by giardiasis and campylobacteriosis. The estimated waterborne disability-adjusted life year (DALY) burden for campylobacteriosis (2,004; 95% UI: 0-5,831) was 7-fold greater than other study pathogens and exceeded the WHO guidelines for drinking water quality (1 × 10 -6 DALY per person per year) by 90-fold. However, these estimates include disease transmitted via either drinking or recreational water exposure. More precise country-specific and drinking water-specific attribution estimates would better define the health burden from drinking water and inform changes to treatment requirements.

Porcine respiratory disease complex: Interaction of vaccination and porcine circovirus type 2, porcine reproductive and respiratory syndrome virus, and Mycoplasma hyopneumoniae.

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Chae, Chanhee

2016-06-01

Porcine respiratory disease is a multifactorial and complex disease caused by a combination of infectious pathogens, environmental stressors, differences in production systems, and various management practices; hence the name porcine respiratory disease complex (PRDC) is used. Porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), and Mycoplasma hyopneumoniae are considered to be the most important pathogens that cause PRDC. Although interactions among the three major respiratory pathogens are well documented, it is also necessary to understand the interaction between vaccines and the three major respiratory pathogens. PRRSV and M. hyopneumoniae are well known to potentiate PCV2-associated lesions; however, PRRSV and mycoplasmal vaccines can both enhance PCV2 viraemia regardless of the effects of the actual PRRSV or M. hyopneumoniae infection. On the other hand, M. hyopneumoniae potentiates the severity of pneumonia induced by PRRSV, and vaccination against M. hyopneumoniae alone is also able to decrease PRRSV viraemia and PRRSV-induced lung lesions in dually infected pigs. This review focuses on (1) interactions between PCV2, PRRSV, and M. hyopneumoniae; and (2) interactions between vaccines and the three major respiratory pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

The contribution of social behaviour to the transmission of influenza A in a human population.

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Kucharski, Adam J; Kwok, Kin O; Wei, Vivian W I; Cowling, Benjamin J; Read, Jonathan M; Lessler, Justin; Cummings, Derek A; Riley, Steven

2014-06-01

Variability in the risk of transmission for respiratory pathogens can result from several factors, including the intrinsic properties of the pathogen, the immune state of the host and the host's behaviour. It has been proposed that self-reported social mixing patterns can explain the behavioural component of this variability, with simulated intervention studies based on these data used routinely to inform public health policy. However, in the absence of robust studies with biological endpoints for individuals, it is unclear how age and social behaviour contribute to infection risk. To examine how the structure and nature of social contacts influenced infection risk over the course of a single epidemic, we designed a flexible disease modelling framework: the population was divided into a series of increasingly detailed age and social contact classes, with the transmissibility of each age-contact class determined by the average contacts of that class. Fitting the models to serologically confirmed infection data from the 2009 Hong Kong influenza A/H1N1p pandemic, we found that an individual's risk of infection was influenced strongly by the average reported social mixing behaviour of their age group, rather than by their personal reported contacts. We also identified the resolution of social mixing that shaped transmission: epidemic dynamics were driven by intense contacts between children, a post-childhood drop in risky contacts and a subsequent rise in contacts for individuals aged 35-50. Our results demonstrate that self-reported social contact surveys can account for age-associated heterogeneity in the transmission of a respiratory pathogen in humans, and show robustly how these individual-level behaviours manifest themselves through assortative age groups. Our results suggest it is possible to profile the social structure of different populations and to use these aggregated data to predict their inherent transmission potential.

Replication, pathogenicity, shedding, and transmission of Zaire ebolavirus in pigs.

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Kobinger, Gary P; Leung, Anders; Neufeld, James; Richardson, Jason S; Falzarano, Darryl; Smith, Greg; Tierney, Kevin; Patel, Ami; Weingartl, Hana M

2011-07-15

(See the editorial commentary by Bausch, on pages 179-81.) Reston ebolavirus was recently detected in pigs in the Philippines. Specific antibodies were found in pig farmers, indicating exposure to the virus. This important observation raises the possibility that pigs may be susceptible to Ebola virus infection, including from other species, such as Zaire ebolavirus (ZEBOV), and can transmit to other susceptible hosts. This study investigated whether ZEBOV, a species commonly reemerging in central Africa, can replicate and induce disease in pigs and can be transmitted to naive animals. Domesticated Landrace pigs were challenged through mucosal exposure with a total of 1 ×10(6) plaque-forming units of ZEBOV and monitored for virus replication, shedding, and pathogenesis. Using similar conditions, virus transmission from infected to naive animals was evaluated in a second set of pigs. Following mucosal exposure, pigs replicated ZEBOV to high titers (reaching 10(7) median tissue culture infective doses/mL), mainly in the respiratory tract, and developed severe lung pathology. Shedding from the oronasal mucosa was detected for up to 14 days after infection, and transmission was confirmed in all naive pigs cohabiting with inoculated animals. These results shed light on the susceptibility of pigs to ZEBOV infection and identify an unexpected site of virus amplification and shedding linked to transmission of infectious virus.

Promising approaches for the treatment and prevention of viral respiratory illnesses.

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Papadopoulos, Nikolaos G; Megremis, Spyridon; Kitsioulis, Nikolaos A; Vangelatou, Olympia; West, Peter; Xepapadaki, Paraskevi

2017-10-01

Viral respiratory tract infections are the most common human ailments, leading to enormous health and economic burden. Hundreds of viral species and subtypes have been associated with these conditions, with influenza viruses, respiratory syncytial virus, and rhinoviruses being the most frequent and with the highest burden. When considering prevention or treatment of viral respiratory tract infections, potential targets include the causative pathogens themselves but also the immune response, disease transmission, or even just the symptoms. Strategies targeting all these aspects are developing concurrently, and several novel and promising approaches are emerging. In this perspective we overview the entire range of options and highlight some of the most promising approaches, including new antiviral agents, symptomatic or immunomodulatory drugs, the re-emergence of natural remedies, and vaccines and public health policies toward prevention. Wide-scale prevention through immunization appears to be within reach for respiratory syncytial virus and promising for influenza virus, whereas additional effort is needed in regard to rhinovirus, as well as other respiratory tract viruses. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Early emergence of Yersinia pestis as a severe respiratory pathogen.

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Zimbler, Daniel L; Schroeder, Jay A; Eddy, Justin L; Lathem, Wyndham W

2015-06-30

Yersinia pestis causes the fatal respiratory disease pneumonic plague. Y. pestis recently evolved from the gastrointestinal pathogen Y. pseudotuberculosis; however, it is not known at what point Y. pestis gained the ability to induce a fulminant pneumonia. Here we show that the acquisition of a single gene encoding the protease Pla was sufficient for the most ancestral, deeply rooted strains of Y. pestis to cause pneumonic plague, indicating that Y. pestis was primed to infect the lungs at a very early stage in its evolution. As Y. pestis further evolved, modern strains acquired a single amino-acid modification within Pla that optimizes protease activity. While this modification is unnecessary to cause pneumonic plague, the substitution is instead needed to efficiently induce the invasive infection associated with bubonic plague. These findings indicate that Y. pestis was capable of causing pneumonic plague before it evolved to optimally cause invasive infections in mammals.

Association of serum Clara cell protein CC16 with respiratory infections and immune response to respiratory pathogens in elite athletes.

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Kurowski, Marcin; Jurczyk, Janusz; Jarzębska, Marzanna; Moskwa, Sylwia; Makowska, Joanna S; Krysztofiak, Hubert; Kowalski, Marek L

2014-04-15

Respiratory epithelium integrity impairment caused by intensive exercise may lead to exercise-induced bronchoconstriction. Clara cell protein (CC16) has anti-inflammatory properties and its serum level reflects changes in epithelium integrity and airway inflammation. This study aimed to investigate serum CC16 in elite athletes and to seek associations of CC16 with asthma or allergy, respiratory tract infections (RTIs) and immune response to respiratory pathogens. The study was performed in 203 Olympic athletes. Control groups comprised 53 healthy subjects and 49 mild allergic asthmatics. Serum levels of CC16 and IgG against respiratory viruses and Mycoplasma pneumoniae were assessed. Allergy questionnaire for athletes was used to determine symptoms and exercise pattern. Current versions of ARIA and GINA guidelines were used when diagnosing allergic rhinitis and asthma, respectively. Asthma was diagnosed in 13.3% athletes, of whom 55.6% had concomitant allergic rhinitis. Allergic rhinitis without asthma was diagnosed in 14.8% of athletes. Mean CC16 concentration was significantly lower in athletes versus healthy controls and mild asthmatics. Athletes reporting frequent RTIs had significantly lower serum CC16 and the risk of frequent RTIs was more than 2-fold higher in athletes with low serum CC16 (defined as equal to or less than 4.99 ng/ml). Athletes had significantly higher anti-adenovirus IgG than healthy controls while only non-atopic athletes had anti-parainfluenza virus IgG significantly lower than controls. In all athletes weak correlation of serum CC16 and anti-parainfluenza virus IgG was present (R = 0.20, p athletes a weak positive correlations of CC16 with IgG specific for respiratory syncytial virus (R = 0.29, p = 0.009), parainfluenza virus (R = 0.31, p = 0.01) and adenovirus (R = 0.27, p = 0.02) were seen as well. Regular high-load exercise is associated with decrease in serum CC16 levels. Athletes with decreased CC16 are

Methods for air cleaning and protection of building occupants from airborne pathogens

Energy Technology Data Exchange (ETDEWEB)

Bolashikov, Z.D.; Melikov, A.K. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Nils Koppels Alle, building 402, 2800 Lyngby (Denmark)

2009-07-15

This article aims to draw the attention of the scientific community towards the elevated risks of airborne transmission of diseases and the associated risks of epidemics or pandemics. The complexity of the problem and the need for multidisciplinary research is highlighted. The airborne route of transmission, i.e. the generation of pathogen laden droplets originating in the respiratory tract of an infected individual, the survivability of the pathogens, their dispersal indoors and their transfer to a healthy person are reviewed. The advantages and the drawbacks of air dilution, filtration, ultraviolet germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification from pathogens are analyzed with respect to currently used air distribution principles. The importance of indoor air characteristics, such as temperature, relative humidity and velocity for the efficiency of each method is analyzed, taking into consideration the nature of the pathogens themselves. The applicability of the cleaning methods to the different types of total volume air distribution used at present indoors, i.e. mixing, displacement and underfloor ventilation, as well as advanced air distribution techniques (such as personalized ventilation) is discussed. (author)

D701N mutation in the PB2 protein contributes to the pathogenicity of H5N1 avian influenza viruses but not transmissibility in guinea pigs

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Peirong eJiao

2014-11-01

Full Text Available H5N1 highly pathogenic avian influenza virus (HPAIV of clade 2.3.2 has been circulating in waterfowl in Southern China since 2003. Our previous studies showed that certain H5N1 HPAIV isolates within clade 2.3.2 from Southern China had high pathogenicity in different birds. Guinea pigs have been successfully used as models to evaluate the transmissibility of AIVs and other species of influenza viruses in mammalian hosts. However, few studies have reported pathogenicity and transmissibility of H5N1 HPAIVs of this clade in guinea pigs. In this study, we selected an H5N1 HPAIV isolate, A/duck/Guangdong/357/2008, to investigate the pathogenicity and transmissibility of the virus in guinea pigs. The virus had high pathogenicity in mice; additionally, it only replicated in some tissues of the guinea pigs without production of clinical signs, but was transmissible among guinea pigs. Interestingly, virus isolates from co-caged guinea pigs had the D701N mutation in the PB2 protein. These mutant viruses showed higher pathogenicity in mice and higher replication capability in guinea pigs but did not demonstrate enhanced the transmissibility among guinea pigs. These findings indicate the transmission of the H5N1 virus between mammals could induce virus mutations, and the mutant viruses might have higher pathogenicity in mammals without higher transmissibility. Therefore, the continued evaluation of the pathogenicity and transmissibility of avian influenza virus (AIVs in mammals is critical to the understanding of the evolutionary characteristics of AIVs and the emergence of potential pandemic strains.

Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards

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Costa-Hurtado, Mar; Shepherd, Eric; DeJesus, Eric; Smith, Diane; Spackman, Erica; Kapczynski, Darrell R.; Suarez, David L.; Stallknecht, David E.; Swayne, David E.

2016-01-01

ABSTRACT Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010, and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses. To better understand why Gs/GD H5 HPAI viruses infect and transmit more efficiently in waterfowl than other HPAI viruses, groups of mallard ducks were challenged with one of 14 different H5 and H7 HPAI viruses, including a Gs/GD lineage H5N1 (clade 2.2) virus from Mongolia, part of the 2005 dispersion, and the H5N8 and H5N2 index HPAI viruses (clade 2.3.4.4) from the United States, part of the 2014 dispersion. All virus-inoculated ducks and contact exposed ducks became infected and shed moderate to high titers of the viruses, with the exception that mallards were resistant to Ck/Pennsylvania/83 and Ck/Queretaro/95 H5N2 HPAI virus infection. Clinical signs were only observed in ducks challenged with the H5N1 2005 virus, which all died, and with the H5N8 and H5N2 2014 viruses, which had decreased weight gain and fever. These three viruses were also shed in higher titers by the ducks, which could facilitate virus transmission and spread. This study highlights the possible role of wild waterfowl in the spread of HPAI viruses. IMPORTANCE The spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the Gs/GD lineage by migratory waterfowl is a serious concern for animal and public health. H5 and H7 HPAI viruses are considered to be adapted to gallinaceous species (chickens, turkeys, quail, etc.) and less likely to infect and transmit in wild ducks. In order to understand why this is different with certain Gs/GD lineage H5 HPAI viruses, we compared the pathogenicity and transmission of several H5 and H7 HPAI viruses from previous poultry outbreaks to Gs/GD lineage H5 viruses, including H5N1 (clade 2.2), H5N8 and H5N2 (clade 2.3.4.4) viruses, in

Whole Genome Sequence Analysis of Pig Respiratory Bacterial Pathogens with Elevated Minimum Inhibitory Concentrations for Macrolides.

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Dayao, Denise Ann Estarez; Seddon, Jennifer M; Gibson, Justine S; Blackall, Patrick J; Turni, Conny

2016-10-01

Macrolides are often used to treat and control bacterial pathogens causing respiratory disease in pigs. This study analyzed the whole genome sequences of one clinical isolate of Actinobacillus pleuropneumoniae, Haemophilus parasuis, Pasteurella multocida, and Bordetella bronchiseptica, all isolated from Australian pigs to identify the mechanism underlying the elevated minimum inhibitory concentrations (MICs) for erythromycin, tilmicosin, or tulathromycin. The H. parasuis assembled genome had a nucleotide transition at position 2059 (A to G) in the six copies of the 23S rRNA gene. This mutation has previously been associated with macrolide resistance but this is the first reported mechanism associated with elevated macrolide MICs in H. parasuis. There was no known macrolide resistance mechanism identified in the other three bacterial genomes. However, strA and sul2, aminoglycoside and sulfonamide resistance genes, respectively, were detected in one contiguous sequence (contig 1) of A. pleuropneumoniae assembled genome. This contig was identical to plasmids previously identified in Pasteurellaceae. This study has provided one possible explanation of elevated MICs to macrolides in H. parasuis. Further studies are necessary to clarify the mechanism causing the unexplained macrolide resistance in other Australian pig respiratory pathogens including the role of efflux systems, which were detected in all analyzed genomes.

Novel avian-origin human influenza A(H7N9) can be transmitted between ferrets via respiratory droplets.

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Xu, Lili; Bao, Linlin; Deng, Wei; Dong, Libo; Zhu, Hua; Chen, Ting; Lv, Qi; Li, Fengdi; Yuan, Jing; Xiang, Zhiguang; Gao, Kai; Xu, Yanfeng; Huang, Lan; Li, Yanhong; Liu, Jiangning; Yao, Yanfeng; Yu, Pin; Li, Xiyan; Huang, Weijuan; Zhao, Xiang; Lan, Yu; Guo, Junfeng; Yong, Weidong; Wei, Qiang; Chen, Honglin; Zhang, Lianfeng; Qin, Chuan

2014-02-15

The outbreak of human infections caused by novel avian-origin influenza A(H7N9) in China since March 2013 underscores the need to better understand the pathogenicity and transmissibility of these viruses in mammals. In a ferret model, the pathogenicity of influenza A(H7N9) was found to be less than that of an influenza A(H5N1) strain but comparable to that of 2009 pandemic influenza A(H1N1), based on the clinical signs, mortality, virus dissemination, and results of histopathologic analyses. Influenza A(H7N9) could replicate in the upper and lower respiratory tract, the heart, the liver, and the olfactory bulb. It is worth noting that influenza A(H7N9) exhibited a low level of transmission between ferrets via respiratory droplets. There were 4 mutations in the virus isolated from the contact ferret: D678Y in the gene encoding PB2, R157K in the gene encoding hemagglutinin (H3 numbering), I109T in the gene encoding nucleoprotein, and T10I in the gene encoding neuraminidase. These data emphasized that avian-origin influenza A(H7N9) can be transmitted between mammals, highlighting its potential for human-to-human transmissibility.

Gene flow and pathogen transmission among bobcats (Lynx rufus) in a fragmented urban landscape

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Lee, Justin S.; Ruell, Emily W.; Boydston, Erin E.; Lyren, Lisa M.; Alonso, Robert S.; Troyer, Jennifer L.; Crooks, Kevin R.; VandeWoude, Sue

2012-01-01

Urbanization can result in the fragmentation of once contiguous natural landscapes into a patchy habitat interspersed within a growing urban matrix. Animals living in fragmented landscapes often have reduced movement among habitat patches because of avoidance of intervening human development, which potentially leads to both reduced gene flow and pathogen transmission between patches. Mammalian carnivores with large home ranges, such as bobcats (Lynx rufus), may be particularly sensitive to habitat fragmentation. We performed genetic analyses on bobcats and their directly transmitted viral pathogen, feline immunodeficiency virus (FIV), to investigate the effects of urbanization on bobcat movement. We predicted that urban development, including major freeways, would limit bobcat movement and result in genetically structured host and pathogen populations. We analysed molecular markers from 106 bobcats and 19 FIV isolates from seropositive animals in urban southern California. Our findings indicate that reduced gene flow between two primary habitat patches has resulted in genetically distinct bobcat subpopulations separated by urban development including a major highway. However, the distribution of genetic diversity among FIV isolates determined through phylogenetic analyses indicates that pathogen genotypes are less spatially structured--exhibiting a more even distribution between habitat fragments. We conclude that the types of movement and contact sufficient for disease transmission occur with enough frequency to preclude structuring among the viral population, but that the bobcat population is structured owing to low levels of effective bobcat migration resulting in gene flow. We illustrate the utility in using multiple molecular markers that differentially detect movement and gene flow between subpopulations when assessing connectivity.

Three pathogens in sympatric populations of pumas, bobcats, and domestic cats: Implications for infections disease transmission

Science.gov (United States)

Bevins, Sarah N.; Carver, Scott; Boydston, Erin E.; Lyren, Lisa M.; Alldredge, Mat; Logan, Kenneth A.; Riley, Seth P.D.; Fisher, Robert N.; Vickers, T. Winston; Boyce, Walter; Salman, Mo; Lappin, Michael R.; Crooks, Kevin R.; VandeWoude, Sue

2012-01-01

Anthropogenic landscape change can lead to increased opportunities for pathogen transmission between domestic and non-domestic animals. Pumas, bobcats, and domestic cats are sympatric in many areas of North America and share many of the same pathogens, some of which are zoonotic. We analyzed bobcat, puma, and feral domestic cat samples collected from targeted geographic areas. We examined exposure to three pathogens that are taxonomically diverse (bacterial, protozoal, viral), that incorporate multiple transmission strategies (vector-borne, environmental exposure/ingestion, and direct contact), and that vary in species-specificity. Bartonella spp., Feline Immunodeficiency Virus (FIV), and Toxoplasma gondii IgG were detected in all three species with mean respective prevalence as follows: puma 16%, 41% and 75%; bobcat 31%, 22% and 43%; domestic cat 45%, 10% and 1%. Bartonella spp. were highly prevalent among domestic cats in Southern California compared to other cohort groups. Feline Immunodeficiency Virus exposure was primarily associated with species and age, and was not influenced by geographic location. Pumas were more likely to be infected with FIV than bobcats, with domestic cats having the lowest infection rate. Toxoplasma gondii seroprevalence was high in both pumas and bobcats across all sites; in contrast, few domestic cats were seropositive, despite the fact that feral, free ranging domestic cats were targeted in this study. Interestingly, a directly transmitted species-specific disease (FIV) was not associated with geographic location, while exposure to indirectly transmitted diseases – vector-borne for Bartonella spp. and ingestion of oocysts via infected prey or environmental exposure for T. gondii – varied significantly by site. Pathogens transmitted by direct contact may be more dependent upon individual behaviors and intra-specific encounters. Future studies will integrate host density, as well as landscape features, to better

Risk for interspecies transmission of zoonotic pathogens during poultry processing and pork production in Peru: A qualitative study.

Science.gov (United States)

Carnero, A M; Kitayama, K; Diaz, D A; Garvich, M; Angulo, N; Cama, V A; Gilman, R H; Bayer, A M

2018-03-30

Interspecies transmission of pathogens is an unfrequent but naturally occurring event and human activities may favour opportunities not previously reported. Reassortment of zoonotic pathogens like influenza A virus can result from these activities. Recently, swine and birds have played a central role as "mixing vessels" for epidemic and pandemic events related to strains like H1N1 and H5N1. Unsafe practices in poultry markets and swine farms can lead to interspecies transmission, favouring the emergence of novel strains. Thus, understanding practices that lead to interspecies interactions is crucial. This qualitative study aimed to evaluate poultry processing practices in formal and informal markets and the use of leftovers by swine farmers in three Peruvian cities: Lima (capital), Tumbes (coastal) and Tarapoto (jungle). We conducted 80 direct observations at formal and informal markets and interviewed 15 swine farmers. Processors slaughter and pluck chickens and vendors and/or processors eviscerate chickens. Food safety and hygiene practices were suboptimal or absent, although some heterogeneity was observed between cities and chicken vendors versus processors. Both vendors (76%) and processors (100%) sold the chicken viscera leftovers to swine farmers, representing the main source of chicken viscera for swine farms (53%). Swine farmers fed the chicken viscera to their swine. Chicken viscera cooking times varied widely and were insufficient in some cases. Non-abattoired poultry leads to the sale of poultry leftovers to small-scale swine farms, resulting in indirect but frequent interspecies contacts that can lead to interspecies transmission of bacterial pathogens or the reassortment of influenza A viruses. These interactions are exacerbated by suboptimal safety and hygiene conditions. People involved in these activities constitute an at-risk population who could play a central role in preventing the transmission of pathogens between species. Educational

Immune response in the lungs following oral immunization with bacterial lysates of respiratory pathogens.

Science.gov (United States)

Ruedl, C; Frühwirth, M; Wick, G; Wolf, H

1994-03-01

We have investigated the local immune response of the BALB/c mouse respiratory tract after oral immunization with a bacterial lysate of seven common respiratory pathogens. After two immunization on five consecutive days, we examined the immunoglobulin (immunoglobulin G [IgG], IgM, and IgA) secretion rates of cells isolated from the lungs and compared them with those of spleen cells of orally immunized and nonimmunized animals by using a new test system based on time-resolved fluorescence. The procedure followed the principle of the classical ELISPOT test with nitrocellulose-bottomed microtiter plates, but europium (Eu3+)-linked streptavidin rather than enzyme-conjugated streptavidin was used, with the advantage of quantifying secreted immunoglobulins instead of detecting single antibody-secreting cells. Lymphocytes isolated from the lungs of treated animals revealed significant increases in total and antigen-specific IgA synthesis compared with the rates of the controls, whereas IgG and IgM production rates showed no remarkable differences. In addition, the sera of treated mice revealed higher antigen-specific IgA titers but not increased IgM and IgG levels. We conclude that priming the gut-associated lymphoid tissue with bacterial antigens of pneumotropic microorganisms can elicit an enhanced IgA response in a distant mucosal effector site, such as the respiratory tract, according to the concept of a common mucosa-associated immune system.

Genetic data provide evidence for wind-mediated transmission of highly pathogenic avian influenza.

Science.gov (United States)

Ypma, Rolf J F; Jonges, Marcel; Bataille, Arnaud; Stegeman, Arjan; Koch, Guus; van Boven, Michiel; Koopmans, Marion; van Ballegooijen, W Marijn; Wallinga, Jacco

2013-03-01

Outbreaks of highly pathogenic avian influenza in poultry can cause severe economic damage and represent a public health threat. Development of efficient containment measures requires an understanding of how these influenza viruses are transmitted between farms. However, the actual mechanisms of interfarm transmission are largely unknown. Dispersal of infectious material by wind has been suggested, but never demonstrated, as a possible cause of transmission between farms. Here we provide statistical evidence that the direction of spread of avian influenza A(H7N7) is correlated with the direction of wind at date of infection. Using detailed genetic and epidemiological data, we found the direction of spread by reconstructing the transmission tree for a large outbreak in the Netherlands in 2003. We conservatively estimate the contribution of a possible wind-mediated mechanism to the total amount of spread during this outbreak to be around 18%.

Adenovirus respiratory tract infections in Peru.

Directory of Open Access Journals (Sweden)

Julia S Ampuero

Full Text Available BACKGROUND: Currently, there is a paucity of data regarding human adenovirus (HAdv circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru. METHODS/PRINCIPAL FINDINGS: Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI or severe acute respiratory infection (SARI were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected. CONCLUSIONS/SIGNIFICANCE: HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness.

Adenovirus respiratory tract infections in Peru.

Science.gov (United States)

Ampuero, Julia S; Ocaña, Víctor; Gómez, Jorge; Gamero, María E; Garcia, Josefina; Halsey, Eric S; Laguna-Torres, V Alberto

2012-01-01

Currently, there is a paucity of data regarding human adenovirus (HAdv) circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru. Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI) or severe acute respiratory infection (SARI) were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected. HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness.

Adenovirus Respiratory Tract Infections in Peru

Science.gov (United States)

Ampuero, Julia S.; Ocaña, Víctor; Gómez, Jorge; Gamero, María E.; Garcia, Josefina; Halsey, Eric S.; Laguna-Torres, V. Alberto

2012-01-01

Background Currently, there is a paucity of data regarding human adenovirus (HAdv) circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru. Methods/Principal Findings Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI) or severe acute respiratory infection (SARI) were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected. Conclusions/Significance HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness. PMID:23056519

Social and Economic Aspects of the Transmission of Pathogenic Bacteria between Wildlife and Food Animals: A Thematic Analysis of Published Research Knowledge.

Science.gov (United States)

Fournier, A; Young, I; Rajić, A; Greig, J; LeJeune, J

2015-09-01

Wildlife is a known reservoir of pathogenic bacteria, including Mycobacterium bovis and Brucella spp. Transmission of these pathogens between wildlife and food animals can lead to damaging impacts on the agri-food industry and public health. Several international case studies have highlighted the complex and cross-sectoral challenges involved in preventing and managing these potential transmission risks. The objective of our study was to develop a better understanding of the socio-economic aspects of the transmission of pathogenic bacteria between wildlife and food animals to support more effective and sustainable risk mitigation strategies. We conducted qualitative thematic analysis on a purposive sample of 30/141 articles identified in a complementary scoping review of the literature in this area and identified two key themes. The first related to the framing of this issue as a 'wicked problem' that depends on a complex interaction of social factors and risk perceptions, governance and public policy, and economic implications. The second theme consisted of promising approaches and strategies to prevent and mitigate the potential risks from transmission of pathogenic bacteria between wildlife and food animals. These included participatory, collaborative and multidisciplinary decision-making approaches and the proactive incorporation of credible scientific evidence and local contextual factors into solutions. The integration of these approaches to address 'wicked problems' in this field may assist stakeholders and decision-makers in improving the acceptability and sustainability of future strategies to reduce the transmission of pathogenic bacteria between wildlife and food animals. © 2015 Zoonoses and Public Health © 2015 Her Majesty the Queen in Right of Canada Reproduced with the permission of the Minister of the Public Health Agency of Canada.

Low Pathogenic Avian Influenza (H7N1) Transmission Between Wild Ducks and Domestic Ducks

DEFF Research Database (Denmark)

Therkildsen, O. R.; Jensen, Trine Hammer; Handberg, Kurt

2011-01-01

This article describes a virological investigation in a mixed flock of ducks and geese following detection of avian influenza virus antibodies in domestic geese. Low pathogenic H7N1 was found in both domestic and wild birds, indicating that transmission of virus was likely to have taken place...

Transmission routes maintaining a viral pathogen of steelhead trout within a complex multi-host assemblage

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Breyta, Rachel; Brito, Ilana L.; Ferguson, Paige; Kurath, Gael; Naish, Kerry A.; Purcell, Maureen; Wargo, Andrew R.; LaDeau, Shannon L.

2017-01-01

This is the first comprehensive region wide, spatially explicit epidemiologic analysis of surveillance data of the aquatic viral pathogen infectious hematopoietic necrosis virus (IHNV) infecting native salmonid fish. The pathogen has been documented in the freshwater ecosystem of the Pacific Northwest of North America since the 1950s, and the current report describes the disease ecology of IHNV during 2000–2012. Prevalence of IHNV infection in monitored salmonid host cohorts ranged from 8% to 30%, with the highest levels observed in juvenile steelhead trout. The spatial distribution of all IHNV-infected cohorts was concentrated in two sub-regions of the study area, where historic burden of the viral disease has been high. During the study period, prevalence levels fluctuated with a temporal peak in 2002. Virologic and genetic surveillance data were analyzed for evidence of three separate but not mutually exclusive transmission routes hypothesized to be maintaining IHNV in the freshwater ecosystem. Transmission between year classes of juvenile fish at individual sites (route 1) was supported at varying levels of certainty in 10%–55% of candidate cases, transmission between neighboring juvenile cohorts (route 2) was supported in 31%–78% of candidate cases, and transmission from adult fish returning to the same site as an infected juvenile cohort was supported in 26%–74% of candidate cases. The results of this study indicate that multiple specific transmission routes are acting to maintain IHNV in juvenile fish, providing concrete evidence that can be used to improve resource management. Furthermore, these results demonstrate that more sophisticated analysis of available spatio-temporal and genetic data is likely to yield greater insight in future studies.

Elucidating Transmission Patterns From Internet Reports: Ebola and Middle East Respiratory Syndrome as Case Studies

OpenAIRE

Chowell, Gerardo; Cleaton, Julie M.; Viboud, Cecile

2016-01-01

The paucity of traditional epidemiological data during epidemic emergencies calls for alternative data streams to characterize the key features of an outbreak, including the nature of risky exposures, the reproduction number, and transmission heterogeneities. We illustrate the potential of Internet data streams to improve preparedness and response in outbreak situations by drawing from recent work on the 2014–2015 Ebola epidemic in West Africa and the 2015 Middle East respiratory syndrome (ME...

A Case Study of Respiratory Disease in a Veal Calf Operation

Science.gov (United States)

Palechek, Neil P.; Schoonderwoerd, Matt; Perry, Allen W.

1987-01-01

An outbreak of respiratory disease occurred in a central Alberta veal operation, after production capacity had been increased fourfold. Mortality rate reached 24.6% despite agressive antibiotic therapy. A review of the records revealed a cyclical disease pattern in each room. Weekly cleaning of occupied calf rooms was correlated with the disease pattern. Aerosols generated by a high pressure sprayer appeared to trigger transmission of respiratory pathogens in malnourished neonatal calves. Disease occurrence decreased and profitability increased sixfold after the introduction of the following measures: 1) discontinuing the use of the high pressure washer in the occupied calf rooms, 2) feeding calves a better quality milk replacer with supplemental milk for the poorest calves, 3) sale-yard calf purchases were abandoned in favor of direct buying. PMID:17422807

Histophilus somni biofilm formation in cardiopulmonary tissue of the bovine host following respiratory challenge

DEFF Research Database (Denmark)

Sandal, Indra; Shao, Jian Q.; Annadata, Satish

2009-01-01

Biofilms form in a variety of host sites following infection with many bacterial species. However, the study of biofilms in a host is hindered due to the lack of protocols for the proper experimental investigation of biofilms in vivo. Histophilus somni is an agent of respiratory and systemic...... diseases in bovines, and readily forms biofilms in vitro. In the present study the capability of H. somni to form biofilms in cardiopulmonary tissue following experimental respiratory infection in the bovine host was examined by light microscopy, transmission electron microscopy, immunoelectron microscopy...... haemagglutinin (FHA), predicted to be involved in attachment. Thus, this investigation demonstrated that H. somni is capable of forming a biofilm in its natural host, that such a biofilm may be capable of harboring other bovine respiratory disease pathogens, and that the genes responsible for biofilm formation...

Airborne transmission of a highly pathogenic avian influenza strain H5N1 between groups of chickens quantified in an experimental setting.

NARCIS (Netherlands)

Spekreijse, D.; Bouma, A.; Koch, G.; Stegeman, J.A.

2011-01-01

Highly pathogenic avian influenza (HPAI) is a devastating viral disease of poultry and quick control of outbreaks is vital. Airborne transmission has often been suggested as a route of transmission between flocks, but knowledge of the rate of transmission via this route is sparse. In the current

Seasonal and pandemic human influenza viruses attach better to human upper respiratory tract epithelium than avian influenza viruses.

Science.gov (United States)

van Riel, Debby; den Bakker, Michael A; Leijten, Lonneke M E; Chutinimitkul, Salin; Munster, Vincent J; de Wit, Emmie; Rimmelzwaan, Guus F; Fouchier, Ron A M; Osterhaus, Albert D M E; Kuiken, Thijs

2010-04-01

Influenza viruses vary markedly in their efficiency of human-to-human transmission. This variation has been speculated to be determined in part by the tropism of influenza virus for the human upper respiratory tract. To study this tropism, we determined the pattern of virus attachment by virus histochemistry of three human and three avian influenza viruses in human nasal septum, conchae, nasopharynx, paranasal sinuses, and larynx. We found that the human influenza viruses-two seasonal influenza viruses and pandemic H1N1 virus-attached abundantly to ciliated epithelial cells and goblet cells throughout the upper respiratory tract. In contrast, the avian influenza viruses, including the highly pathogenic H5N1 virus, attached only rarely to epithelial cells or goblet cells. Both human and avian viruses attached occasionally to cells of the submucosal glands. The pattern of virus attachment was similar among the different sites of the human upper respiratory tract for each virus tested. We conclude that influenza viruses that are transmitted efficiently among humans attach abundantly to human upper respiratory tract, whereas inefficiently transmitted influenza viruses attach rarely. These results suggest that the ability of an influenza virus to attach to human upper respiratory tract is a critical factor for efficient transmission in the human population.

Secondary infection with Streptococcus suis serotype 7 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs.

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Xu, Min; Wang, Shujie; Li, Linxi; Lei, Liancheng; Liu, Yonggang; Shi, Wenda; Wu, Jiabin; Li, Liqin; Rong, Fulong; Xu, Mingming; Sun, Guangli; Xiang, Hua; Cai, Xuehui

2010-08-09

Porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis are common pathogens in pigs. In samples collected during the porcine high fever syndrome (PHFS) outbreak in many parts of China, PRRSV and S. suis serotype 7 (SS7) have always been isolated together. To determine whether PRRSV-SS7 coinfection was the cause of the PHFS outbreak, we evaluated the pathogenicity of PRRSV and/or SS7 in a pig model of single and mixed infection. Respiratory disease, diarrhea, and anorexia were observed in all infected pigs. Signs of central nervous system (CNS) disease were observed in the highly pathogenic PRRSV (HP-PRRSV)-infected pigs (4/12) and the coinfected pigs (8/10); however, the symptoms of the coinfected pigs were clearly more severe than those of the HP-PRRSV-infected pigs. The mortality rate was significantly higher in the coinfected pigs (8/10) than in the HP-PRRSV- (2/12) and SS7-infected pigs (0/10). The deceased pigs of the coinfected group had symptoms typical of PHFS, such as high fever, anorexia, and red coloration of the ears and the body. The isolation rates of HP-PRRSV and SS7 were higher and the lesion severity was greater in the coinfected pigs than in monoinfected pigs. HP-PRRSV infection increased susceptibility to SS7 infection, and coinfection of HP-PRRSV with SS7 significantly increased the pathogenicity of SS7 to pigs.

Secondary infection with Streptococcus suis serotype 7 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs

Directory of Open Access Journals (Sweden)

Xu Min

2010-08-01

Full Text Available Abstract Background Porcine reproductive and respiratory syndrome virus (PRRSV and Streptococcus suis are common pathogens in pigs. In samples collected during the porcine high fever syndrome (PHFS outbreak in many parts of China, PRRSV and S. suis serotype 7 (SS7 have always been isolated together. To determine whether PRRSV-SS7 coinfection was the cause of the PHFS outbreak, we evaluated the pathogenicity of PRRSV and/or SS7 in a pig model of single and mixed infection. Results Respiratory disease, diarrhea, and anorexia were observed in all infected pigs. Signs of central nervous system (CNS disease were observed in the highly pathogenic PRRSV (HP-PRRSV-infected pigs (4/12 and the coinfected pigs (8/10; however, the symptoms of the coinfected pigs were clearly more severe than those of the HP-PRRSV-infected pigs. The mortality rate was significantly higher in the coinfected pigs (8/10 than in the HP-PRRSV- (2/12 and SS7-infected pigs (0/10. The deceased pigs of the coinfected group had symptoms typical of PHFS, such as high fever, anorexia, and red coloration of the ears and the body. The isolation rates of HP-PRRSV and SS7 were higher and the lesion severity was greater in the coinfected pigs than in monoinfected pigs. Conclusion HP-PRRSV infection increased susceptibility to SS7 infection, and coinfection of HP-PRRSV with SS7 significantly increased the pathogenicity of SS7 to pigs.

Public preferences for vaccination programmes during pandemics caused by pathogens transmitted through respiratory droplets - a discrete choice experiment in four European countries, 2013

NARCIS (Netherlands)

D. Determann (Domino); I.J. Korfage (Ida); A. Fagerlin (Angela); E.W. Steyerberg (Ewout); M.C.J. Bliemer (Michiel); H.A.C.M. Voeten (Hélène); J.H. Richardus (Jan Hendrik); M.S. Lambooij (Mattijs); E.W. de Bekker-Grob (Esther)

2016-01-01

textabstractThis study aims to quantify and compare preferences of citizens from different European countries for vaccination programme characteristics during pandemics, caused by pathogens which are transmitted through respiratory droplets. Internet panel members, nationally representative based on

Infection control and prevention practices implemented to reduce transmission risk of Middle East respiratory syndrome-coronavirus in a tertiary care institution in Saudi Arabia.

Science.gov (United States)

Butt, Taimur S; Koutlakis-Barron, Irene; AlJumaah, Suliman; AlThawadi, Sahar; AlMofada, Saleh

2016-05-01

Transmission of Middle East respiratory syndrome-coronavirus (MERS-CoV) among health care workers (HCWs) and patients has been documented with mortality rate approximating 36%. We propose advanced infection control measures (A-IC) used in conjunction with basic infection control measures (B-IC) help reduce pathogen transmission. B-IC include standard and transmission-based precautions. A-IC are initiatives implemented within our center to enhance effectiveness of B-IC. Study effectiveness of combining B-IC and A-IC to prevent transmission of MERS-CoV to HCWs. A retrospective observational study was undertaken. A-IC measures include administrative support with daily rounds; infection control risk assessment; timely screening, isolation, and specimen analysis; collaboration; epidemic planning; stockpiling; implementation of contingency plans; full personal protective equipment use for advanced airway management; use of a real-time electronic isolation flagging system; infection prevention and control team on-call protocols; pretransfer MERS-CoV testing; and education. A total of 874 real-time polymerase chain reaction MERS-CoV tests were performed during the period beginning July 1, 2013, and ending January 31, 2015. Six hundred ninety-four non-HCWs were tested, of these 16 tested positive for MERS-CoV and their infection was community acquired. Sixty-nine percent of the confirmed MERS-CoV-positive cases were men, with an average age of 56 years (range, 19-84 years). Of the total tested for MERS-CoV, 180 individuals were HCWs with zero positivity. Adhering to a combination of B-IC and A-IC reduces the risk of MERS-CoV transmission to HCWs. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Dromedary camels and the transmission of Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

Science.gov (United States)

Hemida, Maged G; Elmoslemany, Ahmed; Al-Hizab, Fahad; Alnaeem, Abdulmohsen; Almathen, Faisal; Faye, Bernard; Chu, Daniel KW; Perera, Ranawaka A; Peiris, Malik

2015-01-01

Middle East respiratory syndrome coronavirus (MERS-CoV) is an existential threat to global public health. The virus has been repeatedly detected in dromedary camels (Camelus dromedarius). Adult animals in many countries in the Middle East as well as in North and East Africa showed high (>90%) sero-prevalence to the virus. MERS-CoV isolated from dromedaries is genetically and phenotypically similar to viruses from humans. We summarise current understanding of the ecology of MERS-CoV in animals and transmission at the animal-human interface. We review aspects of husbandry, animal movements and trade and the use and consumption of camel dairy and meat products in the Middle East that may be relevant to the epidemiology of MERS. We also highlight the gaps in understanding the transmission of this virus in animals and from animals to humans. PMID:26256102

Comparison of the in vitro activities of several new fluoroquinolones against respiratory pathogens and their abilities to select fluoroquinolone resistance.

Science.gov (United States)

Boswell, F J; Andrews, J M; Jevons, G; Wise, R

2002-10-01

In this study the in vitro activities and pharmacodynamic properties of moxifloxacin, levofloxacin, gatifloxacin and gemifloxacin were compared on recently isolated respiratory pathogens and strains of Streptococcus pneumoniae with known mechanisms of fluoroquinolone resistance. In addition, the resistance selection frequencies of moxifloxacin and levofloxacin on three recently isolated respiratory pathogens and four strains of S. pneumoniae with known mechanisms of fluoroquinolone resistance were investigated. The four fluoroquinolones had similar activities against both Moraxella catarrhalis (MIC(90)s 0.015-0.06 mg/L) and Haemophilus influenzae (MIC(90)s 0.008-0.03 mg/L). More marked differences in activity were noted with S. pneumoniae, with MIC(90)s of 0.25, 1, 0.5 and 0.03 mg/L for moxifloxacin, levofloxacin, gatifloxacin and gemifloxacin, respectively. With the S. pneumoniae strains, the four fluoroquinolones exhibited similar concentration-dependent time-kill kinetics. The resistance selection frequencies of levofloxacin were higher than those of moxifloxacin at concentrations equivalent to those at the end of the dosing interval. Therefore moxifloxacin may have less of an impact on the development of resistance than levofloxacin.

Respiratory Syncytial Virus Infection (RSV): Transmission and Prevention

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... of Search Controls Search Form Controls Cancel Submit Respiratory Syncytial Virus Infection (RSV) Note: Javascript is disabled ... 2018 Content source: National Center for Immunization and Respiratory Diseases (NCIRD) , Division of Viral Diseases Email Recommend ...

Concordance in diagnostic testing for respiratory pathogens of bighorn sheep

Science.gov (United States)

Walsh, Daniel P.; Cassirer, E. Frances; Bonds, Michael D.; Brown, Daniel R.; Edwards, William H.; Weiser, Glen C.; Drew, Mark L.; Briggs, Robert E.; Fox, Karen A.; Miller, Michael W.; Shanthalingam, Sudarvili; Srikumaran, Subramaniam; Besser, Thomas E.

2016-01-01

Reliable diagnostic tests are essential for disease investigation and management. This is particularly true for diseases of free-ranging wildlife where sampling is logistically difficult precluding retesting. Clinical assays for wildlife diseases frequently vary among laboratories because of lack of appropriate standardized commercial kits. Results of diagnostic testing may also be called into question when investigators report different etiologies for disease outbreaks, despite similar clinical and pathologic findings. To evaluate reliability of diagnostic testing for respiratory pathogens of bighorn sheep (Ovis canadensis), we conducted a series of ring tests across 6 laboratories routinely involved in detection of Mycoplasma ovipneumoniae, Pasteurellaceae, lktA (the Pasteurellaceae gene encoding leukotoxin), and 3 reference laboratories. Consistency of results for replicate samples within laboratories was high (median agreement = 1.0). Agreement between laboratories was high for polymerase chain reaction (PCR) detection of M. ovipneumoniae and culture isolation of Mannheimia spp. and Bibersteinia trehalosi(median agreement = 0.89–0.95, Kappa = 0.65–0.74), and lower for PCR detection of Mannheimiaspp. lktA (median agreement = 0.58, Kappa = 0.12). Most errors on defined status samples were false negatives, suggesting test sensitivity was a greater problem than specificity. However, tests for M. haemolytica and lktA yielded some false positive results. Despite differences in testing protocols, median agreement among laboratories and correct classification of controls for most agents was ≥0.80, meeting or exceeding the standard required by federal proficiency testing programs. This information is valuable for interpreting test results, laboratory quality assessments, and advancing diagnosis of respiratory disease in wild sheep. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Linking social and pathogen transmission networks using microbial genetics in giraffe (Giraffa camelopardalis).

Science.gov (United States)

VanderWaal, Kimberly L; Atwill, Edward R; Isbell, Lynne A; McCowan, Brenda

2014-03-01

Although network analysis has drawn considerable attention as a promising tool for disease ecology, empirical research has been hindered by limitations in detecting the occurrence of pathogen transmission (who transmitted to whom) within social networks. Using a novel approach, we utilize the genetics of a diverse microbe, Escherichia coli, to infer where direct or indirect transmission has occurred and use these data to construct transmission networks for a wild giraffe population (Giraffe camelopardalis). Individuals were considered to be a part of the same transmission chain and were interlinked in the transmission network if they shared genetic subtypes of E. coli. By using microbial genetics to quantify who transmits to whom independently from the behavioural data on who is in contact with whom, we were able to directly investigate how the structure of contact networks influences the structure of the transmission network. To distinguish between the effects of social and environmental contact on transmission dynamics, the transmission network was compared with two separate contact networks defined from the behavioural data: a social network based on association patterns, and a spatial network based on patterns of home-range overlap among individuals. We found that links in the transmission network were more likely to occur between individuals that were strongly linked in the social network. Furthermore, individuals that had more numerous connections or that occupied 'bottleneck' positions in the social network tended to occupy similar positions in the transmission network. No similar correlations were observed between the spatial and transmission networks. This indicates that an individual's social network position is predictive of transmission network position, which has implications for identifying individuals that function as super-spreaders or transmission bottlenecks in the population. These results emphasize the importance of association patterns in

Quantifying type-specific reproduction numbers for nosocomial pathogens: evidence for heightened transmission of an Asian sequence type 239 MRSA clone.

Directory of Open Access Journals (Sweden)

Ben S Cooper

Full Text Available An important determinant of a pathogen's success is the rate at which it is transmitted from infected to susceptible hosts. Although there are anecdotal reports that methicillin-resistant Staphylococcus aureus (MRSA clones vary in their transmissibility in hospital settings, attempts to quantify such variation are lacking for common subtypes, as are methods for addressing this question using routinely-collected MRSA screening data in endemic settings. Here we present a method to quantify the time-varying transmissibility of different subtypes of common bacterial nosocomial pathogens using routine surveillance data. The method adapts approaches for estimating reproduction numbers based on the probabilistic reconstruction of epidemic trees, but uses relative hazards rather than serial intervals to assign probabilities to different sources for observed transmission events. The method is applied to data collected as part of a retrospective observational study of a concurrent MRSA outbreak in the United Kingdom with dominant endemic MRSA clones (ST22 and ST36 and an Asian ST239 MRSA strain (ST239-TW in two linked adult intensive care units, and compared with an approach based on a fully parametric transmission model. The results provide support for the hypothesis that the clones responded differently to an infection control measure based on the use of topical antiseptics, which was more effective at reducing transmission of endemic clones. They also suggest that in one of the two ICUs patients colonized or infected with the ST239-TW MRSA clone had consistently higher risks of transmitting MRSA to patients free of MRSA. These findings represent some of the first quantitative evidence of enhanced transmissibility of a pandemic MRSA lineage, and highlight the potential value of tailoring hospital infection control measures to specific pathogen subtypes.

Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

Directory of Open Access Journals (Sweden)

Alix M Denoncourt

2014-05-01

Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

Baby bottle steam sterilizers disinfect home nebulizers inoculated with bacterial respiratory pathogens.

Science.gov (United States)

Towle, Dana; Callan, Deborah A; Farrel, Patricia A; Egan, Marie E; Murray, Thomas S

2013-09-01

Contaminated nebulizers are a potential source of bacterial infection but no single method is universally accepted for disinfection. We hypothesized that baby-bottle steam sterilizers effectively disinfect home nebulizers. Home nebulizers were inoculated with the common CF respiratory pathogens methicillin resistant Staphylococcus aureus, Burkholderia cepacia, Haemophilus influenzae, mucoid and non mucoid Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The nebulizers were swabbed for bacterial growth, treated with either the AVENT (Philips), the NUK Quick & Ready (Gerber) or DRY-POD (Camera Baby) baby bottle steam sterilizer and reswabbed for bacterial growth. All steam sterilizers were effective at disinfecting all home nebulizers. Viable bacteria were not recovered from any inoculated site after steam treatment, under any conditions tested. Steam treatment is an effective disinfection method. Additional studies are needed to confirm whether these results are applicable to the clinical setting. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Hand rub consumption and hand hygiene compliance are not indicators of pathogen transmission in intensive care units.

NARCIS (Netherlands)

Eckmanns, T; Schwab, F; Bessert, J; Wettstein, R; Behnke, M; Grundmann, Hajo; Rüden, H; Gastmeier, P

2006-01-01

The objective of this study was to investigate whether nosocomial infection (NI) rates, hand hygiene compliance rates and the amount of alcohol-based hand rub used for hand disinfection are useful indicators of pathogen transmission in intensive care units (ICUs), and whether they could be helpful

Pathobiology and transmission of highly and low pathogenic avian influenza viruses in European quail (Coturnix c. coturnix).

Science.gov (United States)

Bertran, Kateri; Dolz, Roser; Busquets, Núria; Gamino, Virginia; Vergara-Alert, Júlia; Chaves, Aida J; Ramis, Antonio; Abad, F Xavier; Höfle, Ursula; Majó, Natàlia

2013-03-28

European quail (Coturnix c. coturnix) may share with Japanese quail (Coturnix c. japonica) its potential as an intermediate host and reservoir of avian influenza viruses (AIV). To elucidate this question, European quail were experimentally challenged with two highly pathogenic AIV (HPAIV) (H7N1/HP and H5N1/HP) and one low pathogenic AIV (LPAIV) (H7N2/LP). Contact animals were also used to assess the viral transmission among birds. Severe neurological signs and mortality rates of 67% (H7N1/HP) and 92% (H5N1/HP) were observed. Although histopathological findings were present in both HPAIV-infected groups, H5N1/HP-quail displayed a broader viral antigen distribution and extent of microscopic lesions. Neither clinical nor pathological involvement was observed in LPAIV-infected quail. Consistent long-term viral shedding and effective transmission to naive quail was demonstrated for the three studied AIV. Drinking water arose as a possible transmission route and feathers as a potential origin of HPAIV dissemination. The present study demonstrates that European quail may play a major role in AI epidemiology, highlighting the need to further understand its putative role as an intermediate host for avian/mammalian reassortant viruses.

Mixture model to assess the extent of cross-transmission of multidrug-resistant pathogens in hospitals.

Science.gov (United States)

Mikolajczyk, Rafael T; Kauermann, Göran; Sagel, Ulrich; Kretzschmar, Mirjam

2009-08-01

Creation of a mixture model based on Poisson processes for assessment of the extent of cross-transmission of multidrug-resistant pathogens in the hospital. We propose a 2-component mixture of Poisson processes to describe the time series of detected cases of colonization. The first component describes the admission process of patients with colonization, and the second describes the cross-transmission. The data set used to illustrate the method consists of the routinely collected records for methicillin-resistant Staphylococcus aureus (MRSA), imipenem-resistant Pseudomonas aeruginosa, and multidrug-resistant Acinetobacter baumannii over a period of 3 years in a German tertiary care hospital. For MRSA and multidrug-resistant A. baumannii, cross-transmission was estimated to be responsible for more than 80% of cases; for imipenem-resistant P. aeruginosa, cross-transmission was estimated to be responsible for 59% of cases. For new cases observed within a window of less than 28 days for MRSA and multidrug-resistant A. baumannii or 40 days for imipenem-resistant P. aeruginosa, there was a 50% or greater probability that the cause was cross-transmission. The proposed method offers a solution to assessing of the extent of cross-transmission, which can be of clinical use. The method can be applied using freely available software (the package FlexMix in R) and it requires relatively little data.

HIV-TRACE (Transmission Cluster Engine): a tool for large scale molecular epidemiology of HIV-1 and other rapidly evolving pathogens.

Science.gov (United States)

Kosakovsky Pond, Sergei L; Weaver, Steven; Leigh Brown, Andrew J; Wertheim, Joel O

2018-01-31

In modern applications of molecular epidemiology, genetic sequence data are routinely used to identify clusters of transmission in rapidly evolving pathogens, most notably HIV-1. Traditional 'shoeleather' epidemiology infers transmission clusters by tracing chains of partners sharing epidemiological connections (e.g., sexual contact). Here, we present a computational tool for identifying a molecular transmission analog of such clusters: HIV-TRACE (TRAnsmission Cluster Engine). HIV-TRACE implements an approach inspired by traditional epidemiology, by identifying chains of partners whose viral genetic relatedness imply direct or indirect epidemiological connections. Molecular transmission clusters are constructed using codon-aware pairwise alignment to a reference sequence followed by pairwise genetic distance estimation among all sequences. This approach is computationally tractable and is capable of identifying HIV-1 transmission clusters in large surveillance databases comprising tens or hundreds of thousands of sequences in near real time, i.e., on the order of minutes to hours. HIV-TRACE is available at www.hivtrace.org and from github.com/veg/hivtrace, along with the accompanying result visualization module from github.com/veg/hivtrace-viz. Importantly, the approach underlying HIV-TRACE is not limited to the study of HIV-1 and can be applied to study outbreaks and epidemics of other rapidly evolving pathogens. © The Author 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cytokine responses to two common respiratory pathogens in children are dependent on interleukin-1β

Directory of Open Access Journals (Sweden)

Alice C-H. Chen

2017-10-01

Full Text Available Protracted bacterial bronchitis (PBB in young children is a common cause of prolonged wet cough and may be a precursor to bronchiectasis in some children. Although PBB and bronchiectasis are both characterised by neutrophilic airway inflammation and a prominent interleukin (IL-1β signature, the contribution of the IL-1β pathway to host defence is not clear. This study aimed to compare systemic immune responses against common pathogens in children with PBB, bronchiectasis and control children and to determine the importance of the IL-1β pathway. Non-typeable Haemophilus influenzae (NTHi stimulation of peripheral blood mononuclear cells (PBMCs from control subjects (n=20, those with recurrent PBB (n=20 and bronchiectasis (n=20 induced high concentrations of IL-1β, IL-6, interferon (IFN-γ and IL-10. Blocking with an IL-1 receptor antagonist (IL-1Ra modified the cellular response to pathogens, inhibiting cytokine synthesis by NTHi-stimulated PBMCs and rhinovirus-stimulated PBMCs (in a separate PBB cohort. Inhibition of IFN-γ production by IL-1Ra was observed across multiple cell types, including CD3+ T cells and CD56+ NK cells. Our findings highlight the extent to which IL-1β regulates the cellular immune response against two common respiratory pathogens. While blocking the IL-1β pathway has the potential to reduce inflammation, this may come at the cost of protective immunity against NTHi and rhinovirus.

The burden of seasonal respiratory infections on a national telehealth service in England.

Science.gov (United States)

Morbey, R A; Harcourt, S; Pebody, R; Zambon, M; Hutchison, J; Rutter, J; Thomas, H; Smith, G E; Elliot, A J

2017-07-01

Seasonal respiratory illnesses present a major burden on primary care services. We assessed the burden of respiratory illness on a national telehealth system in England and investigated the potential for providing early warning of respiratory infection. We compared weekly laboratory reports for respiratory pathogens with telehealth calls (NHS 111) between week 40 in 2013 and week 29 in 2015. Multiple linear regression was used to identify which pathogens had a significant association with respiratory calls. Children aged respiratory pathogens explained over 83% of the variation in cold/flu, cough and difficulty breathing calls. Based on the first two seasons available, the greatest burden was associated with respiratory syncytial virus (RSV) and influenza, with associations found in all age bands. The most sensitive signal for influenza was calls for 'cold/flu', whilst for RSV it was calls for cough. The best-fitting models showed calls increasing a week before laboratory specimen dates. Daily surveillance of these calls can provide early warning of seasonal rises in influenza and RSV, contributing to the national respiratory surveillance programme.

Patients' potential role in the transmission of health care-associated infections: prevalence of contamination with bacterial pathogens and patient attitudes toward hand hygiene.

Science.gov (United States)

Istenes, Nancy; Bingham, James; Hazelett, Susan; Fleming, Eileen; Kirk, Jane

2013-09-01

Transmission of health care-associated infections (HAIs) has been primarily attributed to health care workers, and hand hygiene is considered the most important means to reduce transmission. Whereas hand hygiene research has focused on reducing health care worker hand contamination and improving hand hygiene compliance, contamination of patients' hands and their role in the transmission of HAIs remains unknown. Patients' hands were sampled by a "glove juice" recovery method and enumerated for the presence of common health care-associated pathogens. Patient demographics and other covariates were collected to determine their association with patient hand contamination. Patient attitudes and practices toward hand hygiene were also surveyed and analyzed. Of the 100 patients in the study, 39% of hands were contaminated with at least 1 pathogenic organism, and 8% were contaminated with 2 or more pathogens 48 hours after admission. Patient admission from or discharge to an outside institution and self-reported functional limitations were the only covariates that were significantly associated with hand contamination. Pathogenic organisms can be frequently detected on hands of acute care patients. Future studies are needed to better understand the relationship between patient hand contamination and the acquisition of HAIs in addition to the role patient hand hygiene can play in reducing HAIs. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

A Naturally Transmitted Epitheliotropic Polyomavirus Pathogenic in Immunodeficient Rats: Characterization, Transmission, and Preliminary Epidemiologic Studies.

Science.gov (United States)

Besch-Williford, Cynthia; Pesavento, Patricia; Hamilton, Shari; Bauer, Beth; Kapusinszky, Beatrix; Phan, Tung; Delwart, Eric; Livingston, Robert; Cushing, Susan; Watanabe, Rie; Levin, Stephen; Berger, Diana; Myles, Matthew

2017-07-01

We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Unbiased viral metagenomic sequencing of lesioned tissues identified a novel polyomavirus, provisionally named Rattus norvegicus polyomavirus 2 (RatPyV2), which clustered with Washington University (WU) polyomavirus in the Wuki clade of the Betapolyomavirus genus. In situ hybridization analyses and quantitative polymerase chain reaction (PCR) results demonstrated viral nucleic acids in epithelium of respiratory, glandular, and reproductive tissues. Polyomaviral disease was reproduced in Foxn1 rnu nude rats cohoused with infected rats or experimentally inoculated with virus. After development of RatPyV2-specific diagnostic assays, a survey of immune-competent rats from North American research institutions revealed detection of RatPyV2 in 7 of 1,000 fecal samples by PCR and anti-RatPyV2 antibodies in 480 of 1,500 serum samples. These findings suggest widespread infection in laboratory rat populations, which may have profound implications for established models of respiratory injury. Additionally, RatPyV2 infection studies may provide an important system to investigate the pathogenesis of WU polyomavirus diseases of man.

Using egg production data to quantify within-flock transmission of low pathogenic avian influenza virus in commercial layer chickens

NARCIS (Netherlands)

Gonzales, J.L.; Elbers, A.R.W.; Goot, van der J.A.; Bontje, D.M.; Koch, G.; Wit, de J.J.; Stegeman, J.A.

2012-01-01

Even though low pathogenic avian influenza viruses (LPAIv) affect the poultry industry of several countries in the world, information about their transmission characteristics in poultry is sparse. Outbreak reports of LPAIv in layer chickens have described drops in egg production that appear to be

Respiratory bacterial infections in cystic fibrosis

DEFF Research Database (Denmark)

Ciofu, Oana; Hansen, Christine R; Høiby, Niels

2013-01-01

PURPOSE OF REVIEW: Bacterial respiratory infections are the main cause of morbidity and mortality in patients with cystic fibrosis (CF). Pseudomonas aeruginosa remains the main pathogen in adults, but other Gram-negative bacteria such as Achromobacter xylosoxidans and Stenotrophomonas maltophilia...... respiratory tract (nasal sampling) should be investigated and both infection sites should be treated....

Detection of viruses and atypical bacteria associated with acute respiratory infection of children in Hubei, China.

Science.gov (United States)

Wu, Zegang; Li, Yan; Gu, Jian; Zheng, Hongyun; Tong, Yongqing; Wu, Qing

2014-02-01

Acute respiratory infection is the major cause of disease and death in children, particularly in developing countries. However, the spectrum of pathogenic viruses and atypical bacteria that exist in many of these countries remains incompletely characterized. The aim of this study was to examine the spectrum of pathogenic viruses and atypical bacteria associated with acute respiratory infection in children under the age of 16. A total of 10 435 serum sera specimens were collected from hospitalized children presenting with acute respiratory infection symptoms. Indirect immunofluorescence assays were performed to detect immunoglobulin M antibodies against nine common pathogens: mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila, coxiella burnetii and chamydophila pneumonia. Of the 10 435 specimens examined, 7046 tested positive for at least one pathogen. Among all of the tested pathogens, mycoplasma pneumonia had the highest detection rate (56.9%). Influenza virus A and influenza virus B epidemics occurred during both winter and summer. The detection rate of respiratory syncytial virus and adenovirus was higher in spring. Cases of mixed infection were more complex: 4136 specimens (39.6%) tested positive for ≥2 pathogens. There were statistically significant difference in detection rates of mycoplasma pneumonia, influenza virus B, respiratory syncytial virus, parainfluenza virus, adenovirus, influenza virus A, legionella pneumophila and chamydophila pneumonia among different age groups (P acute respiratory infection among children in Hubei of China were mycoplasma pneumonia, influenza virus B and respiratory syncytial virus. The detection rates for each pathogen displayed specific seasonal and age group variations. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

Respiratory Infections in the U.S. Military: Recent Experience and Control

Science.gov (United States)

Cooper, Michael J.; Myers, Christopher A.; Cummings, James F.; Vest, Kelly G.; Russell, Kevin L.; Sanchez, Joyce L.; Hiser, Michelle J.; Gaydos, Charlotte A.

2015-01-01

SUMMARY This comprehensive review outlines the impact of military-relevant respiratory infections, with special attention to recruit training environments, influenza pandemics in 1918 to 1919 and 2009 to 2010, and peacetime operations and conflicts in the past 25 years. Outbreaks and epidemiologic investigations of viral and bacterial infections among high-risk groups are presented, including (i) experience by recruits at training centers, (ii) impact on advanced trainees in special settings, (iii) morbidity sustained by shipboard personnel at sea, and (iv) experience of deployed personnel. Utilizing a pathogen-by-pathogen approach, we examine (i) epidemiology, (ii) impact in terms of morbidity and operational readiness, (iii) clinical presentation and outbreak potential, (iv) diagnostic modalities, (v) treatment approaches, and (vi) vaccine and other control measures. We also outline military-specific initiatives in (i) surveillance, (ii) vaccine development and policy, (iii) novel influenza and coronavirus diagnostic test development and surveillance methods, (iv) influenza virus transmission and severity prediction modeling efforts, and (v) evaluation and implementation of nonvaccine, nonpharmacologic interventions. PMID:26085551

Severe acute respiratory syndrome vaccine efficacy in ferrets: whole killed virus and adenovirus-vectored vaccines.

Science.gov (United States)

See, Raymond H; Petric, Martin; Lawrence, David J; Mok, Catherine P Y; Rowe, Thomas; Zitzow, Lois A; Karunakaran, Karuna P; Voss, Thomas G; Brunham, Robert C; Gauldie, Jack; Finlay, B Brett; Roper, Rachel L

2008-09-01

Although the 2003 severe acute respiratory syndrome (SARS) outbreak was controlled, repeated transmission of SARS coronavirus (CoV) over several years makes the development of a SARS vaccine desirable. We performed a comparative evaluation of two SARS vaccines for their ability to protect against live SARS-CoV intranasal challenge in ferrets. Both the whole killed SARS-CoV vaccine (with and without alum) and adenovirus-based vectors encoding the nucleocapsid (N) and spike (S) protein induced neutralizing antibody responses and reduced viral replication and shedding in the upper respiratory tract and progression of virus to the lower respiratory tract. The vaccines also diminished haemorrhage in the thymus and reduced the severity and extent of pneumonia and damage to lung epithelium. However, despite high neutralizing antibody titres, protection was incomplete for all vaccine preparations and administration routes. Our data suggest that a combination of vaccine strategies may be required for effective protection from this pathogen. The ferret may be a good model for SARS-CoV infection because it is the only model that replicates the fever seen in human patients, as well as replicating other SARS disease features including infection by the respiratory route, clinical signs, viral replication in upper and lower respiratory tract and lung damage.

Peculiar liquid-feeding and pathogen transmission behavior of Aedes togoi and comparison with Anopheles sinensis

Science.gov (United States)

Lee, Sang Joon; Kang, Dooho; Lee, Seung Chul; Ha, Young-Ran

2016-02-01

Female mosquitoes transmit various diseases as vectors during liquid-feeding. Identifying the determinants of vector efficiency is a major scientific challenge in establishing strategies against these diseases. Infection rate and transmission efficiency are interconnected with the mosquito-induced liquid-feeding flow as main indexes of vector efficiency. However, the relationship between liquid-feeding characteristics and pathogen remains poorly understood. The liquid-feeding behavior of Aedes togoi and Anopheles sinensis was comparatively investigated in conjunction with vector efficiency via micro-particle image velocimetry. The flow rates and ratio of the ejection volume of Aedes togoi were markedly higher than those of Anophels sinensis. These differences would influence pathogen re-ingestion. Wall shear stresses of these mosquito species were also clearly discriminatory affecting the infective rates of vector-borne diseases. The variations in volume of two pump chambers and diameter of proboscis of these mosquito species were compared to determine the differences in the liquid-feeding process. Liquid-feeding characteristics influence vector efficiency; hence, this study can elucidate the vector efficiency of mosquitoes and the vector-pathogen interactions and contribute to the development of strategies against vector-borne diseases.

Prevalence of pathogens from Mollicutes class in cattle affected by respiratory diseases and molecular characteristics of Mycoplasma bovis field strains

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Szacawa Ewelina

2016-12-01

Full Text Available Introduction: Mycoplasma bovis is one of the main pathogens involved in cattle pneumonia. Other mycoplasmas have also been directly implicated in respiratory diseases in cattle. The prevalence of different Mycoplasma spp. in cattle affected by respiratory diseases and molecular characteristics of M. bovis field strains were evaluated. Material and Methods: In total, 713 nasal swabs from 73 cattle herds were tested. The uvrC gene fragment was amplified by PCR and PCR products were sequenced. PCR/DGGE and RAPD were performed. Results: It was found that 39 (5.5% samples were positive for M. bovis in the PCR and six field strains had point nucleotide mutations. Additionally, the phylogenetic analysis of 20 M. bovis field strains tested with RAPD showed two distinct groups of M. bovis strains sharing only 3.8% similarity. PCR/DGGE analysis demonstrated the presence of bacteria belonging to the Mollicutes class in 79.1% of DNA isolates. The isolates were identified as: Mycoplasma bovirhinis, M. dispar, M. bovis, M. canis, M. arginini, M. canadense, M. bovoculi, M. alkalescens, and Ureaplasma diversum. Conclusion: Different Mycoplasma spp. strains play a crucial role in inducing respiratory diseases in cattle.

Animal models of human respiratory syncytial virus disease

NARCIS (Netherlands)

Bem, Reinout A.; Domachowske, Joseph B.; Rosenberg, Helene F.

2011-01-01

Infection with the human pneumovirus pathogen, respiratory syncytial virus (hRSV), causes a wide spectrum of respiratory disease, notably among infants and the elderly. Laboratory animal studies permit detailed experimental modeling of hRSV disease and are therefore indispensable in the search for

Transmission of Middle East respiratory syndrome coronavirus ...

African Journals Online (AJOL)

... hand hygiene, and cough etiquette, would minimize the infection rate among HCPs. The required consumables for maintaining hand hygiene should be readily available to all HCPs. Keywords: Middle East respiratory syndrome coronavirus (MERS-CoV), Systematic review, healthcareassociated infections, Coronaviruses ...

Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.

Science.gov (United States)

Dutta, Bhabesh; Gitaitis, Ronald; Smith, Samuel; Langston, David

2014-01-01

The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea) to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean) and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6) colony forming units (CFUs)/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion). Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO) assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating), respectively and they were not significantly different (P = 0.67). The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating) and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03). None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be colonized by

Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.

Directory of Open Access Journals (Sweden)

Bhabesh Dutta

Full Text Available The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6 colony forming units (CFUs/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion. Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating, respectively and they were not significantly different (P = 0.67. The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03. None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be

An Epithelial Integrin Regulates the Amplitude of Protective Lung Interferon Responses against Multiple Respiratory Pathogens.

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Victoria A Meliopoulos

2016-08-01

Full Text Available The healthy lung maintains a steady state of immune readiness to rapidly respond to injury from invaders. Integrins are important for setting the parameters of this resting state, particularly the epithelial-restricted αVβ6 integrin, which is upregulated during injury. Once expressed, αVβ6 moderates acute lung injury (ALI through as yet undefined molecular mechanisms. We show that the upregulation of β6 during influenza infection is involved in disease pathogenesis. β6-deficient mice (β6 KO have increased survival during influenza infection likely due to the limited viral spread into the alveolar spaces leading to reduced ALI. Although the β6 KO have morphologically normal lungs, they harbor constitutively activated lung CD11b+ alveolar macrophages (AM and elevated type I IFN signaling activity, which we traced to the loss of β6-activated transforming growth factor-β (TGF-β. Administration of exogenous TGF-β to β6 KO mice leads to reduced numbers of CD11b+ AMs, decreased type I IFN signaling activity and loss of the protective phenotype during influenza infection. Protection extended to other respiratory pathogens such as Sendai virus and bacterial pneumonia. Our studies demonstrate that the loss of one epithelial protein, αVβ6 integrin, can alter the lung microenvironment during both homeostasis and respiratory infection leading to reduced lung injury and improved survival.

Respiratory Infections and Antibiotic Usage in Common Variable Immunodeficiency.

Science.gov (United States)

Sperlich, Johannes M; Grimbacher, Bodo; Workman, Sarita; Haque, Tanzina; Seneviratne, Suranjith L; Burns, Siobhan O; Reiser, Veronika; Vach, Werner; Hurst, John R; Lowe, David M

Patients with common variable immunodeficiency (CVID) suffer frequent respiratory tract infections despite immunoglobulin replacement and are prescribed significant quantities of antibiotics. The clinical and microbiological nature of these exacerbations, the symptomatic triggers to take antibiotics, and the response to treatment have not been previously investigated. To describe the nature, frequency, treatment, and clinical course of respiratory tract exacerbations in patients with CVID and to describe pathogens isolated during respiratory tract exacerbations. We performed a prospective diary card exercise in 69 patients with CVID recruited from a primary immunodeficiency clinic in the United Kingdom, generating 6210 days of symptom data. We collected microbiology (sputum microscopy and culture, atypical bacterial PCR, and mycobacterial culture) and virology (nasopharyngeal swab multiplex PCR) samples from symptomatic patients with CVID. There were 170 symptomatic exacerbations and 76 exacerbations treated by antibiotics. The strongest symptomatic predictors for commencing antibiotics were cough, shortness of breath, and purulent sputum. There was a median delay of 5 days from the onset of symptoms to commencing antibiotics. Episodes characterized by purulent sputum responded more quickly to antibiotics, whereas sore throat and upper respiratory tract symptoms responded less quickly. A pathogenic virus was isolated in 56% of respiratory exacerbations and a potentially pathogenic bacteria in 33%. Patients with CVID delay and avoid treatment of symptomatic respiratory exacerbations, which could result in structural lung damage. However, viruses are commonly represented and illnesses dominated by upper respiratory tract symptoms respond poorly to antibiotics, suggesting that antibiotic usage could be better targeted. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Detecção, transmissão e patogenicidade de fungos em sementes de angico-vermelho (Parapiptadenia rigida Detection, transmission and pathogenicity of fungi on seeds of Parapiptadenia rigida ("angico-vermelho"

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Caciara Gonzatto Maciel

2012-12-01

Full Text Available Angico-vermelho (Parapiptadenia rigida (Benth. Brenan é uma espécie nativa de grande valor ecológico e econômico, importante para a recomposição de áreas degradadas. O presente trabalho avaliou incidência, transmissão e patogenicidade de fungos associados a sementes de angico-vermelho de distintas procedências do Estado do Rio Grande do Sul. Para isso, utilizaram-se três amostras de sementes, com as quais realizaram-se testes de germinação, sanidade empregando-se o método do papel-filtro (PF e de plaqueamento em batata-dextrose-ágar (BDA, transmissão e patogenicidade dos fungos. A germinação das sementes de angico-vermelho variou de 63 a 91 %. Os fungos considerados potencialmente patogênicos encontrados associados as sementes de angico-vermelho foram: Alternaria sp.; Botrytis sp.; Fusarium sp.; Cladosporium sp. e Pestalotia sp.; sendo que Fusarium sp. foi detectado em todas as amostras pelo método PF, e foi transmitido via semente causando má formação do sistema radicular e dos cotilédones e tombamento de pré emergência. Sua patogenicidade foi confirmada."Angico-vermelho" (Parapiptadenia rigida (Benth. Brenan is a native species of great ecological and economic importance for the recovery of degraded areas. This study evaluated the incidence, the transmission and the pathogenicity of fungi associated with "angico-vermelho" seeds from different provenances of the state of Rio Grande do Sul. Thus, we used three samples of seeds, with which germination and sanity tests were carried out by adopting the methods of filter paper (FP, plating on potato dextrose agar (PDA, transmission and pathogenicity of fungi. Germination of "angico-vermelho" seeds ranged from 63-91%. The fungi considered potentially pathogenic and found associated with "angico-vermelho" seeds were: Alternaria sp.; Botrytis sp.; Fusarium sp.; Cladosporium sp. and Pestalotia sp.. Fusarium sp. was detected in all samples according to the FP method and was

Use of isotopes as model substances to elucidate the mode of transmission of pathogens to animals and plants by arthropod vectors

International Nuclear Information System (INIS)

Kloft, W.J.; Kloft, E.S.

1980-01-01

Experimental work was begun with J.F. Butler and L.A. DuBose on the biting flies Stomoxys calcitrans (L.) and Haematobia irritans (L.), which are important ectoparasites of livestock. Several possible mechanisms for the transmission of pathogenic materials to animals were defined, using radioisotopes: (1) mechanical transmission from contaminated mouthparts; (2) transfer through regurgitation; (3) transfer via saliva; (4) transfer through the alimentary tract. A generalized scheme was developed for the paths of uptake and excretion of radioisotopes through the organism of insects. First, experiments applied this model to blood-feeding arthropods such as the stable fly and hornfly, tsetse flies, sheep keds (Melophagus ovinus L.), mosquitoes (Culex sp., Aedes sp.), Triatoma infestans Klug (Hemiptera, Triatomidae), and the tick Ornithodorus moubata Murray. Very similar principles and possibilities for the transfer of pathogens also appear to apply to plant-sucking aphids (vectors of virus diseases in plants) as to blood-feeding arthropods. Regurgitation found in biting flies, appears in ticks as well as in Triatomidae and tsetse flies (in the last two only under stress conditions) and could even be observed in aphids. Thus, aphids and certain biting arthropods can immediately transfer pathogens after feeding on an infected host plant or animal, on migrating to another host, findings mainly possible through using radioisotopes. The results on aphids include discussion of the ingestion-egestion hypothesis of noncirculative virus transmission, described by Harris in 1977

Experimental infection of macaques with a wild water bird-derived highly pathogenic avian influenza virus (H5N1.

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Tomoko Fujiyuki

Full Text Available Highly pathogenic avian influenza virus (HPAIV continues to threaten human health. Non-human primate infection models of human influenza are desired. To establish an animal infection model with more natural transmission and to determine the pathogenicity of HPAIV isolated from a wild water bird in primates, we administered a Japanese isolate of HPAIV (A/whooper swan/Hokkaido/1/2008, H5N1 clade 2.3.2.1 to rhesus and cynomolgus monkeys, in droplet form, via the intratracheal route. Infection of the lower and upper respiratory tracts and viral shedding were observed in both macaques. Inoculation of rhesus monkeys with higher doses of the isolate resulted in stronger clinical symptoms of influenza. Our results demonstrate that HPAIV isolated from a water bird in Japan is pathogenic in monkeys by experimental inoculation, and provide a new method for HPAIV infection of non-human primate hosts, a good animal model for investigation of HPAIV pathogenicity.

Epidemiologic analysis of respiratory viral infections among Singapore military servicemen in 2016.

Science.gov (United States)

Lau, Yuk-Fai; Koh, Wee-Hong Victor; Kan, Clement; Dua, Poh-Choo Alethea; Lim, Ai-Sim Elizabeth; Liaw, Chin-Wen Jasper; Gao, Qiu-Han; Chng, Jeremiah; Lee, Vernon J; Tan, Boon-Huan; Loh, Jin-Phang

2018-03-12

Respiratory illnesses have been identified as a significant factor leading to lost training time and morbidity among Singapore military recruits. A surveillance programme has been put in place to determine etiological agents responsible for febrile, as well as afebrile respiratory illnesses in a military camp. The goal of the study is to better understand the epidemiology of these diseases and identify potential countermeasures to protect military recruits against them. From Jan 2016 - Jan 2017, a total of 2647 respiratory cases were enrolled into the surveillance programme. The cases were further stratified into Febrile Respiratory Illness (FRI, with body temperature > 37.5 °C) or Acute Respiratory Illness (ARI, with body temperature respiratory diseases in military focused largely on FRI cases. With the expanded surveillance to ARI cases, this study allows unbiased evaluation of the impact of respiratory disease pathogens among recruits in a military environment. The results show that several pathogens have a much bigger role in causing respiratory diseases in this cohort.

A novel anti-influenza copper oxide containing respiratory face mask.

Science.gov (United States)

Borkow, Gadi; Zhou, Steve S; Page, Tom; Gabbay, Jeffrey

2010-06-25

Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66+/-0.51 and 6.17+/-0.37 log(10)TCID(50) of human influenza A virus (H1N1) and avian influenza virus (H9N2), respectively, under simulated breathing conditions (28.3 L/min). Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were masks 5.03+/-0.54 log(10)TCID(50). The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical barrier properties. The use of biocidal masks may significantly reduce the risk of hand or environmental contamination, and thereby subsequent infection, due to improper handling and disposal of the masks.

Monitoring of antimicrobial susceptibility of respiratory tract pathogens isolated from diseased cattle and pigs across Europe, 2009-2012: VetPath results.

Science.gov (United States)

El Garch, Farid; de Jong, Anno; Simjee, Shabbir; Moyaert, Hilde; Klein, Ulrich; Ludwig, Carolin; Marion, Hervé; Haag-Diergarten, Silke; Richard-Mazet, Alexandra; Thomas, Valérie; Siegwart, Ed

2016-10-15

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme that collects pathogens from diseased cattle, pigs and poultry. In the current study, 996 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 10 countries during 2009-2012. Pasteurella multocida, Mannheimia haemolytica and Histophilus somni from cattle and P. multocida, Actinobacillus pleuropneumoniae, Haemophilus parasuis, Bordetella bronchiseptica and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MIC values of 16 or 17 antibiotics were assessed centrally by broth microdilution following CLSI standards. Results were interpreted using CLSI breakpoints where available. Cattle isolates were generally highly susceptible to most antibiotics, except to tetracycline (3.0-12.0% resistance). Low levels of resistance (0-4.0%) were observed for the macrolide antibiotics. Resistance to spectinomycin varied from 0 to 6.0%. In pig isolates similar observations were made. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tulathromycin, tiamulin and tilmicosin was absent or <2%. Trimethoprim/sulfamethoxazole resistance varied from 1.9 to 5.3%, but tetracycline resistance varied from 20.4% in P. multocida to 88.1% in S. suis. For most antibiotics and pathogens the percentage resistance remained unchanged or only increased numerically as compared to that of the period 2002-2006. In conclusion, absence or low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from livestock. Comparison of all antibiotics and organisms was hampered since for almost half of the antibiotics no CLSI-defined breakpoints were available. Copyright © 2016

Incidence, etiology, and symptomatology of upper respiratory illness in elite athletes.

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Spence, Luke; Brown, Wendy J; Pyne, David B; Nissen, Michael D; Sloots, Theo P; McCormack, Joseph G; Locke, A Simon; Fricker, Peter A

2007-04-01

Upper respiratory illness (URI) is the most common medical condition affecting elite athletes. The aims of this study were to identify and evaluate the incidence, pathogenic etiology, and symptomatology of acute URI during a 5-month training and competition period. Thirty-two elite and 31 recreationally competitive triathletes and cyclists, and 20 sedentary controls (age range 18.0-34.1 yr) participated in a prospective surveillance study. Nasopharyngeal and throat swabs were collected from subjects presenting with two or more defined upper respiratory symptoms. Swabs were analyzed using microscopy, culture, and PCR testing for typical and atypical respiratory pathogens. The Wisconsin Upper Respiratory Symptom Survey (WURSS-44) was used to assess symptomatology and functional impairment. Thirty-seven URI episodes were reported in 28 subjects. Incidence rate ratios for illness were higher in both the control subjects (1.93, 95% CI: 0.72-5.18) and elite athletes (4.50, 1.91-10.59) than in the recreationally competitive athletes. Infectious agents were identified in only 11 (two control, three recreationally competitive, and six elite) out of 37 illness episodes. Rhinovirus was the most common respiratory pathogen isolated. Symptom and functional impairment severity scores were higher in subjects with an infectious pathogen episode, particularly on illness days 3-4. The results confirm a higher rate of URI among elite athletes than recreationally competitive athletes during this training and competition season. However, because pathogens were isolated in fewer than 30% of URI cases, further study is required to uncover the causes of unidentified but symptomatic URI in athletes. Despite the common perception that all URI are infections, physicians should consider both infectious and noninfectious causes when athletes present with symptoms.

Smog exposure and host resistance to respiratory pathogens

Science.gov (United States)

The US EPA is evaluating the health effects of photochemical smog on respiratory, cardiovascular and metabolic health (https://www.epa.gov/air-research/secondary-organic-aerosol-soas-research). Smog exposure has been associated with an increased risk of allergy and decreased res...

Transmission of severe acute respiratory syndrome in dynamical small-world networks

Science.gov (United States)

Masuda, Naoki; Konno, Norio; Aihara, Kazuyuki

2004-03-01

The outbreak of severe acute respiratory syndrome (SARS) is still threatening the world because of a possible resurgence. In the current situation that effective medical treatments such as antiviral drugs are not discovered yet, dynamical features of the epidemics should be clarified for establishing strategies for tracing, quarantine, isolation, and regulating social behavior of the public at appropriate costs. Here we propose a network model for SARS epidemics and discuss why superspreaders emerged and why SARS spread especially in hospitals, which were key factors of the recent outbreak. We suggest that superspreaders are biologically contagious patients, and they may amplify the spreads by going to potentially contagious places such as hospitals. To avoid mass transmission in hospitals, it may be a good measure to treat suspected cases without hospitalizing them. Finally, we indicate that SARS probably propagates in small-world networks associated with human contacts and that the biological nature of individuals and social group properties are factors more important than the heterogeneous rates of social contacts among individuals. This is in marked contrast with epidemics of sexually transmitted diseases or computer viruses to which scale-free network models often apply.

Taking forward a ‘One Health’ approach for turning the tide against the Middle East respiratory syndrome coronavirus and other zoonotic pathogens with epidemic potential

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Alimuddin Zumla

2016-06-01

Full Text Available The appearance of novel pathogens of humans with epidemic potential and high mortality rates have threatened global health security for centuries. Over the past few decades new zoonotic infectious diseases of humans caused by pathogens arising from animal reservoirs have included West Nile virus, Yellow fever virus, Ebola virus, Nipah virus, Lassa Fever virus, Hanta virus, Dengue fever virus, Rift Valley fever virus, Crimean-Congo haemorrhagic fever virus, severe acute respiratory syndrome coronavirus, highly pathogenic avian influenza viruses, Middle East Respiratory Syndrome Coronavirus, and Zika virus. The recent Ebola Virus Disease epidemic in West Africa and the ongoing Zika Virus outbreak in South America highlight the urgent need for local, regional and international public health systems to be be more coordinated and better prepared. The One Health concept focuses on the relationship and interconnectedness between Humans, Animals and the Environment, and recognizes that the health and wellbeing of humans is intimately connected to the health of animals and their environment (and vice versa. Critical to the establishment of a One Health platform is the creation of a multidisciplinary team with a range of expertise including public health officers, physicians, veterinarians, animal husbandry specialists, agriculturalists, ecologists, vector biologists, viral phylogeneticists, and researchers to co-operate, collaborate to learn more about zoonotic spread between animals, humans and the environment and to monitor, respond to and prevent major outbreaks. We discuss the unique opportunities for Middle Eastern and African stakeholders to take leadership in building equitable and effective partnerships with all stakeholders involved in human and health systems to take forward a ‘One Health’ approach to control such zoonotic pathogens with epidemic potential.

The role of the local microbial ecosystem in respiratory health and disease.

Science.gov (United States)

de Steenhuijsen Piters, Wouter A A; Sanders, Elisabeth A M; Bogaert, Debby

2015-08-19

Respiratory tract infections are a major global health concern, accounting for high morbidity and mortality, especially in young children and elderly individuals. Traditionally, highly common bacterial respiratory tract infections, including otitis media and pneumonia, were thought to be caused by a limited number of pathogens including Streptococcus pneumoniae and Haemophilus influenzae. However, these pathogens are also frequently observed commensal residents of the upper respiratory tract (URT) and form-together with harmless commensal bacteria, viruses and fungi-intricate ecological networks, collectively known as the 'microbiome'. Analogous to the gut microbiome, the respiratory microbiome at equilibrium is thought to be beneficial to the host by priming the immune system and providing colonization resistance, while an imbalanced ecosystem might predispose to bacterial overgrowth and development of respiratory infections. We postulate that specific ecological perturbations of the bacterial communities in the URT can occur in response to various lifestyle or environmental effectors, leading to diminished colonization resistance, loss of containment of newly acquired or resident pathogens, preluding bacterial overgrowth, ultimately resulting in local or systemic bacterial infections. Here, we review the current body of literature regarding niche-specific upper respiratory microbiota profiles within human hosts and the changes occurring within these profiles that are associated with respiratory infections. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2012: General view of the pathogens' antibacterial susceptibility.

Science.gov (United States)

Yanagihara, Katsunori; Watanabe, Akira; Aoki, Nobuki; Matsumoto, Tetsuya; Yoshida, Masaki; Sato, Junko; Wakamura, Tomotaro; Sunakawa, Keisuke; Kadota, Junichi; Kiyota, Hiroshi; Iwata, Satoshi; Kaku, Mitsuo; Hanaki, Hideaki; Ohsaki, Yoshinobu; Fujiuchi, Satoru; Takahashi, Manabu; Takeuchi, Kenichi; Takeda, Hiroaki; Ikeda, Hideki; Miki, Makoto; Nakanowatari, Susumu; Takahashi, Hiroshi; Utagawa, Mutsuko; Nishiya, Hajime; Kawakami, Sayoko; Morino, Eriko; Takasaki, Jin; Mezaki, Kazuhisa; Chonabayashi, Naohiko; Tanaka, Chie; Sugiura, Hideko; Goto, Hajime; Saraya, Takeshi; Kurai, Daisuke; Katono, Yasuhiro; Inose, Rika; Niki, Yoshihito; Takuma, Takahiro; Kudo, Makoto; Ehara, Shigeru; Sato, Yoshimi; Tsukada, Hiroki; Watabe, Nobuei; Honma, Yasuo; Mikamo, Hiroshige; Yamagishi, Yuka; Nakamura, Atsushi; Ohashi, Minoru; Seki, Masafumi; Hamaguchi, Shigeto; Toyokawa, Masahiro; Fujikawa, Yasunori; Mitsuno, Noriko; Ukimura, Akira; Miyara, Takayuki; Nakamura, Takahito; Mikasa, Keiichi; Kasahara, Kei; Ui, Koji; Fukuda, Saori; Nakamura, Akihiro; Morimura, Mika; Yamashita, Mikio; Takesue, Yoshio; Wada, Yasunao; Sugimoto, Keisuke; Kusano, Nobuchika; Nose, Motoko; Mihara, Eiichirou; Kuwabara, Masao; Doi, Masao; Watanabe, Yaeko; Tokuyasu, Hirokazu; Hino, Satoshi; Negayama, Kiyoshi; Mukae, Hiroshi; Kawanami, Toshinori; Ota, Toshiyuki; Fujita, Masaki; Honda, Junichi; Hiramatsu, Kazufumi; Aoki, Yosuke; Fukuoka, Mami; Magarifuchi, Hiroki; Nagasawa, Zenzo; Kaku, Norihito; Fujita, Jiro; Higa, Futoshi; Tateyama, Masao

2017-09-01

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be β-lactamase-producing ampicillin-resistant strains, and 37.2% to be β-lactamase-non-producing ampicillin-resistant strains. Extended spectrum β-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo β-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Seasonal variations of respiratory viruses detected from children with respiratory tract infections in Riyadh, Saudi Arabia

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Saad S. Albogami

2018-03-01

Full Text Available ARTIs have a huge impact in health systems in which 20–30% of all hospital admissions and 30–60% of practitioner visits are related to respiratory tract infections. The aim of this study is to determine the prevalence, age distribution, and seasonal variation of respiratory viruses. This study was descriptive retrospective study in which all patients 14 years of age and below who presented with signs and symptoms of ARTIs between January 2013 and December 2014 and had respiratory specimen tested by direct immunofluorescence assays for viruses identification were included in the study. During that period, a total of 4611 patients who presented with ARTIs from January 2013 to December 2014 were investigated, viruses were detected in 1115 (24%. RSV was associated with 97.4% of the total viral pathogens. Viruses were detected throughout all the two years with a peak in winter; Dec (n: 265, Jan (n: 418, Feb (n: 218, and Mar (n: 109. Viral pathogens are very important cause of ARTIs in our region. RSV was the most common virus detected with the highest detection rate in children who are two years old and below. A multi-center surveillance with more sensitive detection methods like PCR may help to provide a comprehensive understanding of virus distribution in our area, which may contribute implant an effective prevention approach for each virus. Keywords: Pediatrics, Infectious diseases, Respiratory infections, Respiratory syncytial virus, Saudi Arabia

Bordetella pertussis transmission

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Bordetella pertussis and Bordetella bronchiseptica are Gram negative bacterial respiratory pathogens. B. pertussis is the causative agent of whooping cough and is considered a human-adapted variant of B. bronchiseptica. B. pertussis and B. bronchiseptica share mechanisms of pathogenesis and are gene...

Factors Associated with Lower Respiratory Tract Infections in HIV-Exposed Uninfected Infants.

Science.gov (United States)

Weinberg, Adriana; Mussi-Pinhata, Marisa M; Yu, Qilu; Cohen, Rachel A; Almeida, Volia C; Amaral, Fabiana R; Freimanis, Laura; Harris, Donald Robert; Smith, Christiana; Siberry, George

2018-06-01

To identify factors that predispose human immunodeficiency virus (HIV)-exposed uninfected infants (HEUs) to higher incidence of severe infections, hospitalization, and death in the first 6-24 months of life compared with HEUs with and without lower respiratory tract infection (LRTI) in the first 6 months of life. Nested case-control study of 107 LRTI+ infants enrolled in the International Site Development Initiative (NISDI) Perinatal and Longitudinal Study in Latin American Countries (LILAC) studies with and 140 LRTI- in the first 6 months, matched by date and place of birth. Infants and mothers had plasma antibodies measured against respiratory syncytial virus (RSV), parainfluenza (PIV) 1, 2, 3, influenza, and pneumococcus 1, 5, 6B, and 14. Compared with LRTI-, mothers of LRTI+ HEUs had lower years of education, lower CD4 + cells, and higher HIV plasma viral load at delivery, but similar use of antiretrovirals and cotrimoxazole and other sociodemographic characteristics. LRTI+ and LRTI- HEUs had similar demographic and hematological characteristics and antibody concentrations against respiratory pathogens at birth. At 6 months, the rates of seroconversions to respiratory pathogens and antibody responses to tetanus vaccine were also similar. However, antibody concentrations to RSV were significantly higher in LRTI+ compared with LRTI- HEUs and marginally higher to PIV1. Maternal factors associated with advanced HIV disease, but unrelated to the use of antiretrovirals, cotrimoxazole, or the level of maternal antibodies against respiratory pathogens, contribute to the increased risk of LRTI in HEUs. In HEUs, antiretroviral and cotrimoxazole use, exposure to respiratory pathogens and humoral immune responses were not associated with the incidence of LRTI.

Vaginal microbicides: detecting toxicities in vivo that paradoxically increase pathogen transmission

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Abusuwwa Raed

2006-06-01

Full Text Available Abstract Background Microbicides must protect against STD pathogens without causing unacceptable toxic effects. Microbicides based on nonoxynol-9 (N9 and other detergents disrupt sperm, HSV and HIV membranes, and these agents are effective contraceptives. But paradoxically N9 fails to protect women against HIV and other STD pathogens, most likely because it causes toxic effects that increase susceptibility. The mouse HSV-2 vaginal transmission model reported here: (a Directly tests for toxic effects that increase susceptibility to HSV-2, (b Determines in vivo whether a microbicide can protect against HSV-2 transmission without causing toxicities that increase susceptibility, and (c Identifies those toxic effects that best correlate with the increased HSV susceptibility. Methods Susceptibility was evaluated in progestin-treated mice by delivering a low-dose viral inoculum (0.1 ID50 at various times after delivering the candidate microbicide to detect whether the candidate increased the fraction of mice infected. Ten agents were tested – five detergents: nonionic (N9, cationic (benzalkonium chloride, BZK, anionic (sodium dodecylsulfate, SDS, the pair of detergents in C31G (C14AO and C16B; one surface active agent (chlorhexidine; two non-detergents (BufferGel®, and sulfonated polystyrene, SPS; and HEC placebo gel (hydroxyethylcellulose. Toxic effects were evaluated by histology, uptake of a 'dead cell' dye, colposcopy, enumeration of vaginal macrophages, and measurement of inflammatory cytokines. Results A single dose of N9 protected against HSV-2 for a few minutes but then rapidly increased susceptibility, which reached maximum at 12 hours. When applied at the minimal concentration needed for brief partial protection, all five detergents caused a subsequent increase in susceptibility at 12 hours of ~20–30-fold. Surprisingly, colposcopy failed to detect visible signs of the N9 toxic effect that increased susceptibility at 12 hours. Toxic

ANTIMICROBIAL SUSCEPTIBILITY PROFILE OF MICROBIAL PATHOGENS ISOLATED FROM CALVES WITH RESPIRATORY DISEASES

OpenAIRE

George Cosmin Nadas; Flore Chirila; Cosmina Bouari; Nicodim Fit

2016-01-01

Introduction: Respiratory disease in calves is an actual problem, a major cause of economic losses due to mortality, growth delay and improper development. These conditions are frequent in calves due to the weaning stress, transport and environmental changes. Aims: The aim of this study was the isolation of bacteria from 30 calves with respiratory disorders and their antibiotic susceptibility testing. Materials and methods: Samples were collected from calves with respiratory disorders...

[Immunomodulators in Therapy of Respiratory Infections].

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Isakov, V A; Isakov, D V

2014-01-01

Viral infections provoke dysbalance in the interferon system and inhibition of the cellular and phagocytic responses of the host. Long-term persistence of pathogenic viruses and bacteria induce atopy and could aggravate chronic respiratory diseases. The up-to-date classification of immunomodulators is described. High efficacy of interferon inductors, such as cycloferon and some others as auxiliary means in therapy or prophylaxis (immunorehabilitation) of viral respiratory infections in adults and children was shown.

A highly pathogenic avian influenza virus H5N1 with 2009 pandemic H1N1 internal genes demonstrated increased replication and transmission in pigs

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This study investigated the pathogenicity and transmissibility of a reverse-genetics derived highly pathogenic avian influenza (HPAI) H5N1 influenza A virus (IAV), A/Iraq/775/06, and a reassortant virus comprised of the HA and NA from A/Iraq/775/06 and the internal genes of a 2009 pandemic H1N1, A/N...

Influenza Transmission in the Mother-Infant Dyad Leads to Severe Disease, Mammary Gland Infection, and Pathogenesis by Regulating Host Responses.

Science.gov (United States)

Paquette, Stéphane G; Banner, David; Huang, Stephen S H; Almansa, Raquel; Leon, Alberto; Xu, Luoling; Bartoszko, Jessica; Kelvin, David J; Kelvin, Alyson A

2015-10-01

Seasonal influenza viruses are typically restricted to the human upper respiratory tract whereas influenza viruses with greater pathogenic potential often also target extra-pulmonary organs. Infants, pregnant women, and breastfeeding mothers are highly susceptible to severe respiratory disease following influenza virus infection but the mechanisms of disease severity in the mother-infant dyad are poorly understood. Here we investigated 2009 H1N1 influenza virus infection and transmission in breastfeeding mothers and infants utilizing our developed infant-mother ferret influenza model. Infants acquired severe disease and mortality following infection. Transmission of the virus from infants to mother ferrets led to infection in the lungs and mother mortality. Live virus was also found in mammary gland tissue and expressed milk of the mothers which eventually led to milk cessation. Histopathology showed destruction of acini glandular architecture with the absence of milk. The virus was localized in mammary epithelial cells of positive glands. To understand the molecular mechanisms of mammary gland infection, we performed global transcript analysis which showed downregulation of milk production genes such as Prolactin and increased breast involution pathways indicated by a STAT5 to STAT3 signaling shift. Genes associated with cancer development were also significantly increased including JUN, FOS and M2 macrophage markers. Immune responses within the mammary gland were characterized by decreased lymphocyte-associated genes CD3e, IL2Ra, CD4 with IL1β upregulation. Direct inoculation of H1N1 into the mammary gland led to infant respiratory infection and infant mortality suggesting the influenza virus was able to replicate in mammary tissue and transmission is possible through breastfeeding. In vitro infection studies with human breast cells showed susceptibility to H1N1 virus infection. Together, we have shown that the host-pathogen interactions of influenza virus

Pathogenesis, Transmissibility, and Tropism of a Highly Pathogenic Avian Influenza A(H7N7) Virus Associated With Human Conjunctivitis in Italy, 2013.

Science.gov (United States)

Belser, Jessica A; Creager, Hannah M; Zeng, Hui; Maines, Taronna R; Tumpey, Terrence M

2017-09-15

H7 subtype influenza viruses represent a persistent public health threat because of their continued detection in poultry and ability to cause human infection. An outbreak of highly pathogenic avian influenza H7N7 virus in Italy during 2013 resulted in 3 cases of human conjunctivitis. We determined the pathogenicity and transmissibility of influenza A/Italy/3/2013 virus in mouse and ferret models and examined the replication kinetics of this virus in several human epithelial cell types. The moderate virulence observed in mammalian models and the capacity for transmission in a direct contact model underscore the need for continued study of H7 subtype viruses. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Dysbiosis of upper respiratory tract microbiota in elderly pneumonia patients

NARCIS (Netherlands)

Piters, Wouter A. A. de Steenhuijsen; Huijskens, Elisabeth G. W.; Wyllie, Anne L.; Biesbroek, Giske; van den Bergh, Menno R.; Veenhoven, Reinier H.; Wang, Xinhui; Trzcinski, Krzysztof; Bonten, Marc J.; Rossen, John W. A.; Sanders, Elisabeth A. M.; Bogaert, Debby

Bacterial pneumonia is a major cause of morbidity and mortality in elderly. We hypothesize that dysbiosis between regular residents of the upper respiratory tract (URT) microbiome, that is balance between commensals and potential pathogens, is involved in pathogen overgrowth and consequently

Replication and Transmission of the Novel Bovine Influenza D Virus in a Guinea Pig Model.

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Sreenivasan, Chithra; Thomas, Milton; Sheng, Zizhang; Hause, Ben M; Collin, Emily A; Knudsen, David E B; Pillatzki, Angela; Nelson, Eric; Wang, Dan; Kaushik, Radhey S; Li, Feng

2015-12-01

Influenza D virus (FLUDV) is a novel influenza virus that infects cattle and swine. The goal of this study was to investigate the replication and transmission of bovine FLUDV in guinea pigs. Following direct intranasal inoculation of animals, the virus was detected in nasal washes of infected animals during the first 7 days postinfection. High viral titers were obtained from nasal turbinates and lung tissues of directly inoculated animals. Further, bovine FLUDV was able to transmit from the infected guinea pigs to sentinel animals by means of contact and not by aerosol dissemination under the experimental conditions tested in this study. Despite exhibiting no clinical signs, infected guinea pigs developed seroconversion and the viral antigen was detected in lungs of animals by immunohistochemistry. The observation that bovine FLUDV replicated in the respiratory tract of guinea pigs was similar to observations described previously in studies of gnotobiotic calves and pigs experimentally infected with bovine FLUDV but different from those described previously in experimental infections in ferrets and swine with a swine FLUDV, which supported virus replication only in the upper respiratory tract and not in the lower respiratory tract, including lung. Our study established that guinea pigs could be used as an animal model for studying this newly emerging influenza virus. Influenza D virus (FLUDV) is a novel emerging pathogen with bovine as its primary host. The epidemiology and pathogenicity of the virus are not yet known. FLUDV also spreads to swine, and the presence of FLUDV-specific antibodies in humans could indicate that there is a potential for zoonosis. Our results showed that bovine FLUDV replicated in the nasal turbinate and lungs of guinea pigs at high titers and was also able to transmit from an infected animal to sentinel animals by contact. The fact that bovine FLUDV replicated productively in both the upper and lower respiratory tracts of guinea pigs

Protective roles of free avian respiratory macrophages in captive birds

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Mbuvi P. Mutua

Full Text Available In the mammalian lung, respiratory macrophages provide front line defense against invading pathogens and particulate matter. In birds, respiratory macrophages are known as free avian respiratory macrophages (FARM and a dearth of the cells in the avian lung has been purported to foreordain a weak first line of pulmonary defense, a condition associated with high mortality of domestic birds occasioned by respiratory inflictions. Avian pulmonary mechanisms including a three tiered aerodynamic filtration system, tight epithelial junctions and an efficient mucociliary escalator system have been known to supplement FARM protective roles. Current studies, however, report FARM to exhibit an exceptionally efficient phagocytic capacity and are effective in elimination of invading pathogens. In this review, we also report on effects of selective synthetic peroxisome proliferator activated receptor gamma (PPAR γ agonists on non phlogistic phagocytic properties in the FARM. To develop effective therapeutic interventions targeting FARM in treatment and management of respiratory disease conditions in the poultry, further studies are required to fully understand the role of FARM in innate and adaptive immune responses.

The public health implications of pathogens in polluted aquatic ...

African Journals Online (AJOL)

The public health implications of pathogens in polluted aquatic ecosystems: a review. ... Pathogen contamination in water sources and related diseases constitute ... of public water supply and most importantly, increased rate of human mortality. ... illnesses related to respiratory, gastrointestinal and dermatological systems, ...

Respiratory diseases among U.S. military personnel: countering emerging threats.

OpenAIRE

Gray, G. C.; Callahan, J. D.; Hawksworth, A. W.; Fisher, C. A.; Gaydos, J. C.

1999-01-01

Emerging respiratory disease agents, increased antibiotic resistance, and the loss of effective vaccines threaten to increase the incidence of respiratory disease in military personnel. We examine six respiratory pathogens (adenoviruses, influenza viruses, Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumoniae, and Bordetella pertussis) and review the impact of the diseases they cause, past efforts to control these diseases in U.S. military personnel, as well as current treat...

Influenza and Other Respiratory Viruses Involved in Severe Acute Respiratory Disease in Northern Italy during the Pandemic and Postpandemic Period (2009–2011

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Elena Pariani

2014-01-01

Full Text Available Since 2009 pandemic, international health authorities recommended monitoring severe and complicated cases of respiratory disease, that is, severe acute respiratory infection (SARI and acute respiratory distress syndrome (ARDS. We evaluated the proportion of SARI/ARDS cases and deaths due to influenza A(H1N1pdm09 infection and the impact of other respiratory viruses during pandemic and postpandemic period (2009–2011 in northern Italy; additionally we searched for unknown viruses in those cases for which diagnosis remained negative. 206 respiratory samples were collected from SARI/ARDS cases and analyzed by real-time RT-PCR/PCR to investigate influenza viruses and other common respiratory pathogens; also, a virus discovery technique (VIDISCA-454 was applied on those samples tested negative to all pathogens. Influenza A(H1N1pdm09 virus was detected in 58.3% of specimens, with a case fatality rate of 11.3%. The impact of other respiratory viruses was 19.4%, and the most commonly detected viruses were human rhinovirus/enterovirus and influenza A(H3N2. VIDISCA-454 enabled the identification of one previously undiagnosed measles infection. Nearly 22% of SARI/ARDS cases did not obtain a definite diagnosis. In clinical practice, great efforts should be dedicated to improving the diagnosis of severe respiratory disease; the introduction of innovative molecular technologies, as VIDISCA-454, will certainly help in reducing such “diagnostic gap.”

Avian influenza virus transmission to mammals.

Science.gov (United States)

Herfst, S; Imai, M; Kawaoka, Y; Fouchier, R A M

2014-01-01

Influenza A viruses cause yearly epidemics and occasional pandemics. In addition, zoonotic influenza A viruses sporadically infect humans and may cause severe respiratory disease and fatalities. Fortunately, most of these viruses do not have the ability to be efficiently spread among humans via aerosols or respiratory droplets (airborne transmission) and to subsequently cause a pandemic. However, adaptation of these zoonotic viruses to humans by mutation or reassortment with human influenza A viruses may result in airborne transmissible viruses with pandemic potential. Although our knowledge of factors that affect mammalian adaptation and transmissibility of influenza viruses is still limited, we are beginning to understand some of the biological traits that drive airborne transmission of influenza viruses among mammals. Increased understanding of the determinants and mechanisms of airborne transmission may aid in assessing the risks posed by avian influenza viruses to human health, and preparedness for such risks. This chapter summarizes recent discoveries on the genetic and phenotypic traits required for avian influenza viruses to become airborne transmissible between mammals.

Clinical predictors of the leading pathogens in human immunodeficiency virus-infected adults with community-onset bacteremia in the emergency department: The importance of transmission routes

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Ching-Chi Lee

2018-06-01

Conclusion: Focusing on the two key pathogens in HIV-infected adults with community-onset bacteremia, IDU was one of independent predictors associated with S. aureus infection, whereas MSM was the leading risk factor of S. enterica infection. Although the proposed predictive model of these pathogens has been not established, a scoring system involving the transmission risk of HIV may be of use for the early identification of these patients for clinicians.

Antimicrobial susceptibility monitoring of respiratory tract pathogens isolated from diseased cattle and pigs across Europe: the VetPath study.

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de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Moyaert, Hilde; El Garch, Farid; Maher, Kirsty; Morrissey, Ian; Butty, Pascal; Klein, Ulrich; Marion, Hervé; Rigaut, Delphine; Vallé, Michel

2014-08-06

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme collecting pathogens from diseased antimicrobial non-treated cattle, pigs and poultry. In the current study, 1001 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 11 countries during 2002-2006. Pasteurella multocida and Mannheimia haemolytica from cattle and P. multocida, Actinobacillus pleuropneumoniae and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MICs of 16 antibiotics were assessed centrally by broth microdilution following CLSI recommendations. Results were interpreted using CLSI breakpoints where available. P. multocida (231) and M. haemolytica (138) isolates were all susceptible to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin and trimethoprim/sulfamethoxazole. Resistance to florfenicol and spectinomycin was 0.4% and 3.5% in P. multocida, respectively, and absent in M. haemolytica isolates. Tetracycline resistance was 5.7% and 14.6% for P. multocida and M. haemolytica. In pigs, 230 P. multocida, 220 A. pleuropneumoniae and 182 S. suis isolates were recovered. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tiamulin and tilmicosin was absent or <1%. Trimethoprim/sulfamethoxazole resistance was 3-6% and tetracycline resistance varied from 14.7% in A. pleuropneumoniae to 81.8% in S. suis. In conclusion, low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from cattle and pigs. Since for approximately half of the antibiotics in this panel no CLSI-defined breakpoints were available, setting of the missing veterinary breakpoints is important. Copyright © 2014 Elsevier B.V. All rights reserved.

No evidence of transmission of H5N1 highly pathogenic avian influenza to humans after unprotected contact with infected wild swans.

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Wallensten, A; Salter, M; Bennett, S; Brown, I; Hoschler, K; Oliver, I

2010-02-01

Highly pathogenic avian influenza (HPAI) subtype H5N1 remains a public health threat as long as it circulates in wild and domestic birds. Information on the transmissibility of H5N1 HPAI from wild birds is needed for evidence-based public health advice. We investigated if transmission of H5N1 HPAI had taken place in people that had unprotected contact with infected wild mute swans during an incident at the Abbotsbury Swannery in Dorset, England. Thirteen people who had been exposed to infected swans were contacted and actively followed up for symptoms. Serology was taken after 30 days. We did not find evidence of transmission of H5N1 HPAI to humans during the incident. The incident provided a rare opportunity to study the transmissibility of the virus from wild birds to humans.

Determinants of Arbovirus Vertical Transmission in Mosquitoes.

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Sebastian Lequime

2016-05-01

Full Text Available Vertical transmission (VT and horizontal transmission (HT of pathogens refer to parental and non-parental chains of host-to-host transmission. Combining HT with VT enlarges considerably the range of ecological conditions in which a pathogen can persist, but the factors governing the relative frequency of each transmission mode are poorly understood for pathogens with mixed-mode transmission. Elucidating these factors is particularly important for understanding the epidemiology of arthropod-borne viruses (arboviruses of public health significance. Arboviruses are primarily maintained by HT between arthropod vectors and vertebrate hosts in nature, but are occasionally transmitted vertically in the vector population from an infected female to her offspring, which is a proposed maintenance mechanism during adverse conditions for HT. Here, we review over a century of published primary literature on natural and experimental VT, which we previously assembled into large databases, to identify biological factors associated with the efficiency of arbovirus VT in mosquito vectors. Using a robust statistical framework, we highlight a suite of environmental, taxonomic, and physiological predictors of arbovirus VT. These novel insights contribute to refine our understanding of strategies employed by arboviruses to persist in the environment and cause substantial public health concern. They also provide hypotheses on the biological processes underlying the relative VT frequency for pathogens with mixed-mode transmission that can be tested empirically.

Middle East respiratory syndrome in children. Dental considerations

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Fares S. Al-Sehaibany

2017-04-01

Full Text Available As of January 2016, 1,633 laboratory-confirmed cases of Middle East Respiratory Syndrome Coronavirus (MERS-CoV infection and 587 MERS-related deaths have been reported by the World Health Organization globally. Middle East Respiratory Syndrome Coronavirus may occur sporadically in communities or may be transmitted within families or hospitals. The number of confirmed MERS-CoV cases among healthcare workers has been increasing. Middle East Respiratory Syndrome Coronavirus may also spread through aerosols generated during various dental treatments, resulting in transmission between patients and dentists. As MERS-CoV cases have also been reported among children, pediatric dentists are at risk of MERS-CoV infection. This review discusses MERS-CoV infection in children and healthcare workers, especially pediatric dentists, and considerations pertaining to pediatric dentistry. Although no cases of MERS-CoV transmission between a patient and a dentist have yet been reported, the risk of MERS-CoV transmission from an infected patient may be high due to the unique work environment of dentists (aerosol generation.

A novel anti-influenza copper oxide containing respiratory face mask.

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Gadi Borkow

Full Text Available BACKGROUND: Protective respiratory face masks protect the nose and mouth of the wearer from vapor drops carrying viruses or other infectious pathogens. However, incorrect use and disposal may actually increase the risk of pathogen transmission, rather than reduce it, especially when masks are used by non-professionals such as the lay public. Copper oxide displays potent antiviral properties. A platform technology has been developed that permanently introduces copper oxide into polymeric materials, conferring them with potent biocidal properties. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate that impregnation of copper oxide into respiratory protective face masks endows them with potent biocidal properties in addition to their inherent filtration properties. Both control and copper oxide impregnated masks filtered above 99.85% of aerosolized viruses when challenged with 5.66+/-0.51 and 6.17+/-0.37 log(10TCID(50 of human influenza A virus (H1N1 and avian influenza virus (H9N2, respectively, under simulated breathing conditions (28.3 L/min. Importantly, no infectious human influenza A viral titers were recovered from the copper oxide containing masks within 30 minutes (< or = 0.88 log(10TCID(50, while 4.67+/-1.35 log(10TCID(50 were recovered from the control masks. Similarly, the infectious avian influenza titers recovered from the copper oxide containing masks were < or = 0.97+/-0.01 log(10TCID(50 and from the control masks 5.03+/-0.54 log(10TCID(50. The copper oxide containing masks successfully passed Bacterial Filtration Efficacy, Differential Pressure, Latex Particle Challenge, and Resistance to Penetration by Synthetic Blood tests designed to test the filtration properties of face masks in accordance with the European EN 14683:2005 and NIOSH N95 standards. CONCLUSIONS/SIGNIFICANCE: Impregnation of copper oxide into respiratory protective face masks endows them with potent anti-influenza biocidal properties without altering their physical

Mitigation strategies to reduce the generation and transmission of airborne highly pathogenic avian influenza virus particles during processing of infected poultry.

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Bertran, Kateri; Clark, Andrew; Swayne, David E

2018-06-08

Airborne transmission of H5N1 highly pathogenic avian influenza (HPAI) viruses has occurred among poultry and from poultry to humans during home or live-poultry market slaughter of infected poultry, and such transmission has been experimentally reproduced. In this study, we investigated simple, practical changes in the processing of H5N1 virus-infected chickens to reduce infectious airborne particles and their transmission. Our findings suggest that containing the birds during the killing and bleeding first step by using a disposable plastic bag, a commonly available cooking pot widely used in Egypt (halla), or a bucket significantly reduces generation of infectious airborne particles and transmission to ferrets. Similarly, lack of infectious airborne particles was observed when processing vaccinated chickens that had been challenged with HPAI virus. Moreover, the use of a mechanical defeatherer significantly increased total number of particles in the air compared to manual defeathering. This study confirms that simple changes in poultry processing can efficiently mitigate generation of infectious airborne particles and their transmission to humans. Published by Elsevier GmbH.

Significance of Moraxella catarrhalis as a causative organism of lower respiratory tract infections

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M.O. Ramadan

2017-07-01

Conclusion: This study shows that when microbiological and clinical criteria are met, M. catarrhalis when isolated should be considered as a pathogen causing lower respiratory tract infections. M. catarrhalis, lower respiratory tract infections.

Application of Enrofloxacin and Orbifloxacin Disks Approved in Japan for Susceptibility Testing of Representative Veterinary Respiratory Pathogens

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HARADA, Kazuki; USUI, Masaru; ASAI, Tetsuo

2014-01-01

ABSTRACT In this study, susceptibilities of Pasteurella multocida, Mannheimia haemolytica and Actinobacillus pleuropneumoniae to enrofloxacin and orbifloxacin were tested using an agar diffusion method with the commercial disks and a broth microdilution method. Good correlation between the 2 methods for enrofloxacin and orbifloxacin was observed for P. multocida (r = −0.743 and −0.818, respectively), M. haemolytica (r = −0.739 and −0.800, respectively) and A. pleuropneumoniae (r = −0.785 and −0.809, respectively). Based on the Clinical and Laboratory Standards Institute interpretive criteria for enrofloxacin, high-level categorical agreement between the 2 methods was found for P. multocida (97.9%), M. haemolytica (93.8%) and A. pleuropneumoniae (92.0%). Our findings indicate that the tested commercial disks can be applied for susceptibility testing of veterinary respiratory pathogens. PMID:25008965

Quantitative transmission characteristics of different H5 low pathogenic avian influenza viruses in Muscovy ducks.

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Niqueux, Éric; Picault, Jean-Paul; Amelot, Michel; Allée, Chantal; Lamandé, Josiane; Guillemoto, Carole; Pierre, Isabelle; Massin, Pascale; Blot, Guillaume; Briand, François-Xavier; Rose, Nicolas; Jestin, Véronique

2014-01-10

EU annual serosurveillance programs show that domestic duck flocks have the highest seroprevalence of H5 antibodies, demonstrating the circulation of notifiable avian influenza virus (AIV) according to OIE, likely low pathogenic (LP). Therefore, transmission characteristics of LPAIV within these flocks can help to understand virus circulation and possible risk of propagation. This study aimed at estimating transmission parameters of four H5 LPAIV (three field strains from French poultry and decoy ducks, and one clonal reverse-genetics strain derived from one of the former), using a SIR model to analyze data from experimental infections in SPF Muscovy ducks. The design was set up to accommodate rearing on wood shavings with a low density of 1.6 ducks/m(2): 10 inoculated ducks were housed together with 15 contact-exposed ducks. Infection was monitored by RNA detection on oropharyngeal and cloacal swabs using real-time RT-PCR with a cutoff corresponding to 2-7 EID50. Depending on the strain, the basic reproduction number (R0) varied from 5.5 to 42.7, confirming LPAIV could easily be transmitted to susceptible Muscovy ducks. The lowest R0 estimate was obtained for a H5N3 field strain, due to lower values of transmission rate and duration of infectious period, whereas reverse-genetics derived H5N1 strain had the highest R0. Frequency and intensity of clinical signs were also variable between strains, but apparently not associated with longer infectious periods. Further comparisons of quantitative transmission parameters may help to identify relevant viral genetic markers for early detection of potentially more virulent strains during surveillance of LPAIV. Copyright © 2013 Elsevier B.V. All rights reserved.

Protection of mice against lethal infection with highly pathogenic H7N7 influenza A virus by using a recombinant low-pathogenicity vaccine strain.

NARCIS (Netherlands)

V.J. Munster (Vincent); M.I. Spronken (Monique); T.M. Bestebroer (Theo); C. Baas (Chantal); W.E.Ph. Beyer (Walter); G.F. Rimmelzwaan (Guus); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); E. de Wit (Emmie)

2005-01-01

textabstractIn 2003, an outbreak of highly pathogenic avian influenza occurred in The Netherlands. The avian H7N7 virus causing the outbreak was also detected in 88 humans suffering from conjunctivitis or mild respiratory symptoms and one person who died of pneumonia and acute respiratory distress

Incidence and etiology of hospitalized acute respiratory infections in the Egyptian Delta.

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Rowlinson, Emily; Dueger, Erica; Mansour, Adel; Azzazy, Nahed; Mansour, Hoda; Peters, Lisa; Rosenstock, Summer; Hamid, Sarah; Said, Mayar M; Geneidy, Mohamed; Abd Allah, Monier; Kandeel, Amr

2017-01-01

Acute Respiratory Infections (ARI) are responsible for nearly two million childhood deaths worldwide. A limited number of studies have been published on the epidemiology of viral respiratory pathogens in Egypt. A total of 6113 hospitalized patients >1 month of age with suspected ARI were enrolled between June 23, 2009 and December 31, 2013. Naso- and oropharyngeal specimens were collected and tested for influenza A and B, respiratory syncytial virus, human metapneumovirus, adenovirus, and parainfluenza viruses 1-3. Blood specimens from children 1-11 months were cultured and bacterial growth was identified by polymerase chain reaction. Results from a healthcare utilization survey on the proportion of persons seeking care for ARI was used to calculate adjusted ARI incidence rates in the surveillance population. The proportion of patients with a viral pathogen detected decreased with age from 67% in patients age 1-11 months to 19% in patients ≥65 years of age. Influenza was the dominant viral pathogen detected in patients ≥1 year of age (13.9%). The highest incidence rates for hospitalized ARI were observed in children 1-11 months (1757.9-5537.5/100 000 population) and RSV was the most commonly detected pathogen in this age group. In this study population, influenza is the largest viral contributor to hospitalized ARIs and children 1-11 months of age experience a high rate of ARI hospitalizations. This study highlights a need for surveillance of additional viral pathogens and alternative detection methods for bacterial pathogens, which may reveal a substantial proportion of as yet unidentified etiologies in adults. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Microbial flora variations in the respiratory tract of mice

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Rosa Cangemi de Gutierrez

1999-09-01

Full Text Available A stable microbial system in the respiratory tract acts as an important defense mechanism against pathogenic microorganisms. Perturbations in this system may allow pathogens to establish. In an ecological environment such as the respiratory tract, there are many diverse factors that play a role in the establishment of the indigenous flora. In the present work we studied the normal microbial flora of different areas of the respiratory tract of mice and their evolution from the time the mice were born. Our interest was to know which were the dominant groups of microorganisms in each area, which were the first capable of colonizing and which dominated over time to be used as probiotic microorganisms. Our results show that Gram negative facultatively anaerobic bacilli and strict anaerobic microorganisms were the last ones to appear in the bronchia, while aerobic and Gram positive cocci were present in all the areas of the respiratory tract. The number of facultative aerobes and strict anaerobes were similar in the nasal passage, pharynx instilled and trachea, but lower in bronchia. The dominant species were Streptococcus viridans and Staphylococcus saprophyticcus, followed by S. epidermidis, Lactobacilli and S. cohnii I which were present on every studied days but at different proportions. This paper is the first part of a research topic investigating the protective effect of the indigenous flora against pathogens using the mice as an experimental model.

The clinical features of respiratory infections caused by the Streptococcus anginosus group

OpenAIRE

Noguchi, Shingo; Yatera, Kazuhiro; Kawanami, Toshinori; Yamasaki, Kei; Naito, Keisuke; Akata, Kentaro; Shimabukuro, Ikuko; Ishimoto, Hiroshi; Yoshii, Chiharu; Mukae, Hiroshi

2015-01-01

Background The Streptococcus anginosus group (SAG) play important roles in respiratory infections. It is ordinarily difficult to distinguish them from contaminations as the causative pathogens of respiratory infections because they are often cultured in respiratory specimens. Therefore, it is important to understand the clinical characteristics and laboratory findings of respiratory infections caused by the SAG members. The aim of this study is to clarify the role of the SAG bacteria in respi...

Influenza interaction with cocirculating pathogens and its impact on surveillance, pathogenesis, and epidemic profile: A key role for mathematical modelling.

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Lulla Opatowski

2018-02-01

Full Text Available Evidence is mounting that influenza virus interacts with other pathogens colonising or infecting the human respiratory tract. Taking into account interactions with other pathogens may be critical to determining the real influenza burden and the full impact of public health policies targeting influenza. This is particularly true for mathematical modelling studies, which have become critical in public health decision-making. Yet models usually focus on influenza virus acquisition and infection alone, thereby making broad oversimplifications of pathogen ecology. Herein, we report evidence of influenza virus interactions with bacteria and viruses and systematically review the modelling studies that have incorporated interactions. Despite the many studies examining possible associations between influenza and Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Neisseria meningitidis, respiratory syncytial virus (RSV, human rhinoviruses, human parainfluenza viruses, etc., very few mathematical models have integrated other pathogens alongside influenza. The notable exception is the pneumococcus-influenza interaction, for which several recent modelling studies demonstrate the power of dynamic modelling as an approach to test biological hypotheses on interaction mechanisms and estimate the strength of those interactions. We explore how different interference mechanisms may lead to unexpected incidence trends and possible misinterpretation, and we illustrate the impact of interactions on public health surveillance using simple transmission models. We demonstrate that the development of multipathogen models is essential to assessing the true public health burden of influenza and that it is needed to help improve planning and evaluation of control measures. Finally, we identify the public health, surveillance, modelling, and biological challenges and propose avenues of research for the coming years.

Relevance of indirect transmission for wildlife disease surveillance

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Martin Lange

2016-11-01

Full Text Available Epidemiological models of infectious diseases are essential tools in support of risk assessment, surveillance design and contingency planning in public and animal health. Direct pathogen transmission from host to host is an essential process of each host-pathogen system and respective epidemiological modelling concepts. It is widely accepted that numerous diseases involve indirect transmission through pathogens shed by infectious hosts to their environment. However, epidemiological models largely do not represent pathogen persistence outside the host explicitly. We hypothesize that this simplification might bias management-related model predictions for disease agents that can persist outside their host for a certain time span. We adapted an individual-based, spatially explicit epidemiological model that can mimic both transmission processes. One version explicitly simulated indirect pathogen transmission through a contaminated environment. A second version simulated direct host-to-host transmission only. We aligned the model variants by the transmission potential per infectious host (i.e. basic reproductive number R0 and the spatial transmission kernel of the infection to allow unbiased comparison of predictions. The quantitative model results are provided for the example of surveillance plans for early detection of foot-and-mouth disease in wild boar, a social host.We applied systematic sampling strategies on the serological status of randomly selected host individuals in both models. We compared between the model variants the time to detection and the area affected prior to detection, measures that strongly influence mitigation costs. Moreover, the ideal sampling strategy to detect the infection in a given time frame was compared between both models.We found the simplified, direct transmission model to underestimate necessary sample size by up to one order of magnitude, but to overestimate the area put under control measures. Thus, the model

Characterization of Candida species isolated from cases of lower respiratory tract infection.

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Jha, B J; Dey, S; Tamang, M D; Joshy, M E; Shivananda, P G; Brahmadatan, K N

2006-01-01

(1) To identify and characterize the Candida species isolates from lower respiratory tract infection. (2) to determine the rate of isolation of Candida species from sputum samples. This study was carried out in the Department of Microbiology, Manipal Teaching Hospital, Pokhara, Nepal from June 2002 to January 2003. A total of 462 sputum samples were collected from patients suspected lower respiratory tract infection. The samples were processed as Gram staining to find out the suitability of the specimen, cultured on Sabouraud's Dextrose Agar (SDA) and also on blood agar and chocolate agar to identify the potential lower respiratory tract pathogens. For the identification of Candida, sputum samples were processed for Gram stain, culture, germ tube test, production of chlamydospore, sugar fermentation and assimilation test. For the identification of bacteria, Gram stain, culture, and biochemical tests were performed by standardized procedure. Out of 462 samples, 246 (53.24%) samples grew potential pathogens of lower respiratory tract. Among them Haemophilus influenzae 61(24.79%) and Streptococcus pneumoniae 57 (23.17%) were the predominant bacterial pathogens. Candida species were isolated from 30 samples (12.2%). The majority of Candida species amongst the Candida isolates were Candida albicans 21(70%) followed by Candida tropicalis 4(13.33%). Candida krusei 3(10%), Candida parapsilosis 1(3.33%) and Candida stellatoidea 1(3.33%). The highest rate of isolation of Candida was between the age of 71 and 80. Candida isolation from sputum samples is important as found in the present study in which Candida species were the third most common pathogen isolated from patients with lower respiratory tract infection.

Viral etiology, seasonality and severity of hospitalized patients with severe acute respiratory infections in the Eastern Mediterranean Region, 2007-2014.

Science.gov (United States)

Horton, Katherine C; Dueger, Erica L; Kandeel, Amr; Abdallat, Mohamed; El-Kholy, Amani; Al-Awaidy, Salah; Kohlani, Abdul Hakim; Amer, Hanaa; El-Khal, Abel Latif; Said, Mayar; House, Brent; Pimentel, Guillermo; Talaat, Maha

2017-01-01

Little is known about the role of viral respiratory pathogens in the etiology, seasonality or severity of severe acute respiratory infections (SARI) in the Eastern Mediterranean Region. Sentinel surveillance for SARI was conducted from December 2007 through February 2014 at 20 hospitals in Egypt, Jordan, Oman, Qatar and Yemen. Nasopharyngeal and oropharyngeal swabs were collected from hospitalized patients meeting SARI case definitions and were analyzed for infection with influenza, respiratory syncytial virus (RSV), adenovirus (AdV), human metapneumovirus (hMPV) and human parainfluenza virus types 1-3 (hPIV1-3). We analyzed surveillance data to calculate positivity rates for viral respiratory pathogens, describe the seasonality of those pathogens and determine which pathogens were responsible for more severe outcomes requiring ventilation and/or intensive care and/or resulting in death. At least one viral respiratory pathogen was detected in 8,753/28,508 (30.7%) samples tested for at least one pathogen and 3,497/9,315 (37.5%) of samples tested for all pathogens-influenza in 3,345/28,438 (11.8%), RSV in 3,942/24,503 (16.1%), AdV in 923/9,402 (9.8%), hMPV in 617/9,384 (6.6%), hPIV1 in 159/9,402 (1.7%), hPIV2 in 85/9,402 (0.9%) and hPIV3 in 365/9,402 (3.9%). Multiple pathogens were identified in 501/9,316 (5.4%) participants tested for all pathogens. Monthly variation, indicating seasonal differences in levels of infection, was observed for all pathogens. Participants with hMPV infections and participants less than five years of age were significantly less likely than participants not infected with hMPV and those older than five years of age, respectively, to experience a severe outcome, while participants with a pre-existing chronic disease were at increased risk of a severe outcome, compared to those with no reported pre-existing chronic disease. Viral respiratory pathogens are common among SARI patients in the Eastern Mediterranean Region. Ongoing surveillance is

Community Respiratory Viruses as a Cause of Lower Respiratory Tract Infections Following Suppressive Chemotherapy in Cancer Patients

International Nuclear Information System (INIS)

El-Mahallawy, H.A.; Ibrahim, M.H.; Shalaby, L.; Kandil

2005-01-01

Community respiratory viruses are an important cause of respiratory disease in the immunocompromised patients with cancer. To evaluate the occurrence and clinical significance of respiratory virus infections in hospitalized cancer patients at National Cancer Institute, Cairo University, during anticancer treatment, we studied cases that developed episodes of lower respiratory tract infections (LRTI). Patients and Methods: Thirty patients with LRTI were studied clinically, radiologically, and microbiologically. Sputum cultures were done and an immunofluorescence search for IgM antibodies of influenza A and B, parainfluenza serotypes 1,2 and 3, adenovirus, respiratory syncytial virus, Legionella pneumophila, Coxiella burnettii, Chlamydia pneumoniae, and Mycoplasma pneumoniae were performed on serum samples of patients. The main presenting symptom was cough and expectoration. Hematologic malignancy was the underlying disease in 86.6% of cases. Blood cultures were positive in II patients (36.6%) only. Sputum cultures revealed a bacterial pathogen in [3 cases and fungi in 3; whereas viral and atypical bacterial lgM antibodies were detected in 13 and 4 patients; respectively. Influenza virus was the commonest virus detected, being of type B in 4 cases, type A in one case and mixed A and B in another 5 cases; followed by RSV in 5 patients. Taken together, bacteria were identified as a single cause of LRTI in 10 cases, viruses in 6, fungi in 3 and mixed causes in 7. Still, there were 4 undiagnosed cases. This study showed that respiratory viruses are common in LRTI, either as a single cause or mixed with bacterial pathogens. in hospitalized cancer patients receiving chemotherapy. Diagnostic tests for respiratory viruses should be incorporated in the routine diagnostic study of patients with hematologic malignancies. Also, it must be emphasized that early CT chest is crucial as a base-line prior to initiation of anti-fungal or anti-viral therapy. In cancer patients with a

Susceptibility of swine to H5 and H7 low pathogenic avian influenza viruses.

Science.gov (United States)

Balzli, Charles; Lager, Kelly; Vincent, Amy; Gauger, Phillip; Brockmeier, Susan; Miller, Laura; Richt, Juergen A; Ma, Wenjun; Suarez, David; Swayne, David E

2016-07-01

The ability of pigs to become infected with low pathogenic avian influenza (LPAI) viruses and then generate mammalian adaptable influenza A viruses is difficult to determine. Yet, it is an important link to understanding any relationship between LPAI virus ecology and possible epidemics among swine and/or humans. Assess susceptibility of pigs to LPAI viruses found within the United States and their direct contact transmission potential. Pigs were inoculated with one of ten H5 or H7 LPAI viruses selected from seven different bird species to test infectivity, virulence, pathogenesis, and potential to transmit virus to contact pigs through histological, RRT-PCR and seroconversion data. Although pigs were susceptible to infection with each of the LPAI viruses, no clinical disease was recognized in any pig. During the acute phase of the infection, minor pulmonary lesions were found in some pigs and one or more pigs in each group were RRT-PCR-positive in the lower respiratory tract, but no virus was detected in upper respiratory tract (negative nasal swabs). Except for one group, one or more pigs in each LPAI group developed antibody. No LPAI viruses transmitted to contact pigs. LPAI strains from various bird populations within the United States are capable of infecting pigs. Although adaptability and transmission of individual strains seem unlikely, the subclinical nature of the infections demonstrates the need to improve sampling and testing methods to more accurately measure incidence of LPAI virus infection in pigs, and their potential role in human-zoonotic LPAI virus dynamics. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Streptococcus pneumoniae enhances human respiratory syncytial virus infection in vitro and in vivo

NARCIS (Netherlands)

D.T. Nguyen (Tien); R.P.L. Louwen (Rogier); Elberse, K. (Karin); G. van Amerongen (Geert); S. Yüksel (Selma); A. Luijendijk (Ad); A.D.M.E. Osterhaus (Albert); W.P. Duprex (William Paul); R.L. de Swart (Rik)

2015-01-01

textabstractHuman respiratory syncytial virus (HRSV) and Streptococcus pneumoniae are important causative agents of respiratory tract infections. Both pathogens are associated with seasonal disease outbreaks in the pediatric population, and can often be detected simultaneously in infants

Transmission and immunopathology of the avian influenza virus A/Anhui/1/2013 (H7N9) human isolate in three commonly commercialized avian species.

Science.gov (United States)

Vidaña, B; Dolz, R; Busquets, N; Ramis, A; Sánchez, R; Rivas, R; Valle, R; Cordón, I; Solanes, D; Martínez, J; Majó, N

2018-05-01

H7N9 virus infection is a global concern, given that it can cause severe infection and mortality in humans. However, the understanding of H7N9 epidemiology, animal reservoir species and zoonotic risk remains limited. This work evaluates the pathogenicity, transmissibility and local innate immune response of three avian species harbouring different respiratory distribution of α2,6 and α2,3 SA receptors. Muscovy ducks, European quails and SPF chickens were intranasally inoculated with 10 5 embryo infectious dose (EID) 50 of the human H7N9 (A/Anhui/1/2013) influenza isolate. None of the avian species showed clinical signs or macroscopic lesions, and only mild microscopic lesions were observed in the upper respiratory tract of quail and chickens. Quail presented more severe histopathologic lesions and avian influenza virus (AIV) positivity by immunohistochemistry (IHC), which correlated with higher IL-6 responses. In contrast, Muscovy ducks were resistant to disease and presented higher IFNα and TLR7 response. In all species, viral shedding was higher in the respiratory than in the digestive tract. Higher viral shedding was observed in quail, followed by chicken and ducks, which presented similar viral titres. Efficient transmission was observed in all contact quail and half of the Muscovy ducks, while no transmission was observed between chicken. All avian species showed viral shedding in drinking water throughout infection. © 2017 Blackwell Verlag GmbH.

Tracing pathogens in the food chain

NARCIS (Netherlands)

Brul, S.; Fratamico, P.M.; McMeekin, T.A.

2010-01-01

Successful methods for the detection and investigation of outbreaks of foodborne disease are essential for ensuring consumer safety. Increased understanding of the transmission of pathogens in food chains will also assist efforts to safeguard public health. Tracing pathogens in the food chain

Respiratory viruses in children hospitalized for acute lower respiratory tract infection in Ghana.

Science.gov (United States)

Kwofie, Theophilus B; Anane, Yaw A; Nkrumah, Bernard; Annan, Augustina; Nguah, Samuel B; Owusu, Michael

2012-04-10

Acute respiratory tract infections are one of the major causes of morbidity and mortality among young children in developing countries. Information on the viral aetiology of acute respiratory infections in developing countries is very limited. The study was done to identify viruses associated with acute lower respiratory tract infection among children less than 5 years. Nasopharyngeal samples and blood cultures were collected from children less than 5 years who have been hospitalized for acute lower respiratory tract infection. Viruses and bacteria were identified using Reverse Transcriptase Real-Time Polymerase Chain Reaction and conventional biochemical techniques. Out of 128 patients recruited, 33(25.88%%, 95%CI: 18.5% to 34.2%) were positive for one or more viruses. Respiratory Syncytial Virus (RSV) was detected in 18(14.1%, 95%CI: 8.5% to 21.3%) patients followed by Adenoviruses (AdV) in 13(10.2%, 95%CI: 5.5% to 16.7%), Parainfluenza (PIV type: 1, 2, 3) in 4(3.1%, 95%CI: 0.9% to 7.8%) and influenza B viruses in 1(0.8%, 95%CI: 0.0 to 4.3). Concomitant viral and bacterial co-infection occurred in two patients. There were no detectable significant differences in the clinical signs, symptoms and severity for the various pathogens isolated. A total of 61.1% (22/36) of positive viruses were detected during the rainy season and Respiratory Syncytial Virus was the most predominant. The study has demonstrated an important burden of respiratory viruses as major causes of childhood acute respiratory infection in a tertiary health institution in Ghana. The data addresses a need for more studies on viral associated respiratory tract infection.

Pathogenicity of highly pathogenic avian influenza virus in mammals

NARCIS (Netherlands)

de Wit, Emmie; Kawaoka, Yoshihiro; de Jong, Menno D.; Fouchier, Ron A. M.

2008-01-01

In recent years, there has been an increase in outbreaks of highly pathogenic avian influenza (HPAI) in poultry. Occasionally, these outbreaks have resulted in transmission of influenza viruses to humans and other mammals, with symptoms ranging from conjunctivitis to pneumonia and death. Here, the

Southward autumn migration of waterfowl facilitates cross-continental transmission of the highly pathogenic avian influenza H5N1 virus

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Xu, Yanjie; Gong, Peng; Wielstra, Ben; Si, Yali

2016-08-01

The highly pathogenic avian influenza subtype H5N1 (HPAI H5N1) is a worldwide zoonotic infectious disease, threatening humans, poultry and wild birds. The role of wild birds in the spread of HPAI H5N1 has previously been investigated by comparing disease spread patterns with bird migration routes. However, the different roles that the southward autumn and northward spring migration might play in virus transmission have hardly been explored. Using direction analysis, we analyze HPAI H5N1 transmission directions and angular concentration of currently circulating viral clades, and compare these with waterfowl seasonal migration directions along major waterfowl flyways. Out of 22 HPAI H5N1 transmission directions, 18 had both a southward direction and a relatively high concentration. Differences between disease transmission and waterfowl migration directions were significantly smaller for autumn than for spring migration. The four northward transmission directions were found along Asian flyways, where the initial epicenter of the virus was located. We suggest waterfowl first picked up the virus from East Asia, then brought it to the north via spring migration, and then spread it to other parts of world mainly by autumn migration. We emphasize waterfowl autumn migration plays a relatively important role in HPAI H5N1 transmission compared to spring migration.

Propagation of respiratory aerosols by the vuvuzela.

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Ka-Man Lai

Full Text Available Vuvuzelas, the plastic blowing horns used by sports fans, recently achieved international recognition during the FIFA World Cup soccer tournament in South Africa. We hypothesised that vuvuzelas might facilitate the generation and dissemination of respiratory aerosols. To investigate the quantity and size of aerosols emitted when the instrument is played, eight healthy volunteers were asked to blow a vuvuzela. For each individual the concentration of particles in expelled air was measured using a six channel laser particle counter and the duration of blowing and velocity of air leaving the vuvuzela were recorded. To allow comparison with other activities undertaken at sports events each individual was also asked to shout and the measurements were repeated while using a paper cone to confine the exhaled air. Triplicate measurements were taken for each individual. The mean peak particle counts were 658 × 10(3 per litre for the vuvuzela and 3.7 × 10(3 per litre for shouting, representing a mean log(10 difference of 2.20 (95% CI: 2.03,2.36; p 97% of particles captured from either the vuvuzela or shouting were between 0.5 and 5 microns in diameter. Mean peak airflows recorded for the vuvuzela and shouting were 6.1 and 1.8 litres per second respectively. We conclude that plastic blowing horns (vuvuzelas have the capacity to propel extremely large numbers of aerosols into the atmosphere of a size able to penetrate the lower lung. Some respiratory pathogens are spread via contaminated aerosols emitted by infected persons. Further investigation is required to assess the potential of the vuvuzela to contribute to the transmission of aerosol borne diseases. We recommend, as a precautionary measure, that people with respiratory infections should be advised not to blow their vuvuzela in enclosed spaces and where there is a risk of infecting others.

Transmission of MERS-coronavirus in household contacts

NARCIS (Netherlands)

Drosten, Christian; Meyer, Benjamin; Müller, Marcel A; Corman, Victor M; Al-Masri, Malak; Hossain, Raheela; Madani, Hosam; Sieberg, Andrea; Bosch, Berend Jan|info:eu-repo/dai/nl/273306049; Lattwein, Erik; Alhakeem, Raafat F; Assiri, Abdullah M; Hajomar, Waleed; Albarrak, Ali M; Al-Tawfiq, Jaffar A; Zumla, Alimuddin I; Memish, Ziad A

2014-01-01

BACKGROUND: Strategies to contain the Middle East respiratory syndrome coronavirus (MERS-CoV) depend on knowledge of the rate of human-to-human transmission, including subclinical infections. A lack of serologic tools has hindered targeted studies of transmission. METHODS: We studied 26 index

Pathogen intelligence

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Michael eSteinert

2014-01-01

Full Text Available Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behaviour, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behaviour, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies.

Transmission of the gut microbiota: spreading of health

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Browne, Hilary P.; Neville, B. Anne; Forster, Samuel C.; Lawley, Trevor D.

2018-01-01

Transmission of commensal intestinal bacteria between humans could promote health by establishing, maintaining and replenishing microbial diversity in the microbiota of an individual. Unlike pathogens, the routes of transmission for commensal bacteria remain unappreciated and poorly understood, despite the likely commonalities between both. Consequently, broad infection control measures that are designed to prevent pathogen transmission and infection, such as oversanitation and the overuse of antibiotics, may inadvertently affect human health by altering normal commensal transmission. In this Review, we discuss the mechanisms and factors that influence host-to-host transmission of the intestinal microbiota and examine how a better understanding of these processes will identify new approaches to nurture and restore transmission routes that are used by beneficial bacteria. PMID:28603278

Cellular immune responses to respiratory viruses

NARCIS (Netherlands)

van Helden, M.J.G.

2011-01-01

When a respiratory virus successfully infects the lungs, cascades of immune responses are initiated aimed to remove the pathogen. Immediate non-specific protection is provided by the innate immune system and this reduces the viral load during the first days of infection. The adaptive immune response

Middle East respiratory syndrome: A new global threat

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Pradeep Kumar Bhatia

2016-01-01

Full Text Available The outbreak of Middle East respiratory syndrome (MERS is reported from Saudi Arabia and the Republic of Korea. It is a respiratory disease caused by coronavirus. Camels are considered as a source for MERS transmission in humans, although the exact source is unknown. Human-to-human transmission is reported in the community with droplet and contact spread being the possible modes. Most patients without any underlying diseases remain asymptomatic or develop mild clinical disease, but some patients require critical care for mechanical ventilation, dialysis and other organ support. MERS is a disease with pandemic potential and awareness, and surveillance can prevent such further outbreaks.

Hypoxemic Respiratory Failure from Acute Respiratory Distress Syndrome Secondary to Leptospirosis

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Shannon M. Fernando

2017-01-01

Full Text Available Acute respiratory distress syndrome (ARDS, characterized by hypoxemic respiratory failure, is associated with a mortality of 30–50% and is precipitated by both direct and indirect pulmonary insults. Treatment is largely supportive, consisting of lung protective ventilation and thereby necessitating Intensive Care Unit (ICU admission. The most common precipitant is community-acquired bacterial pneumonia, but other putative pathogens include viruses and fungi. On rare occasions, ARDS can be secondary to tropical disease. Accordingly, a history should include travel to endemic regions. Leptospirosis is a zoonotic disease most common in the tropics and typically associated with mild pulmonary complications. We describe a case of a 25-year-old male with undiagnosed leptospirosis, presenting with fever and severe hypoxemic respiratory failure, returning from a Costa Rican holiday. There was no other organ failure. He was intubated and received lung protective ventilation. His condition improved after ampicillin and penicillin G were added empirically. This case illustrates the rare complication of ARDS from leptospirosis, the importance of taking a travel history, and the need for empiric therapy because of diagnostic delay.

Middle East respiratory syndrome coronavirus transmission among health care workers: Implication for infection control.

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Alfaraj, Sarah H; Al-Tawfiq, Jaffar A; Altuwaijri, Talal A; Alanazi, Marzouqa; Alzahrani, Nojoom; Memish, Ziad A

2018-02-01

Many outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) have occurred in health care settings and involved health care workers (HCWs). We describe the occurrence of an outbreak among HCWs and attempt to characterize at-risk exposures to improve future infection control interventions. This study included an index case and all HCW contacts. All contacts were screened for MERS-CoV using polymerase chain reaction. During the study period in 2015, the index case was a 30-year-old Filipino nurse who had a history of unprotected exposure to a MERS-CoV-positive case on May 15, 2015, and had multiple negative tests for MERS-CoV. Weeks later, she was diagnosed with pulmonary tuberculosis and MERS-CoV infection. A total of 73 staff were quarantined for 14 days, and nasopharyngeal swabs were taken on days 2, 5, and 12 postexposure. Of those contacts, 3 (4%) were confirmed positive for MERS-CoV. An additional 18 staff were quarantined and had MERS-CoV swabs. A fourth case was confirmed positive on day 12. Subsequent contact investigations revealed a fourth-generation transmission. Only 7 (4.5%) of the total 153 contacts were positive for MERS-CoV. The role of HCWs in MERS-CoV transmission is complex. Although most MERS-CoV-infected HCWs are asymptomatic or have mild disease, fatal infections can occur and HCWs can play a major role in propagating health care facility outbreaks. This investigation highlights the need to continuously review infection control guidance relating to the role of HCWs in MERS-CoV transmission in health care outbreaks, especially as it relates to the complex questions on definition of risky exposures, who to test, and the frequency of MERS-CoV testing; criteria for who to quarantine and for how long; and clearance and return to active duty criteria. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Emergence of highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) in medium-scale swine farms in southeastern Cambodia.

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Tornimbene, B; Frossard, J-P; Chhim, V; Sorn, S; Guitian, J; Drew, T W

2015-01-01

Since 2006, reports from China and Viet Nam have alerted of an emergent highly pathogenic variant of porcine reproductive and respiratory syndrome virus (HP-PRRSV) in that region. The frequent occurrence of outbreaks in these countries puts Cambodian pig farms at high risk of infection, but no study had been conducted to investigate the presence of HP-PRRS in Cambodian farms. We investigated the presence of HP-PRRS in medium-scale (semi-commercial) swine farms in the Cambodian southeastern region. Specifically, one province bordering Viet Nam (Takeo) was selected due to the concentration of most semi-commercial farms in that province. A cross-sectional study was carried out, between July and September 2010 to assess whether the prevalence of infection in these farms was indicative of recent spread of PPRSV and to identify risk factors for infection. The number of farms to be sampled was established using methods for Lot Quality Assurance Surveys (LQAS), in order to achieve a pre-established ability to discriminate between two different prevalence settings. The target population comprised all semi-commercial farms in Takeo province from which a random sample of 35 farms was selected. Selected farms were visited and questionnaires administered to gather information on farm characteristics and husbandry practices. Blood samples from individual pigs were collected in each of the study farms and tested for PRRSV, along with a number of other swine respiratory pathogens in order to investigate potential interactions. Our results showed that the virus was already present in Takeo semi-commercial pig population (LQAS herd prevalence ≥85%) at the time of sampling. The presence of sows in the farm and farm density were significantly associated (P<0.05) with the introduction and the presence of PRRS - but this was an unadjusted association as small sample size precluded multivariate analysis. Spatiotemporal description of the supposed pattern of infection revealed that the

Respiratory viruses in children hospitalized for acute lower respiratory tract infection in Ghana

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Kwofie Theophilus B

2012-04-01

Full Text Available Abstract Background Acute respiratory tract infections are one of the major causes of morbidity and mortality among young children in developing countries. Information on the viral aetiology of acute respiratory infections in developing countries is very limited. The study was done to identify viruses associated with acute lower respiratory tract infection among children less than 5 years. Method Nasopharyngeal samples and blood cultures were collected from children less than 5 years who have been hospitalized for acute lower respiratory tract infection. Viruses and bacteria were identified using Reverse Transcriptase Real-Time Polymerase Chain Reaction and conventional biochemical techniques. Results Out of 128 patients recruited, 33(25.88%%, 95%CI: 18.5% to 34.2% were positive for one or more viruses. Respiratory Syncytial Virus (RSV was detected in 18(14.1%, 95%CI: 8.5% to 21.3% patients followed by Adenoviruses (AdV in 13(10.2%, 95%CI: 5.5% to 16.7%, Parainfluenza (PIV type: 1, 2, 3 in 4(3.1%, 95%CI: 0.9% to 7.8% and influenza B viruses in 1(0.8%, 95%CI: 0.0 to 4.3. Concomitant viral and bacterial co-infection occurred in two patients. There were no detectable significant differences in the clinical signs, symptoms and severity for the various pathogens isolated. A total of 61.1% (22/36 of positive viruses were detected during the rainy season and Respiratory Syncytial Virus was the most predominant. Conclusion The study has demonstrated an important burden of respiratory viruses as major causes of childhood acute respiratory infection in a tertiary health institution in Ghana. The data addresses a need for more studies on viral associated respiratory tract infection.

Eicosanoids and Respiratory Viral Infection: Coordinators of Inflammation and Potential Therapeutic Targets

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Mary K. McCarthy

2012-01-01

Full Text Available Viruses are frequent causes of respiratory infection, and viral respiratory infections are significant causes of hospitalization, morbidity, and sometimes mortality in a variety of patient populations. Lung inflammation induced by infection with common respiratory pathogens such as influenza and respiratory syncytial virus is accompanied by increased lung production of prostaglandins and leukotrienes, lipid mediators with a wide range of effects on host immune function. Deficiency or pharmacologic inhibition of prostaglandin and leukotriene production often results in a dampened inflammatory response to acute infection with a respiratory virus. These mediators may, therefore, serve as appealing therapeutic targets for disease caused by respiratory viral infection.

Relating phylogenetic trees to transmission trees of infectious disease outbreaks.

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Ypma, Rolf J F; van Ballegooijen, W Marijn; Wallinga, Jacco

2013-11-01

Transmission events are the fundamental building blocks of the dynamics of any infectious disease. Much about the epidemiology of a disease can be learned when these individual transmission events are known or can be estimated. Such estimations are difficult and generally feasible only when detailed epidemiological data are available. The genealogy estimated from genetic sequences of sampled pathogens is another rich source of information on transmission history. Optimal inference of transmission events calls for the combination of genetic data and epidemiological data into one joint analysis. A key difficulty is that the transmission tree, which describes the transmission events between infected hosts, differs from the phylogenetic tree, which describes the ancestral relationships between pathogens sampled from these hosts. The trees differ both in timing of the internal nodes and in topology. These differences become more pronounced when a higher fraction of infected hosts is sampled. We show how the phylogenetic tree of sampled pathogens is related to the transmission tree of an outbreak of an infectious disease, by the within-host dynamics of pathogens. We provide a statistical framework to infer key epidemiological and mutational parameters by simultaneously estimating the phylogenetic tree and the transmission tree. We test the approach using simulations and illustrate its use on an outbreak of foot-and-mouth disease. The approach unifies existing methods in the emerging field of phylodynamics with transmission tree reconstruction methods that are used in infectious disease epidemiology.

Environmental Contamination as an Important Route for the Transmission of the Hospital Pathogen VRE: Modeling and Prediction of Classical Interventions

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M Wolkewitz

2008-01-01

Full Text Available Background In addition to the close contact between patients and medical staff, the contamination of surfaces plays an important role in the transmission of pathogens such as vancomycin-resistant enterococci (VRE. Mathematical modeling is a very convenient tool for hospital infection control as it allows the quantitative prediction of the effects of special hygiene and control interventions. Methods We present a compartmental model which describes the dynamics of transmission from patient to patient, also taking into account the interaction with medical staff and environmental contamination. Empirical data from a VRE outbreak in the onco-haematological unit at the University Medical Center Freiburg (Germany were collected with 100 consecutive admissions being followed up for 90 days. Stochastical simulations were used to predict the prevalence of patients colonised with VRE at the time when at least one of the following interventions were introduced: hand hygiene, disinfection of surfaces, cohorting, screening and antibiotic reduction. Results Graphical figures show the temporal dynamics of several simulation scenarios. If no prevention or intervention is present, simulations based on transmission models predict an expected endemic prevalence per ward of 0.83 (95% CI:0.66, 1.00 after the first infected person enters the unit. Interventions may reduce this prevalence, but only the combination of several interventions can control a VRE outbreak. Conclusions The model predicts that only the combination of several interventions can control an VRE outbreak in this setting. The inclusion of environmental contamination improves the compartmental model and allows a prediction of the efficacy of the disinfection of surfaces. These results can be applied to other settings and will therefore help to understand and control the spread of nosocomial pathogens.

Human Respiratory Syncytial Virus and Human Metapneumovirus

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Luciana Helena Antoniassi da Silva

2009-08-01

Full Text Available The human respiratory syncytial virus (hRSV and the human metapneumovírus (hMPV are main etiological agents of acute respiratory infections (ARI. The ARI is an important cause of childhood morbidity and mortality worldwide.  hRSV and hMPV are members of the Paramyxoviridae. They are enveloped, non-segmented viruses, with negative-sense single stranded genomes. Respiratory syncytial virus (hRSV is the best characterized agent viral of this group, associated with respiratory diseases in lower respiratory tract. Recently, a new human pathogen belonging to the subfamily Pneumovirinae was identified, the human metapneumovirus (hMPV, which is structurally similar to the hRSV, in genomic organization, viral structure, antigenicity and clinical symptoms.  The subfamily Pneumovirinae contains two genera: genus Pneumovirus contains hRSV, the bovine (bRSV, as well as the ovine and caprine respiratory syncytial virus and pneumonia virus of mice, the second genus Metapneumovirus, consists of avian metapneumovirus (aMPV and human metapneumovirus (hMPV. In this work, we present a brief narrative review of the literature on important aspects of the biology, epidemiology and clinical manifestations of infections by two respiratory viruses.

Cell wall modifications during conidial maturation of the human pathogenic fungus Pseudallescheria boydii

NARCIS (Netherlands)

Ghamrawi, Sarah; Rénier, Gilles; Saulnier, Patrick; Cuenot, Stéphane; Zykwinska, Agata; Dutilh, Bas E; Thornton, Christopher; Faure, Sébastien; Bouchara, Jean-Philippe

Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory

Cell Wall Modifications during Conidial Maturation of the Human Pathogenic Fungus Pseudallescheria boydii

NARCIS (Netherlands)

Ghamrawi, S.; Renier, G.; Saulnier, P.; Cuenot, S.; Zykwinska, A.; Dutilh, B.E.; Thornton, C.; Faure, S.; Bouchara, J.P.

2014-01-01

Progress in extending the life expectancy of cystic fibrosis (CF) patients remains jeopardized by the increasing incidence of fungal respiratory infections. Pseudallescheria boydii (P. boydii), an emerging pathogen of humans, is a filamentous fungus frequently isolated from the respiratory

Helichrysum arenarium subsp. arenarium: phenolic composition and antibacterial activity against lower respiratory tract pathogens.

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Gradinaru, Adina C; Silion, Mihaela; Trifan, Adriana; Miron, Anca; Aprotosoaie, Ana C

2014-01-01

The aim of this study was to investigate the phenolic content and antibacterial activity of the methanol extract from Helichrysum arenarium (L.) Moench subsp. arenarium inflorescences against lower respiratory tract pathogens (standard strains and clinical isolates). The extract was characterised by a total phenolic content of 160.17 mg/g. Several caffeic acid conjugates (chlorogenic acid and dicaffeoylquinic acids) and flavonoids (apigenin, naringenin, apigenin-7-O-glucoside and naringenin-O-hexosides) were identified as major constituents by HPLC-DAD-ESI-MS. Staphylococcus aureus ATCC 25923 was more susceptible to Helichrysum extract than Streptococcus pneumoniae ATCC 49619 (minimum inhibitory concentration [MIC] = 0.62  and 1.25 mg/mL, respectively). The extract exhibited similar antibacterial effects against methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae clinical isolates (MIC = 2.5 mg/mL) displaying a higher activity against ampicillin-resistant Moraxella catarrhalis isolate (MIC = 0.15 mg/mL). The combination with ciprofloxacin exhibited additivity against both standard strains (fractional inhibitory concentration [FIC] index = 0.75 and 0.73) and S. aureus isolates (FIC index = 0.62) and synergy against S. pneumoniae isolates (FIC index = 0.5).

The evolution of transmission mode

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Forbes, Mark R.; Hauffe, Heidi C.; Kallio, Eva R.; Okamura, Beth; Sait, Steven M.

2017-01-01

This article reviews research on the evolutionary mechanisms leading to different transmission modes. Such modes are often under genetic control of the host or the pathogen, and often in conflict with each other via trade-offs. Transmission modes may vary among pathogen strains and among host populations. Evolutionary changes in transmission mode have been inferred through experimental and phylogenetic studies, including changes in transmission associated with host shifts and with evolution of the unusually complex life cycles of many parasites. Understanding the forces that determine the evolution of particular transmission modes presents a fascinating medley of problems for which there is a lack of good data and often a lack of conceptual understanding or appropriate methodologies. Our best information comes from studies that have been focused on the vertical versus horizontal transmission dichotomy. With other kinds of transitions, theoretical approaches combining epidemiology and population genetics are providing guidelines for determining when and how rapidly new transmission modes may evolve, but these are still in need of empirical investigation and application to particular cases. Obtaining such knowledge is a matter of urgency in relation to extant disease threats. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289251

Transcriptomic analysis reveals the potential of highly pathogenic PRRS virus to modulate immune system activation related to host-pathogen and damage associated signaling in infected porcine monocytes

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One of the largest risks to the continued stability of the swine industry is by pathogens like porcine reproductive and respiratory syndrome virus (PRRSV) that can decimate production as it spreads among individuals. These infections can be low or highly pathogenic, and because it infects monocytic ...

Prevalence and clinical significance of respiratory viruses and bacteria detected in tuberculosis patients compared to household contact controls in Tanzania: a cohort study.

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Mhimbira, F; Hiza, H; Mbuba, E; Hella, J; Kamwela, L; Sasamalo, M; Ticlla, M; Said, K; Mhalu, G; Chiryamkubi, M; Schindler, C; Reither, K; Gagneux, S; Fenner, L

2018-03-23

To describe the prevalence of respiratory pathogens in tuberculosis (TB) patients and in their household contact controls, and to determine the clinical significance of respiratory pathogens in TB patients. We studied 489 smear-positive adult TB patients and 305 household contact controls without TB with nasopharyngeal swab samples within an ongoing prospective cohort study in Dar es Salaam, Tanzania, between 2013 and 2015. We used multiplex real-time PCR to detect 16 respiratory viruses and seven bacterial pathogens from nasopharyngeal swabs. The median age of the study participants was 33 years; 61% (484/794) were men, and 21% (168/794) were HIV-positive. TB patients had a higher prevalence of HIV (28.6%; 140/489) than controls (9.2%; 28/305). Overall prevalence of respiratory viral pathogens was 20.4% (160/794; 95%CI 17.7-23.3%) and of bacterial pathogens 38.2% (303/794; 95%CI 34.9-41.6%). TB patients and controls did not differ in the prevalence of respiratory viruses (Odds Ratio [OR] 1.00, 95%CI 0.71-1.44), but respiratory bacteria were less frequently detected in TB patients (OR 0.70, 95%CI 0.53-0.94). TB patients with both respiratory viruses and respiratory bacteria were likely to have more severe disease (adjusted OR [aOR] 1.6, 95%CI 1.1-2.4; p 0.011). TB patients with respiratory viruses tended to have more frequent lung cavitations (aOR 1.6, 95%CI 0.93-2.7; p 0.089). Respiratory viruses are common for both TB patients and household controls. TB patients may present with more severe TB disease, particularly when they are co-infected with both bacteria and viruses. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies ), 2013. Scientific Opinion on the substantiation of a health claim related to Yestimun ® and defence against pathogens in the upper respiratory tract pursuant to Article 13(5) of R egulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

substantiation of a health claim related to Yestimun® and defence against pathogens in the upper respiratory tract. The food that is the subject of the health claim, Yestimun®, which consists of (1,3)-(1,6)-β-D-glucans from brewer’s yeast cell wall, is sufficiently characterised. The claimed effect, defence...... established between the consumption of Yestimun® ((1,3)-(1,6)-β-D-glucans from brewer’s yeast cell wall) and defence against pathogens in the upper respiratory tract. © European Food Safety Authority, 2013...

Pathogens and diseases of freshwater mussels in the United States: Studies on bacterial transmission and depuration

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Starliper, Clifford E.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

Unionid mussels are recognized as important contributors to healthy aquatic ecosystems, as well as bioindicators of environmental perturbations. Because they are sedentary, filter feeding animals and require hosts (i.e., fishes) to transform embryonic glochidia, mussels are susceptible to direct adverse environmental parameters, and indirect parameters that restrict the timely presence of the host(s). Their numbers have declined in recent decades to a point that this fauna is regarded as one of the most imperiled in North America. The most significant threat to populations of native unionids in recent years has been the introduction and spread of zebra mussels Dreissena polymorpha. Many federal and state agencies, and private interests are now engaged in mussel conservation efforts, including collecting selected imperiled species from impacted rivers and lakes and propagating them at refuges for future population augmentations. One essential consideration with mussel propagation and their intensive culture at refugia is the prevention of pathogen introductions and control of diseases. Currently, there are few reports of etiological agents causing diseases among freshwater mussels; however, because of increased observations of mussel die-offs in conjunction with transfers of live animals between natural waters and refugia, disease problems can be anticipated to emerge. This review summarizes research to develop bacterial isolation techniques, study pathogen transmission between fish and mussels, identify causes of seasonal mussel die-offs, and develop non-destructive methods for pathogen detection. These efforts were done to develop disease preventative techniques for use by resource managers to avoid potential large-scale disease problems in restoration and population augmentation efforts among imperiled populations.

Incidence and etiology of hospitalized acute respiratory infections in the Egyptian Delta

OpenAIRE

Rowlinson, Emily; Dueger, Erica; Mansour, Adel; Azzazy, Nahed; Mansour, Hoda; Peters, Lisa; Rosenstock, Summer; Hamid, Sarah; Said, Mayar M.; Geneidy, Mohamed; Abd Allah, Monier; Kandeel, Amr

2016-01-01

Introduction Acute Respiratory Infections (ARI) are responsible for nearly two million childhood deaths worldwide. A limited number of studies have been published on the epidemiology of viral respiratory pathogens in Egypt. Methods A total of 6113 hospitalized patients >1?month of age with suspected ARI were enrolled between June 23, 2009 and December 31, 2013. Naso? and oropharyngeal specimens were collected and tested for influenza A and B, respiratory syncytial virus, human metapneumovirus...

ANTIMICROBIAL SUSCEPTIBILITY PROFILE OF MICROBIAL PATHOGENS ISOLATED FROM CALVES WITH RESPIRATORY DISEASES

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George Cosmin Nadas

2016-11-01

Full Text Available Introduction: Respiratory disease in calves is an actual problem, a major cause of economic losses due to mortality, growth delay and improper development. These conditions are frequent in calves due to the weaning stress, transport and environmental changes. Aims: The aim of this study was the isolation of bacteria from 30 calves with respiratory disorders and their antibiotic susceptibility testing. Materials and methods: Samples were collected from calves with respiratory disorders (nasal discharge aged 6 to 9 weeks in 2 series, using sterile swabs. Samples were initially inoculated on blood agar and MacConkey agar following the characteristics of the colonies and microscopic examination that enabled the identification of bacterial species. Isolated strains were used to flood Mueller-Hinton agar to carry out sensitivity testing. The antibiotics tested were represented by: Amoxicillin with clavulanic acid, Gentamicin, Florfenicol, Enrofloxacin, Marbofloxacin, Penicillin G, Cefquinone, Tulathromycin, Ceftiofur, Tylosin and Cephalotin. Results: Genus Streptococcus have been identified in 23 samples, followed by Staphylococcus identified in 14 samples, and Bacillus spp., in 10 nasal swabs; The most common bacteria associations were represented by Streptococcus-Staphylococcus, Streptococcus-Staphylococcus-Bacillus, and Streptococcus-E.coli. The most efficient antibiotic was Cefquinome (Cobactan, followed by Penicillin G and Amoxicillin with clavulanic acid (Amoxiclav; the least effective antibiotics were Florfenicol and Tulathromycin. Conclusions: The study carried out on nasal discharge samples collected from calves with respiratory disorders and their antimicrobial profile testing led to the following conclusions: 1 Low susceptibility to Florfenicol is caused by previous treatments when this molecule was excessively used and without prior sensitivity testing. 2 Cefquinome may represent an emergency therapeutic antibiotic for respiratory

First Time Isolation of From a Respiratory Sample

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Stefanie Deinhardt-Emmer

2018-01-01

Full Text Available We describe the first isolation of Mycobacterium hassiacum , a rapid-growing, partial acid-resistant mycobacterium, in a respiratory specimen from a patient with exacerbated chronic obstructive pulmonary disease. To provide therapeutic recommendation for future cases, antibiotic susceptibility testing of 3 clinical isolates was performed by broth microdilution. All strains tested showed susceptibility to clarithromycin, imipenem, ciprofloxacin, and doxycycline. The role of M hassiacum as a respiratory pathogen remains unclear and needs to be evaluated by future reports.

A new paradigm in respiratory hygiene: modulating respiratory secretions to contain cough bioaerosol without affecting mucus clearance

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Bonilla Gloria

2007-08-01

Full Text Available Abstract Background Several strategies and devices have been designed to protect health care providers from acquiring transmissible respiratory diseases while providing care. In modulating the physical characteristics of the respiratory secretions to minimize the aerosolization that facilitates transmission of airborne diseases, a fundamental premise is that the prototype drugs have no adverse effect on the first line of respiratory defense, clearance of mucus by ciliary action. Methods To assess and demonstrate the primary mechanism of our mucomodulators (XLs, we have built our evidence moving from basic laboratory studies to an ex-vivo model and then to an in-vivo large animal model. We exposed anesthetized dogs without hypersecretion to different dose concentrations of aerosolized XL "B", XL "D" and XL "S". We assessed: cardio-respiratory pattern, tracheal mucus clearance, airway patency, and mucus viscoelastic changes. Results Exposure of frog palate mucus to XLs did not affect the clearance of mucus by ciliary action. Dogs maintained normal cardio-respiratory pattern with XL administration. Tracheal mucociliary clearance in anesthetized dogs indicated a sustained 40% mean increase. Tracheal mucus showed increased filance, and there was no mucus retention in the airways. Conclusion The ex-vivo frog palate and the in-vivo mammalian models used in this study, appear to be appropriate and complement each other to better assess the effects that our mucomodulators exert on the mucociliary clearance defence mechanism. The physiological function of the mucociliary apparatus was not negatively affected in any of the two epithelial models. Airway mucus crosslinked by mucomodulators is better cleared from an intact airway and normally functioning respiratory system, either due to enhanced interaction with cilia or airflow-dependent mechanisms. Data obtained in this study allow us to assure that we have complied with the fundamental requirement

Discovery of a novel canine respiratory coronavirus support genetic recombination among betacoronavirus1.

Science.gov (United States)

Lu, Shuai; Wang, Yanqun; Chen, Yingzhu; Wu, Bingjie; Qin, Kun; Zhao, Jincun; Lou, Yongliang; Tan, Wenjie

2017-06-02

Although canine respiratory coronavirus (CRCoV) is an important respiratory pathogen that is prevalent in many countries, only one complete genome sequence of CRCoV (South Korea strain K37) has been obtained to date. Genome-wide analyses and recombination have rarely been conducted, as small numbers of samples and limited genomic characterization have previously prevented further analyses. Herein, we report a unique CRCoV strain, denoted strain BJ232, derived from a CRCoV-positive dog with a mild respiratory infection. Phylogenetic analysis based on complete genome of all available coronaviruses consistently show that CRCoV BJ232 is most closely related to human coronavirus OC43 (HCoV-OC43) and BCoV, forming a separate clade that split off early from other Betacoronavirus 1. Based on the phylogenetic and SimPlot analysis we propose that CRCoV-K37 was derived from genetic recombination between CRCoV-BJ232 and BCoV. In detail, spike (S) gene of CRCoV-K37 clustered with CRCoV-BJ232. However orf1ab, membrane (M) and nucleocapsid (N) genes were more related to Bovine coronavirus (BCoV) than CRCoV-B232. Molecular epidemic analysis confirmed the prevalence of CRCoV-BJ232 lineage around the world for a long time. Recombinant events among Betacoronavirus 1 may have implications for CRCoV transmissibility. All these findings provide further information regarding the origin of CRCoV. Copyright © 2017. Published by Elsevier B.V.

Early Characterization of the Severity and Transmissibility of Pandemic Influenza Using Clinical Episode Data from Multiple Populations.

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Pete Riley

2015-09-01

Full Text Available The potential rapid availability of large-scale clinical episode data during the next influenza pandemic suggests an opportunity for increasing the speed with which novel respiratory pathogens can be characterized. Key intervention decisions will be determined by both the transmissibility of the novel strain (measured by the basic reproductive number R0 and its individual-level severity. The 2009 pandemic illustrated that estimating individual-level severity, as described by the proportion pC of infections that result in clinical cases, can remain uncertain for a prolonged period of time. Here, we use 50 distinct US military populations during 2009 as a retrospective cohort to test the hypothesis that real-time encounter data combined with disease dynamic models can be used to bridge this uncertainty gap. Effectively, we estimated the total number of infections in multiple early-affected communities using the model and divided that number by the known number of clinical cases. Joint estimates of severity and transmissibility clustered within a relatively small region of parameter space, with 40 of the 50 populations bounded by: pC, 0.0133-0.150 and R0, 1.09-2.16. These fits were obtained despite widely varying incidence profiles: some with spring waves, some with fall waves and some with both. To illustrate the benefit of specific pairing of rapidly available data and infectious disease models, we simulated a future moderate pandemic strain with pC approximately ×10 that of 2009; the results demonstrating that even before the peak had passed in the first affected population, R0 and pC could be well estimated. This study provides a clear reference in this two-dimensional space against which future novel respiratory pathogens can be rapidly assessed and compared with previous pandemics.

Inhaled Antibiotic Therapy in Chronic Respiratory Diseases

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Diego J. Maselli

2017-05-01

Full Text Available The management of patients with chronic respiratory diseases affected by difficult to treat infections has become a challenge in clinical practice. Conditions such as cystic fibrosis (CF and non-CF bronchiectasis require extensive treatment strategies to deal with multidrug resistant pathogens that include Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, Burkholderia species and non-tuberculous Mycobacteria (NTM. These challenges prompted scientists to deliver antimicrobial agents through the pulmonary system by using inhaled, aerosolized or nebulized antibiotics. Subsequent research advances focused on the development of antibiotic agents able to achieve high tissue concentrations capable of reducing the bacterial load of difficult-to-treat organisms in hosts with chronic respiratory conditions. In this review, we focus on the evidence regarding the use of antibiotic therapies administered through the respiratory system via inhalation, nebulization or aerosolization, specifically in patients with chronic respiratory diseases that include CF, non-CF bronchiectasis and NTM. However, further research is required to address the potential benefits, mechanisms of action and applications of inhaled antibiotics for the management of difficult-to-treat infections in patients with chronic respiratory diseases.

Genetic deficiency of GABA differentially regulates respiratory and non-respiratory motor neuron development.

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Matthew J Fogarty

Full Text Available Central nervous system GABAergic and glycinergic synaptic activity switches from postsynaptic excitation to inhibition during the stage when motor neuron numbers are being reduced, and when synaptic connections are being established onto and by motor neurons. In mice this occurs between embryonic (E day 13 and birth (postnatal day 0. Our previous work on mice lacking glycinergic transmission suggested that altered motor neuron activity levels correspondingly regulated motor neuron survival and muscle innervation for all respiratory and non respiratory motor neuron pools, during this period of development [1]. To determine if GABAergic transmission plays a similar role, we quantified motor neuron number and the extent of muscle innervation in four distinct regions of the brain stem and spinal cord; hypoglossal, phrenic, brachial and lumbar motor pools, in mice lacking the enzyme GAD67. These mice display a 90% drop in CNS GABA levels ( [2]; this study. For respiratory-based motor neurons (hypoglossal and phrenic motor pools, we have observed significant drops in motor neuron number (17% decline for hypoglossal and 23% decline for phrenic and muscle innervations (55% decrease. By contrast for non-respiratory motor neurons of the brachial lateral motor column, we have observed an increase in motor neuron number (43% increase and muscle innervations (99% increase; however for more caudally located motor neurons within the lumbar lateral motor column, we observed no change in either neuron number or muscle innervation. These results show in mice lacking physiological levels of GABA, there are distinct regional changes in motor neuron number and muscle innervation, which appear to be linked to their physiological function and to their rostral-caudal position within the developing spinal cord. Our results also suggest that for more caudal (lumbar regions of the spinal cord, the effect of GABA is less influential on motor neuron development compared to

Bovine respiratory syncytial virus : immunopathology and vaccine evaluation

NARCIS (Netherlands)

Antonis, A.F.G.

2010-01-01

Human and bovine RSVs cause severe disease in humans and in cattle respectively. They have been recognised as important respiratory pathogens in the last five decades, and this has resulted in significant research activities on the pathogenesis and intervention strategies around the world.

A Prospective One-Year Microbiologic Survey of Combined Pneumonia and Respiratory Failure.

Science.gov (United States)

Fisher, Kristen; Trupka, Tracy; Micek, Scott T; Juang, Paul; Kollef, Marin H

2017-10-01

Pneumonia and respiratory failure are common problems in the intensive care unit (ICU) setting, often occurring together. The relative prevalence of pneumonia types (community acquired, hospital acquired, ventilator associated) and causative pathogens is not well described in patients with respiratory failure. This was a prospective observational cohort study conducted in the medical ICU (34 beds) of Barnes-Jewish Hospital, an academic referral center of 1,300 beds from January 2016-December 2016. All patients who were prospectively adjudicated to have respiratory failure and pneumonia (RFP) regardless of pneumonia type were classified into one of four microbiologic categories: pathogen negative, antibiotic-susceptible pathogen (according to ceftriaxone susceptibility), antibiotic-resistant pathogen, and viruses. The primary outcomes assessed were the hospital mortality rate and inappropriate initial antibiotic therapy (IIAT) for non-viral pathogens. Among 364 consecutive patients with RFP, 63 (17.3%) had organisms that were antibiotic susceptible, 104 (28.6%) had antibiotic-resistant organisms, 118 (32.4%) were pathogen negative, and 79 (21.7%) had viral infections. For these categories, IIAT occurred in 3.2%, 21.2%, 0.8%, and 0, respectively (p < 0.001). Vasopressor-requiring shock was present in 61.9%, 72.1%, 68.6%, and 67.1%, respectively (p = 0.585), and the hospital mortality rates were 27.0%, 48.1%, 31.4%, and 36.7%, respectively (p = 0.020). Multivariable logistic regression analysis identified IIAT as an independent predictor of in-hospital death (adjusted odds ratio 5.28; 95% confidence interval 2.72-10.22; p = 0.012). Male gender, increasing Acute Physiology and Chronic Health Evaluation (APACHE) II scores, greater age, and the presence of shock also predicted death. Microbiologic categorization of patients with RFP suggests that antibiotic-resistant pathogens and viruses are associated with the highest mortality rates. Vasopressor

Targeting the Mitochondrial Respiratory Chain of Cryptococcus through Antifungal Chemosensitization: A Model for Control of Non-Fermentative Pathogens

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Kathleen L. Chan

2013-07-01

Full Text Available Enhanced control of species of Cryptococcus, non-fermentative yeast pathogens, was achieved by chemosensitization through co-application of certain compounds with a conventional antimicrobial drug. The species of Cryptococcus tested showed higher sensitivity to mitochondrial respiratory chain (MRC inhibition compared to species of Candida. This higher sensitivity results from the inability of Cryptococcus to generate cellular energy through fermentation. To heighten disruption of cellular MRC, octyl gallate (OG or 2,3-dihydroxybenzaldehyde (2,3-DHBA, phenolic compounds inhibiting mitochondrial functions, were selected as chemosensitizers to pyraclostrobin (PCS; an inhibitor of complex III of MRC. The cryptococci were more susceptible to the chemosensitization (i.e., PCS + OG or 2,3-DHBA than the Candida with all Cryptococcus strains tested being sensitive to this chemosensitization. Alternatively, only few of the Candida strains showed sensitivity. OG possessed higher chemosensitizing potency than 2,3-DHBA, where the concentration of OG required with the drug to achieve chemosensitizing synergism was much lower than that required of 2,3-DHBA. Bioassays with gene deletion mutants of the model yeast Saccharomyces cerevisiae showed that OG or 2,3-DHBA affect different cellular targets. These assays revealed mitochondrial superoxide dismutase or glutathione homeostasis plays a relatively greater role in fungal tolerance to 2,3-DHBA or OG, respectively. These findings show that application of chemosensitizing compounds that augment MRC debilitation is a promising strategy to antifungal control against yeast pathogens.

Design, development and experimental trialof a tailored cytotoxic T-cell vaccine againstPorcine Reproductive and RespiratorySyndrome Virus-2

DEFF Research Database (Denmark)

Welner, Simon

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important threats against the global swine production industry. The virus infects alveolar macrophages that leads to respiratory distress, fever, pneumonia and gives way to secondary respiratory pathogens. Infection...

Seasonal variations of respiratory viruses detected from children with respiratory tract infections in Riyadh, Saudi Arabia.

Science.gov (United States)

Albogami, Saad S; Alotaibi, Meshal R; Alsahli, Saud A; Masuadi, Emad; Alshaalan, Mohammad

ARTIs have a huge impact in health systems in which 20-30% of all hospital admissions and 30-60% of practitioner visits are related to respiratory tract infections. The aim of this study is to determine the prevalence, age distribution, and seasonal variation of respiratory viruses. This study was descriptive retrospective study in which all patients 14 years of age and below who presented with signs and symptoms of ARTIs between January 2013 and December 2014 and had respiratory specimen tested by direct immunofluorescence assays for viruses identification were included in the study. During that period, a total of 4611 patients who presented with ARTIs from January 2013 to December 2014 were investigated, viruses were detected in 1115 (24%). RSV was associated with 97.4% of the total viral pathogens. Viruses were detected throughout all the two years with a peak in winter; Dec (n: 265), Jan (n: 418), Feb (n: 218), and Mar (n: 109). Viral pathogens are very important cause of ARTIs in our region. RSV was the most common virus detected with the highest detection rate in children who are two years old and below. A multi-center surveillance with more sensitive detection methods like PCR may help to provide a comprehensive understanding of virus distribution in our area, which may contribute implant an effective prevention approach for each virus. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Childhood acute lower respiratory tract infections in Northern Nigeria

African Journals Online (AJOL)

2015-03-02

Mar 2, 2015 ... cause of childhood morbidity and deaths worldwide1, 2. Of the estimated 7.6 ... years of age with community-acquired pneumonia. (CAP) would require ..... mon respiratory pathogens, such as Haemophilus influ- enzae and ...

Scientific Opinion on the substantiation of a health claim related to Bifidobacterium bifidum CNCM I-3426 and defence against pathogens in the upper respiratory tract pursuant to Article 13(5) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

2015-01-01

Following an application from Lallemand Health Solutions, submitted pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of France, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation...... effect. The Panel considers that no conclusions can be drawn from either of the human studies for the scientific substantiation of the claim. In the absence of evidence of an effect of B. bifidum CNCM I3426 on defence against pathogens in the upper respiratory tract in humans, the results of the in vitro...... study submitted cannot be used as a source of data for the scientific substantiation of the claim. The Panel concludes that a cause and effect relationship has not been established between the consumption of B. bifidum CNCM I-3426 and defence against pathogens in the upper respiratory tract....

Direct bacterial loop-mediated isothermal amplification detection on the pathogenic features of the nosocomial pathogen - Methicillin resistant Staphylococcus aureus strains with respiratory origins.

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Lin, Qun; Xu, Pusheng; Li, Jiaowu; Chen, Yin; Feng, Jieyi

2017-08-01

Loop-mediated isothermal amplification based detection assays using bacterial culture or colony for direct detection of methicillin resistant Staphylococcus aureus(MRSA) had been developed and evaluated, followed by its extensive application on a large scale of clinical MRSA isolated from respiratory origins, including nasal swabs and sputums. Six primers, including outer primers, inner primers and loop primers, were specifically designed for recognizing eight distinct sequences on four targets: 16SrRNA, femA, mecA and orfX. Twenty-seven reference strains were used to develop, evaluate and optimize this assay. Then, a total of 532 clinical MRSA isolates were employed for each detected targets. And the results were determined through both visual observation of the color change by naked eye and electrophoresis. The specific of each primer had been confirmed, and the optimal amplification was obtained under 65 °C for 40 min. The limit of detections (LOD) of bacteria culture LAMP assays were determined to be 10 4  CFU/ml for 16S rRNA, femA, as well as orfX and 10 5  CFU/ml for mecA, respectively. The established novel assays on MRSA detection may provide new strategies for rapid detection of foodborne pathogens. Copyright © 2017. Published by Elsevier Ltd.

Can antibodies against flies alter malaria transmission in birds by changing vector behavior?

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Ghosh, Suma; Waite, Jessica L; Clayton, Dale H; Adler, Frederick R

2014-10-07

Transmission of insect-borne diseases is shaped by the interactions among parasites, vectors, and hosts. Any factor that alters movement of infected vectors from infected to uninfeced hosts will in turn alter pathogen spread. In this paper, we study one such pathogen-vector-host system, avian malaria in pigeons transmitted by fly ectoparasites, where both two-way and three-way interactions play a key role in shaping disease spread. Bird immune defenses against flies can decrease malaria prevalence by reducing fly residence time on infected birds or increase disease prevalence by enhancing fly movement and thus infection transmission. We develop a mathematical model that illustrates how these changes in vector behavior influence pathogen transmission and show that malaria prevalence is maximized at an intermediate level of defense avoidance by the flies. Understanding how host immune defenses indirectly alter disease transmission by influencing vector behavior has implications for reducing the transmission of human malaria and other vectored pathogens. Published by Elsevier Ltd.

The onset of virus shedding and clinical signs in chickens infected with high-pathogenicity and low-pathogenicity avian influenza viruses.

Science.gov (United States)

Spickler, Anna R; Trampel, Darrell W; Roth, James A

2008-12-01

Some avian influenza viruses may be transmissible to mammals by ingestion. Cats and dogs have been infected by H5N1 avian influenza viruses when they ate raw poultry, and two human H5N1 infections were linked to the ingestion of uncooked duck blood. The possibility of zoonotic influenza from exposure to raw poultry products raises concerns about flocks with unrecognized infections. The present review examines the onset of virus shedding and the development of clinical signs for a variety of avian influenza viruses in chickens. In experimentally infected birds, some high-pathogenicity avian influenza (HPAI) and low-pathogenicity avian influenza (LPAI) viruses can occur in faeces and respiratory secretions as early as 1 to 2 days after inoculation. Some HPAI viruses have also been found in meat 1 day after inoculation and in eggs after 3 days. There is no evidence that LPAI viruses can be found in meat, and the risk of their occurrence in eggs is poorly understood. Studies in experimentally infected birds suggest that clinical signs usually develop within a few days of virus shedding; however, some models and outbreak descriptions suggest that clinical signs may not become evident for a week or more in some H5 or H7 HPAI-infected flocks. During this time, avian influenza viruses might be found in poultry products. LPAI viruses can be shed in asymptomatically infected or minimally affected flocks, but these viruses are unlikely to cause significant human disease.

Effect of cleaning and disinfection of toys on infectious diseases and micro-organisms in daycare nurseries

DEFF Research Database (Denmark)

Ibfelt, T.; Engelund, E. H.; Schultz, Anna Charlotte

2015-01-01

Background: The rising number of children in daycare nurseries increases opportunities for the transmission of infectious diseases. Pathogens may be transmitted directly from child to child via sneezing, coughing and touching, or indirectly via the environment. Toys are among the fomites with the......Background: The rising number of children in daycare nurseries increases opportunities for the transmission of infectious diseases. Pathogens may be transmitted directly from child to child via sneezing, coughing and touching, or indirectly via the environment. Toys are among the fomites...... with the highest pathogen load, but their role in disease transmission is unknown. Aim: To determine if washing and disinfection of toys can reduce sickness absence and microbial pathogen load in the nursery environment. Methods: Twelve nurseries (caring for 587 children) were randomized to intervention...... sampling points in each nursery were examined for bacteria and respiratory viruses. Results: The presence of respiratory virus DNA/RNA was widespread, but very few pathogenic bacteria were found in the environment. The intervention reduced the presence of adenovirus [odds ratio (OR) 2.4, 95% confidence...

Respiratory tract infection during Hajj

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Alzeer Abdulaziz

2009-01-01

Full Text Available Respiratory tract infection during Hajj (pilgrimage to Mecca is a common illness, and it is responsible for most of the hospital admissions. Influenza virus is the leading cause of upper respiratory tract infection during Hajj, and pneumonia can be serious. Taking into account the close contacts among the pilgrims, as well as the crowding, the potential for transmission of M. tuberculosis is expected to be high. These pilgrims can be a source for spreading infection on their return home. Although vaccination program for influenza is implemented, its efficacy is uncertain in this religious season. Future studies should concentrate on prevention and mitigation of these infections.

Cross host transmission in the emergence of MERS coronavirus

NARCIS (Netherlands)

C.B.E.M. Reusken (Chantal); V.S. Raj (Stalin); M.P.G. Koopmans D.V.M. (Marion); B.L. Haagmans (Bart)

2016-01-01

textabstractCoronaviruses (CoVs) able to infect humans emerge through cross-host transmission from animals. There is substantial evidence that the recent Middle East respiratory syndrome (MERS)-CoV outbreak is fueled by zoonotic transmission from dromedary camels. This is largely based on the fact

Chlamydiae in febrile children with respiratory tract symptoms and age-matched controls, Ghana

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H. Bühl

2018-03-01

Full Text Available Members of the Chlamydiales order are obligate intracellular pathogens causing acute and chronic infectious diseases. Chlamydiaceae are established agents of community- and zoonotically acquired respiratory tract infections, and emerging pathogens among the Chlamydia-related bacteria have been implicated in airway infections. The role of both in airway infections in Africa is underexplored. We performed a case -control study on the prevalence of Chlamydiaceae and Chlamydia-related emerging pathogens in children with febrile respiratory tract infections in West Africa, Ghana. Using a pan-Chlamydiales broad-range real-time PCR, we detected chlamydial DNA in 11 (1.9% of 572 hospitalized febrile children with respiratory tract symptoms and in 24 (4.3% of 560 asymptomatic age-matched controls (p 0.03. Chlamydiaceae were found to be common among both symptomatic and healthy Ghanaian children, with Chlamydia pneumoniae being the most prevalent species. Parachlamydiaceae were detected in two children without symptoms but not in the symptomatic group. We identified neither Chlamydia psittaci nor Simkania negevensis but a member of a new chlamydial family that shared 90.2% sequence identity with the 16S rRNA gene of the zoonotic pathogen Chlamydia pecorum. In addition, we found a new Chlamydia-related species that belonged to a novel family sharing 91.3% 16S rRNA sequence identity with Candidatus Syngnamydia venezia. The prevalence and spectrum of chlamydial species differed from previous results obtained from children of other geographic regions and our study indicates that both, Chlamydiaceae and Chlamydia-related bacteria, are not clearly linked to clinical symptoms in Ghanaian children. Keywords: Children, Chlamydia, Chlamydia-related bacteria, febrile respiratory tract infection, Ghana

Discovery of a divergent HPIV4 from respiratory secretions using second and third generation metagenomic sequencing

DEFF Research Database (Denmark)

Alquezar Planas, David Eugenio; Mourier, Tobias; Bruhn, Christian Anders Wathne

2013-01-01

Molecular detection of viruses has been aided by high-throughput sequencing, permitting the genomic characterization of emerging strains. In this study, we comprehensively screened 500 respiratory secretions from children with upper and/or lower respiratory tract infections for viral pathogens. T...

Human to human transmission of arthropod-borne pathogens

NARCIS (Netherlands)

Martina, B.E.; Barzon, L.; Pijlman, G.P.; Fuente, J. de la; Rizzoli, A.; Wammes, L.J.; Takken, W.; Rij, R.P. van; Papa, A.

2017-01-01

Human-to-human (H2H) transmitted arthropod-borne pathogens are a growing burden worldwide, with malaria and dengue being the most common mosquito-borne H2H transmitted diseases. The ability of vectors to get infected by humans during a blood meal to further propel an epidemic depends on complex

Spectrum and potency of ceftaroline against leading pathogens causing community-acquired respiratory tract and skin and soft tissue infections in Latin America, 2010

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Robert K. Flamm

Full Text Available Ceftaroline, the active metabolite of the prodrug ceftaroline fosamil, is a cephalosporin with in vitro bactericidal activity against Gram-positive organisms, including methicillinsusceptible and -resistant Staphylococcus aureus, β-haemolytic and viridans group streptococci, and Streptococcus pneumoniae, as well as common Gram-negative organisms. In this study a total of 986 isolates collected in 2010 from patients in 15 medical centers in five Latin American countries from the Assessing Worldwide Antimicrobial Resistance Evaluation Program were identified as community-acquired respiratory tract or skin and soft tissue infection pathogens. Ceftaroline was the most potent agent tested against S. pneumoniae with a MIC90 value (0.12 µg/mL that was eight-fold lower than ceftriaxone, levofloxacin, and linezolid. Its spectrum of coverage (100.0% susceptible was similar to tigecycline, linezolid, levofloxacin and vancomycin. Against Haemophilus influenzae and Moraxella catarrhalis, ceftaroline was the most active agent tested. The activity of ceftaroline against S. aureus (including MRSA was similar to that of vancomycin and tetracycline (MIC90,1 µg/mL and linezolid (MIC90,2 Jg/mL. The 1-haemolytic streptococci exhibited 100.0% susceptibility to ceftaroline. Ceftaroline activity against Escherichia coli, Klebsiella spp., and Enterobacter spp. was similar to that of ceftriaxone and ceftazidime. These parenteral cephalosporin agents have potent activity against non-extended-spectrum These parenteral cephalosporin agents have potent activity against non-extended-spectrum-lactamase-phenotype strains, but are not active against extended-spectrum β-lactamase-phenotype strains. These results confirm the in vitro activity of ceftaroline against pathogens common in communityacquired respiratory tract and skin and soft tissue infection in Latin America, and suggest that ceftaroline fosamil could be an important therapeutic option for these infections.

Human to human transmission of arthropod-borne pathogens

NARCIS (Netherlands)

Martina, Byron E.; Barzon, Luisa; Pijlman, Gorben P.; Fuente, de la José; Rizzoli, Annapaola; Wammes, Linda J.; Takken, Willem; Rij, van Ronald P.; Papa, Anna

2017-01-01

Human-to-human (H2H) transmitted arthropod-borne pathogens are a growing burden worldwide, with malaria and dengue being the most common mosquito-borne H2H transmitted diseases. The ability of vectors to get infected by humans during a blood meal to further propel an epidemic depends on complex

Modes of transmission of influenza B virus in households.

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Benjamin J Cowling

Full Text Available While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei "aerosols" in transmission is controversial.In Hong Kong and Bangkok, in 2008-11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a positive rapid influenza diagnostic test result, subjects were randomly allocated to one of three household-based interventions: hand hygiene, hand hygiene plus face masks, and a control group. Index cases plus their household contacts were followed for 7-10 days to identify secondary infections by reverse transcription polymerase chain reaction (RT-PCR testing of respiratory specimens. Index cases with RT-PCR-confirmed influenza B were included in the present analyses. We used a mathematical model to make inferences on the modes of transmission, facilitated by apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We estimated that approximately 37% and 26% of influenza B virus transmission was via the aerosol mode in households in Hong Kong and Bangkok, respectively. In the fitted model, influenza B virus infections were associated with a 56%-72% risk of fever plus cough if infected via aerosol route, and a 23%-31% risk of fever plus cough if infected via the other two modes of transmission.Aerosol transmission may be an important mode of spread of influenza B virus. The point estimates of aerosol transmission were slightly lower for influenza B virus compared to previously published estimates for influenza A virus in both Hong Kong and Bangkok. Caution should be taken in interpreting these findings because of the multiple assumptions inherent in the model, including that there is limited biological evidence to date supporting a difference in the clinical features of influenza B virus infection by different modes.

Pathogen-avoidance mechanisms and the stigmatization of obese people

NARCIS (Netherlands)

Park, Justin H.; Schaller, Mark; Crandall, Christian S.

2007-01-01

Humans possess pathogen-avoidance mechanisms that respond to the visual perception of morphological anomalies in others. We investigated whether obesity may trigger these mechanisms. Study I revealed that people who are chronically concerned about pathogen transmission have more negative attitudes

Identifying the age cohort responsible for transmission in a natural outbreak of Bordetella bronchiseptica.

Directory of Open Access Journals (Sweden)

Gráinne H Long

2010-12-01

Full Text Available Identifying the major routes of disease transmission and reservoirs of infection are needed to increase our understanding of disease dynamics and improve disease control. Despite this, transmission events are rarely observed directly. Here we had the unique opportunity to study natural transmission of Bordetella bronchiseptica--a directly transmitted respiratory pathogen with a wide mammalian host range, including sporadic infection of humans--within a commercial rabbitry to evaluate the relative effects of sex and age on the transmission dynamics therein. We did this by developing an a priori set of hypotheses outlining how natural B. bronchiseptica infections may be transmitted between rabbits. We discriminated between these hypotheses by using force-of-infection estimates coupled with random effects binomial regression analysis of B. bronchiseptica age-prevalence data from within our rabbit population. Force-of-infection analysis allowed us to quantify the apparent prevalence of B. bronchiseptica while correcting for age structure. To determine whether transmission is largely within social groups (in this case litter, or from an external group, we used random-effect binomial regression to evaluate the importance of social mixing in disease spread. Between these two approaches our results support young weanlings--as opposed to, for example, breeder or maternal cohorts--as the age cohort primarily responsible for B. bronchiseptica transmission. Thus age-prevalence data, which is relatively easy to gather in clinical or agricultural settings, can be used to evaluate contact patterns and infer the likely age-cohort responsible for transmission of directly transmitted infections. These insights shed light on the dynamics of disease spread and allow an assessment to be made of the best methods for effective long-term disease control.

Clinical and epidemiological predictors of transmission in Severe Acute Respiratory Syndrome (SARS

Directory of Open Access Journals (Sweden)

Leong Hoe

2006-10-01

Full Text Available Abstract Background Only a minority of probable SARS cases caused transmission. We assess if any epidemiological or clinical factors in SARS index patients were associated with increased probability of transmission. Methods We used epidemiological and clinical data on probable SARS patients admitted to Tan Tock Seng Hospital. Using a case-control approach, index patients who had probable SARS who subsequently transmitted the disease to at least one other patient were analysed as "cases" against patients with no transmission as "controls", using multivariate logistic regression analysis. Results 98 index patients were available for analysis (22 with transmission, 76 with no transmission. Covariates positively associated with transmission in univariate analysis at p 650 IU/L (OR 6.4, 23.8 and 4.7 respectively. Conclusion Clinical and epidemiological factors can help us to explain why transmission was observed in some instances but not in others.

Advanced Role of Neutrophils in Common Respiratory Diseases

Directory of Open Access Journals (Sweden)

Jinping Liu

2017-01-01

Full Text Available Respiratory diseases, always being a threat towards the health of people all over the world, are most tightly associated with immune system. Neutrophils serve as an important component of immune defense barrier linking innate and adaptive immunity. They participate in the clearance of exogenous pathogens and endogenous cell debris and play an essential role in the pathogenesis of many respiratory diseases. However, the pathological mechanism of neutrophils remains complex and obscure. The traditional roles of neutrophils in severe asthma, chronic obstructive pulmonary diseases (COPD, pneumonia, lung cancer, pulmonary fibrosis, bronchitis, and bronchiolitis had already been reviewed. With the development of scientific research, the involvement of neutrophils in respiratory diseases is being brought to light with emerging data on neutrophil subsets, trafficking, and cell death mechanism (e.g., NETosis, apoptosis in diseases. We reviewed all these recent studies here to provide you with the latest advances about the role of neutrophils in respiratory diseases.

Design and methods of a social network isolation study for reducing respiratory infection transmission: The eX-FLU cluster randomized trial.

Science.gov (United States)

Aiello, Allison E; Simanek, Amanda M; Eisenberg, Marisa C; Walsh, Alison R; Davis, Brian; Volz, Erik; Cheng, Caroline; Rainey, Jeanette J; Uzicanin, Amra; Gao, Hongjiang; Osgood, Nathaniel; Knowles, Dylan; Stanley, Kevin; Tarter, Kara; Monto, Arnold S

2016-06-01

Social networks are increasingly recognized as important points of intervention, yet relatively few intervention studies of respiratory infection transmission have utilized a network design. Here we describe the design, methods, and social network structure of a randomized intervention for isolating respiratory infection cases in a university setting over a 10-week period. 590 students in six residence halls enrolled in the eX-FLU study during a chain-referral recruitment process from September 2012-January 2013. Of these, 262 joined as "seed" participants, who nominated their social contacts to join the study, of which 328 "nominees" enrolled. Participants were cluster-randomized by 117 residence halls. Participants were asked to respond to weekly surveys on health behaviors, social interactions, and influenza-like illness (ILI) symptoms. Participants were randomized to either a 3-Day dorm room isolation intervention or a control group (no isolation) upon illness onset. ILI cases reported on their isolation behavior during illness and provided throat and nasal swab specimens at onset, day-three, and day-six of illness. A subsample of individuals (N=103) participated in a sub-study using a novel smartphone application, iEpi, which collected sensor and contextually-dependent survey data on social interactions. Within the social network, participants were significantly positively assortative by intervention group, enrollment type, residence hall, iEpi participation, age, gender, race, and alcohol use (all Pisolation from social networks in a university setting. These data provide an unparalleled opportunity to address questions about isolation and infection transmission, as well as insights into social networks and behaviors among college-aged students. Several important lessons were learned over the course of this project, including feasible isolation durations, the need for extensive organizational efforts, as well as the need for specialized programmers and server

Inferring epidemiologic dynamics from viral evolution: 2014–2015 Eurasian/North American highly pathogenic avian influenza viruses exceed transmission threshold, R0 = 1, in wild birds and poultry in North America

Science.gov (United States)

Grear, Daniel R.; Hall, Jeffrey S.; Dusek, Robert; Ip, Hon S.

2018-01-01

Highly pathogenic avian influenza virus (HPAIV) is a multihost pathogen with lineages that pose health risks for domestic birds, wild birds, and humans. One mechanism of intercontinental HPAIV spread is through wild bird reservoirs, and wild birds were the likely sources of a Eurasian (EA) lineage HPAIV into North America in 2014. The introduction resulted in several reassortment events with North American (NA) lineage low-pathogenic avian influenza viruses and the reassortant EA/NA H5N2 went on to cause one of the largest HPAIV poultry outbreaks in North America. We evaluated three hypotheses about novel HPAIV introduced into wild and domestic bird hosts: (i) transmission of novel HPAIVs in wild birds was restricted by mechanisms associated with highly pathogenic phenotypes; (ii) the HPAIV poultry outbreak was not self-sustaining and required viral input from wild birds; and (iii) reassortment of the EA H5N8 generated reassortant EA/NA AIVs with a fitness advantage over fully Eurasian lineages in North American wild birds. We used a time-rooted phylodynamic model that explicitly incorporated viral population dynamics with evolutionary dynamics to estimate the basic reproductive number (R0) and viral migration among host types in domestic and wild birds, as well as between the EA H5N8 and EA/NA H5N2 in wild birds. We did not find evidence to support hypothesis (i) or (ii) as our estimates of the transmission parameters suggested that the HPAIV outbreak met or exceeded the threshold for persistence in wild birds (R0 > 1) and poultry (R0 ≈ 1) with minimal estimated transmission among host types. There was also no evidence to support hypothesis (iii) because R0 values were similar among EA H5N8 and EA/NA H5N2 in wild birds. Our results suggest that this novel HPAIV and reassortments did not encounter any transmission barriers sufficient to prevent persistence when introduced to wild or domestic birds.

Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses

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Domann Eugen

2011-02-01

Full Text Available Abstract Background Black elderberries (Sambucus nigra L. are well known as supportive agents against common cold and influenza. It is further known that bacterial super-infection during an influenza virus (IV infection can lead to severe pneumonia. We have analyzed a standardized elderberry extract (Rubini, BerryPharma AG for its antimicrobial and antiviral activity using the microtitre broth micro-dilution assay against three Gram-positive bacteria and one Gram-negative bacteria responsible for infections of the upper respiratory tract, as well as cell culture experiments for two different strains of influenza virus. Methods The antimicrobial activity of the elderberry extract was determined by bacterial growth experiments in liquid cultures using the extract at concentrations of 5%, 10%, 15% and 20%. The inhibitory effects were determined by plating the bacteria on agar plates. In addition, the inhibitory potential of the extract on the propagation of human pathogenic H5N1-type influenza A virus isolated from a patient and an influenza B virus strain was investigated using MTT and focus assays. Results For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria of Streptococcus pyogenes and group C and G Streptococci, and the Gram-negative bacterium Branhamella catarrhalis in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses. Conclusion Rubini elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses. The activities shown suggest that additional and alternative approaches to combat infections might be provided by this natural product.

Trends in admissions for acute respiratory infections in children: an inter-country comparison between Western Australia and England

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Hannah Moore

2017-04-01

The availability of similar datasets in two economically similar countries in different hemispheres has afforded the opportunity to characterise and compare the epidemiology of paediatric respiratory infections over a 13 year period. Future analyses will allow us to assess differences in coding practices, seasonality and risk factors such as socio-economic deprivation and prematurity. Furthermore the availability of linked laboratory data for respiratory pathogens in each jurisdiction will allow for comparisons of pathogen-specific epidemiology and the impact of universal vaccination programs.

Simultaneous detection of respiratory syncytial virus types A and B ...

African Journals Online (AJOL)

... A and B and influenza virus types A and B in community-acquired pneumonia by ... It is impossible to distinguish the cause of viral respiratory infections by their ... and pathogen-specific technique of multiplex RT-PCR in order to accomplish ...

Reliable typing of MERS-CoV variants with a small genome fragment

NARCIS (Netherlands)

S.L. Smits (Saskia); V.S. Raj (Stalin); S.D. Pas (Suzan); C.B.E.M. Reusken (Chantal); K.A. Mohran (Khaled A.); E. Farag (Elmoubasher); H.E. Al Romaihi (Hamad); M.M. AlHajri (Mohd); B.L. Haagmans (Bart); M.P.G. Koopmans D.V.M. (Marion)

2015-01-01

textabstractBackground: Middle East Respiratory Syndrome coronavirus (. MERS-CoV) is an emerging pathogen that causes lower respiratory tract infection in humans. Camels are the likely animal source for zoonotic infection, although exact transmission modes remain to be determined. Human-to-human

Excretion patterns of human metapneumovirus and respiratory syncytial virus among young children

DEFF Research Database (Denmark)

von Linstow, Marie-Louise; Eugen-Olsen, Jesper; Koch, A

2006-01-01

of the infected children showed to have an upper respiratory tract infection when following up. CONCLUSION: Viral RNA was present in nasal secretions, saliva, sweat, and faeces, but whether or not the virions were infectious and constitute a potential mode of transmission remains to be shown in future studies.......BACKGROUND: As respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause serious respiratory tract infections, the routes of transmission of these viruses are important to elucidate. We examined the modes of virus shedding and shedding duration of RSV and hMPV in young children....... METHODS: From each child in a group of 44 children (37 RSV-positive, 6 hMPV-positive, and 1 co-infected child), aged between 0.5-38 months, hospitalised at Hvidovre Hospital, Copenhagen, Denmark, one nasopharyngeal aspirate (NPA), saliva, urine, and faeces sample were collected at inclusion and weekly...

The potential role of migratory birds in the transmission of zoonoses

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Vasilios Tsiouris

2008-12-01

Full Text Available The instinct for survival leads migratory birds to exploit seasonal opportunities for breeding habitats and food supplies. Consequently, they travel across national and international borders. These birds are distinguished in local migrants, short-distance, long-distance and vagrant and nomadic migrants. They can transfer micro-organisms across the globe and play a significant role in the ecology and circulation of pathogenic organisms. They are implicated in the transmission of zoonoses as biological and mechanical carriers and as hosts and carriers of infected ectoparasites. They can cause water-borne, tick-borne and insect-borne diseases. Favourable agents, such as seasonality and stress due to migration, influence the transmission of pathogens. The migration of birds is a natural phenomenon that is followed by the unavoidable repercussions of the participation of these birds as carriers or hosts in the transmission of pathogens. It is not possible to interrupt this sequence but risks can be minimised by controlling and preventing perilous situations. Surveillance of wetlands, ‘stopovers’, places of destination and wintering regions can be done. Furthermore, the implementation strict biosecurity measures that reduce contact with migratory birds will limit the transmission of pathogens.

Clinical and virological factors associated with gastrointestinal symptoms in patients with acute respiratory infection: a two-year prospective study in general practice medicine.

Science.gov (United States)

Minodier, Laetitia; Masse, Shirley; Capai, Lisandru; Blanchon, Thierry; Ceccaldi, Pierre-Emmanuel; van der Werf, Sylvie; Hanslik, Thomas; Charrel, Remi; Falchi, Alessandra

2017-11-22

Gastrointestinal (GI) symptoms, such as diarrhea, vomiting, abdominal pain and nausea are not an uncommon manifestation of an acute respiratory infection (ARI). We therefore evaluated clinical and microbiological factors associated with the presence of GI symptoms in patients consulting a general practitioner (GP) for ARI. Nasopharyngeal swabs, stool specimens and clinical data from patients presenting to GPs with an ARI were prospectively collected during two winter seasons (2014-2016). Samples were tested by quantitative real-time PCR for 12 respiratory pathogen groups and for 12 enteric pathogens. Two hundred and four of 331 included patients (61.6%) were positive for at least one respiratory pathogen. Sixty-nine stools (20.8%) were positive for at least one pathogen (respiratory and/or enteric). GI symptoms were more likely declared in case of laboratory confirmed-enteric infection (adjusted odds ratio (aOR) = 3.2; 95% confidence interval [CI] [1.2-9.9]; p = 0.02) or human coronavirus (HCoV) infection (aOR = 2.7; [1.2-6.8]; p = 0.02). Consumption of antipyretic medication before the consultation seemed to reduce the risk of developing GI symptoms for patients with laboratory-confirmed influenza (aOR = 0.3; [0.1-0.6]; p = 0.002). The presence of GI symptoms in ARI patients could not be explained by the detection of respiratory pathogens in stools. However, the detection of enteric pathogens in stool samples could explained by the presence of GI symptoms in some of ARI cases. The biological mechanisms explaining the association between the presence of HCoVs in nasopharynx and GI symptoms need to be explored.

Immunomodulatory role for membrane vesicles released by THP-1 macrophages and respiratory pathogens during macrophage infection.

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Volgers, Charlotte; Benedikter, Birke J; Grauls, Gert E; Savelkoul, Paul H M; Stassen, Frank R M

2017-11-13

During infection, inflammation is partially driven by the release of mediators which facilitate intercellular communication. Amongst these mediators are small membrane vesicles (MVs) that can be released by both host cells and Gram-negative and -positive bacteria. Bacterial membrane vesicles are known to exert immuno-modulatory and -stimulatory actions. Moreover, it has been proposed that host cell-derived vesicles, released during infection, also have immunostimulatory properties. In this study, we assessed the release and activity of host cell-derived and bacterial MVs during the first hours following infection of THP-1 macrophages with the common respiratory pathogens non-typeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Using a combination of flow cytometry, tunable resistive pulse sensing (TRPS)-based analysis and electron microscopy, we demonstrated that the release of MVs occurs by both host cells and bacteria during infection. MVs released during infection and bacterial culture were found to induce a strong pro-inflammatory response by naive THP-1 macrophages. Yet, these MVs were also found to induce tolerance of host cells to secondary immunogenic stimuli and to enhance bacterial adherence and the number of intracellular bacteria. Bacterial MVs may play a dual role during infection, as they can both trigger and dampen immune responses thereby contributing to immune defence and bacterial survival.

Group A Rotaviruses in Chinese Bats: Genetic Composition, Serology, and Evidence for Bat-to-Human Transmission and Reassortment.

Science.gov (United States)

He, Biao; Huang, Xiaohong; Zhang, Fuqiang; Tan, Weilong; Matthijnssens, Jelle; Qin, Shaomin; Xu, Lin; Zhao, Zihan; Yang, Ling'en; Wang, Quanxi; Hu, Tingsong; Bao, Xiaolei; Wu, Jianmin; Tu, Changchun

2017-06-15

Bats are natural reservoirs for many pathogenic viruses, and increasing evidence supports the notion that bats can also harbor group A rotaviruses (RVAs), important causative agents of diarrhea in children and young animals. Currently, 8 RVA strains possessing completely novel genotype constellations or genotypes possibly originating from other mammals have been identified from African and Chinese bats. However, all the data were mainly based on detection of RVA RNA, present only during acute infections, which does not permit assessment of the true exposure of a bat population to RVA. To systematically investigate the genetic diversity of RVAs, 547 bat anal swabs or gut samples along with 448 bat sera were collected from five South Chinese provinces. Specific reverse transcription-PCR (RT-PCR) screening found four RVA strains. Strain GLRL1 possessed a completely novel genotype constellation, whereas the other three possessed a constellation consistent with the MSLH14-like genotype, a newly characterized group of viruses widely prevalent in Chinese insectivorous bats. Among the latter, strain LZHP2 provided strong evidence of cross-species transmission of RVAs from bats to humans, whereas strains YSSK5 and BSTM70 were likely reassortants between typical MSLH14-like RVAs and human RVAs. RVA-specific antibodies were detected in 10.7% (48/448) of bat sera by an indirect immunofluorescence assay (IIFA). Bats in Guangxi and Yunnan had a higher RVA-specific antibody prevalence than those from Fujian and Zhejiang provinces. These observations provide evidence for cross-species transmission of MSLH14-like bat RVAs to humans, highlighting the impact of bats as reservoirs of RVAs on public health. IMPORTANCE Bat viruses, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Ebola, Hendra, and Nipah viruses, are important pathogens causing outbreaks of severe emerging infectious diseases. However, little is known about bat viruses capable

Pathogen dynamics in a partial migrant : Interactions between mallards (Anas platyrhynchos) and avian influenza viruses

NARCIS (Netherlands)

Dijk, J.G.B. van

2014-01-01

Zoonotic pathogens may pose a serious threat for humans, requiring a better understanding of the ecology and transmission of these pathogens in their natural (wildlife) hosts. The zoonotic pathogen studied in this thesis is low pathogenic avian influenza virus (LPAIV). This pathogen circulates

Comparative pathology of chickens experimentally inoculated with avian influenza viruses of low and high pathogenicity.

Science.gov (United States)

Mo, I P; Brugh, M; Fletcher, O J; Rowland, G N; Swayne, D E

1997-01-01

Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen-free chickens inoculated intratracheally with avian influenza virus (AIV) isolates of either low or high pathogenicity. Viruses of low pathogenicity, previously characterized as mildly pathogenic (MP), included A/chicken/Pennsylvania/21525/83 (H5N2) (MP-Penn) and A/chicken/Alabama/7395/75 (H4N8) (MP-Alab). Viruses of high pathogenicity included A/chicken/Pennsylvania/1370/83 (H5N2), A/chicken/Victoria/A185/85 (H7N7), and A/turkey/Ontario/7732/66 (H5N9). Extremely variable clinical signs ranging from mild respiratory distress to high mortality were present among chickens inoculated with these viruses. Chickens inoculated with highly pathogenic (HP) virus had histologic lesions of necrosis and inflammation in cloacal bursa, thymus, spleen, heart, pancreas, kidney, brain, trachea, lung, and skeletal muscle, whereas chickens inoculated with MP virus had histologic lesions most frequently in lung and trachea or lacked histologic lesions. Immunospecific staining for avian influenza viral proteins was most common in cells within heart, lung, kidney, brain, and pancreas of chicken inoculated with HP viruses, but immunospecific staining was present only and infrequently in trachea and lung of chickens inoculated with MP-Penn AIV. MP-Alab did not produce lesions nor have viral antigen in inoculated chickens but did produce serologic evidence of infection. The pattern of organ involvement and viral antigen distribution in chickens intratracheally inoculated with HP AIV isolates indicates a common capability to spread beyond the respiratory tract and confirms the pantrophic replicative, pathobiologic, and lethal nature of the viruses. However, variability in severity and lesion distribution exists between different HP AIVs. By contrast, MP viruses had the ability to replicate in respiratory or enteric tracts or both and produce lesions

Experimental investigation of alternative transmission functions: Quantitative evidence for the importance of nonlinear transmission dynamics in host-parasite systems.

Science.gov (United States)

Orlofske, Sarah A; Flaxman, Samuel M; Joseph, Maxwell B; Fenton, Andy; Melbourne, Brett A; Johnson, Pieter T J

2018-05-01

Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms. To differentiate among 10 candidate transmission functions, we used a novel experimental design in which we independently varied four factors-duration of exposure, numbers of parasites, numbers of hosts and parasite density-in laboratory infection experiments. We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anaesthesia addressed the effects of host behaviour on transmission form. Across all experiments, nonlinear transmission forms involving either a power law or a negative binomial function were the best-fitting models and consistently outperformed the linear density-dependent and density-independent functions. By testing previously published data for two other host-macroparasite systems, we also found support for the same nonlinear transmission forms. Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across host-pathogen systems, nonlinear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Grepafloxacin Clinical Program for Lower Respiratory Tract Infections

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Arne C Rodloff

1998-01-01

Full Text Available The present paper evaluates the clinical trial program in lower respiratory tract infections treated with a new fluoroquinolone antibiotic, grepafloxacin. Unlike older quinolones, grepafloxacin has excellent activity against Gram-positive organisms, which include Streptococcus pneumoniae and “atypical” pathogens Legionella species. Mycoplasma pneumoniae and Chlamydia pneumoniae. Grepafloxacin has a long half-life of 12 to 15 h, which allows once daily dosing. Six studies have been conducted regarding community-acquired lower respiratory tract infections (LRTls, four about community-acquired pneumonia (CAP and two about acute bacterial exacerbations of chronic bronchitis (ABECB . In these studies, grepafloxacin demonstrated clinical equivalence with standard therapies. but, in patients with documented infections. grepafloxacin was statistically superior to amoxycillin in both CAP and ABECB. The new fluoroquinolone has a good safety profile, comparable with that of ciprofloxacin. The most common adverse effects of grepafloxacin were nausea and a metallic taste; however, these effects resulted in only a few discontinuations of therapy. With the increasing prevalence of resistance in pathogens isolated from community-acquired LRTIs, grepafloxacin offers a good alternative for monotherapy in these patients.

Local induction of IgT responses to pathogens and microbiota in the gill of rainbow trout

DEFF Research Database (Denmark)

Xu, Zhen; Parra, David; Takizawa, Fumio

Gas exchange structures are critical for acquiring oxygen, but hey also represent portals for pathogen entry. Local mucosal immunoglobulin (Ig) responses against pathogens in specialized respiratory organshave only been described in tetrapods. We have previously shown that IgT is an Ig specialize...

NORMAL NASOPHARYNGEAL MICROFLORA AS A RESERVOIR OF MULTIRESISTANT STRAINS OF UPPER RESPIRATORY TRACT INFECTIONS

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Minukhin V.V.

2015-05-01

Full Text Available Nasopharinheal carriage of bacteria may play a central role in the development and spread of respiratory infections. In addition, so-called "healthy" carriage is often transformed under the influence of various factors into an active infection.It is necessary to take into account not only the range of possible pathogens, but also trends in the development of antibiotic resistance of leading etiologic agents while choosing tactics of antimicrobial therapy. The investigation was designed to study the role of normal microflora of the nasopharynx as a reservoir of resistant strains of respiratory infections. Materials and Methods. Fifty three healthy individuals and 168 patients with acute upper respiratory tract infections who had been treated in CEHC "Kharkiv Municipal Clinical Hospital № 30" were examined. Microbiological study included isolation and identification of pathogens in accordance with the Order of the Ministry of Health Care № 535 from 22.04.1985., determination of the sensitivity of microorganisms to antibiotics by diffusion method according to the Order of the Ministry of Health Care of Ukraine № 167 from 05.04.2007. Results and discussion. Bacteriological study of nasal swabs of healthy people showed that the composition of the microflora of the nasopharynx contained potentially pathogenic microorganisms. Among the isolated microorganisms essential place was occupied by S. epidermidis and S. aureus, both in monoculture and association. Epidermal staphylococcus was isolated in 36 % and Staphylococcus aureus in 27% of cases. Pneumococcus and hemolytic streptococcus of group A were isolated in 23 and 14% of cases, respectively. One hundred and eighty strains of opportunistic microorganisms were isolated in the study of nasopharyngeal microflora of patients with acute upper respiratory tract infection. The leading role belonged to S. pyogenes (40.5% and S.epidermidis (33,3%. S. aureus (12,8% and S.pneumoniae (10,6% were next

Highly pathogenic avian influenza.

Science.gov (United States)

Swayne, D E; Suarez, D L

2000-08-01

Highly pathogenic (HP) avian influenza (AI) (HPAI) is an extremely contagious, multi-organ systemic disease of poultry leading to high mortality, and caused by some H5 and H7 subtypes of type A influenza virus, family Orthomyxoviridae. However, most AI virus strains are mildly pathogenic (MP) and produce either subclinical infections or respiratory and/or reproductive diseases in a variety of domestic and wild bird species. Highly pathogenic avian influenza is a List A disease of the Office International des Epizooties, while MPAI is neither a List A nor List B disease. Eighteen outbreaks of HPAI have been documented since the identification of AI virus as the cause of fowl plague in 1955. Mildly pathogenic avian influenza viruses are maintained in wild aquatic bird reservoirs, occasionally crossing over to domestic poultry and causing outbreaks of mild disease. Highly pathogenic avian influenza viruses do not have a recognised wild bird reservoir, but can occasionally be isolated from wild birds during outbreaks in domestic poultry. Highly pathogenic avian influenza viruses have been documented to arise from MPAI viruses through mutations in the haemagglutinin surface protein. Prevention of exposure to the virus and eradication are the accepted methods for dealing with HPAI. Control programmes, which imply allowing a low incidence of infection, are not an acceptable method for managing HPAI, but have been used during some outbreaks of MPAI. The components of a strategy to deal with MPAI or HPAI include surveillance and diagnosis, biosecurity, education, quarantine and depopulation. Vaccination has been used in some control and eradication programmes for AI.

Pathogens transmitted in animal feces in low- and middle-income countries.

Science.gov (United States)

Delahoy, Miranda J; Wodnik, Breanna; McAliley, Lydia; Penakalapati, Gauthami; Swarthout, Jenna; Freeman, Matthew C; Levy, Karen

2018-05-01

Animals found in close proximity to humans in low-and middle-income countries (LMICs) harbor many pathogens capable of infecting humans, transmissible via their feces. Contact with animal feces poses a currently unquantified-though likely substantial-risk to human health. In LMIC settings, human exposure to animal feces may explain some of the limited success of recent water, sanitation, and hygiene interventions that have focused on limiting exposure to human excreta, with less attention to containing animal feces. We conducted a review to identify pathogens that may substantially contribute to the global burden of disease in humans through their spread in animal feces in the domestic environment in LMICs. Of the 65 potentially pathogenic organisms considered, 15 were deemed relevant, based on burden of disease and potential for zoonotic transmission. Of these, five were considered of highest concern based on a substantial burden of disease for which transmission in animal feces is potentially important: Campylobacter, non-typhoidal Salmonella (NTS), Lassa virus, Cryptosporidium, and Toxoplasma gondii. Most of these have a wide range of animal hosts, except Lassa virus, which is spread through the feces of rats indigenous to sub-Saharan Africa. Combined, these five pathogens cause close to one million deaths annually. More than half of these deaths are attributed to invasive NTS. We do not estimate an overall burden of disease from improperly managed animal feces in LMICs, because it is unknown what proportion of illnesses caused by these pathogens can be attributed to contact with animal feces. Typical water quantity, water quality, and handwashing interventions promoted in public health and development address transmission routes for both human and animal feces; however, sanitation interventions typically focus on containing human waste, often neglecting the residual burden of disease from pathogens transmitted via animal feces. This review compiles evidence on

Linking social and spatial networks to viral community phylogenetics reveals subtype-specific transmission dynamics in African lions.

Science.gov (United States)

Fountain-Jones, Nicholas M; Packer, Craig; Troyer, Jennifer L; VanderWaal, Kimberly; Robinson, Stacie; Jacquot, Maude; Craft, Meggan E

2017-10-01

Heterogeneity within pathogen species can have important consequences for how pathogens transmit across landscapes; however, discerning different transmission routes is challenging. Here, we apply both phylodynamic and phylogenetic community ecology techniques to examine the consequences of pathogen heterogeneity on transmission by assessing subtype-specific transmission pathways in a social carnivore. We use comprehensive social and spatial network data to examine transmission pathways for three subtypes of feline immunodeficiency virus (FIV Ple ) in African lions (Panthera leo) at multiple scales in the Serengeti National Park, Tanzania. We used FIV Ple molecular data to examine the role of social organization and lion density in shaping transmission pathways and tested to what extent vertical (i.e., father- and/or mother-offspring relationships) or horizontal (between unrelated individuals) transmission underpinned these patterns for each subtype. Using the same data, we constructed subtype-specific FIV Ple co-occurrence networks and assessed what combination of social networks, spatial networks or co-infection best structured the FIV Ple network. While social organization (i.e., pride) was an important component of FIV Ple transmission pathways at all scales, we find that FIV Ple subtypes exhibited different transmission pathways at within- and between-pride scales. A combination of social and spatial networks, coupled with consideration of subtype co-infection, was likely to be important for FIV Ple transmission for the two major subtypes, but the relative contribution of each factor was strongly subtype-specific. Our study provides evidence that pathogen heterogeneity is important in understanding pathogen transmission, which could have consequences for how endemic pathogens are managed. Furthermore, we demonstrate that community phylogenetic ecology coupled with phylodynamic techniques can reveal insights into the differential evolutionary pressures acting

Activity of Bryophyllum pinnatum S. Kurz extracts on respiratory tract ...

African Journals Online (AJOL)

These fractions were subjected to antibacterial testing against respiratory tract pathogenic bacteria. The n-hexane soluble fraction showed activity against the selected microorganism with highest on Staphylococcus aureus (12mm), Klebsiella pneumonia (11mm) and Salmonella typhi (08mm); ethyl acetate soluble fraction ...

Epidemiology and clinical profile of pathogens responsible for the hospitalization of children in Sousse area, Tunisia.

Directory of Open Access Journals (Sweden)

Ines Brini

Full Text Available This study aimed to identify a broad spectrum of respiratory pathogens from hospitalized and not-preselected children with acute respiratory tract infections in the Farhat Hached University-hospital of Sousse, Tunisia. Between September 2013 and December 2014, samples from 372 children aged between 1 month and 5 years were collected, and tested using multiplex real-time RT-PCR by a commercial assay for 21 respiratory pathogens. In addition, samples were screened for the presence of Streptococcus pneumoniae 16S rDNA using real-time PCR. The viral distribution and its association with clinical symptoms were statistically analyzed. Viral pathogens were detected in 342 (91.93% of the samples of which 28.76% were single positive and 63.17% had multiple infections. The most frequent detected viruses were rhinovirus (55.64%, respiratory syncytial virus A/B (33.06%, adenovirus (25.00%, coronavirus NL63, HKU1, OC43, and 229E (21.50%, and metapneumovirus A/B (16.12%. Children in the youngest age group (1-3 months exhibited the highest frequencies of infection. Related to their frequency of detection, RSV A/B was the most associated pathogen with patient's demographic situation and clinical manifestations (p<0.05. Parainfluenza virus 1-4 and parechovirus were found to increase the risk of death (p<0.05. Adenovirus was statistically associated to the manifestation of gastroenteritis (p = 0.004. Rhinovirus infection increases the duration of oxygen support (p = 0.042. Coronavirus group was statistically associated with the manifestation of bronchiolitis (p = 0.009 and laryngitis (p = 0.017. Streptococcus pneumoniae DNA was detected in 143 (38.44% of tested samples. However, only 53 samples had a concentration of C-reactive protein from equal to higher than 20 milligrams per liter, and 6 of them were single positive for Streptocuccus pneumoniae. This study confirms the high incidence of respiratory viruses in children hospitalized for acute respiratory tract

Association between respiratory infections in early life and later asthma is independent of virus type

DEFF Research Database (Denmark)

Bønnelykke, Klaus; Vissing, Nadja Hawwa; Sevelsted, Astrid

2015-01-01

associated with increased risk of asthma by age 7 years with similar odds ratios for all viruses and pathogenic bacteria. After adjustment for the frequency of respiratory episodes, the particular triggers were no longer associated with asthma. CONCLUSION: The number of respiratory episodes in the first......BACKGROUND: Lower respiratory tract infections in the first years of life are associated with later asthma, and this observation has led to a focus on the potential causal role of specific respiratory viruses, such as rhinoviruses and respiratory syncytial virus, in asthma development. However......, many respiratory viruses and bacteria trigger similar respiratory symptoms and it is possible that the important risk factors for asthma are the underlying susceptibility to infection and the exaggerated reaction to such triggers rather than the particular triggering agent. OBJECTIVE: We sought...

Comparison of three methods for ascertainment of contact information relevant to respiratory pathogen transmission in encounter networks

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Nathan Paula M

2010-06-01

Full Text Available Abstract Background Mathematical models of infection that consider targeted interventions are exquisitely dependent on the assumed mixing patterns of the population. We report on a pilot study designed to assess three different methods (one retrospective, two prospective for obtaining contact data relevant to the determination of these mixing patterns. Methods 65 adults were asked to record their social encounters in each location visited during 6 study days using a novel method whereby a change in physical location of the study participant triggered data entry. Using a cross-over design, all participants recorded encounters on 3 days in a paper diary and 3 days using an electronic recording device (PDA. Participants were randomised to first prospective recording method. Results Both methods captured more contacts than a pre-study questionnaire, but ascertainment using the paper diary was superior to the PDA (mean difference: 4.52 (95% CI 0.28, 8.77. Paper diaries were found more acceptable to the participants compared with the PDA. Statistical analysis confirms that our results are broadly consistent with those reported from large-scale European based surveys. An association between household size (trend 0.14, 95% CI (0.06, 0.22, P P Conclusions The study's location-based reporting design allows greater scope compared to other methods for examining differences in the characteristics of encounters over a range of environments. Improved parameterisation of dynamic transmission models gained from work of this type will aid in the development of more robust decision support tools to assist health policy makers and planners.

Diagnostic Value of Nasopharyngeal Aspirates in Children with Lower Respiratory Tract Infections

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Ai-Zhen Lu

2017-01-01

Conclusions: NPAs are less invasive diagnostic respiratory specimens, a negative NPA result is helpful in “rule out” lower airway infection; however, a positive result does not reliably “rule in” the presence of pathogens.

Experimental airborne transmission of PRRS virus

DEFF Research Database (Denmark)

Kristensen, C.S.; Bøtner, Anette; Takai, H.

2004-01-01

A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1 m...

Progress in Vaccine-Preventable and Respiratory Infectious Diseases-First 10 Years of the CDC National Center for Immunization and Respiratory Diseases, 2006-2015.

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Schuchat, Anne; Anderson, Larry J; Rodewald, Lance E; Cox, Nancy J; Hajjeh, Rana; Pallansch, Mark A; Messonnier, Nancy E; Jernigan, Daniel B; Wharton, Melinda

2018-07-01

The need for closer linkages between scientific and programmatic areas focused on addressing vaccine-preventable and acute respiratory infections led to establishment of the National Center for Immunization and Respiratory Diseases (NCIRD) at the Centers for Disease Control and Prevention. During its first 10 years (2006-2015), NCIRD worked with partners to improve preparedness and response to pandemic influenza and other emergent respiratory infections, provide an evidence base for addition of 7 newly recommended vaccines, and modernize vaccine distribution. Clinical tools were developed for improved conversations with parents, which helped sustain childhood immunization as a social norm. Coverage increased for vaccines to protect adolescents against pertussis, meningococcal meningitis, and human papillomavirus-associated cancers. NCIRD programs supported outbreak response for new respiratory pathogens and oversaw response of the Centers for Disease Control and Prevention to the 2009 influenza A(H1N1) pandemic. Other national public health institutes might also find closer linkages between epidemiology, laboratory, and immunization programs useful.

Low pathogenic avian influenza isolates from wild birds replicate and transmit via contact in ferrets without prior adaptation.

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Driskell, Elizabeth A; Pickens, Jennifer A; Humberd-Smith, Jennifer; Gordy, James T; Bradley, Konrad C; Steinhauer, David A; Berghaus, Roy D; Stallknecht, David E; Howerth, Elizabeth W; Tompkins, Stephen Mark

2012-01-01

Direct transmission of avian influenza viruses to mammals has become an increasingly investigated topic during the past decade; however, isolates that have been primarily investigated are typically ones originating from human or poultry outbreaks. Currently there is minimal comparative information on the behavior of the innumerable viruses that exist in the natural wild bird host. We have previously demonstrated the capacity of numerous North American avian influenza viruses isolated from wild birds to infect and induce lesions in the respiratory tract of mice. In this study, two isolates from shorebirds that were previously examined in mice (H1N9 and H6N1 subtypes) are further examined through experimental inoculations in the ferret with analysis of viral shedding, histopathology, and antigen localization via immunohistochemistry to elucidate pathogenicity and transmission of these viruses. Using sequence analysis and glycan binding analysis, we show that these avian viruses have the typical avian influenza binding pattern, with affinity for cell glycoproteins/glycolipids having terminal sialic acid (SA) residues with α 2,3 linkage [Neu5Ac(α2,3)Gal]. Despite the lack of α2,6 linked SA binding, these AIVs productively infected both the upper and lower respiratory tract of ferrets, resulting in nasal viral shedding and pulmonary lesions with minimal morbidity. Moreover, we show that one of the viruses is able to transmit to ferrets via direct contact, despite its binding affinity for α 2,3 linked SA residues. These results demonstrate that avian influenza viruses, which are endemic in aquatic birds, can potentially infect humans and other mammals without adaptation. Finally this work highlights the need for additional study of the wild bird subset of influenza viruses in regard to surveillance, transmission, and potential for reassortment, as they have zoonotic potential.

A Sensitive Assay for Virus Discovery in Respiratory Clinical Samples

NARCIS (Netherlands)

de Vries, Michel; Deijs, Martin; Canuti, Marta; van Schaik, Barbera D. C.; Faria, Nuno R.; van de Garde, Martijn D. B.; Jachimowski, Loes C. M.; Jebbink, Maarten F.; Jakobs, Marja; Luyf, Angela C. M.; Coenjaerts, Frank E. J.; Claas, Eric C. J.; Molenkamp, Richard; Koekkoek, Sylvie M.; Lammens, Christine; Leus, Frank; Goossens, Herman; Ieven, Margareta; Baas, Frank; van der Hoek, Lia

2011-01-01

In 5-40% of respiratory infections in children, the diagnostics remain negative, suggesting that the patients might be infected with a yet unknown pathogen. Virus discovery cDNA-AFLP (VIDISCA) is a virus discovery method based on recognition of restriction enzyme cleavage sites, ligation of adaptors

Unexpected infection outcomes of China-origin H7N9 low pathogenicity avian influenza virus in turkeys.

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Slomka, Marek J; Seekings, Amanda H; Mahmood, Sahar; Thomas, Saumya; Puranik, Anita; Watson, Samantha; Byrne, Alexander M P; Hicks, Daniel; Nunez, Alejandro; Brown, Ian H; Brookes, Sharon M

2018-05-09

The China-origin H7N9 low pathogenicity avian influenza virus (LPAIV) emerged as a zoonotic threat in 2013 where it continues to circulate in live poultry markets. Absence of overt clinical signs in poultry is a typical LPAIV infection outcome, and has contributed to its insidious maintenance in China. This study is the first description of H7N9 LPAIV (A/Anhui/1/13) infection in turkeys, with efficient transmission to two additional rounds of introduced contact turkeys which all became infected during cohousing. Surprisingly, mortality was observed in six of eight (75%) second-round contact turkeys which is unusual for LPAIV infection, with unexpected systemic dissemination to many organs beyond the respiratory and enteric tracts, but interestingly no accompanying mutation to highly pathogenic AIV. The intravenous pathogenicity index score for a turkey-derived isolate (0.39) affirmed the LPAIV phenotype. However, the amino acid change L235Q in the haemagglutinin gene occurred in directly-infected turkeys and transmitted to the contacts, including those that died and the two which resolved infection to survive to the end of the study. This polymorphism was indicative of a reversion from mammalian to avian adaptation for the H7N9 virus. This study underlined a new risk to poultry in the event of H7N9 spread beyond China.

Epidemiological study of people living in rural North Carolina for novel respiratory viruses.

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Wang, X; Anderson, B D; Pulscher, L A; Bailey, E S; Yondon, M; Gray, G C

2018-02-01

During the last 10 years, scientists have grown increasingly aware that emerging respiratory viruses are often zoonotic in their origin. These infections can originate from or be amplified in livestock. Less commonly recognized are instances when humans have transmitted their respiratory pathogens to animals (reverse zoonoses). Even with this knowledge of viral exchange at the human-livestock interface, few studies have been conducted to understand this cross-over. In this pilot study, we examined persons with influenza-like illness at an outpatient clinic for evidence of infection with novel zoonotic respiratory pathogens in rural North Carolina where there are dense swine and poultry farming. Environmental air sampling was also conducted. From July 2016 to March 2017, a total of 14 human subjects were enrolled and sampled, and 192 bioaerosol samples were collected. Of the 14 human subject samples molecularly tested, three (21.4%) were positive for influenza A, one (7.1%) for influenza B and one (7.1%) for human enterovirus. Of the 192 bioaerosol samples collected and tested by real-time RT-PCR or PCR, three (1.6%) were positive for influenza A and two (1.0%) for adenovirus. No evidence was found for novel zoonotic respiratory viruses. © 2017 Blackwell Verlag GmbH.

Genome Sequence of Canine Polyomavirus in Respiratory Secretions of Dogs with Pneumonia of Unknown Etiology.

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Delwart, Eric; Kapusinszky, Beatrix; Pesavento, Patricia A; Estrada, Marko; Seguin, M Alexis; Leutenegger, Christian M

2017-07-20

We report here the first canine polyomavirus genome, identified by metagenomics in respiratory secretions of two dogs with severe pneumonia, which tested negative for all canine respiratory pathogens except Mycoplasma cynos The isolate, Canis familiaris polyomavirus 1 (DogPyV-1), is a beta polyomavirus whose closest known LT antigen relatives are primate polyomaviruses. Copyright © 2017 Delwart et al.

Processes for managing pathogens.

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Godfree, Alan; Farrell, Joseph

2005-01-01

Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

Aggressive chemotherapy and the selection of drug resistant pathogens.

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Silvie Huijben

2013-09-01

Full Text Available Drug resistant pathogens are one of the key public health challenges of the 21st century. There is a widespread belief that resistance is best managed by using drugs to rapidly eliminate target pathogens from patients so as to minimize the probability that pathogens acquire resistance de novo. Yet strong drug pressure imposes intense selection in favor of resistance through alleviation of competition with wild-type populations. Aggressive chemotherapy thus generates opposing evolutionary forces which together determine the rate of drug resistance emergence. Identifying treatment regimens which best retard resistance evolution while maximizing health gains and minimizing disease transmission requires empirical analysis of resistance evolution in vivo in conjunction with measures of clinical outcomes and infectiousness. Using rodent malaria in laboratory mice, we found that less aggressive chemotherapeutic regimens substantially reduced the probability of onward transmission of resistance (by >150-fold, without compromising health outcomes. Our experiments suggest that there may be cases where resistance evolution can be managed more effectively with treatment regimens other than those which reduce pathogen burdens as fast as possible.

Impact of the Respiratory Microbiome on Host Responses to Respiratory Viral Infection

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Maxime Pichon

2017-11-01

Full Text Available Viruses are responsible for most of both upper and lower acute respiratory infections (ARIs. The microbiome—the ecological community of microorganisms sharing the body space, which has gained considerable interest over the last decade—is modified in health and disease states. Even if most of these disturbances have been previously described in relation to chronic disorders of the gastrointestinal microbiome, after a short reminder of microbiome characteristics and methods of characterization, this review will describe the impact of the microbiome (mainly respiratory on host responses to viral ARIs. The microbiome has a direct environmental impact on the host cells but also an indirect impact on the immune system, by enhancing innate or adaptive immune responses. In microbial infections, especially in viral infections, these dramatic modifications could lead to a dramatic impact responsible for severe clinical outcomes. Studies focusing on the microbiome associated with transcriptomic analyses of the host response and deep characterization of the pathogen would lead to a better understanding of viral pathogenesis and open avenues for biomarker development and innovative therapeutics.

Pneumonia, Acute Respiratory Distress Syndrome, and Early Immune-Modulator Therapy

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Kyung-Yil Lee

2017-02-01

Full Text Available Acute respiratory distress syndrome (ARDS is caused by infectious insults, such as pneumonia from various pathogens or related to other noninfectious events. Clinical and histopathologic characteristics are similar across severely affected patients, suggesting that a common mode of immune reaction may be involved in the immunopathogenesis of ARDS. There may be etiologic substances that have an affinity for respiratory cells and induce lung cell injury in cases of ARDS. These substances originate not only from pathogens, but also from injured host cells. At the molecular level, these substances have various sizes and biochemical characteristics, classifying them as protein substances and non-protein substances. Immune cells and immune proteins may recognize and act on these substances, including pathogenic proteins and peptides, depending upon the size and biochemical properties of the substances (this theory is known as the protein-homeostasis-system hypothesis. The severity or chronicity of ARDS depends on the amount of etiologic substances with corresponding immune reactions, the duration of the appearance of specific immune cells, or the repertoire of specific immune cells that control the substances. Therefore, treatment with early systemic immune modulators (corticosteroids and/or intravenous immunoglobulin as soon as possible may reduce aberrant immune responses in the potential stage of ARDS.

Community-acquired respiratory infections are common in patients with non-Hodgkin lymphoma and multiple myeloma.

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Lavi, Noa; Avivi, Irit; Kra-Oz, Zipora; Oren, Ilana; Hardak, Emilia

2018-07-01

Available data suggest that respiratory infections are associated with increased morbidity and mortality in patients hospitalized due to acute leukemia and allogeneic stem cell transplantation (allo-SCT). However, the precise incidence, risk factors, and severity of respiratory infection, mainly community-acquired, in patients with lymphoma and multiple myeloma (MM) are not fully determined. The current study aimed to investigate risk factors for respiratory infections and their clinical significance in patients with B cell non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) in the first year of diagnosis. Data of consecutive patients diagnosed with NHL or MM and treated at the Rambam Hematology Inpatient and Outpatient Units between 01/2011 and 03/2012 were evaluated. Information regarding anticancer treatment, incidence and course of respiratory infections, and infection-related outcomes was analyzed. One hundred and sixty episodes of respiratory infections were recorded in 103 (49%) of 211 (73-MM, 138-NHL) patients; 126 (79%) episodes were community-acquired, 47 (29%) of them required hospitalization. In univariate analysis, age respiratory infection risk (P = 0.058, 0.038, and 0.001, respectively). Ninety episodes (56% of all respiratory episodes) were examined for viral pathogens. Viral infections were documented in 25/90 (28%) episodes, 21 (84%) of them were community-acquired, requiring hospitalization in 5 (24%) cases. Anti-flu vaccination was performed in 119 (56%) patients. Two of the six patients diagnosed with influenza were vaccinated. Respiratory infections, including viral ones, are common in NHL and MM. Most infections are community-acquired and have a favorable outcome. Rapid identification of viral pathogens allows avoiding antibiotic overuse in this patient population.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections.

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Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Gormley, Stuart; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2015-01-01

Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1-4), rhinovirus, adenovirus (A-F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011-2013. The results were corroborated in an independent cohort collected in the UK. A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12-24 months age group. The most frequently observed co-infection patterns were RSV-Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV-bocavirus / bocavirus-influenza (5 patients, 5.2%, UK cohort). The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12-24 months of age. The clinical significance of these findings is unclear but should warrant further analysis.

In vitro activity of five tetracyclines and some other antimicrobial agents against four porcine respiratory tract pathogens.

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Pijpers, A; Van Klingeren, B; Schoevers, E J; Verheijden, J H; Van Miert, A S

1989-09-01

The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.

Feeder density enhances house finch disease transmission in experimental epidemics.

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Moyers, Sahnzi C; Adelman, James S; Farine, Damien R; Thomason, Courtney A; Hawley, Dana M

2018-05-05

Anthropogenic food provisioning of wildlife can alter the frequency of contacts among hosts and between hosts and environmental sources of pathogens. Despite the popularity of garden bird feeding, few studies have addressed how feeders influence host contact rates and disease dynamics. We experimentally manipulated feeder density in replicate aviaries containing captive, pathogen-naive, groups of house finches ( Haemorhous mexicanus ) and continuously tracked behaviours at feeders using radio-frequency identification devices. We then inoculated one bird per group with Mycoplasma gallisepticum (Mg), a common bacterial pathogen for which feeders are fomites of transmission, and assessed effects of feeder density on house finch behaviour and pathogen transmission. We found that pathogen transmission was significantly higher in groups with the highest density of bird feeders, despite a significantly lower rate of intraspecific aggressive interactions relative to the low feeder density groups. Conversely, among naive group members that never showed signs of disease, we saw significantly higher concentrations of Mg-specific antibodies in low feeder density groups, suggesting that birds in low feeder density treatments had exposure to subclinical doses of Mg. We discuss ways in which the density of garden bird feeders could play an important role in mediating the intensity of Mg epidemics.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'. © 2018 The Author(s).

Efficacy of combined vaccination against Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus in dually infected pigs.

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Bourry, Olivier; Fablet, Christelle; Simon, Gaëlle; Marois-Créhan, Corinne

2015-11-18

Porcine respiratory disease complex (PRDC) is one of the main causes of economic losses for swine producers. This complex is due to a combination of different pathogens and their interactions. Two major pathogens involved in PRDC are Mycoplasma hyopneumoniae (Mhp) and porcine reproductive and respiratory syndrome virus (PRRSV). The objectives of this study were (i) to develop an experimental model of dual Mhp/PRRSV infection in SPF pigs with European strains of Mhp and PRRSV and (ii) to assess and compare the effects of single Mhp, single PRRSV or combined Mhp/PRRSV vaccination against this dual infection. Pigs dually infected with Mhp and PRRSV showed a combination of symptoms characteristic of each pathogen but no significant exacerbation of pathogenicity. Thus, the co-infected pigs displayed coughing and pneumonia typical of Mhp infection in addition to PRRSV-related hyperthermia and decrease in average daily gain (ADG). Hyperthermia was reduced in PRRSV vaccinated animals (single or combined vaccination), whereas ADG was restored in Mhp/PRRSV vaccinated pigs only. Regarding respiratory symptoms and lung lesions, no vaccine decreased coughing. However, all vaccines reduced the pneumonia score but more so in animals receiving the Mhp vaccine, whether single or combined. This vaccine also decreased the Mhp load in the respiratory tract. In conclusion, combined vaccination against both Mhp and PRRSV efficiently pooled the efficacy of each single PRRSV and Mhp vaccination and could be an interesting tool to control PRDC in European swine production. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterizing the transmission potential of zoonotic infections from minor outbreaks.

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Adam J Kucharski

2015-04-01

Full Text Available The transmission potential of a novel infection depends on both the inherent transmissibility of a pathogen, and the level of susceptibility in the host population. However, distinguishing between these pathogen- and population-specific properties typically requires detailed serological studies, which are rarely available in the early stages of an outbreak. Using a simple transmission model that incorporates age-stratified social mixing patterns, we present a novel method for characterizing the transmission potential of subcritical infections, which have effective reproduction number R<1, from readily available data on the size of outbreaks. We show that the model can identify the extent to which outbreaks are driven by inherent pathogen transmissibility and pre-existing population immunity, and can generate unbiased estimates of the effective reproduction number. Applying the method to real-life infections, we obtained accurate estimates for the degree of age-specific immunity against monkeypox, influenza A(H5N1 and A(H7N9, and refined existing estimates of the reproduction number. Our results also suggest minimal pre-existing immunity to MERS-CoV in humans. The approach we describe can therefore provide crucial information about novel infections before serological surveys and other detailed analyses are available. The methods would also be applicable to data stratified by factors such as profession or location, which would make it possible to measure the transmission potential of emerging infections in a wide range of settings.

A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii.

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Fernanda F M Mazzillo

Full Text Available Toxoplasma gondii is a land-derived parasite that infects humans and marine mammals. Infections are a significant cause of mortality for endangered southern sea otters (Enhydra lutris nereis, but the transmission mechanism is poorly understood. Otter exposure to T. gondii has been linked to the consumption of marine turban snails in kelp (Macrocystis pyrifera forests. It is unknown how turban snails acquire oocysts, as snails scrape food particles attached to surfaces, whereas T. gondii oocysts enter kelp beds as suspended particles via runoff. We hypothesized that waterborne T. gondii oocysts attach to kelp surfaces when encountering exopolymer substances (EPS forming the sticky matrix of biofilms on kelp, and thus become available to snails. Results of a dietary composition analysis of field-collected snails and of kelp biofilm indicate that snails graze the dense kelp-biofilm assemblage composed of pennate diatoms and bacteria inserted within the EPS gel-like matrix. To test whether oocysts attach to kelp blades via EPS, we designed a laboratory experiment simulating the kelp forest canopy in tanks spiked with T. gondii surrogate microspheres and controlled for EPS and transparent exopolymer particles (TEP - the particulate form of EPS. On average, 19% and 31% of surrogates were detected attached to kelp surfaces covered with EPS in unfiltered and filtered seawater treatments, respectively. The presence of TEP in the seawater did not increase surrogate attachment. These findings support a novel transport mechanism of T. gondii oocysts: as oocysts enter the kelp forest canopy, a portion adheres to the sticky kelp biofilms. Snails grazing this biofilm encounter oocysts as 'bycatch' and thereby deliver the parasite to sea otters that prey upon snails. This novel mechanism can have health implications beyond T. gondii and otters, as a similar route of pathogen transmission may be implicated with other waterborne pathogens to marine wildlife and

Mycological assessment of sediments in Ligurian beaches in the Northwestern Mediterranean: pathogens and opportunistic pathogens.

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Salvo, Vanessa-Sarah; Fabiano, Mauro

2007-05-01

Sediments of five Ligurian beaches in compliance with European Union bathing water regulations were studied based on the characteristics of the fungal assemblage during the tourism season. Among the 179 taxa of filamentous fungi isolated, 120 were opportunistic pathogens, such as Acremonium sp., and the genus Penicillium was also present as the pathogenic species P. citrinum. Furthermore, 5% of the total filamentous fungi belonged to the dermatophyte genus Microsporum, whose species can cause mycoses. Beach sediments showed elevated densities of opportunistic pathogens, of pathogenic filamentous fungi, and of yeasts during the tourism season. Although monitoring of beach sediments for microbiological contamination is not mandatory, and disease transmission from sediments has not yet been demonstrated, our study suggests that beach sediments may act as a reservoir of potential pathogens, including fungi. In addition, the mycoflora displayed high sensitivity to critical environmental situations in the beaches studied. Therefore, the fungal community can be a useful tool for assessing the quality of sandy beaches in terms of sanitary and environmental quality.

Antibody-secreting cells in respiratory tract tissues in the absence of eosinophils as supportive partners.

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Sealy, Robert E; Surman, Sherri L; Vogel, Peter; Hurwitz, Julia L

2016-11-01

Antibody-secreting cells (ASCs) in respiratory tract tissues provide a first line of defense against invading pathogens. These cells often secrete IgA that is efficiently transcytosed across epithelial barriers into the airway lumen where pathogens can be blocked at their point of entry. Previous literature has reported that in the bone marrow, eosinophils are required for the maintenance of ASCs, and that eosinophils co-localize with ASCs as nearest neighbors. To determine if these rules similarly apply to the maintenance of ASCs in respiratory tract tissues, we evaluated virus-specific responses 1 month and 4 months following an intranasal virus infection of eosinophil-null (∆dblGATA-1) mice. Results showed that ASCs were fractionally reduced, but were nonetheless observed in respiratory tract tissues in the absence of eosinophils. Virus-specific antibodies were similarly observed in the airways of eosinophil-deficient mice. Respiratory tract ASCs were also present in mice lacking neutrophils (Mcl1 ∆M ). The staining of tissue sections from the upper respiratory tract of wild-type mice following viral infections demonstrated that virus-specific ASCs were most frequently situated adjacent to epithelial cells rather than eosinophils or neutrophils. Taken together, these data emphasize that rules for cell maintenance are not absolute and that ASCs can survive in the respiratory tract without eosinophils or neutrophils as their nearest neighbors. © The Japanese Society for Immunology. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation

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Luana Carneiro Diniz SOUZA

2017-06-01

Full Text Available Abstract The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU, and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP. Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1% developed VAP, 10 (52.63% did not develop pneumonia and one (5.26% had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p < 0.05. Pathogens that are present in tracheal aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

PB1-F2 Protein Does Not Impact the Virulence of Triple-Reassortant H3N2 Swine Influenza Virus in Pigs but Alters Pathogenicity and Transmission in Turkeys.

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Deventhiran, Jagadeeswaran; Kumar, Sandeep R P; Raghunath, Shobana; Leroith, Tanya; Elankumaran, Subbiah

2016-01-01

PB1-F2 protein, the 11th influenza A virus (IAV) protein, is considered to play an important role in primary influenza virus infection and postinfluenza secondary bacterial pneumonia in mice. The functional role of PB1-F2 has been reported to be a strain-specific and host-specific phenomenon. Its precise contribution to the pathogenicity and transmission of influenza virus in mammalian host, such as swine, and avian hosts, such as turkeys, remain largely unknown. In this study, we explored the role of PB1-F2 protein of triple-reassortant (TR) H3N2 swine influenza virus (SIV) in pigs and turkeys. Using the eight-plasmid reverse genetics system, we rescued wild-type SIV A/swine/Minnesota/1145/2007 (H3N2) (SIV 1145-WT), a PB1-F2 knockout mutant (SIV 1145-KO), and its N66S variant (SIV 1145-N66S). The ablation of PB1-F2 in SIV 1145 modulated early-stage apoptosis but did not affect the viral replication in swine alveolar macrophage cells. In pigs, PB1-F2 expression did not affect nasal shedding, lung viral load, immunophenotypes, and lung pathology. On the other hand, in turkeys, SIV 1145-KO infected poults, and its in-contacts developed clinical signs earlier than SIV 1145-WT groups and also displayed more extensive histopathological changes in intestine. Further, turkeys infected with SIV 1145-N66S displayed poor infectivity and transmissibility. The more extensive histopathologic changes in intestine and relative transmission advantage observed in turkeys infected with SIV 1145-KO need to be further explored. Taken together, these results emphasize the host-specific roles of PB1-F2 in the pathogenicity and transmission of IAV. Novel triple-reassortant H3N2 swine influenza virus emerged in 1998 and spread rapidly among the North American swine population. Subsequently, it showed an increased propensity to reassort, generating a range of reassortants. Unlike classical swine influenza virus, TR SIV produces a full-length PB1-F2 protein, which is considered an important

The epizootiology of the highly pathogenic avian influenza prior to ...

African Journals Online (AJOL)

The epizootiology of the highly pathogenic avian influenza prior to the anticipated pandemic of the early twenty first century. ... Transmission of highly pathogenic H5N1 from domestic fowls back to migratory waterfowl in western China has increased the geographic spread. This has grave consequences for the poultry ...

The transmissibility of highly pathogenic avian influenza in commercial poultry in industrialised countries.

Directory of Open Access Journals (Sweden)

Tini Garske

2007-04-01

Full Text Available With the increased occurrence of outbreaks of H5N1 worldwide there is concern that the virus could enter commercial poultry farms with severe economic consequences.We analyse data from four recent outbreaks of highly pathogenic avian influenza (HPAI in commercial poultry to estimate the farm-to-farm reproductive number for HPAI. The reproductive number is a key measure of the transmissibility of HPAI at the farm level because it can be used to evaluate the effectiveness of the control measures. In these outbreaks the mean farm-to-farm reproductive number prior to controls ranged from 1.1 to 2.4, with the maximum farm-based reproductive number in the range 2.2 to 3.2. Enhanced bio-security, movement restrictions and prompt isolation of the infected farms in all four outbreaks substantially reduced the reproductive number, but it remained close to the threshold value 1 necessary to ensure the disease will be eradicated.Our results show that depending on the particular situation in which an outbreak of avian influenza occurs, current controls might not be enough to eradicate the disease, and therefore a close monitoring of the outbreak is required. The method we used for estimating the reproductive number is straightforward to implement and can be used in real-time. It therefore can be a useful tool to inform policy decisions.

Sexual transmission of a plant pathogenic bacterium, Candidatus Liberibacter asiaticus, between conspecific insect vectors during mating.

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Rajinder S Mann

Full Text Available Candidatus Liberibacter asiaticus is a fastidious, phloem-inhabiting, gram-negative bacterium transmitted by Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae. The bacterium is the presumed causal agent of huanglongbing (HLB, one of the most destructive and economically important diseases of citrus. We investigated whether Las is transmitted between infected and uninfected D. citri adults during courtship. Our results indicate that Las was sexually transmitted from Las-infected male D. citri to uninfected females at a low rate (<4% during mating. Sexual transmission was not observed following mating of infected females and uninfected males or among adult pairs of the same sex. Las was detected in genitalia of both sexes and also in eggs of infected females. A latent period of 7 days or more was required to detect the bacterium in recipient females. Rod shaped as well as spherical structures resembling Las were observed in ovaries of Las-infected females with transmission electron microscopy, but were absent in ovaries from uninfected D. citri females. The size of the rod shaped structures varied from 0.39 to 0.67 µm in length and 0.19 to 0.39 µm in width. The spherical structures measured from 0.61 to 0.80 µm in diameter. This investigation provides convincing evidence that a plant pathogenic bacterium is sexually transmitted from male to female insects during courtship and established evidence that bacteria persist in reproductive organs. Moreover, these findings provide an alternative sexually horizontal mechanism for the spread of Las within populations of D. citri, even in the absence of infected host trees.

Retracing the evolutionary path that led to flea-borne transmission of Yersinia pestis.

Science.gov (United States)

Sun, Yi-Cheng; Jarrett, Clayton O; Bosio, Christopher F; Hinnebusch, B Joseph

2014-05-14

Yersinia pestis is an arthropod-borne bacterial pathogen that evolved recently from Yersinia pseudotuberculosis, an enteric pathogen transmitted via the fecal-oral route. This radical ecological transition can be attributed to a few discrete genetic changes from a still-extant recent ancestor, thus providing a tractable case study in pathogen evolution and emergence. Here, we determined the genetic and mechanistic basis of the evolutionary adaptation of Y. pestis to flea-borne transmission. Remarkably, only four minor changes in the bacterial progenitor, representing one gene gain and three gene losses, enabled transmission by flea vectors. All three loss-of-function mutations enhanced cyclic-di-GMP-mediated bacterial biofilm formation in the flea foregut, which greatly increased transmissibility. Our results suggest a step-wise evolutionary model in which Y. pestis emerged as a flea-borne clone, with each genetic change incrementally reinforcing the transmission cycle. The model conforms well to the ecological theory of adaptive radiation. Copyright © 2014 Elsevier Inc. All rights reserved.

Influence of Novel Highly Pathogenic Avian Influenza A (H5N1 Virus Infection on Migrating Whooper Swans Fecal Microbiota

Directory of Open Access Journals (Sweden)

Na Zhao

2018-02-01

Full Text Available The migration of wild birds plays an important role in the transmission and spread of H5 highly pathogenic avian influenza (HPAI virus, posing a severe risk to animal and human health. Substantial evidence suggests that altered gut microbial community is implicated in the infection of respiratory influenza virus. However, the influence of H5N1 infection in gut microbiota of migratory birds remains unknown. In January 2015, a novel recombinant H5N1 virus emerged and killed about 100 migratory birds, mainly including whooper swans in Sanmenxia Reservoir Area of China. Here, we describe the first fecal microbiome diversity study of H5N1-infected migratory birds. By investigating the influence of H5N1 infection on fecal bacterial communities in infected and uninfected individuals, we found that H5N1 infection shaped the gut microbiota composition by a difference in the dominance of some genera, such as Aeromonas and Lactobacillus. We also found a decreased α diversity and increased β diversity in infectious individuals. Our results highlight that increases in changes in pathogen-containing gut communities occur when individuals become infected with H5N1. Our study may provide the first evidence that there are statistical association among H5N1 presence and fecal microbiota compositional shifts, and properties of the fecal microbiota may serve as the risk of gut-linked disease in migrates with H5N1 and further aggravate the disease transmission.

Influence of Novel Highly Pathogenic Avian Influenza A (H5N1) Virus Infection on Migrating Whooper Swans Fecal Microbiota.

Science.gov (United States)

Zhao, Na; Wang, Supen; Li, Hongyi; Liu, Shelan; Li, Meng; Luo, Jing; Su, Wen; He, Hongxuan

2018-01-01

The migration of wild birds plays an important role in the transmission and spread of H5 highly pathogenic avian influenza (HPAI) virus, posing a severe risk to animal and human health. Substantial evidence suggests that altered gut microbial community is implicated in the infection of respiratory influenza virus. However, the influence of H5N1 infection in gut microbiota of migratory birds remains unknown. In January 2015, a novel recombinant H5N1 virus emerged and killed about 100 migratory birds, mainly including whooper swans in Sanmenxia Reservoir Area of China. Here, we describe the first fecal microbiome diversity study of H5N1-infected migratory birds. By investigating the influence of H5N1 infection on fecal bacterial communities in infected and uninfected individuals, we found that H5N1 infection shaped the gut microbiota composition by a difference in the dominance of some genera, such as Aeromonas and Lactobacillus . We also found a decreased α diversity and increased β diversity in infectious individuals. Our results highlight that increases in changes in pathogen-containing gut communities occur when individuals become infected with H5N1. Our study may provide the first evidence that there are statistical association among H5N1 presence and fecal microbiota compositional shifts, and properties of the fecal microbiota may serve as the risk of gut-linked disease in migrates with H5N1 and further aggravate the disease transmission.

Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees

OpenAIRE

Youngsteadt, Elsa; Appler, R. Holden; L?pez-Uribe, Margarita M.; Tarpy, David R.; Frank, Steven D.

2015-01-01

Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus), the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens....

[Etiological analysis and establishment of a discriminant model for lower respiratory tract infections in hospitalized patients].

Science.gov (United States)

Chen, Y S; Lin, X H; Li, H R; Hua, Z D; Lin, M Q; Huang, W S; Yu, T; Lyu, H Y; Mao, W P; Liang, Y Q; Peng, X R; Chen, S J; Zheng, H; Lian, S Q; Hu, X L; Yao, X Q

2017-12-12

Objective: To analyze the pathogens of lower respiratory tract infection(LRTI) including bacterial, viral and mixed infection, and to establish a discriminant model based on clinical features in order to predict the pathogens. Methods: A total of 243 hospitalized patients with lower respiratory tract infections were enrolled in Fujian Provincial Hospital from April 2012 to September 2015. The clinical data and airway (sputum and/or bronchoalveolar lavage) samples were collected. Microbes were identified by traditional culture (for bacteria), loop-mediated isothermal amplification(LAMP) and gene sequencing (for bacteria and atypical pathogen), or Real-time quantitative polymerase chain reaction (Real-time PCR)for viruses. Finally, a discriminant model was established by using the discriminant analysis methods to help to predict bacterial, viral and mixed infections. Results: Pathogens were detected in 53.9% (131/243) of the 243 cases.Bacteria accounted for 23.5%(57/243, of which 17 cases with the virus, 1 case with Mycoplasma pneumoniae and virus), mainly Pseudomonas Aeruginosa and Klebsiella Pneumonia. Atypical pathogens for 4.9% (12/243, of which 3 cases with the virus, 1 case of bacteria and viruses), all were mycoplasma pneumonia. Viruses for 34.6% (84/243, of which 17 cases of bacteria, 3 cases with Mycoplasma pneumoniae, 1 case with Mycoplasma pneumoniae and bacteria) of the cases, mainly Influenza A virus and Human Cytomegalovirus, and other virus like adenovirus, human parainfluenza virus, respiratory syncytial virus, human metapneumovirus, human boca virus were also detected fewly. Seven parameters including mental status, using antibiotics prior to admission, complications, abnormal breath sounds, neutrophil alkaline phosphatase (NAP) score, pneumonia severity index (PSI) score and CRUB-65 score were enrolled after univariate analysis, and discriminant analysis was used to establish the discriminant model by applying the identified pathogens as the

Variation among sows in response to porcine reproductive and respiratory syndrome

NARCIS (Netherlands)

Rashidi, H.; Mulder, H.A.; Mathur, P.K.; Knol, E.F.; Arendonk, van J.A.M.

2014-01-01

Porcine reproductive and respiratory syndrome (PRRS) is a viral disease with negative impacts on reproduction of sows. Genetic selection to improve the response of sows to PRRS could be an approach to control the disease. Determining sow response to PRRS requires knowing pathogen burden and sow

[Study of etiologic factors of infectious diseases of respiratory tract in school-age children during period of remission of a respiratory disease].

Science.gov (United States)

Maĭorov, R V; Chereshneva, M V; Chereshnev, V A

2013-01-01

Detect features of microflora of upper respiratory tract on the example of flora of palatine tonsils and level of antibodies against intracellular parasites as markers of etiologic factors of respiratory infections in school-age children in remission period. 466 children from frequently and episodically ill groups were examined. Bacteriologic study of smears from the surface of palatine tonsils was carried out in all the children. By using EIA with the corresponding commercial test systems IgG level against Herpes simplex virus, Cytomegalovirus, Chlamydophila pneumoniae, Mycoplasma pneumoniae, Human respiratory syncytial virus was determined in blood sera according to instruction manual. During remission period of infectious process in the structure of microflora of upper respiratory tract in frequently ill children characteristic differences from their episodically ill peers were detected. In children with frequent respiratory infections a higher occurrence of antibodies against intracellular causative agents of these diseases was also detected. In the group of frequently ill, a direct correlation between frequency of infectious diseases of respiratory tract and occurrence of carriage of pathogenic and opportunistic microorgan isms as well as increase of antibodies against Herpesviridae, Cytomegalovirus, C. pneumoniae and M. pneumoniae was detected. Higher occurrence ofintra- and extra-cellular infectious agents as well as their associations may be considered as one of the reasons of insufficient effectiveness of prophylaxis measures in frequently ill children.

Simultaneous inference of phylogenetic and transmission trees in infectious disease outbreaks

Science.gov (United States)

2017-01-01

Whole-genome sequencing of pathogens from host samples becomes more and more routine during infectious disease outbreaks. These data provide information on possible transmission events which can be used for further epidemiologic analyses, such as identification of risk factors for infectivity and transmission. However, the relationship between transmission events and sequence data is obscured by uncertainty arising from four largely unobserved processes: transmission, case observation, within-host pathogen dynamics and mutation. To properly resolve transmission events, these processes need to be taken into account. Recent years have seen much progress in theory and method development, but existing applications make simplifying assumptions that often break up the dependency between the four processes, or are tailored to specific datasets with matching model assumptions and code. To obtain a method with wider applicability, we have developed a novel approach to reconstruct transmission trees with sequence data. Our approach combines elementary models for transmission, case observation, within-host pathogen dynamics, and mutation, under the assumption that the outbreak is over and all cases have been observed. We use Bayesian inference with MCMC for which we have designed novel proposal steps to efficiently traverse the posterior distribution, taking account of all unobserved processes at once. This allows for efficient sampling of transmission trees from the posterior distribution, and robust estimation of consensus transmission trees. We implemented the proposed method in a new R package phybreak. The method performs well in tests of both new and published simulated data. We apply the model to five datasets on densely sampled infectious disease outbreaks, covering a wide range of epidemiological settings. Using only sampling times and sequences as data, our analyses confirmed the original results or improved on them: the more realistic infection times place more

Simultaneous inference of phylogenetic and transmission trees in infectious disease outbreaks.

Science.gov (United States)

Klinkenberg, Don; Backer, Jantien A; Didelot, Xavier; Colijn, Caroline; Wallinga, Jacco

2017-05-01

Whole-genome sequencing of pathogens from host samples becomes more and more routine during infectious disease outbreaks. These data provide information on possible transmission events which can be used for further epidemiologic analyses, such as identification of risk factors for infectivity and transmission. However, the relationship between transmission events and sequence data is obscured by uncertainty arising from four largely unobserved processes: transmission, case observation, within-host pathogen dynamics and mutation. To properly resolve transmission events, these processes need to be taken into account. Recent years have seen much progress in theory and method development, but existing applications make simplifying assumptions that often break up the dependency between the four processes, or are tailored to specific datasets with matching model assumptions and code. To obtain a method with wider applicability, we have developed a novel approach to reconstruct transmission trees with sequence data. Our approach combines elementary models for transmission, case observation, within-host pathogen dynamics, and mutation, under the assumption that the outbreak is over and all cases have been observed. We use Bayesian inference with MCMC for which we have designed novel proposal steps to efficiently traverse the posterior distribution, taking account of all unobserved processes at once. This allows for efficient sampling of transmission trees from the posterior distribution, and robust estimation of consensus transmission trees. We implemented the proposed method in a new R package phybreak. The method performs well in tests of both new and published simulated data. We apply the model to five datasets on densely sampled infectious disease outbreaks, covering a wide range of epidemiological settings. Using only sampling times and sequences as data, our analyses confirmed the original results or improved on them: the more realistic infection times place more

Simultaneous inference of phylogenetic and transmission trees in infectious disease outbreaks.

Directory of Open Access Journals (Sweden)

Don Klinkenberg

2017-05-01

Full Text Available Whole-genome sequencing of pathogens from host samples becomes more and more routine during infectious disease outbreaks. These data provide information on possible transmission events which can be used for further epidemiologic analyses, such as identification of risk factors for infectivity and transmission. However, the relationship between transmission events and sequence data is obscured by uncertainty arising from four largely unobserved processes: transmission, case observation, within-host pathogen dynamics and mutation. To properly resolve transmission events, these processes need to be taken into account. Recent years have seen much progress in theory and method development, but existing applications make simplifying assumptions that often break up the dependency between the four processes, or are tailored to specific datasets with matching model assumptions and code. To obtain a method with wider applicability, we have developed a novel approach to reconstruct transmission trees with sequence data. Our approach combines elementary models for transmission, case observation, within-host pathogen dynamics, and mutation, under the assumption that the outbreak is over and all cases have been observed. We use Bayesian inference with MCMC for which we have designed novel proposal steps to efficiently traverse the posterior distribution, taking account of all unobserved processes at once. This allows for efficient sampling of transmission trees from the posterior distribution, and robust estimation of consensus transmission trees. We implemented the proposed method in a new R package phybreak. The method performs well in tests of both new and published simulated data. We apply the model to five datasets on densely sampled infectious disease outbreaks, covering a wide range of epidemiological settings. Using only sampling times and sequences as data, our analyses confirmed the original results or improved on them: the more realistic infection

Surveillance of Severe Acute Respiratory Infection (SARI) for Hospitalized Patients in Northern Vietnam, 2011-2014.

Science.gov (United States)

Nguyen, Hang Khanh Le; Nguyen, Son Vu; Nguyen, Anh Phuong; Hoang, Phuong Mai Vu; Le, Thanh Thi; Nguyen, Thach Co; Hoang, Huong Thu; Vuong, Cuong Duc; Tran, Loan Thi Thanh; Le, Mai Quynh

2017-09-25

Severe acute respiratory infections (SARI) are leading causes of hospitalization, morbidity, and mortality in children worldwide. The aim of this study was to identify viral pathogens responsible for SARI in northern Vietnam in the period from 2011 to 2014. Throat swabs and tracheal aspirates were collected from SARI patients according to WHO guidelines. The presence of 13 different viral pathogens (influenza A[H1N1]pdm09; A/H3N2; A/H5; A/H7 and B; para influenza 1,2,3; RSV; HMPV; adeno; severe acute respiratory syndrome-CoV and rhino) was tested by conventional/real-time reverse transcription-polymerase chain reaction. During the study period, 975 samples were collected and tested. More than 30% (32.1%, 313 samples) of the samples showed evidence of infection with influenza viruses, including A/H3N2 (48 samples), A (H1N1) pdm09 (221 samples), influenza B (42 samples), and co-infection of A (H1N1) pdm09 or A/H3N2 and influenza B (2 samples). Other respiratory pathogens were detected in 101 samples, including rhinovirus (73 samples), adenovirus (10 samples), hMPV (9 samples), parainfluenza 3 (5 samples), parainfluenza 2 (3 samples), and RSV (1 sample). Influenza A/H5, A/H7, or SARS-CoV were not detected. Respiratory viral infection, particularly infection of influenza and rhinoviruses, were associated with high rates of SARI hospitalization, and future studies correlating the clinical aspects are needed to design interventions, including targeted vaccination.

Enhancement of Immune Memory Responses to Respiratory Infection

Science.gov (United States)

2017-08-01

Unlimited Distribution 13. SUPPLEMENTARY NOTES 14. ABSTRACT Maintenance of long - term immunological memory against pathogens is crucial for the rapid...highly expressed in memory B cells in mice, and Atg7 is required for maintenance of long - term memory B cells needed to protect against influenza...AWARD NUMBER: W81XWH-16-1-0361 TITLE: Enhancement of Immune Memory Responses to Respiratory Infection PRINCIPAL INVESTIGATORs: Dr Farrah

[The composition and antimicrobial resistance of isolates from lower respiratory tract and blood in hospitalized patients in respiratory ward: a multicenter national study in China].

Science.gov (United States)

Tang, X; Zhuo, C; Xu, Y C; Zhong, N S

2018-04-12

Objective: To investigate the species and antimicrobial resistance of bacterial pathogens isolated from hospitalized patients in respiratory ward in China. Methods: This was a multicenter retrospective study based on a national epidemiological network called China Antimicrobial Resistance Surveillance System (CARSS). The non-repetitive strains isolated from lower respiratory tract and blood samples in 91 hospitals from seven geographic regions of CARSS were reviewed. The distribution of specimen type, hospital level (secondary and tertiary hospital), patient age group [geriatric (>65 years old), adult (15 to 65 years old), pediatric (28 days to 14 years old ) and newborn group (≤28 days)] and ward type (respiratory intensive care unit and general respiratory ward) were analyzed for MRSA, PRSP, CREC, CRKP, CRPA, CRAB, ESBL-EC and ESBL-KP. The categorical variables were analyzed by chi-square test using SPSS 16.0 statistical software. P respiratory tract (LRT), 2 649 isolates from blood and 5 017 isolates from other samples (urine and secretions)] from 48 752 inpatients (without illness type information) were enrolled in the study. 90.2% (45 491/50 417) isolates were obtained from 63 tertiary hospitals. According to patients' age, all cases were divided into 4 groups, i. e. geriatric(46.0%, 23 177/50 417), adult(29.9%, 15 092/50 417), pediatric(24.0%, 12 112/50 417) and newborn group(0.0%, 36/50 417). All isolates were obtained from respiratory intensive care unit (6.2%, 3 129/50 417) or general respiratory wards (93.8%, 47 288/50 417). The majority of bacterial pathogens were isolated from lower respiratory and blood culture samples, which accounted for 90.0% of all the samples (45 400/50 417). Sputum accounted for 81.6% (41 131/50 417) of samples, and the leading 4 isolates were K . pneumonia (18.9%, 7 784/41 131), P . aeruginosa (13.6%, 5 580/41 131), A . baumanni (11.3%, 4 644/41 131) and S . pneumonia (11.1%, 4 564/41 131). Blood samples accounted for 5.3% (2

Management of infections in critically ill returning travellers in the intensive care unit—I: considerations on infection control and transmission of resistance

Directory of Open Access Journals (Sweden)

Hakan Leblebicioglu

2016-07-01

Full Text Available Depending on their destinations and activities, international travellers are at a significant risk of contracting both communicable and non-communicable diseases. On return to their home countries, such travellers may require intensive care. The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV, and more recently Ebola haemorrhagic fever, has highlighted the risks. Other well-known communicable pathogens such as methicillin-resistant Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae have been described previously. However, malaria remains by far the most important cause of death. The issues related to imported antibiotic resistance and protection from highly contagious diseases are reviewed here. Surveillance strategies based on epidemiological data (country visited, duration of travel, and time elapsed since return and clinical syndromes, together with systematic search policies, are usually mandatory to limit the risk of an outbreak. Single-bed hospital rooms and isolation according to symptoms should be the rule while awaiting laboratory test results. Because person-to-person contact is the main route of transmission, healthcare workers should implement specific prevention strategies.

Respiratory infection rates differ between geographically distant paediatric cystic fibrosis cohorts

Directory of Open Access Journals (Sweden)

Kathryn A. Ramsey

2016-09-01

Full Text Available Respiratory infections are a major cause of pulmonary decline in children with cystic fibrosis (CF. We compared the prevalence of infection in early life at geographically distant CF treatment centres participating in the same surveillance programme in Australia. Lower airway microbiology, inflammation and structural lung disease at annual review were evaluated for 260 children 0–8 years old with CF at 1032 visits to CF treatment centres in Melbourne or Perth. Melbourne patients were more likely to be culture-positive for common respiratory pathogens at all age groups (odds ratio (OR 1.85, 95% CI 1.33–2.58. Subjects 5 years old. Patients at both centres had a similar rate of hospitalisations and prescribed antibiotics. No procedural differences were identified that could explain the disparity between pathogen prevalence. Geographical differences in early acquisition of infection may contribute to variability in outcomes between CF centres.

Pathogenicity of the Korean H5N8 highly pathogenic avian influenza virus in commercial domestic poultry species.

Science.gov (United States)

Lee, Dong-Hun; Kwon, Jung-Hoon; Noh, Jin-Yong; Park, Jae-Keun; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Lee, Sang-Won; Song, Chang-Seon

2016-01-01

In 2014, the highly pathogenic avian influenza (HPAI) virus H5N8 triggered outbreaks in wild birds and poultry farms in South Korea. In the present study, we investigated the pathogenicity of the H5N8 HPAI virus, belonging to the clade 2.3.4.4, in different species of poultry. For this, we examined clinical signs and viral shedding levels following intranasal inoculation of the virus in 3-week-old commercial layer chickens and quails, 10-week-old Korean native chickens, and 8-week-old Muscovy ducks. Intranasal inoculation with 10(6.0) viruses at 50% egg-infective dose resulted in 100% mortality in the layer chickens (8/8) and quails (4/4), but 60% and 0% deaths in the Korean native chickens (3/5) and Muscovy ducks (0/4), respectively. In addition, transmission of the inoculated virus to contact-exposed birds was evident in all the species used in this study. Based on our results, we conclude that the H5N8 HPAI virus has lower pathogenicity and transmissibility in poultry species compared with previously reported H5N1 HPAI viruses.

Contact transmission of influenza virus between ferrets imposes a looser bottleneck than respiratory droplet transmission allowing propagation of antiviral resistance

Science.gov (United States)

Frise, Rebecca; Bradley, Konrad; van Doremalen, Neeltje; Galiano, Monica; Elderfield, Ruth A.; Stilwell, Peter; Ashcroft, Jonathan W.; Fernandez-Alonso, Mirian; Miah, Shahjahan; Lackenby, Angie; Roberts, Kim L.; Donnelly, Christl A.; Barclay, Wendy S.

2016-01-01

Influenza viruses cause annual seasonal epidemics and occasional pandemics. It is important to elucidate the stringency of bottlenecks during transmission to shed light on mechanisms that underlie the evolution and propagation of antigenic drift, host range switching or drug resistance. The virus spreads between people by different routes, including through the air in droplets and aerosols, and by direct contact. By housing ferrets under different conditions, it is possible to mimic various routes of transmission. Here, we inoculated donor animals with a mixture of two viruses whose genomes differed by one or two reverse engineered synonymous mutations, and measured the transmission of the mixture to exposed sentinel animals. Transmission through the air imposed a tight bottleneck since most recipient animals became infected by only one virus. In contrast, a direct contact transmission chain propagated a mixture of viruses suggesting the dose transferred by this route was higher. From animals with a mixed infection of viruses that were resistant and sensitive to the antiviral drug oseltamivir, resistance was propagated through contact transmission but not by air. These data imply that transmission events with a looser bottleneck can propagate minority variants and may be an important route for influenza evolution. PMID:27430528

Detection of bacterial and viral pathogens in hospitalized children with acute respiratory illness and determination of different socio demographic factors as important cause of the disease in Odisha, India

Directory of Open Access Journals (Sweden)

Bhagyalaxmi Biswal

2017-10-01

Full Text Available The paper an attempt has been made to analysis the status of acute respiratory tract infection among children in India. In the present study we aimed to present first time the detection of viruses, bacteria and mix infection of viruses and bacteria in hospitalized children with ARI and also to analyze the influence of socioeconomic status of parent in two divergent geographical settings of Odisha. Hospitalized children with ARI aged <5 were recruited from July 2014 to June 2015. Nasopharyngeal/Oropharyngial swabs were collected for detection of common respiratory viruses by reverse transcriptase chain reaction (RT-PCR. Bacteria were isolated by routine culture methods. Bivitiate analysis including chi square was used as test of significance. The analysis revealed 150 (56% were detected with ≥1 bacteria, 40 (15% with ≥ 1virus, 22 (8.2% with ≥ 2 bacteria and 20 (7-4% with both bacteria and virus. Most frequently detected pathogens were Klebsiella pneumonae (18.3%, Sptrptococcus pneumonae (12.7%, Parainfluenza A (36.6% and Influenza- A18 (30%. Incidences of pathogens were detected more among children <1 year, Gender discrimination in the form of dietary neglect of the female children has also been noted mostly in case of tribal patients. The present study had identified low socioeconomic status, poor housing conditions, illiterate mothers, birth weight, tobacco smoking families and nutritional status as important determinants for ARI. Interventions to improve these modifiable risk factors can significantly reduce the ARI burden among children especially in tribal population.

The CRP/FNR family protein Bcam1349 is a c-di-GMP effector that regulates biofilm formation in the respiratory pathogen Burkholderia cenocepacia

DEFF Research Database (Denmark)

Fazli, Mustafa; O'Connell, Aileen; Nilsson, Martin

2011-01-01

Burkholderia cenocepacia is an opportunistic respiratory pathogen that can cause severe infections in immune-compromised individuals and is associated with poor prognosis for patients suffering from cystic fibrosis. The second messenger cyclic diguanosine monophosphate (c-di-GMP) has been shown...... to control a wide range of functions in bacteria, but little is known about these regulatory mechanisms in B. cenocepacia. Here we investigated the role that c-di-GMP plays in the regulation of biofilm formation and virulence in B. cenocepacia. Elevated intracellular levels of c-di-GMP promoted wrinkly...... colony, pellicle and biofilm formation in B. cenocepacia. A screen for transposon mutants unable to respond to elevated levels of c-di-GMP led to the identification of the mutant bcam1349 that did not display increased biofilm and pellicle formation with excessive c-di-GMP levels, and displayed a biofilm...

Protection against avian metapneumovirus subtype C in turkeys immunized via the respiratory tract with inactivated virus.

Science.gov (United States)

Cha, Ra Mi; Khatri, Mahesh; Sharma, Jagdev M

2011-01-10

Avian metapneumovirus subtype C (aMPV/C) causes a severe upper respiratory tract (URT) infection in turkeys. Turkeys were inoculated oculonasally with inactivated aMPV/C adjuvanted with synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid (Poly IC). Immunized turkeys had elevated numbers of mucosal IgA+ cells in the URT and increased levels of virus-specific IgG and IgA in the lachrymal fluid and IgG in the serum. After 7 or 21 days post immunization, turkeys were challenged oculonasally with pathogenic aMPV/C. Immunized groups were protected against respiratory lesions induced by the challenge virus. Further, the viral copy number of the challenge virus in the URT were significantly lower in the immunized turkeys than in the unimmunized turkeys (P<0.05). These results showed that inactivated aMPV/C administered by the respiratory route induced protective immunity against pathogenic virus challenge. Copyright © 2010 Elsevier Ltd. All rights reserved.

An individual-based model of transmission of resistant bacteria in a veterinary teaching hospital.

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Neeraj Suthar

Full Text Available Veterinary nosocomial infections caused by antibiotic resistant bacteria cause increased morbidity, higher cost and length of treatment and increased zoonotic risk because of the difficulty in treating them. In this study, an individual-based model was developed to investigate the effects of movements of canine patients among ten areas (transmission points within a veterinary teaching hospital, and the effects of these movements on transmission of antibiotic susceptible and resistant pathogens. The model simulates contamination of transmission points, healthcare workers, and patients as well as the effects of decontamination of transmission points, disinfection of healthcare workers, and antibiotic treatments of canine patients. The model was parameterized using data obtained from hospital records, information obtained by interviews with hospital staff, and the published literature. The model suggested that transmission resulting from contact with healthcare workers was common, and that certain transmission points (housing wards, diagnostics room, and the intensive care unit presented higher risk for transmission than others (lobby and surgery. Sensitivity analyses using a range of parameter values demonstrated that the risk of acquisition of colonization by resistant pathogens decreased with shorter patient hospital stays (P<0.0001, more frequent decontamination of transmission points and disinfection of healthcare workers (P<0.0001 and better compliance of healthcare workers with hygiene practices (P<0.0001. More frequent decontamination of heavily trafficked transmission points was especially effective at reducing transmission of the model pathogen.

Use of molecular hydrogen as an energy substrate by human pathogenic bacteria.

Science.gov (United States)

Maier, R J

2005-02-01

Molecular hydrogen is produced as a fermentation by-product in the large intestine of animals and its production can be correlated with the digestibility of the carbohydrates consumed. Pathogenic Helicobacter species (Helicobacter pylori and H. hepaticus) have the ability to use H(2) through a respiratory hydrogenase, and it was demonstrated that the gas is present in the tissues colonized by these pathogens (the stomach and the liver respectively of live animals). Mutant strains of H. pylori unable to use H(2) are deficient in colonizing mice compared with the parent strain. On the basis of available annotated gene sequence information, the enteric pathogen Salmonella, like other enteric bacteria, contains three putative membrane-associated H(2)-using hydrogenase enzymes. From the analysis of gene-targeted mutants it is concluded that each of the three membrane-bound hydrogenases of Salmonella enterica serovar Typhimurium are coupled with an H(2)-oxidizing respiratory pathway. From microelectrode probe measurements on live mice, H(2) could be detected at approx. 50 muM levels within the tissues (liver and spleen), which are colonized by Salmonella. The half-saturation affinity of whole cells of these pathogens for H(2) is much less than this, so it is expected that the (H(2)-utilizing) hydrogenase enzymes be saturated with the reducing substrate in vivo. All three enteric NiFe hydrogenase enzymes contribute to virulence of the bacterium in a typhoid fever-mouse model, and the combined removal of all three hydrogenases resulted in a strain that is avirulent and (in contrast with the parent strain) one that is not able to pass the intestinal tract to invade liver or spleen tissue. It is proposed that H(2) utilization and specifically its oxidation, coupled with a respiratory pathway, is required for energy production to permit growth and maintain efficient virulence of a number of pathogenic bacteria during infection of animals. These would be expected to include

Respiratory microbes present in the nasopharynx of children hospitalised with suspected pulmonary tuberculosis in Cape Town, South Africa

Directory of Open Access Journals (Sweden)

Felix S. Dube

2016-10-01

Full Text Available Abstract Background Lower respiratory tract infection in children is increasingly thought to be polymicrobial in origin. Children with symptoms suggestive of pulmonary tuberculosis (PTB may have tuberculosis, other respiratory tract infections or co-infection with Mycobacterium tuberculosis and other pathogens. We aimed to identify the presence of potential respiratory pathogens in nasopharyngeal (NP samples from children with suspected PTB. Method NP samples collected from consecutive children presenting with suspected PTB at Red Cross Children’s Hospital (Cape Town, South Africa were tested by multiplex real-time RT-PCR. Mycobacterial liquid culture and Xpert MTB/RIF was performed on 2 induced sputa obtained from each participant. Children were categorised as definite-TB (culture or qPCR [Xpert MTB/RIF] confirmed, unlikely-TB (improvement of symptoms without TB treatment on follow-up and unconfirmed-TB (all other children. Results Amongst 214 children with a median age of 36 months (interquartile range, [IQR] 19–66 months, 34 (16 % had definite-TB, 86 (40 % had unconfirmed-TB and 94 (44 % were classified as unlikely-TB. Moraxella catarrhalis (64 %, Streptococcus pneumoniae (42 %, Haemophilus influenzae spp (29 % and Staphylococcus aureus (22 % were the most common bacteria detected in NP samples. Other bacteria detected included Mycoplasma pneumoniae (9 %, Bordetella pertussis (7 % and Chlamydophila pneumoniae (4 %. The most common viruses detected included metapneumovirus (19 %, rhinovirus (15 %, influenza virus C (9 %, adenovirus (7 %, cytomegalovirus (7 % and coronavirus O43 (5.6 %. Both bacteria and viruses were detected in 73, 55 and 56 % of the definite, unconfirmed and unlikely-TB groups, respectively. There were no significant differences in the distribution of respiratory microbes between children with and without TB. Using quadratic discriminant analysis, human metapneumovirus, C. pneumoniae, coronavirus 043

Environmental Persistence Influences Infection Dynamics for a Butterfly Pathogen.

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Dara A Satterfield

Full Text Available Many pathogens, including those infecting insects, are transmitted via dormant stages shed into the environment, where they must persist until encountering a susceptible host. Understanding how abiotic conditions influence environmental persistence and how these factors influence pathogen spread are crucial for predicting patterns of infection risk. Here, we explored the consequences of environmental transmission for infection dynamics of a debilitating protozoan parasite (Ophryocystis elektroscirrha that infects monarch butterflies (Danaus plexippus. We first conducted an experiment to observe the persistence of protozoan spores exposed to natural conditions. Experimental results showed that, contrary to our expectations, pathogen doses maintained high infectivity even after 16 days in the environment, although pathogens did yield infections with lower parasite loads after environmental exposure. Because pathogen longevity exceeded the time span of our experiment, we developed a mechanistic model to better explore environmental persistence for this host-pathogen system. Model analysis showed that, in general, longer spore persistence led to higher infection prevalence and slightly smaller monarch population sizes. The model indicated that typical parasite doses shed onto milkweed plants must remain viable for a minimum of 3 weeks for prevalence to increase during the summer-breeding season, and for 11 weeks or longer to match levels of infection commonly reported from the wild, assuming moderate values for parasite shedding rate. Our findings showed that transmission stages of this butterfly pathogen are long-lived and indicated that this is a necessary condition for the protozoan to persist in local monarch populations. This study provides a modeling framework for future work examining the dynamics of an ecologically important pathogen in an iconic insect.

Respiratory guiding system for respiratory motion management in respiratory gated radiotherapy

International Nuclear Information System (INIS)

Kang, Seong Hee; Kim, Dong Su; Kim, Tae Ho; Suh, Tae Suk

2013-01-01

Respiratory guiding systems have been shown to improve the respiratory regularity. This, in turn, improves the efficiency of synchronized moving aperture radiation therapy, and it reduces the artifacts caused by irregular breathing in imaging techniques such as four-dimensional computed tomography (4D CT), which is used for treatment planning in RGRT. We have previously developed a respiratory guiding system that incorporates an individual-specific guiding waveform, which is easy to follow for each volunteer, to improve the respiratory regularity. The present study evaluates the application of this system to improve the respiratory regularity for respiratory-gated radiation therapy (RGRT). In this study, we evaluated the effectiveness of an in-house-developed respiratory guiding system incorporating an individual specific guiding waveform to improve the respiratory regularity for RGRT. Most volunteers showed significantly less residual motion at each phase during guided breathing owing to the improvement in respiratory regularity. Therefore, the respiratory guiding system can clearly reduce the residual, or respiratory, motion in each phase. From the result, the CTV and the PTV margins during RGRT can be reduced by using the respiratory guiding system, which reduces the residual motions, thus improving the accuracy of RGRT

Risk maps for the spread of highly pathogenic avian influenza in poultry.

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Gert Jan Boender

2007-04-01

Full Text Available Devastating epidemics of highly contagious animal diseases such as avian influenza, classical swine fever, and foot-and-mouth disease underline the need for improved understanding of the factors promoting the spread of these pathogens. Here the authors present a spatial analysis of the between-farm transmission of a highly pathogenic H7N7 avian influenza virus that caused a large epidemic in The Netherlands in 2003. The authors developed a method to estimate key parameters determining the spread of highly transmissible animal diseases between farms based on outbreak data. The method allows for the identification of high-risk areas for propagating spread in an epidemiologically underpinned manner. A central concept is the transmission kernel, which determines the probability of pathogen transmission from infected to uninfected farms as a function of interfarm distance. The authors show how an estimate of the transmission kernel naturally provides estimates of the critical farm density and local reproduction numbers, which allows one to evaluate the effectiveness of control strategies. For avian influenza, the analyses show that there are two poultry-dense areas in The Netherlands where epidemic spread is possible, and in which local control measures are unlikely to be able to halt an unfolding epidemic. In these regions an epidemic can only be brought to an end by the depletion of susceptible farms by infection or massive culling. The analyses provide an estimate of the spatial range over which highly pathogenic avian influenza viruses spread between farms, and emphasize that control measures aimed at controlling such outbreaks need to take into account the local density of farms.

Monkeypox disease transmission in an experimental setting: prairie dog animal model.

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Christina L Hutson

Full Text Available Monkeypox virus (MPXV is considered the most significant human public health threat in the genus Orthopoxvirus since the eradication of variola virus (the causative agent of smallpox. MPXV is a zoonotic agent endemic to forested areas of Central and Western Africa. In 2003, MPXV caused an outbreak in the United States due to the importation of infected African rodents, and subsequent sequential infection of North American prairie dogs (Cynomys ludovicianus and humans. In previous studies, the prairie dog MPXV model has successfully shown to be very useful for understanding MPXV since the model emulates key characteristics of human monkeypox disease. In humans, percutaneous exposure to animals has been documented but the primary method of human-to-human MPXV transmission is postulated to be by respiratory route. Only a few animal model studies of MPXV transmission have been reported. Herein, we show that MPXV infected prairie dogs are able to transmit the virus to naive animals through multiple transmission routes. All secondarily exposed animals were infected with MPXV during the course of the study. Notably, animals secondarily exposed appeared to manifest more severe disease; however, the disease course was very similar to those of experimentally challenged animals including inappetence leading to weight loss, development of lesions, production of orthopoxvirus antibodies and shedding of similar levels or in some instances higher levels of MPXV from the oral cavity. Disease was transmitted via exposure to contaminated bedding, co-housing, or respiratory secretions/nasal mucous (we could not definitively say that transmission occurred via respiratory route exclusively. Future use of the model will allow us to evaluate infection control measures, vaccines and antiviral strategies to decrease disease transmission.

Does virus-bacteria coinfection increase the clinical severity of acute respiratory infection?

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Damasio, Guilherme A C; Pereira, Luciane A; Moreira, Suzana D R; Duarte dos Santos, Claudia N; Dalla-Costa, Libera M; Raboni, Sonia M

2015-09-01

This retrospective cohort study investigated the presence of bacteria in respiratory secretions of patients hospitalized with acute respiratory infections and analyzed the impact of viral and bacterial coinfection on severity and the mortality rate. A total of 169 patients with acute respiratory infections were included, viruses and bacteria in respiratory samples were detected using molecular methods. Among all samples, 73.3% and 59.7% were positive for viruses and bacteria, respectively; 45% contained both virus and bacteria. Bacterial coinfection was more frequent in patients infected by community respiratory viruses than influenza A H1N1pdm (83.3% vs. 40.6%). The most frequently bacteria detected were Streptococcus pneumoniae and Haemophilus influenzae. Both species were co-detected in 54 patients and identified alone in 22 and 21 patients, respectively. Overall, there were no significant differences in the period of hospitalization, severity, or mortality rate between patients infected with respiratory viruses alone and those coinfected by viruses and bacteria. The detection of mixed respiratory pathogens is frequent in hospitalized patients with acute respiratory infections, but its impact on the clinical outcome does not appear substantial. However, it should be noted that most of the patients received broad-spectrum antibiotic therapy, which may have contributed to this favorable outcome. © 2015 Wiley Periodicals, Inc.

Co-feeding transmission facilitates strain coexistence in Borrelia burgdorferi, the Lyme disease agent

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S.L. States

2017-06-01

Full Text Available Coexistence of multiple tick-borne pathogens or strains is common in natural hosts and can be facilitated by resource partitioning of the host species, within-host localization, or by different transmission pathways. Most vector-borne pathogens are transmitted horizontally via systemic host infection, but transmission may occur in the absence of systemic infection between two vectors feeding in close proximity, enabling pathogens to minimize competition and escape the host immune response. In a laboratory study, we demonstrated that co-feeding transmission can occur for a rapidly-cleared strain of Borrelia burgdorferi, the Lyme disease agent, between two stages of the tick vector Ixodes scapularis while feeding on their dominant host, Peromyscus leucopus. In contrast, infections rapidly became systemic for the persistently infecting strain. In a field study, we assessed opportunities for co-feeding transmission by measuring co-occurrence of two tick stages on ears of small mammals over two years at multiple sites. Finally, in a modeling study, we assessed the importance of co-feeding on R0, the basic reproductive number. The model indicated that co-feeding increases the fitness of rapidly-cleared strains in regions with synchronous immature tick feeding. Our results are consistent with increased diversity of B. burgdorferi in areas of higher synchrony in immature feeding – such as the midwestern United States. A higher relative proportion of rapidly-cleared strains, which are less human pathogenic, would also explain lower Lyme disease incidence in this region. Finally, if co-feeding transmission also occurs on refractory hosts, it may facilitate the emergence and persistence of new pathogens with a more limited host range.

Clinical requirements in the treatment of today's respiratory tract infections.

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Höffken, G

1993-01-01

Respiratory tract infections (RTIs) are among the most frequent infections in man and lower tract infections account substantially for the overall mortality in hospitals. Regarding the etiology of pneumonias, one has to consider different pathogenic mechanisms, age of the patients, underlying diseases, concomitant medications, symptomatologies, seasonal influences, and clinical conditions, e.g. intensive care environment and mechanical ventilation. To optimize the rational management of respiratory infections, identification of the etiologic agent would be desirable. The decision of how to treat is often based on epidemiologic, clinical, and radiological assessments. Epidemiologic studies have shown a pronounced difference in the etiologic spectrum between community- and hospital-acquired RTIs. In community-acquired pneumonias, pneumococci, Haemophilus influenzae, Legionella, Mycoplasma and viruses predominate, whereas in nosocomially acquired pneumonias, Enterobacteriaceae, e.g. Klebsiella, Proteus, Enterobacter as well as Pseudomonas and staphylococci comprise the most frequent isolates. Empirical therapy has to cover all possible etiologic pathogens which most likely cause the infection. In addition, an adequate kinetic profile, e.g. once or twice daily dosing, sufficient pulmonary tissue or fluid penetration, and acceptable tolerance and costs are prerequisites for optimal therapy. Drugs of choice for the treatment of community-acquired pneumonia are aminobenzylpenicillins or macrolides. Oral cephalosporins exhibit excellent activity against many bacterial pathogens of typical community-acquired pneumonia, and are active against beta-lactamase-producing H. influenzae.

Need for a safe vaccine against respiratory syncytial virus infection

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Joo-Young Kim

2012-09-01

Full Text Available Human respiratory syncytial virus (HRSV is a major cause of severe respiratory tract illnesses in infants and young children worldwide. Despite its importance as a respiratory pathogen, there is currently no licensed vaccine for HRSV. Following failure of the initial trial of formalin-inactivated virus particle vaccine, continuous efforts have been made for the development of safe and efficacious vaccines against HRSV. However, several obstacles persist that delay the development of HRSV vaccine, such as the immature immune system of newborn infants and the possible Th2-biased immune responses leading to subsequent vaccine-enhanced diseases. Many HRSV vaccine strategies are currently being developed and evaluated, including live-attenuated viruses, subunit-based, and vector-based candidates. In this review, the current HRSV vaccines are overviewed and the safety issues regarding asthma and vaccine-induced pathology are discussed.

Upper respiratory tract infections in athletes.

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Page, Clifton L; Diehl, Jason J

2007-07-01

Upper respiratory tract infections (URTIs) represent the most common acute illnesses in the general population and account for the leading acute diagnoses in the outpatient setting. Given the athlete's expectation to return to activity as soon as possible, the sports medicine physician should be able to accurately diagnose and aggressively treat these illnesses. This article discusses the common pathogens, diagnosis, treatment options, and return-to-play decisions for URTIs, with a focus on the common cold, sinusitis, pharyngitis, and infectious mononucleosis in the athlete.

Biofilm formation and cellulose expression by Bordetella avium 197N, the causative agent of bordetellosis in birds and an opportunistic respiratory pathogen in humans.

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McLaughlin, Kimberley; Folorunso, Ayorinde O; Deeni, Yusuf Y; Foster, Dona; Gorbatiuk, Oksana; Hapca, Simona M; Immoor, Corinna; Koza, Anna; Mohammed, Ibrahim U; Moshynets, Olena; Rogalsky, Sergii; Zawadzki, Kamil; Spiers, Andrew J

2017-06-01

Although bacterial cellulose synthase (bcs) operons are widespread within the Proteobacteria phylum, subunits required for the partial-acetylation of the polymer appear to be restricted to a few γ-group soil, plant-associated and phytopathogenic pseudomonads, including Pseudomonas fluorescens SBW25 and several Pseudomonas syringae pathovars. However, a bcs operon with acetylation subunits has also been annotated in the unrelated β-group respiratory pathogen, Bordetella avium 197N. Our comparison of subunit protein sequences and GC content analyses confirms the close similarity between the B. avium 197N and pseudomonad operons and suggests that, in both cases, the cellulose synthase and acetylation subunits were acquired as a single unit. Using static liquid microcosms, we can confirm that B. avium 197N expresses low levels of cellulose in air-liquid interface biofilms and that biofilm strength and attachment levels could be increased by elevating c-di-GMP levels like the pseudomonads, but cellulose was not required for biofilm formation itself. The finding that B. avium 197N is capable of producing cellulose from a highly-conserved, but relatively uncommon bcs operon raises the question of what functional role this modified polymer plays during the infection of the upper respiratory tract or survival between hosts, and what environmental signals control its production. Copyright © 2017 Institut Pasteur. All rights reserved.

The application of ultraviolet germicidal irradiation to control transmission of airborne disease: bioterrorism countermeasure.

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Brickner, Philip W; Vincent, Richard L; First, Melvin; Nardell, Edward; Murray, Megan; Kaufman, Will

2003-01-01

Bioterrorism is an area of increasing public health concern. The intent of this article is to review the air cleansing technologies available to protect building occupants from the intentional release of bioterror agents into congregate spaces (such as offices, schools, auditoriums, and transportation centers), as well as through outside air intakes and by way of recirculation air ducts. Current available technologies include increased ventilation, filtration, and ultraviolet germicidal irradiation (UVGI) UVGI is a common tool in laboratories and health care facilities, but is not familiar to the public, or to some heating, ventilation, and air conditioning engineers. Interest in UVGI is increasing as concern about a possible malicious release of bioterror agents mounts. Recent applications of UVGI have focused on control of tuberculosis transmission, but a wide range of airborne respiratory pathogens are susceptible to deactivation by UVGI. In this article, the authors provide an overview of air disinfection technologies, and an in-depth analysis of UVGI-its history, applications, and effectiveness.

Preventing Airborne Disease Transmission: Review of Methods for Ventilation Design in Health Care Facilities

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Aliabadi, Amir A.; Rogak, Steven N.; Bartlett, Karen H.; Green, Sheldon I.

2011-01-01

Health care facility ventilation design greatly affects disease transmission by aerosols. The desire to control infection in hospitals and at the same time to reduce their carbon footprint motivates the use of unconventional solutions for building design and associated control measures. This paper considers indoor sources and types of infectious aerosols, and pathogen viability and infectivity behaviors in response to environmental conditions. Aerosol dispersion, heat and mass transfer, deposition in the respiratory tract, and infection mechanisms are discussed, with an emphasis on experimental and modeling approaches. Key building design parameters are described that include types of ventilation systems (mixing, displacement, natural and hybrid), air exchange rate, temperature and relative humidity, air flow distribution structure, occupancy, engineered disinfection of air (filtration and UV radiation), and architectural programming (source and activity management) for health care facilities. The paper describes major findings and suggests future research needs in methods for ventilation design of health care facilities to prevent airborne infection risk. PMID:22162813

Ross, macdonald, and a theory for the dynamics and control of mosquito-transmitted pathogens.

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Smith, David L; Battle, Katherine E; Hay, Simon I; Barker, Christopher M; Scott, Thomas W; McKenzie, F Ellis

2012-01-01

Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various "Ross-Macdonald" mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955-1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention.

Anti-Aspergillus Activities of the Respiratory Epithelium in Health and Disease

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Margherita Bertuzzi

2018-01-01

Full Text Available Respiratory epithelia fulfil multiple roles beyond that of gaseous exchange, also acting as primary custodians of lung sterility and inflammatory homeostasis. Inhaled fungal spores pose a continual antigenic, and potentially pathogenic, challenge to lung integrity against which the human respiratory mucosa has developed various tolerance and defence strategies. However, respiratory disease and immune dysfunction frequently render the human lung susceptible to fungal diseases, the most common of which are the aspergilloses, a group of syndromes caused by inhaled spores of Aspergillus fumigatus. Inhaled Aspergillus spores enter into a multiplicity of interactions with respiratory epithelia, the mechanistic bases of which are only just becoming recognized as important drivers of disease, as well as possible therapeutic targets. In this mini-review we examine current understanding of Aspergillus-epithelial interactions and, based upon the very latest developments in the field, we explore two apparently opposing schools of thought which view epithelial uptake of Aspergillus spores as either a curative or disease-exacerbating event.

An Investigation of the Pathology and Pathogens Associated with Porcine Respiratory Disease Complex in Denmark

DEFF Research Database (Denmark)

Hansen, Mette Sif; Pors, S. E.; Jensen, H. E.

2010-01-01

), porcine reproductive and respiratory syndrome virus (both European and US type), porcine circovirus type 2 (PCV2), porcine respiratory coronavirus, porcine cytomegalovirus, Mycoplasma hyopneumoniae and Mycoplasma hyorhinis. All cases had cranioventral lobular bronchopneumonia consistent with PRDC....... There was a broad range of microscopical lesions and the cases were characterized as acute (n=10), subacute (n=24) or chronic (n=114) bronchopneumonia. Five bacterial species, five viruses and two Mycoplasma spp. were detected in different combinations. PCV2, M. hyopneumoniae, M. hyorhinis and Pasteurella multocida...

Neonatal Bacterial Colonization Predispose to Lower Respiratory Infections in Early Childhood

DEFF Research Database (Denmark)

Vissing, Nadja Hawwa

2014-01-01

, and high sensitivity to respiratory, infectious and skin related illness. In particular, sensitivity on LRI was 96%. There was no evidence of bias from concurrent asthmatic disease or socioeconomic status. In conclusion, the study confirmed that COPSAC data is a valid source for investigating childhood......Lower respiratory infections (LRI) in childhood are common and account for considerable morbidity and health care utilization. The frequency of LRI varies significantly between otherwise healthy children, but extrinsic and intrinsic triggers of such variation are poorly understood. Traditionally...... neonatal airway colonization and risk of the LRI in a validated study cohort, and whether a possible association could be reflected in the early immune response to airway pathogens. In study I we aimed to ascertain the quality of information on child’s health, including asthma, allergy, eczema, respiratory...

Mechanism and Clinical Importance of Respiratory Failure Induced by Anticholinesterases

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Ivosevic Anita

2017-12-01

Full Text Available Respiratory failure is the predominant cause of death in humans and animals poisoned with anticholinesterases. Organophosphorus and carbamate anticholinesterases inhibit acetylcholinesterase irreversibly and reversibly, respectively. Some of them contain a quaternary atom that makes them lipophobic, limiting their action at the periphery, i.e. outside the central nervous system. They impair respiratory function primarily by inducing a desensitization block of nicotinic receptors in the neuromuscular synapse. Lipophilic anticholinesterases inhibit the acetylcholinesterase both in the brain and in other tissues, including respiratory muscles. Their doses needed for cessation of central respiratory drive are significantly less than doses needed for paralysis of the neuromuscular transmission. Antagonist of muscarinic receptors atropine blocks both the central and peripheral muscarinic receptors and effectively antagonizes the central respiratory depression produced by anticholinesterases. To manage the peripheral nicotinic receptor hyperstimulation phenomena, oximes as acetylcholinesterase reactivators are used. Addition of diazepam is useful for treatment of seizures, since they are cholinergic only in their initial phase and can contribute to the occurrence of central respiratory depression. Possible involvement of central nicotinic receptors as well as the other neurotransmitter systems – glutamatergic, opioidergic – necessitates further research of additional antidotes.

“Diagnosis of sleep apnea in network” respiratory polygraphy as a decentralization strategy

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Eduardo Borsini

2016-07-01

Conclusions: Physicians were able to diagnosis OSA by doing portable respiratory polygraphy at distance. The remote diagnosis strategy presented short delays, safe data transmission, and low rate of missing data.

Detection of Pathogen Exposure in African Buffalo Using Non-Specific Markers of Inflammation

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Caroline K. Glidden

2018-01-01

Full Text Available Detecting exposure to new or emerging pathogens is a critical challenge to protecting human, domestic animal, and wildlife health. Yet, current techniques to detect infections typically target known pathogens of humans or economically important animals. In the face of the current surge in infectious disease emergence, non-specific disease surveillance tools are urgently needed. Tracking common host immune responses indicative of recent infection may have potential as a non-specific diagnostic approach for disease surveillance. The challenge to immunologists is to identify the most promising markers, which ideally should be highly conserved across pathogens and host species, become upregulated rapidly and consistently in response to pathogen invasion, and remain elevated beyond clearance of infection. This study combined an infection experiment and a longitudinal observational study to evaluate the utility of non-specific markers of inflammation [NSMI; two acute phase proteins (haptoglobin and serum amyloid A, two pro-inflammatory cytokines (IFNγ and TNF-α] as indicators of pathogen exposure in a wild mammalian species, African buffalo (Syncerus caffer. Specifically, in the experimental study, we asked (1 How quickly do buffalo mount NSMI responses upon challenge with an endemic pathogen, foot-and-mouth disease virus; (2 for how long do NSMI remain elevated after viral clearance and; (3 how pronounced is the difference between peak NSMI concentration and baseline NSMI concentration? In the longitudinal study, we asked (4 Are elevated NSMI associated with recent exposure to a suite of bacterial and viral respiratory pathogens in a wild population? Among the four NSMI that we tested, haptoglobin showed the strongest potential as a surveillance marker in African buffalo: concentrations quickly and consistently reached high levels in response to experimental infection, remaining elevated for almost a month. Moreover, elevated haptoglobin was

Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees.

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Elsa Youngsteadt

Full Text Available Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus, the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators.

Urbanization Increases Pathogen Pressure on Feral and Managed Honey Bees.

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Youngsteadt, Elsa; Appler, R Holden; López-Uribe, Margarita M; Tarpy, David R; Frank, Steven D

2015-01-01

Given the role of infectious disease in global pollinator decline, there is a need to understand factors that shape pathogen susceptibility and transmission in bees. Here we ask how urbanization affects the immune response and pathogen load of feral and managed colonies of honey bees (Apis mellifera Linnaeus), the predominant economically important pollinator worldwide. Using quantitative real-time PCR, we measured expression of 4 immune genes and relative abundance of 10 honey bee pathogens. We also measured worker survival in a laboratory bioassay. We found that pathogen pressure on honey bees increased with urbanization and management, and the probability of worker survival declined 3-fold along our urbanization gradient. The effect of management on pathogens appears to be mediated by immunity, with feral bees expressing immune genes at nearly twice the levels of managed bees following an immune challenge. The effect of urbanization, however, was not linked with immunity; instead, urbanization may favor viability and transmission of some disease agents. Feral colonies, with lower disease burdens and stronger immune responses, may illuminate ways to improve honey bee management. The previously unexamined effects of urbanization on honey-bee disease are concerning, suggesting that urban areas may favor problematic diseases of pollinators.

Genomic analysis and pathogenic characteristics of Type 2 porcine reproductive and respiratory syndrome virus nsp2 deletion strains isolated in Korea.

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Choi, Hwan-Won; Nam, Eeuri; Lee, Yoo Jin; Noh, Yun-Hee; Lee, Seung-Chul; Yoon, In-Joong; Kim, Hyun-Soo; Kang, Shien-Young; Choi, Young-Ki; Lee, Changhee

2014-06-04

Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine virus that exhibits genetic and pathogenic heterogeneity among isolates. The present study was conducted to determine the complete genome sequence and pathogenicity of two Korean type 2 PRRSV nonstructural protein 2 (nsp2) deletion mutants, CA-2 and KNU-12-KJ4. The full-length genomes of CA-2 and KNU-12-KJ4 were determined to be 15,018 and 15,019 nucleotides in length, excluding the poly(A) tail, respectively, which were 393- or 392-nucleotide shorter than that of the type 2 NA prototype strain VR-2332 due to the presence of notable large deletions within the nsp2 gene. The genomes of CA-2 and KNU-12-KJ4 consisted of a 189- or 190-nucleotide 5' untranslated region (UTR), a 14,677-nucleotide protein-coding region, and a 151-nucleotide 3' UTR. Whole genome evaluation revealed that the nucleotide sequences of CA-2 and KNU-12-KJ4 are most similar to each other (10.7% sequence divergence), and then to the Korean strain CA-1 (11.3% sequence divergence) and the US strain MN184C (13.1% sequence divergence), respectively. To evaluate the in vitro immunity of nsp2 deletion variants, we sought to explore alteration of inflammatory cytokine and chemokine expression in PAM-pCD163 cells infected with each virus strain using quantitative real-time RT-PCR. Cytokine genes including IL-8, IL-10, and TNF-α, and chemokines such as MCP-1 and RANTES were found to be significantly elevated in nsp2 deletion virus-infected PAM cells. In contrast, expression of interferons (IFN-β, γ, and λ) and antiviral genes including ISG-15, -54, and -56 were unchanged or down-regulated in PAM cells infected with the nsp2 deletion mutants. Animal studies to assess the pathogenicity of nsp2 deletion PRRSVs demonstrated that both CA-2 and KNU-12-KJ4 strains notably produce weight loss in infected pigs. Furthermore, the nsp2 deletion mutants replicated well in pigs with significantly increased and prolonged

Early animal farming and zoonotic disease dynamics: modelling brucellosis transmission in Neolithic goat populations.

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Fournié, Guillaume; Pfeiffer, Dirk U; Bendrey, Robin

2017-02-01

Zoonotic pathogens are frequently hypothesized as emerging with the origins of farming, but evidence of this is elusive in the archaeological records. To explore the potential impact of animal domestication on zoonotic disease dynamics and human infection risk, we developed a model simulating the transmission of Brucella melitensis within early domestic goat populations. The model was informed by archaeological data describing goat populations in Neolithic settlements in the Fertile Crescent, and used to assess the potential of these populations to sustain the circulation of Brucella . Results show that the pathogen could have been sustained even at low levels of transmission within these domestic goat populations. This resulted from the creation of dense populations and major changes in demographic characteristics. The selective harvesting of young male goats, likely aimed at improving the efficiency of food production, modified the age and sex structure of these populations, increasing the transmission potential of the pathogen within these populations. Probable interactions between Neolithic settlements would have further promoted pathogen maintenance. By fostering conditions suitable for allowing domestic goats to become reservoirs of Brucella melitensis , the early stages of agricultural development were likely to promote the exposure of humans to this pathogen.

H9N2 avian influenza transmission and antigenicity

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Low pathogenic H9N2 avian influenza has become endemic in parts of Asia, the Middle East and North Africa causing respiratory disease with occasional mortality. The use of vaccination has become common to try and control the clinical disease, but vaccination has not been shown to be an effective er...

A gravity model for the spread of a pollinator-borne plant pathogen.

Science.gov (United States)

Ferrari, Matthew J; Bjørnstad, Ottar N; Partain, Jessica L; Antonovics, Janis

2006-09-01

Many pathogens of plants are transmitted by arthropod vectors whose movement between individual hosts is influenced by foraging behavior. Insect foraging has been shown to depend on both the quality of hosts and the distances between hosts. Given the spatial distribution of host plants and individual variation in quality, vector foraging patterns may therefore produce predictable variation in exposure to pathogens. We develop a "gravity" model to describe the spatial spread of a vector-borne plant pathogen from underlying models of insect foraging in response to host quality using the pollinator-borne smut fungus Microbotryum violaceum as a case study. We fit the model to spatially explicit time series of M. violaceum transmission in replicate experimental plots of the white campion Silene latifolia. The gravity model provides a better fit than a mean field model or a model with only distance-dependent transmission. The results highlight the importance of active vector foraging in generating spatial patterns of disease incidence and for pathogen-mediated selection for floral traits.

Full-genome analysis of a canine pneumovirus causing acute respiratory disease in dogs, Italy.

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Nicola Decaro

Full Text Available An outbreak of canine infectious respiratory disease (CIRD associated to canine pneumovirus (CnPnV infection is reported. The outbreak occurred in a shelter of the Apulia region and involved 37 out of 350 dogs that displayed cough and/or nasal discharge with no evidence of fever. The full-genomic characterisation showed that the causative agent (strain Bari/100-12 was closely related to CnPnVs that have been recently isolated in the USA, as well as to murine pneumovirus, which is responsible for respiratory disease in mice. The present study represents a useful contribution to the knowledge of the pathogenic potential of CnPnV and its association with CIRD in dogs. Further studies will elucidate the pathogenicity and epidemiology of this novel pneumovirus, thus addressing the eventual need for specific vaccines.

Pathogenic human viruses in coastal waters

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Griffin, Dale W.; Donaldson, Kim A.; Paul, J.H.; Rose, Joan B.

2003-01-01

This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and

Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

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Krusor, Colin; Smith, Woutrina A.; Tinker, M. Tim; Silver, Mary; Conrad, Patricia A.; Shapiro, Karen

2015-01-01

The parasite Toxoplasma gondii is an environmentally persistent pathogen that can cause fatal disease in humans, terrestrial warm-blooded animals and aquatic mammals. Although an association between T. gondii exposure and prey specialization on marine snails was identified in threatened California sea otters, the ability of kelp-dwelling snails to transmit terrestrially derived pathogens has not been previously investigated. The objective of this study was to measure concentration and retention of T. gondii by marine snails in laboratory aquaria, and to test for natural T. gondii contamination in field-collected snails. Following exposure to T. gondii-containing seawater, oocysts were detected by microscopy in snail faeces and tissues for 10 and 3 days respectively. Nested polymerase chain reaction was also applied as a method for confirming putative T. gondii oocysts detected in snail faeces and tissues by microscopy. Toxoplasma gondiiwas not detected in field-collected snails. Results suggest that turban snails are competent transport hosts for T. gondii. By concentrating oocysts in faecal pellets, snails may facilitate entry of T. gondii into the nearshore marine food web. This novel mechanism also represents a general pathway by which marine transmission of terrestrially derived microorganisms can be mediated via pathogen concentration and retention by benthic invertebrates.

Porcine reproductive and respiratory syndrome virus (PRRSV): pathogenesis and interaction with the immune System

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This review addresses important issues of porcine reproductive and respiratory syndrome virus (PRRSV) infection, immunity, pathogenesis and control. Worldwide PRRS is the most economically important infectious disease of pigs. We highlight the latest information on viral genome structure, pathogenic...

Pilot study of participant-collected nasal swabs for acute respiratory infections in a low-income, urban population

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Vargas CY

2016-01-01

Full Text Available Celibell Y Vargas,1 Liqun Wang,1 Yaritza Castellanos de Belliard,1 Maria Morban,1 Hilbania Diaz,1 Elaine L Larson,2,3 Philip LaRussa,1 Lisa Saiman,1,4 Melissa S Stockwell1,5,6 1Department of Pediatrics, 2School of Nursing, 3Department of Epidemiology, Mailman School of Public Health, Columbia University, 4Department of Infection Prevention and Control, NewYork-Presbyterian Hospital, 5Department of Population and Family Health, Mailman School of Public Health, Columbia University, 6NewYork-Presbyterian Hospital, New York, NY, USA Objective: To assess the feasibility and validity of unsupervised participant-collected nasal swabs to detect respiratory pathogens in a low-income, urban minority population. Methods: This project was conducted as part of an ongoing community-based surveillance study in New York City to identify viral etiologies of acute respiratory infection. In January 2014, following sample collection by trained research assistants, participants with acute respiratory infection from 30 households subsequently collected and returned a self-collected/parent-collected nasal swab via mail. Self/parental swabs corresponding with positive reverse transcription polymerase chain reaction primary research samples were analyzed. Results: Nearly all (96.8%, n=30/31 households agreed to participate; 100% reported returning the sample and 29 were received (median time: 8 days. Most (18; 62.1% of the primary research samples were positive. For eight influenza-positive research samples, seven (87.5% self-swabs were also positive. For ten other respiratory pathogen-positive research samples, eight (80.0% self-swabs were positive. Sensitivity of self-swabs for any respiratory pathogen was 83.3% and 87.5% for influenza, and specificity for both was 100%. There was no relationship between level of education and concordance of results between positive research samples and their matching participant swab. Conclusion: In this pilot study, self

Field evidence for leech-borne transmission of amphibian Ichthyophonus sp.

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Raffel, Thomas R; Dillard, James R; Hudson, Peter J

2006-12-01

Parasites have been implicated in mass mortality events and population declines of amphibians around the world. One pathogen associated with mortality events in North America is an Ichthyophonus sp.-like organism that affects red-spotted newts (Notophthalmus viridescens) and several frog species, yet little is known about the distribution of this pathogen in wild populations or the mechanism of transmission. In an effort to identify factors influencing the distribution and abundance of this pathogen, we measured Ichthyophonus sp. prevalence and a series of factors that could contribute to transmission in 16 newt populations during spring 2004. In contrast to our initial hypotheses of trophic transmission, several lines of evidence suggested a role for the amphibian leech (Placobdella picta) in Ichthyophonus sp. transmission. We propose the mechanistic hypothesis that a leech acquires Ichthyophonus sp. infection when inserting its proboscis into the muscles beneath the skin of infected newts and transmits the infection to other newts in subsequent feeding bouts. We also found effects of host sex, body mass, and breeding condition on Ichthyophonus sp. prevalence and the number of attached leeches. The number of leeches attached to newts was strongly related to the proportion of newt habitat containing emergent vegetation, suggesting that anthropogenic eutrophication might lead to more frequent or severe outbreaks of Ichthyophonus sp. infection in amphibians.

Association between pathogens from tracheal aspirate and oral biofilm of patients on mechanical ventilation.

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Souza, Luana Carneiro Diniz; Mota, Vanise Barros Rodrigues da; Carvalho, Alícia Valéria Dos Santos Zaranza de; Corrêa, Rita da Graça Carvalhal Frazão; Libério, Silvana Amado; Lopes, Fernanda Ferreira

2017-06-05

The aim of this study was to detect possible associations between respiratory pathogens from tracheal aspirate and oral biofilm samples in intubated patients in an intensive care unit (ICU), and to identify the most common respiratory pathogens in oral biofilm, particularly in patients that developed ventilator-associated pneumonia (VAP). Two oral biofilm samples were collected from the tongue of intubated patients (at admission and after 48 hours) and analyzed by culture with the Antibiotic Sensitivity Test. The results from the tongue biofilm samples were compared with the tracheal secretions samples. A total of 59.37% of patients exhibited the same species of pathogens in their tracheal aspirate and oral biofilm, of which 8 (42.1%) developed VAP, 10 (52.63%) did not develop pneumonia and one (5.26%) had aspiration pneumonia. There was a statistically significant association between presence of microorganisms in the tracheal and mouth samples for the following pathogens: Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa, Enterobacter gergoviae, Streptococcus spp and Serratia marcescens (p aspirates of intubated patients can be detected in their oral cavity, especially in those who developed VAP or aspiration pneumonia. Thus, the results indicate that an improved oral care in these patients could decrease ICU pneumonia rates.

Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

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Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

2016-01-01

Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

Detection of Influenza C Viruses Among Outpatients and Patients Hospitalized for Severe Acute Respiratory Infection, Minnesota, 2013-2016.

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Thielen, Beth K; Friedlander, Hannah; Bistodeau, Sarah; Shu, Bo; Lynch, Brian; Martin, Karen; Bye, Erica; Como-Sabetti, Kathryn; Boxrud, David; Strain, Anna K; Chaves, Sandra S; Steffens, Andrea; Fowlkes, Ashley L; Lindstrom, Stephen; Lynfield, Ruth

2018-03-19

Existing literature suggests that influenza C typically causes mild respiratory tract disease. However, clinical and epidemiological data are limited. Four outpatient clinics and 3 hospitals submitted clinical data and respiratory specimens through a surveillance network for acute respiratory infection (ARI) from May 2013 through December 2016. Specimens were tested using multitarget nucleic acid amplification for 19-22 respiratory pathogens, including influenza C. Influenza C virus was detected among 59 of 10 202 (0.58%) hospitalized severe ARI cases and 11 of 2282 (0.48%) outpatients. Most detections occurred from December to March, 73% during the 2014-2015 season. Influenza C detections occurred among patients of all ages, with rates being similar between inpatients and outpatients. The highest rate of detection occurred among children aged 6-24 months (1.2%). Among hospitalized cases, 7 required intensive care. Medical comorbidities were reported in 58% of hospitalized cases and all who required intensive care. At least 1 other respiratory pathogen was detected in 40 (66%) cases, most commonly rhinovirus/enterovirus (25%) and respiratory syncytial virus (20%). The hemagglutinin-esterase-fusion gene was sequenced in 37 specimens, and both C/Kanagawa and C/Sao Paulo lineages were detected in inpatients and outpatients. We found seasonal circulation of influenza C with year-to-year variability. Detection was most frequent among young children but occurred in all ages. Some cases that were positive for influenza C, particularly those with comorbid conditions, had severe disease, suggesting a need for further study of the role of influenza C virus in the pathogenesis of respiratory disease.

CURRENT STATUS OF PROBLEM: CHILDREN WITH RECURRENT RESPIRATORY INFECTIONS

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V.A. Bulgakova

2007-01-01

Full Text Available The article deals with children suffered from recurrent respiraatory infections. The authors attempted to summarize the literature data on the research findings of inosine pranobex application (Isoa prinosine, Teva, Israel in complex therapy against virulent and inflammatory diseases. Within recent years, many experts emphaasize the persistence of viruses and other pathogenic microorganaisms in the human body, which leads to changes in reactivity and emergence of the chronic diseases. These disorders are especially urgent for sickly children, suffering from respiratory infections, what well justifies the application of bacteriogenic immunomodulaa tors, interferon synthesis inductors, expediency for incorporating immunomodulators with antiviral action into complex therapy along with special vaccination against flu, pneumococcus and etc.Key words: sickly children, acute respiratory infections, immunomodulators, inosine pranobex.

Non-specific Effect of Vaccines: Immediate Protection against Respiratory Syncytial Virus Infection by a Live Attenuated Influenza Vaccine

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Young J. Lee

2018-01-01

Full Text Available The non-specific effects (NSEs of vaccines have been discussed for their potential long-term beneficial effects beyond direct protection against a specific pathogen. Cold-adapted, live attenuated influenza vaccine (CAIV induces local innate immune responses that provide a broad range of antiviral immunity. Herein, we examined whether X-31ca, a donor virus for CAIVs, provides non-specific cross-protection against respiratory syncytial virus (RSV. The degree of RSV replication was significantly reduced when X-31ca was administered before RSV infection without any RSV-specific antibody responses. The vaccination induced an immediate release of cytokines and infiltration of leukocytes into the respiratory tract, moderating the immune perturbation caused by RSV infection. The potency of protection against RSV challenge was significantly reduced in TLR3-/- TLR7-/- mice, confirming that the TLR3/7 signaling pathways are necessary for the observed immediate and short-term protection. The results suggest that CAIVs provide short-term, non-specific protection against genetically unrelated respiratory pathogens. The additional benefits of CAIVs in mitigating acute respiratory infections for which vaccines are not yet available need to be assessed in future studies.

HEART DISEASE IN CHILDREN WITH RESPIRATORY INFECTIONS

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I. V. Babachenko

2016-01-01

Full Text Available The link between heart disease and infectious pathogens is well known. Despite the high frequency of cardiac pathology in infectious diseases, it is rarely diagnosed because of lack of specific clinical  and  laboratory  symptoms. It is especially  difficult to diagnose in  children. Airborne  infections in the structure of infectious morbidity of children occupy a leading place.The aim of this work was to study the nature of the lesions of the heart  in children suffering from acute infection of the respiratory tract.Materials and  methods: 341 children with acute respiratory infection of moderate severity were surveyed by a method of ECG dispersion mapping. Cardiac  pathology has not previously been determined in these children. Signs of disease of the heart was identified in 76 children (22%. Further study included instrumental (ECG, ECHO-KG,  daily monitoring of ECG, biochemical and  etiological (ELISA, PCR, immunocytochemical research  methods for determining the nature of the damage to the heart and the etiology of the disease.Results. Myocarditis was diagnosed in 2%  of children, a violation of repolarization – in 21%,  heart  rhythm disorders  – in 35%  (AV – blockade in 4%.  Most  often  signs  of heart disease were detected in children with Epstein-Barr virus (32%, streptococcal (28%, cytomegalovirus (25%, herpesvirus type  6 infection (24%. Pathogens from the  group of acute respiratory virus infections were identified in 28%, enterovirus – in  10%,  Haemophilus influenzae – in  10%, Mycoplasma pneumonia – in 10%,  Pneumococcus – in 9%, Chlamydia – in 9%, Parvovirus B19 – in 6%.Conclusion. Sensitive screening test  to  detect cardiac pathology is the method of ECG dispersion mapping. Heart damage in children with respiratory diseases in 60% of cases is associated with  mixed infections. Timely  diagnosis of lesions of the heart in infectious diseases in children allows to adjust the

Current Issues of Antipyretic Therapy in Children with Acute Respiratory Infections

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E. I. Novikova

2013-01-01

Full Text Available This article discusses the current issues in the pediatric practice of seasonal incidence of children with acute respiratory infections. The basic etiological aspects of this pathology, specific clinical symptoms typical for different pathogens, causes of bursts of disease in certain periods are described. Special attention is paid to the tactics of antipyretic therapy in different groups of children with fever and acute respiratory diseases, understand the typical errors in its appointment. The author discusses the domestic and foreign results of using ibuprofen to relieve fever in children with this pathology, comparative efficacy and safety data of ibuprofen with other analgesics-antipyretics.

Nasopharyngeal polymicrobial colonization during health, viral upper respiratory infection and upper respiratory bacterial infection.

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Xu, Qingfu; Wischmeyer, Jareth; Gonzalez, Eduardo; Pichichero, Michael E

2017-07-01

We sought to understand how polymicrobial colonization varies during health, viral upper respiratory infection (URI) and acute upper respiratory bacterial infection to understand differences in infection-prone vs. non-prone patients. Nasopharyngeal (NP) samples were collected from 74 acute otitis media (AOM) infection-prone and 754 non-prone children during 2094 healthy visits, 673 viral URI visits and 631 AOM visits. Three otopathogens Streptococcus pneumoniae (Spn), Nontypeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis (Mcat) were identified by culture. NP colonization rates of multiple otopathogens during health were significantly lower than during viral URI, and during URI they were lower than at onset of upper respiratory bacterial infection in both AOM infection-prone and non-prone children. AOM infection-prone children had higher polymicrobial colonization rates than non-prone children during health, viral URI and AOM. Polymicrobial colonization rates of AOM infection-prone children during health were equivalent to that of non-prone children during viral URI, and during viral URI were equivalent to that of non-prone during AOM infection. Spn colonization was positively associated with NTHi and Mcat colonization during health, but negatively during AOM infection. The infection-prone patients more frequently have multiple potential bacterial pathogens in the NP than the non-prone patients. Polymicrobial interaction in the NP differs during health and at onset of infection. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Do Tick Attachment Times Vary between Different Tick-Pathogen Systems?

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Stephanie L. Richards

2017-05-01

Full Text Available Improvements to risk assessments are needed to enhance our understanding of tick-borne disease epidemiology. We review tick vectors and duration of tick attachment required for pathogen transmission for the following pathogens/toxins and diseases: (1 Anaplasma phagocytophilum (anaplasmosis; (2 Babesia microti (babesiosis; (3 Borrelia burgdorferi (Lyme disease; (4 Southern tick-associated rash illness; (5 Borrelia hermsii (tick-borne relapsing fever; (6 Borrelia parkeri (tick-borne relapsing fever; (7 Borrelia turicatae (tick-borne relapsing fever; (8 Borrelia mayonii; (9 Borrelia miyamotoi; (10 Coxiella burnetii (Query fever; (11 Ehrlichia chaffeensis (ehrlichiosis; (12 Ehrlichia ewingii (ehrlichiosis; (13 Ehrlichia muris; (14 Francisella tularensis (tularemia; (15 Rickettsia 364D; (16 Rickettsia montanensis; (17 Rickettsia parkeri (American boutonneuse fever, American tick bite fever; (18 Rickettsia ricketsii (Rocky Mountain spotted fever; (19 Colorado tick fever virus (Colorado tick fever; (20 Heartland virus; (21 Powassan virus (Powassan disease; (22 tick paralysis neurotoxin; and (23 Galactose-α-1,3-galactose (Mammalian Meat Allergy-alpha-gal syndrome. Published studies for 12 of the 23 pathogens/diseases showed tick attachment times. Reported tick attachment times varied (<1 h to seven days between pathogen/toxin type and tick vector. Not all studies were designed to detect the duration of attachment required for transmission. Knowledge of this important aspect of vector competence is lacking and impairs risk assessment for some tick-borne pathogens.

Host and pathogen ecology drive the seasonal dynamics of a fungal disease, white-nose syndrome.

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Langwig, Kate E; Frick, Winifred F; Reynolds, Rick; Parise, Katy L; Drees, Kevin P; Hoyt, Joseph R; Cheng, Tina L; Kunz, Thomas H; Foster, Jeffrey T; Kilpatrick, A Marm

2015-01-22

Seasonal patterns in pathogen transmission can influence the impact of disease on populations and the speed of spatial spread. Increases in host contact rates or births drive seasonal epidemics in some systems, but other factors may occasionally override these influences. White-nose syndrome, caused by the emerging fungal pathogen Pseudogymnoascus destructans, is spreading across North America and threatens several bat species with extinction. We examined patterns and drivers of seasonal transmission of P. destructans by measuring infection prevalence and pathogen loads in six bat species at 30 sites across the eastern United States. Bats became transiently infected in autumn, and transmission spiked in early winter when bats began hibernating. Nearly all bats in six species became infected by late winter when infection intensity peaked. In summer, despite high contact rates and a birth pulse, most bats cleared infections and prevalence dropped to zero. These data suggest the dominant driver of seasonal transmission dynamics was a change in host physiology, specifically hibernation. Our study is the first, to the best of our knowledge, to describe the seasonality of transmission in this emerging wildlife disease. The timing of infection and fungal growth resulted in maximal population impacts, but only moderate rates of spatial spread. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Pathogenicity and transmission of triple reassortant H3N2 swine influenza A viruses is attenuated following Turkey embryo propagation.

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Raghunath, Shobana; Pudupakam, Raghavendra Sumanth; Deventhiran, Jagadeeswaran; Tevatia, Rahul; Leroith, Tanya

2017-03-01

Genetic lineages of swine influenza A viruses (SIVs) have recently been established in Turkeys in the United States. To identify molecular determinants that are involved in virulence and transmission of SIVs to Turkeys, we sequentially passaged two triple reassortant H3N2 SIV isolates from Minnesota in ten day old specific-pathogen free (SPF) Turkey embryos and tested them in seven-day old Turkey poults. We found that SIV replication in Turkey embryos led to minimal mutations in and around the receptor binding and antigenic sites of the HA molecule, while other gene segments were unchanged. The predominant changes associated with Turkey embryo passage were A223V, V226A and T248I mutations in the receptor-binding and glycosylation sites of the HA molecule. Furthermore, Turkey embryo propagation altered receptor specificity in SIV strain 07-1145. Embryo passaged 07-1145 virus showed a decrease in α2, 6 sialic acid receptor binding compared to the wild type virus. Intranasal infection of wild type SIVs in one-week-old Turkey poults resulted in persistent diarrhea and all the infected birds seroconverted at ten days post infection. The 07-1145 wild type virus also transmitted to age matched in-contact birds introduced one-day post infection. Turkeys infected with embryo passaged viruses displayed no clinical signs and were not transmitted to in-contact poults. Our results suggest that Turkey embryo propagation attenuates recent TR SIVs for infectivity and transmission in one week old Turkeys. Our findings will have important implications in identifying molecular determinants that control the transmission and virulence of TR SIVs in Turkeys and other species. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection and typing of highly pathogenic porcine reproductive and respiratory syndrome virus by multiplex real-time rt-PCR.

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Kerstin Wernike

Full Text Available Porcine reproductive and respiratory syndrome (PRRS causes economic losses in the pig industry worldwide, and PRRS viruses (PRRSV are classified into the two distinct genotypes "North American (NA, type 2" and "European (EU, type 1". In 2006, a highly pathogenic NA strain of PRRSV (HP-PRRSV, characterized by high fever as well as high morbidity and mortality, emerged in swine farms in China. Therefore, a real-time reverse transcription polymerase chain reaction (RT-qPCR assay specific for HP-PRRSV was developed and combined with type 1- and type 2-specific RT-qPCR systems. Furthermore, an internal control, based on a heterologous RNA, was successfully introduced. This final multiplex PRRSV RT-qPCR, detecting and typing PRRSV, had an analytical sensitivity of less than 200 copies per µl for the type 1-assay and 20 copies per µl for the type 2- and HP assays and a high diagnostic sensitivity. A panel of reference strains and field isolates was reliably detected and samples from an animal trial with a Chinese HP-PRRS strain were used for test validation. The new multiplex PRRSV RT-qPCR system allows for the first time the highly sensitive detection and rapid differentiation of PRRSV of both genotypes as well as the direct detection of HP-PRRSV.

Molecular Identification and Epidemiological Features of Human Adenoviruses Associated with Acute Respiratory Infections in Hospitalized Children in Southern China, 2012-2013.

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Chen, Yi; Liu, Fanghua; Wang, Changbing; Zhao, Mingqi; Deng, Li; Zhong, Jiayu; Zhang, Yingying; Ye, Jun; Jing, Shuping; Cheng, Zetao; Guan, Yongxin; Ma, Yi; Sun, Yuanyuan; Zhu, Bing; Zhang, Qiwei

2016-01-01

Acute respiratory infections (ARI) are the major worldwide health problem associated with high morbidity and mortality rates. Human adenovirus (HAdV) is one of the most common pathogens associated with viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics. Total 4,130 children with ARI requiring hospitalization from 2012 to 2013 were retrospectively studied. Throat swab specimens were collected from each patient. Fluorescence Quantitative PCR was performed to detect adenovirus as well as other common ARI-related pathogens. The seven HAdV hypervariable regions (HVRs) of the hexon gene from fifty-seven HAdVs-positive samples collected in the seasonal peaks were sequenced. Phylogenetic analysis of HVRs was also conducted to confirm the molecular types and genetic variation. In addition, epidemiological features and co-infection with other human respiratory pathogens were investigated and analyzed. Of 4,130 hospitalized pediatric patients tested, the positive rates of respiratory syncytial virus (RSV), Mycoplasma pneumoniae (MP), and HAdV were 13.7%, 13.2%, and 12.0%, respectively. The HAdV positive patients accounted for 7.9%, 17.2%, 17.5% and 10.7% in age groups infected with other respiratory pathogens (84/495, 17.0%). The most common co-infection pathogens with HAdV were MP (57.1%) and Human Bocavirus (HBoV) (16.7%). The majority of HAdV infected patients were totally recovered (96.9%, 480/495); However, four (0.8%) patients, who were previously healthy and at the age of 2 years or younger died of pneumonia. Seasonal peaks of HAdV infection occurred in the summer season of 2012 and 2013; the predominant HAdV type was HAdV-3 (70%), followed by HAdV-7 (28%). These epidemiological features were different from those in Northern China. The HAdV-55 was identified and reported for the first time in Guangzhou metropolitan area. Phylogenetic analysis indicated that all the HVR sequences of the hexon gene

Ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment

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Stephen eWikel

2013-11-01

Full Text Available Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex sequence of carefully choreographed host defense responses and tick countermeasures resulting in an environment that facilitates successful blood feeding and establishment of tick-borne infectious agents within the host. Here, we examine diverse patterns of tick attachment to host skin, blood feeding mechanisms, salivary gland transcriptomes, bioactive molecules in tick saliva, timing of pathogen transmission, and host responses to tick bite. Ticks engage and modulate cutaneous and systemic immune defenses involving keratinocytes, natural killer cells, dendritic cells, T cell subpopulations (Th1, Th2, Th17, Treg , B cells, neutrophils, mast cells, basophils, endothelial cells, cytokines, chemokines, complement, and extracellular matrix. A framework is proposed that integrates tick induced changes of skin immune effectors with their ability to respond to tick-borne pathogens. Implications of these changes are addressed. What are the consequences of tick modulation of host cutaneous defenses? Does diversity of salivary gland transcriptomes determine differential modulation of host inflammation and immune defenses and therefore, in part, the clades of pathogens effectively transmitted by different tick species? Do ticks create an immunologically modified cutaneous environment that enhances specific pathogen establishment? Can tick saliva molecules be used to develop vaccines that block pathogen transmission?

Opportunities for optimization: fate of manure-borne pathogens during anaerobic digestion and solids separation

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Anaerobic digestion can inactivate zoonotic pathogens present in cattle manure, which reduces transmission of these pathogens from farms to humans through the environment. However, the variability in extent of inactivation across farms and over time is unknown because most studies have examined pat...

Pathogenicity of Shigella in chickens.

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Shi, Run; Yang, Xia; Chen, Lu; Chang, Hong-tao; Liu, Hong-ying; Zhao, Jun; Wang, Xin-wei; Wang, Chuan-qing

2014-01-01

Shigellosis in chickens was first reported in 2004. This study aimed to determine the pathogenicity of Shigella in chickens and the possibility of cross-infection between humans and chickens. The pathogenicity of Shigella in chickens was examined via infection of three-day-old SPF chickens with Shigella strain ZD02 isolated from a human patient. The virulence and invasiveness were examined by infection of the chicken intestines and primary chicken intestinal epithelial cells. The results showed Shigella can cause death via intraperitoneal injection in SPF chickens, but only induce depression via crop injection. Immunohistochemistry and transmission electron microscopy revealed the Shigella can invade the intestinal epithelia. Immunohistochemistry of the primary chicken intestinal epithelial cells infected with Shigella showed the bacteria were internalized into the epithelial cells. Electron microscopy also confirmed that Shigella invaded primary chicken intestinal epithelia and was encapsulated by phagosome-like membranes. Our data demonstrate that Shigella can invade primary chicken intestinal epithelial cells in vitro and chicken intestinal mucosa in vivo, resulting in pathogenicity and even death. The findings suggest Shigella isolated from human or chicken share similar pathogenicity as well as the possibility of human-poultry cross-infection, which is of public health significance.

Respiratory immune responses in the chicken; Towards development of mucosal avian influenza virus vaccines

NARCIS (Netherlands)

de Geus, E.D.

2012-01-01

Several important poultry pathogens, including avian influenza virus (AIV), enter the host through the mucosae of the respiratory tract (RT) and subsequently disseminate towards other organs in the body. Therefore, animal health significantly depends on the control of infection in the lung tissue by

Vertical Transmission of Bacterial Eye Infections, Angola, 2011–2012

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Alexandre, Isabel; Martínez, Prudencio; Sanz, Iván; Rodriguez-Fernandez, Ana; Fernandez, Itziar; Pastor, Jose Carlos; Ortiz de Lejarazu, Raúl

2015-01-01

To determine transmission rates for neonatal conjunctivitis causative microorganisms in Angola, we analyzed 312 endocervical and 255 conjunctival samples from mothers and newborns, respectively, during 2011–2012. Transmission rates were 50% for Chlamydia trachomatis and Neisseria gonorrhoeae and 10.5% for Mycoplasma genitalium. Possible pathogenic effects of M. genitalium in children’s eyes are unknown. PMID:25695394

Meiosis and Haploid Gametes in the Pathogen Trypanosoma brucei

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Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

2014-01-01

Summary In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence [1]. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector [2, 3] and involves meiosis [4], but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human...

Avian influenza viruses in humans.

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Malik Peiris, J S

2009-04-01

Past pandemics arose from low pathogenic avian influenza (LPAI) viruses. In more recent times, highly pathogenic avian influenza (HPAI) H5N1, LPAI H9N2 and both HPAI and LPAI H7 viruses have repeatedly caused zoonotic disease in humans. Such infections did not lead to sustained human-to-human transmission. Experimental infection of human volunteers and seroepidemiological studies suggest that avian influenza viruses of other subtypes may also infect humans. Viruses of the H7 subtype appear to have a predilection to cause conjunctivitis and influenza-like illness (ILI), although HPAI H7N7 virus has also caused fatal respiratory disease. Low pathogenic H9N2 viruses have caused mild ILI and its occurrence may be under-recognised for this reason. In contrast, contemporary HPAI H5N1 viruses are exceptional in their virulence for humans and differ from human seasonal influenza viruses in their pathogenesis. Patients have a primary viral pneumonia progressing to acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome. Over 380 human cases have been confirmed to date, with an overall case fatality of 63%. The zoonotic transmission of avian influenza is a rare occurrence, butthe greater public health concern is the adaptation of such viruses to efficient human transmission, which could lead to a pandemic. A better understanding of the ecology of avian influenza viruses and the biological determinants of transmissibility and pathogenicity in humans is important for pandemic preparedness.

Phylogeny and population dynamics of respiratory syncytial virus (Rsv) A and B.

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Martinelli, Marianna; Frati, Elena Rosanna; Zappa, Alessandra; Ebranati, Erika; Bianchi, Silvia; Pariani, Elena; Amendola, Antonella; Zehender, Gianguglielmo; Tanzi, Elisabetta

2014-08-30

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants and young children. RSV is characterised by high variability, especially in the G glycoprotein, which may play a significant role in RSV pathogenicity by allowing immune evasion. To reconstruct the origin and phylodynamic history of RSV, we evaluated the genetic diversity and evolutionary dynamics of RSV A and RSV B isolated from children under 3 years old infected in Italy from 2006 to 2012. Phylogenetic analysis revealed that most of the RSV A sequences clustered with the NA1 genotype, and RSV B sequences were included in the Buenos Aires genotype. The mean evolutionary rates for RSV A and RSV B were estimated to be 2.1 × 10(-3) substitutions (subs)/site/year and 3.03 × 10(-3) subs/site/year, respectively. The time of most recent common ancestor for the tree root went back to the 1940s (95% highest posterior density-HPD: 1927-1951) for RSV A and the 1950s (95%HPD: 1951-1960) for RSV B. The RSV A Bayesian skyline plot (BSP) showed a decrease in transmission events ending in about 2005, when a sharp growth restored the original viral population size. RSV B BSP showed a similar trend. Site-specific selection analysis identified 10 codons under positive selection in RSV A sequences and only one site in RSV B sequences. Although RSV remains difficult to control due to its antigenic diversity, it is important to monitor changes in its coding sequences, to permit the identification of future epidemic strains and to implement vaccine and therapy strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

Etiology and Clinical Characteristics of Single and Multiple Respiratory Virus Infections Diagnosed in Croatian Children in Two Respiratory Seasons

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Sunčanica Ljubin-Sternak

2016-01-01

Full Text Available The aim of this study was to determine the causative agent of acute respiratory infection (ARI in hospitalized children, as well as investigate the characteristics of ARIs with single and multiple virus detection in two respiratory seasons. In 2010 and 2015, nasopharyngeal and pharyngeal swabs from a total of 134 children, admitted to the hospital due to ARI, were tested using multiplex PCR. Viral etiology was established in 81.3% of the patients. Coinfection with two viruses was diagnosed in 27.6% of the patients, and concurrent detection of three or more viruses was diagnosed in 12.8% of the patients. The most commonly diagnosed virus in both seasons combined was respiratory syncytial virus (RSV (28.6%, followed by parainfluenza viruses (PIVs types 1–3 (18.4%, rhinovirus (HRV (14.3%, human metapneumovirus (10.1%, adenovirus (AdV (7.1%, influenza viruses types A and B (4.8%, and coronaviruses (4.2%. In 2015, additional pathogens were investigated with the following detection rate: enterovirus (13.2%, bocavirus (HBoV (10.5%, PIV-4 (2.6%, and parechovirus (1.3%. There were no statistical differences between single and multiple virus infection regarding patients age, localization of infection, and severity of disease (P>0.05. AdV, HRV, HBoV, and PIVs were significantly more often detected in multiple virus infections compared to the other respiratory viruses (P<0.001.

Nosocomial infections by respiratory syncytial virus in children

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Maren Karina Machado Echeverría

2017-01-01

Full Text Available Introduction: Acute lower respiratory infections cause high morbidity and mortality in children. Respiratory syncytial virus (RSV is the most prevalent agent. Some viruses cause serious nosocomial infections. In Uruguay, there is no knowledge about the morbidity and mortality of nosocomial infections by RSV. Objective: To determine the prevalence and characteristics of RSV nosocomial infections. Methodology: A descriptive study of acute lower respiratory infections caused by RSV in patients younger than two years, between 1/1/2005 and 31/12/2008 at the Hospital Pediátrico del Centro Hospitalario Pereira Rossell, was made. Results: Were identified 59 patients who represented an annual rate lower than 2/1000 discharges. The monthly distribution of cases was similar to the respiratory infections. No outbreaks were reported. The age of the patients had an average of 8.9 months, 39 were younger than one year, 23 had one or more risk factors for severe disease. Six patients required admission to intensive care unit, all required invasive ventilation, 3 died, none had chronic respiratory failure following the RSV nosocomial infection. Conclusions: During the study period, the RSV nosocomial infections showed a low prevalence, despite it highly contagiousness. They mainly affected young children, carriers of risk factors for severe ALRI. Their evolution was similar to that reported for RSV respiratory infections community acquired. It is important to maintain standards for the control of nosocomial infections, to prevent nosocomial transmission of RSV and prevent the onset of severe disease in hospitalized patients.

Expanding severe acute respiratory infection (SARI) surveillance beyond influenza: The process and data from 1 year of implementation in Vietnam.

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Alroy, Karen A; Do, Trang Thuy; Tran, Phu Dac; Dang, Tan Quang; Vu, Long Ngoc; Le, Nga Thi Hang; Dang, Anh Duc; Ngu, Nghia Duy; Ngo, Tu Huy; Hoang, Phuong Vu Mai; Phan, Lan Trong; Nguyen, Thuong Vu; Nguyen, Long Thanh; Nguyen, Thinh Viet; Vien, Mai Quang; Le, Huy Xuan; Dao, Anh The; Nguyen, Trieu Bao; Pham, Duoc Tho; Nguyen, Van Thi Tuyet; Pham, Thanh Ngoc; Phan, Binh Hai; Whitaker, Brett; Do, Thuy Thi Thu; Dao, Phuong Anh; Balajee, S Arunmozhi; Mounts, Anthony W

2018-05-13

In 2016, as a component of the Global Health Security Agenda, the Vietnam Ministry of Health expanded its existing influenza sentinel surveillance for severe acute respiratory infections (SARI) to include testing for 7 additional viral respiratory pathogens. This article describes the steps taken to implement expanded SARI surveillance in Vietnam and reports data from 1 year of expanded surveillance. The process of expanding the suite of pathogens for routine testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) included laboratory trainings, procurement/distribution of reagents, and strengthening and aligning SARI surveillance epidemiology practices at sentinel sites and regional institutes (RI). Surveillance data showed that of 4003 specimens tested by the RI laboratories, 20.2% (n = 810) were positive for influenza virus. Of the 3193 influenza-negative specimens, 41.8% (n = 1337) were positive for at least 1 non-influenza respiratory virus, of which 16.2% (n = 518), 13.4% (n = 428), and 9.6% (n = 308) tested positive for respiratory syncytial virus, rhinovirus, and adenovirus, respectively. The Government of Vietnam has demonstrated that expanding respiratory viral surveillance by strengthening and building upon an influenza platform is feasible, efficient, and practical. © 2018 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Closed genomes of seven histophilus somni isolates from beef calves with bovine respiratory disease complex

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Histophilus somni is a fastidious gram-negative opportunistic pathogenic Pasteurellacea that affects multiple organ systems and is one of the principle bacterial species contributing to bovine respiratory disease complex (BRDC) in feed yard cattle. Here we present seven closed genomes isolated from...

Transmission of Xylella fastidiosa to Grapevine by the Meadow Spittlebug.

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Cornara, D; Sicard, A; Zeilinger, A R; Porcelli, F; Purcell, A H; Almeida, R P P

2016-11-01

There is little information available on Xylella fastidiosa transmission by spittlebugs (Hemiptera, Cercopoidea). This group of insect vectors may be of epidemiological relevance in certain diseases, so it is important to better understand the basic parameters of X. fastidiosa transmission by spittlebugs. We used grapevines as a host plant and the aphrophorid Philaenus spumarius as a vector to estimate the effect of plant access time on X. fastidiosa transmission to plants; in addition, bacterial population estimates in the heads of vectors were determined and correlated with plant infection status. Results show that transmission efficiency of X. fastidiosa by P. spumarius increased with plant access time, similarly to insect vectors in another family (Hemiptera, Cicadellidae). Furthermore, a positive correlation between pathogen populations in P. spumarius and transmission to plants was observed. Bacterial populations in insects were one to two orders of magnitude lower than those observed in leafhopper vectors, and population size peaked within 3 days of plant access period. These results suggest that P. spumarius has either a limited number of sites in the foregut that may be colonized, or that fluid dynamics in the mouthparts of these insects is different from that in leafhoppers. Altogether our results indicate that X. fastidiosa transmission by spittlebugs is similar to that by leafhoppers. In addition, the relationship between cell numbers in vectors and plant infection may have under-appreciated consequences to pathogen spread.

Stethoscopes as potential intrahospital carriers of pathogenic microorganisms.

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Campos-Murguía, Alejandro; León-Lara, Ximena; Muñoz, Juan M; Macías, Alejandro E; Alvarez, José A

2014-01-01

Stethoscopes can take part in the transmission of health care-associated infections. We cultured 112 stethoscopes by direct imprint on blood agar to estimate the prevalence of potentially pathogenic microorganisms. Forty-eight (47%) produced 50 potentially pathogenic microorganisms; from these, 43 (86%) were Staphylococcus aureus, of which 18 (42%) were methicillin-resistant S. aureus. We concluded that stethoscopes should be considered as potential fomites and must be disinfected routinely before and after each patient contact. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Experimentally infected domestic ducks show efficient transmission of Indonesian H5N1 highly pathogenic avian influenza virus, but lack persistent viral shedding.

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Wibawa, Hendra; Bingham, John; Nuradji, Harimurti; Lowther, Sue; Payne, Jean; Harper, Jenni; Junaidi, Akhmad; Middleton, Deborah; Meers, Joanne

2014-01-01

Ducks are important maintenance hosts for avian influenza, including H5N1 highly pathogenic avian influenza viruses. A previous study indicated that persistence of H5N1 viruses in ducks after the development of humoral immunity may drive viral evolution following immune selection. As H5N1 HPAI is endemic in Indonesia, this mechanism may be important in understanding H5N1 evolution in that region. To determine the capability of domestic ducks to maintain prolonged shedding of Indonesian clade 2.1 H5N1 virus, two groups of Pekin ducks were inoculated through the eyes, nostrils and oropharynx and viral shedding and transmission investigated. Inoculated ducks (n = 15), which were mostly asymptomatic, shed infectious virus from the oral route from 1 to 8 days post inoculation, and from the cloacal route from 2-8 dpi. Viral ribonucleic acid was detected from 1-15 days post inoculation from the oral route and 1-24 days post inoculation from the cloacal route (cycle threshold ducks seroconverted in a range of serological tests by 15 days post inoculation. Virus was efficiently transmitted during acute infection (5 inoculation-infected to all 5 contact ducks). However, no evidence for transmission, as determined by seroconversion and viral shedding, was found between an inoculation-infected group (n = 10) and contact ducks (n = 9) when the two groups only had contact after 10 days post inoculation. Clinical disease was more frequent and more severe in contact-infected (2 of 5) than inoculation-infected ducks (1 of 15). We conclude that Indonesian clade 2.1 H5N1 highly pathogenic avian influenza virus does not persist in individual ducks after acute infection.

Interspecies transmission and limited persistence of low pathogenic avian influenza genomes among Alaska dabbling ducks

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Reeves, Andrew B.; Pearce, John M.; Ramey, Andy M.; Meixell, Brandt; Runstadler, Jonathan A.

2011-01-01

The reassortment and geographic distribution of low pathogenic avian influenza (LPAI) virus genes are well documented, but little is known about the persistence of intact LPAI genomes among species and locations. To examine persistence of entire LPAI genome constellations in Alaska, we calculated the genetic identities among 161 full-genome LPAI viruses isolated across 4 years from five species of duck: northern pintail (Anas acuta), mallard (Anas platyrhynchos), American green-winged teal (Anas crecca), northern shoveler (Anas clypeata) and American wigeon (Anas americana). Based on pairwise genetic distance, highly similar LPAI genomes (>99% identity) were observed within and between species and across a range of geographic distances (up to and >1000 km), but most often between isolates collected 0–10 km apart. Highly similar viruses were detected between years, suggesting inter-annual persistence, but these were rare in our data set with the majority occurring within 0–9 days of sampling. These results identify LPAI transmission pathways in the context of species, space and time, an initial perspective into the extent of regional virus distribution and persistence, and insight into why no completely Eurasian genomes have ever been detected in Alaska. Such information will be useful in forecasting the movement of foreign-origin avian influenza strains should they be introduced to North America.

Acute respiratory viral infections in pediatric cancer patients undergoing chemotherapy

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Eliana C.A. Benites

2014-07-01

Full Text Available OBJECTIVE: to estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI and/or fever. METHODS: cross-sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc and University Hospital (HU, Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland, and real-time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta for detection of influenza virus (H1N1, B, rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ2 or Fisher's exact test. RESULTS: 104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3% was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%, respiratory syncytial virus AB (8.7%, and coronavirus (6.8%. Co-detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7 were positive for viruses. There were no deaths. CONCLUSIONS: the prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co-detection was frequent in patients with cancer and ARIs.

Type IV pili in Francisella – A virulence trait in an intracellular pathogen

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Emelie eNäslund Salomonsson

2011-02-01

Full Text Available Francisella tularensis is a highly virulent intracellular human pathogen that is capable of rapid proliferation in the infected host. Mutants affected in intracellular survival and growth are highly attenuated which highlights the importance of the intracellular phase of the infection. Genomic analysis has revealed that Francisella encodes all genes required for expression of functional type IV pili (Tfp, and in this focused review we summarise recent findings regarding this system in the pathogenesis of tularemia. Tfp are dynamic adhesive structures that have been identified as major virulence determinants in several human pathogens, but it is not obvious what role these structures could have in an intracellular pathogen like Francisella. In the human pathogenic strains, genes required for secretion and assembly of Tfp and one pilin, PilA, have shown to be required for full virulence. Importantly, specific genetic differences have been identified between the different Francisella subspecies where in the most pathogenic type A variants all genes are intact while several Tfp genes are pseudogenes in the less pathogenic type B strains. This suggests that there has been a selection for expression of Tfp with different properties in the different subspecies. There is also a possibility that the genetic differences reflect adaption to different environmental niches of the subspecies and plays a role in transmission of tularemia. This is also in line with recent findings where Tfp pilins are found to be glycosylated which could reflect a role for Tfp in the environment to promote survival and transmission. We are still far from understanding the role of Tfp in virulence and transmission of tularemia, but with the genomic information and genetic tools available we are in a good position to address these issues in the future.

Emerging highly pathogenic H5 avian influenza viruses in France during winter 2015/16: phylogenetic analyses and markers for zoonotic potential.

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Briand, François-Xavier; Schmitz, Audrey; Ogor, Katell; Le Prioux, Aurélie; Guillou-Cloarec, Cécile; Guillemoto, Carole; Allée, Chantal; Le Bras, Marie-Odile; Hirchaud, Edouard; Quenault, Hélène; Touzain, Fabrice; Cherbonnel-Pansart, Martine; Lemaitre, Evelyne; Courtillon, Céline; Gares, Hélène; Daniel, Patrick; Fediaevsky, Alexandre; Massin, Pascale; Blanchard, Yannick; Eterradossi, Nicolas; van der Werf, Sylvie; Jestin, Véronique; Niqueux, Eric

2017-03-02

Several new highly pathogenic (HP) H5 avian influenza virus (AIV) have been detected in poultry farms from south-western France since November 2015, among which an HP H5N1. The zoonotic potential and origin of these AIVs immediately became matters of concern. One virus of each subtype H5N1 (150169a), H5N2 (150233) and H5N9 (150236) was characterised. All proved highly pathogenic for poultry as demonstrated molecularly by the presence of a polybasic cleavage site in their HA protein - with a sequence (HQRRKR/GLF) previously unknown among avian H5 HPAI viruses - or experimentally by the in vivo demonstration of an intravenous pathogenicity index of 2.9 for the H5N1 HP isolate. Phylogenetic analyses based on the full genomes obtained by NGS confirmed that the eight viral segments of the three isolates were all part of avian Eurasian phylogenetic lineage but differed from the Gs/Gd/1/96-like lineage. The study of the genetic characteristics at specific amino acid positions relevant for modulating the adaptation to and the virulence for mammals showed that presently, these viruses possess most molecular features characteristic of AIV and lack some major characteristics required for efficient respiratory transmission to or between humans. The three isolates are therefore predicted to have no significant pandemic potential. This article is copyright of The Authors, 2017.

The Alteration of Nasopharyngeal and Oropharyngeal Microbiota in Children with MPP and Non-MPP

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Zhiwei Lu

2017-12-01

Full Text Available Background: In recent years, the morbidity of Mycoplasma pneumoniae pneumonia (MPP has increased significantly in China. A growing number of studies indicate that imbalanced respiratory microbiota is associated with various respiratory diseases. Methods: We enrolled 119 children, including 60 pneumonia patients and 59 healthy children. Nasopharyngeal (NP and oropharyngeal (OP sampling was performed for 16S ribosomal RNA (16S rRNA gene analysis of all children. Sputum and OP swabs were obtained from patients for pathogen detection. Results: Both the NP and OP microbiota of patients differ significantly from that of healthy children. Diseased children harbor lower microbial diversity and a simpler co-occurrence network in NP and OP. In pneumonia patients, NP and OP microbiota showed greater similarities between each other, suggesting transmission of NP microbiota to the OP. Aside from clinically detected pathogens, NP and OP microbiota analysis has also identified possible pathogens in seven cases with unknown infections. Conclusion: NP and OP microbiota in MPP and non-MPP are definitely similar. Respiratory infection generates imbalanced NP microbiota, which has the potential to transmit to OP. Microbiota analysis also promises to compliment the present means of detecting respiratory pathogens.

Tracking social contact networks with online respondent-driven detection : who recruits whom?

NARCIS (Netherlands)

Stein, Mart L.; van der Heijden, P.G.M.; Buskens, V.W.; van Steenbergen, Jim E.; Bengtsson, Linus; Koppeschaar, Carl E.; Thorson, Anna E.; Kretzschmar, Mirjam E. E.

2015-01-01

Background: Transmission of respiratory pathogens in a population depends on the contact network patterns of individuals. To accurately understand and explain epidemic behaviour information on contact networks is required, but only limited empirical data is available. Online respondent-driven

Tracking social contact networks with online respondent-driven detection : who recruits whom?

NARCIS (Netherlands)

Stein, Mart L; van der Heijden, Peter G M; Buskens, Vincent; van Steenbergen, Jim E; Bengtsson, Linus; Koppeschaar, Carl E; Thorson, Anna; Kretzschmar, MEE

2015-01-01

BACKGROUND: Transmission of respiratory pathogens in a population depends on the contact network patterns of individuals. To accurately understand and explain epidemic behaviour information on contact networks is required, but only limited empirical data is available. Online respondent-driven

Airway inflammation and upper respiratory tract infection in athletes: is there a link?

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Bermon, Stéphane

2007-01-01

Upper Respiratory Tract Infection (URTI) is regarded as the most common medical condition affecting both highly trained and elite athletes, in particular those participating in endurance events. The causes of these disturbances, also occurring during training, remain unclear. Viruses such as rhinovirus, adenovirus and para-influenza virus are frequently reported as the source of URTI. However, in a few comprehensive laboratory and epidemiological studies which reported at least a 30% incidence of URTI, no identifiable pathogens were either reported or studied. A recent, longitudinal study investigated symptomatology and pathogenic etiology in sedentary controls, recreational and elite athletes. The highest incidence of URTI occurred in elite athletes. However; only 11 out of 37 illness episodes overall had pathogenic origins, and most of the unidentified upper respiratory illnesses were shorter in duration and less severe than infectious ones. This concept of inflammation without infection in athletes is quite new and leads us to consider other explanatory pathophysiological conditions. Increases in airway neutrophils, eosinophils and lymphocytes have been described under resting conditions in endurance sports, swimmers and cross-country skiers. These inflammatory patterns may be due to pollutants or chlorine-related compounds in swimmers. After intense exercise similar airways cellular profiles have been reported, with a high amount of bronchial epithelial cells. This increase in airway inflammatory cells in athletes can result from a hyperventilation-induced increase in airway osmolarity stimulating bronchial epithelial cells to release chemotactic factors. Fortunately, in most cases, these inflammatory cells express rather low level of adhesion molecules, explaining why airway inflammation may appear blunted in athletes despite numerous inflammatory cellular elements. However it can be hypothesized that a transient loss of control of this local inflammation, due

Evaluation of respiratory pattern during respiratory-gated radiotherapy

International Nuclear Information System (INIS)

Dobashi, Suguru; Mori, Shinichiro

2014-01-01

The respiratory cycle is not strictly regular, and generally varies in amplitude and period from one cycle to the next. We evaluated the characteristics of respiratory patterns acquired during respiratory gating treatment in more than 300 patients. A total 331 patients treated with respiratory-gated carbon-ion beam therapy were selected from a group of patients with thoracic and abdominal conditions. Respiratory data were acquired for a total of 3,171 fractions using an external respiratory sensing monitor and evaluated for respiratory cycle, duty cycle, magnitude of baseline drift, and intrafractional/interfractional peak inhalation/exhalation positional variation. Results for the treated anatomical sites and patient positioning were compared. Mean ± SD respiratory cycle averaged over all patients was 4.1 ± 1.3 s. Mean ± SD duty cycle averaged over all patients was 36.5 ± 7.3 %. Two types of baseline drift were seen, the first decremental and the second incremental. For respiratory peak variation, the mean intrafractional variation in peak-inhalation position relative to the amplitude in the first respiratory cycle (15.5 ± 9.3 %) was significantly larger than that in exhalation (7.5 ± 4.6 %). Interfractional variations in inhalation (17.2 ± 18.5 %) were also significantly greater than those in exhalation (9.4 ± 10.0 %). Statistically significant differences were observed between patients in the supine position and those in the prone position in mean respiratory cycle, duty cycle, and intra-/interfractional variations. We quantified the characteristics of the respiratory curve based on a large number of respiratory data obtained during treatment. These results might be useful in improving the accuracy of respiratory-gated treatment.

Molecular Identification and Epidemiological Features of Human Adenoviruses Associated with Acute Respiratory Infections in Hospitalized Children in Southern China, 2012-2013.

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Yi Chen

Full Text Available Acute respiratory infections (ARI are the major worldwide health problem associated with high morbidity and mortality rates. Human adenovirus (HAdV is one of the most common pathogens associated with viral ARI, and thus calls for specific diagnosis and better understanding of the epidemiology and clinical characteristics.Total 4,130 children with ARI requiring hospitalization from 2012 to 2013 were retrospectively studied. Throat swab specimens were collected from each patient. Fluorescence Quantitative PCR was performed to detect adenovirus as well as other common ARI-related pathogens. The seven HAdV hypervariable regions (HVRs of the hexon gene from fifty-seven HAdVs-positive samples collected in the seasonal peaks were sequenced. Phylogenetic analysis of HVRs was also conducted to confirm the molecular types and genetic variation. In addition, epidemiological features and co-infection with other human respiratory pathogens were investigated and analyzed.Of 4,130 hospitalized pediatric patients tested, the positive rates of respiratory syncytial virus (RSV, Mycoplasma pneumoniae (MP, and HAdV were 13.7%, 13.2%, and 12.0%, respectively. The HAdV positive patients accounted for 7.9%, 17.2%, 17.5% and 10.7% in age groups <1, 1-3, 3-6 and 6-14 years, respectively. Eighty-four HAdV positive children were co-infected with other respiratory pathogens (84/495, 17.0%. The most common co-infection pathogens with HAdV were MP (57.1% and Human Bocavirus (HBoV (16.7%. The majority of HAdV infected patients were totally recovered (96.9%, 480/495; However, four (0.8% patients, who were previously healthy and at the age of 2 years or younger died of pneumonia. Seasonal peaks of HAdV infection occurred in the summer season of 2012 and 2013; the predominant HAdV type was HAdV-3 (70%, followed by HAdV-7 (28%. These epidemiological features were different from those in Northern China. The HAdV-55 was identified and reported for the first time in Guangzhou

Personal protective equipment and improving compliance among healthcare workers in high-risk settings.

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Honda, Hitoshi; Iwata, Kentaro

2016-08-01

Personal protective equipment (PPE) protects healthcare workers (HCWs) from infection by highly virulent pathogens via exposure to body fluids and respiratory droplets. Given the recent outbreaks of contagious infectious diseases worldwide, including Ebola virus and Middle Eastern respiratory syndrome, there is urgent need for further research to determine optimal PPE use in high-risk settings. This review intends to provide a general understanding of PPE and to provide guidelines for appropriate use based on current evidence. Although previous studies have focused on the efficacy of PPE in preventing transmission of pathogens, recent studies have examined the dangers to HCWs during removal of PPE when risk of contamination is highest. Access to adequate PPE supplies is crucial to preventing transmission of pathogens, especially in resource-limited settings. Adherence to appropriate PPE use is a challenge due to inadequate education on its usage, technical difficulties, and tolerability of PPE in the workplace. Future projects aim at ameliorating this situation, including redesigning PPE which is crucial to improving the safety of HCWs. PPE remains the most important strategy for protecting HCW from potentially fatal pathogens. Further research into optimal PPE design and use to improve the safety of HCWs is urgently needed.

Moderate pathogenic effect of Ligophorus uruguayense (Monogenoidea, Ancyrocephalidae in juvenile mullet Mugil liza (Actinopterygii, Mugilidae from Brazil

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EDUARDO PAHOR-FILHO

2017-10-01

Full Text Available ABSTRACT Monogenoidea pathogenic activity can elicit various histological responses in fish. Species of Ligophorus are specific parasites of mullets, and its relationship with host fish may result in a moderate pathogenic action. In order to ascertain this relationship, estuarine mullets (Mugil liza were collected in an estuary, reared in laboratory, for three weeks, and forwarded for histological and parasitological analyses. Ligophorus uruguayense (Monogenoidea infestation in the gills of the mullets was identified. The severe infestation by only one species of Monogenoidea may result from the specificity of these parasites to mullets. Mullets submitted to histological analysis exhibited respiratory epithelium detachment; mild, moderate and severe hyperplasia of the respiratory epithelium; atrophy; and telangiectasia of the gills. This is the first study reporting that mullets highly infested by Monogenoidea can show mild (100% to severe (20% gill changes with a distinct frequency of occurrence. Because of the high prevalence of mild alterations observed, it is possible to accept that L. uruguayense is moderately pathogenic to M. liza, even during high prevalence and intensity of infestation, as a result of its specificity.

Moderate pathogenic effect of Ligophorus uruguayense (Monogenoidea, Ancyrocephalidae) in juvenile mullet Mugil liza (Actinopterygii, Mugilidae) from Brazil.

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Pahor-Filho, Eduardo; Klosterhoff, Marta C; Marchiori, Natalia C; Pereira, Joaber

2017-01-01

Monogenoidea pathogenic activity can elicit various histological responses in fish. Species of Ligophorus are specific parasites of mullets, and its relationship with host fish may result in a moderate pathogenic action. In order to ascertain this relationship, estuarine mullets (Mugil liza) were collected in an estuary, reared in laboratory, for three weeks, and forwarded for histological and parasitological analyses. Ligophorus uruguayense (Monogenoidea) infestation in the gills of the mullets was identified. The severe infestation by only one species of Monogenoidea may result from the specificity of these parasites to mullets. Mullets submitted to histological analysis exhibited respiratory epithelium detachment; mild, moderate and severe hyperplasia of the respiratory epithelium; atrophy; and telangiectasia of the gills. This is the first study reporting that mullets highly infested by Monogenoidea can show mild (100%) to severe (20%) gill changes with a distinct frequency of occurrence. Because of the high prevalence of mild alterations observed, it is possible to accept that L. uruguayense is moderately pathogenic to M. liza, even during high prevalence and intensity of infestation, as a result of its specificity.

Human milk inactivates pathogens individually, additively, and synergistically.

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Isaacs, Charles E

2005-05-01

Breast-feeding can reduce the incidence and the severity of gastrointestinal and respiratory infections in the suckling neonate by providing additional protective factors to the infant's mucosal surfaces. Human milk provides protection against a broad array of infectious agents through redundancy. Protective factors in milk can target multiple early steps in pathogen replication and target each step with more than one antimicrobial compound. The antimicrobial activity in human milk results from protective factors working not only individually but also additively and synergistically. Lipid-dependent antimicrobial activity in milk results from the additive activity of all antimicrobial lipids and not necessarily the concentration of one particular lipid. Antimicrobial milk lipids and peptides can work synergistically to decrease both the concentrations of individual compounds required for protection and, as importantly, greatly reduce the time needed for pathogen inactivation. The more rapidly pathogens are inactivated the less likely they are to establish an infection. The total antimicrobial protection provided by human milk appears to be far more than can be elucidated by examining protective factors individually.

Beyond R0 Maximisation: On Pathogen Evolution and Environmental Dimensions.

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Lion, Sébastien; Metz, Johan A J

2018-06-01

A widespread tenet is that evolution of pathogens maximises their basic reproduction ratio, R 0 . The breakdown of this principle is typically discussed as exception. Here, we argue that a radically different stance is needed, based on evolutionarily stable strategy (ESS) arguments that take account of the 'dimension of the environmental feedback loop'. The R 0 maximisation paradigm requires this feedback loop to be one-dimensional, which notably excludes pathogen diversification. By contrast, almost all realistic ecological ingredients of host-pathogen interactions (density-dependent mortality, multiple infections, limited cross-immunity, multiple transmission routes, host heterogeneity, and spatial structure) will lead to multidimensional feedbacks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Heliox reduces respiratory system resistance in respiratory syncytial virus induced respiratory failure

NARCIS (Netherlands)

Kneyber, Martin C. J.; van Heerde, Marc; Twisk, Jos W. R.; Plotz, Frans B.; Markhors, Dick G.

2009-01-01

Introduction Respiratory syncytial virus (RSV) lower respiratory tract disease is characterised by narrowing of the airways resulting in increased airway resistance, air-trapping and respiratory acidosis. These problems might be overcome using helium-oxygen gas mixture. However, the effect of

Heliox reduces respiratory system resistance in respiratory syncytial virus induced respiratory failure

NARCIS (Netherlands)

Kneijber, M.C.J.; van Heerde, M.; Twisk, J.W.R.; Plotz, F.; Markhorst, D.G.

2009-01-01

Introduction: Respiratory syncytial virus (RSV) lower respiratory tract disease is characterised by narrowing of the airways resulting in increased airway resistance, air-trapping and respiratory acidosis. These problems might be overcome using helium-oxygen gas mixture. However, the effect of

Epidemiological role of birds in the transmission and maintenance of zoonoses.

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Contreras, A; Gómez-Martín, A; Paterna, A; Tatay-Dualde, J; Prats-Van Der Ham, M; Corrales, J C; De La Fe, C; Sánchez, A

2016-12-01

The risk of zoonoses spreading from birds to humans is lower, quantitatively speaking, than the risk of transmission between other host groups, because the two taxonomic groups share fewer pathogens. Nevertheless, birds have a number of epidemiological characteristics that make them extremely important hosts in the transmission and maintenance of zoonoses, including their susceptibility to pathogens that are extremely hazardous to humans (such as highly pathogenic avian influenza virus, West Nile virus and Chlamydia psittaci) and their ability to travel long distances, especially in the case of migratory birds. The fact that the human diet includes poultry products (meat, eggs and their by-products) also means that most human cases of foodborne zoonoses are infections of avian origin. Lastly, close contact between humans and pet birds or urban birds leads to interactions of public health concern. This article sets out to describe the main factors that determine the role of birds in the epidemiology of zoonotic infections. © OIE (World Organisation for Animal Health), 2016.

Comparison of three multiplex PCR assays for the detection of respiratory viral infections: evaluation of xTAG respiratory virus panel fast assay, RespiFinder 19 assay and RespiFinder SMART 22 assay

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Dabisch-Ruthe Mareike

2012-07-01

Full Text Available Abstract Background A broad spectrum of pathogens is causative for respiratory tract infections, but symptoms are mostly similar. Therefore, the identification of the causative viruses and bacteria is only feasible using multiplex PCR or several monoplex PCR tests in parallel. Methods The analytical sensitivity of three multiplex PCR assays, RespiFinder-19, RespiFinder-SMART-22 and xTAG-Respiratory-Virus-Panel-Fast-Assay (RVP, were compared to monoplex real-time PCR with quantified standardized control material. All assays include the most common respiratory pathogens. Results To compare the analytical sensitivity of the multiplex assays, samples were inoculated with 13 different quantified viruses in the range of 101 to 105 copies/ml. Concordant results were received for rhinovirus, whereas the RVP detected influenzavirus, RSV and hMPV more frequently in low concentrations. The RespiFinder-19 and the RespiFinder-SMART-22 showed a higher analytical sensitivity for adenoviruses and coronaviruses, whereas the RVP was incapable to detect adenovirus and coronavirus in concentrations of 104 copies/ml. The RespiFinder-19 and RespiFinder-SMART-22A did not detect influenzaviruses (104 copies/ml and RSV (103 copies/ml. The detection of all 13 viruses in one sample was only achieved using monoplex PCR. To analyze possible competitive amplification reactions between the different viruses, samples were further inoculated with only 4 different viruses in one sample. Compared to the detection of 13 viruses in parallel, only a few differences were found. The incidence of respiratory viruses was compared in tracheal secretion (TS samples (n = 100 of mechanically ventilated patients in winter (n = 50 and summer (n = 50. In winter, respiratory viruses were detected in 32 TS samples (64% by RespiFinder-19, whereas the detection rate with RVP was only 22%. The most frequent viruses were adenovirus (32% and PIV-2 (20%. Multiple infections were detected

Evolutionary Control of Infectious Disease: Prospects for Vectorborne and Waterborne Pathogens

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Paul W Ewald

1998-09-01

Full Text Available Evolutionary theory may contribute to practical solutions for control of disease by identifying interventions that may cause pathogens to evolve to reduced virulence. Theory predicts, for example, that pathogens transmitted by water or arthropod vectors should evolve to relatively high levels of virulence because such pathogens can gain the evolutionary benefits of relatively high levels of host exploitation while paying little price from host illness. The entrance of Vibrio cholerae into South America in 1991 has generated a natural experiment that allows testing of this idea by determining whether geographic and temporal variations in toxigenicity correspond to variation in the potential for waterborne transmission. Preliminary studies show such correspondences: toxigenicity is negatively associated with access to uncontaminated water in Brazil; and in Chile, where the potential for waterborne transmission is particularly low, toxigenicity of strains declined between 1991 and 1998. In theory vector-proofing of houses should be similarly associated with benignity of vectorborne pathogens, such as the agents of dengue, malaria, and Chagas' disease. These preliminary studies draw attention to the need for definitive prospective experiments to determine whether interventions such as provisioning of uncontaminated water and vector-proofing of houses cause evolutionary reductions in virulence

Gatifloxacin phase IV surveillance trial (TeqCES study) utilizing 5000 primary care physician practices: report of pathogens isolated and susceptibility patterns in community-acquired respiratory tract infections.

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Pfaller, Michael A; Jones, Ronald N

2002-09-01

Recently FDA-approved fluoroquinolones like gatifloxacin possess enhanced activity against Gram-positive pathogens such as Streptococcus pneumoniae. However, experience with adverse events among previously used fluoroquinolones has led to expanded post-marketing investigations of clinical efficacy and safety. An open-label gatifloxacin trial was initiated in early 2000, using 2795 (>15000 enrolled cases) primary care providers for treatment of community-acquired respiratory tract infections (CARTI) such as community-acquired pneumonia (CAP), acute bacterial exacerbation of chronic bronchitis (ABECB), acute sinusitis. Microbiology specimens and sputum slides were referred to a reference laboratory, pathogens identified and reference antimicrobial susceptibility tests performed. Results were classified by infection site, geographic census region and patient profile/demographics. The most frequent pathogens were: for CAP (n = 384)-S. pneumoniae (37%) > Hemophilus influenzae (31%) > Moraxella catarrhalis (13%); for ABECB (528)-H. influenzae (37%) > M. catarrhalis (26%) > S. pneumoniae (17%); and for sinusitis (2691)-M. catarrhalis (29%) > H. influenzae (24%) > S. pneumoniae (17%). H. parainfluenzae (ABECB) and S. aureus (sinusitis) were also commonly isolated. CAP S. pneumoniae isolates had significantly less high-level resistance (5% at > or =2 micro g/ml) than those isolates from ABECB or sinusitis (13-15%). United States census zone differences in S. pneumoniae resistance were identified (greatest in West or East South Central, South Atlantic). S. pneumoniae macrolide resistance was high (23-33%) and H. influenzae clarithromycin susceptibility was only 56-62%. beta-lactamase rates in H. influenzae and M. catarrhalis were 21-29% and 88-92%, respectively. Only one S. pneumoniae was not susceptible to gatifloxacin, and this new fluoroquinolone was fourfold more potent than levofloxacin (MIC(50,) 0.25 vs. 1 micro g/ml). This Phase IV surveillance trial (Teq

Respiratory Viruses and Bacteria among Pilgrims during the 2013 Hajj

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Benkouiten, Samir; Charrel, Rémi; Belhouchat, Khadidja; Drali, Tassadit; Nougairede, Antoine; Salez, Nicolas; Memish, Ziad A.; al Masri, Malak; Fournier, Pierre-Edouard; Raoult, Didier; Brouqui, Philippe; Parola, Philippe

2014-01-01

Pilgrims returning from the Hajj might contribute to international spreading of respiratory pathogens. Nasal and throat swab specimens were obtained from 129 pilgrims in 2013 before they departed from France and before they left Saudi Arabia, and tested by PCR for respiratory viruses and bacteria. Overall, 21.5% and 38.8% of pre-Hajj and post-Hajj specimens, respectively, were positive for ≥1 virus (p = 0.003). One third (29.8%) of the participants acquired ≥1 virus, particularly rhinovirus (14.0%), coronavirus E229 (12.4%), and influenza A(H3N2) virus (6.2%) while in Saudi Arabia. None of the participants were positive for the Middle East respiratory syndrome coronavirus. In addition, 50.0% and 62.0% of pre-Hajj and post-Hajj specimens, respectively, were positive for Streptococcus pneumoniae (p = 0.053). One third (36.3%) of the participants had acquired S. pneumoniae during their stay. Our results confirm high acquisition rates of rhinovirus and S. pneumoniae in pilgrims and highlight the acquisition of coronavirus E229. PMID:25341199

Emergence of respiratory Streptococcus agalactiae isolates in cystic fibrosis patients.

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Vera Eickel

Full Text Available Streptococcus agalactiae is a well-known pathogen for neonates and immunocompromized adults. Beyond the neonatal period, S. agalactiae is rarely found in the respiratory tract. During 2002-2008 we noticed S. agalactiae in respiratory secretions of 30/185 (16% of cystic fibrosis (CF patients. The median age of these patients was 3-6 years older than the median age CF patients not harboring S. agalactiae. To analyze, if the S. agalactiae isolates from CF patients were clonal, further characterization of the strains was achieved by capsular serotyping, surface protein determination and multilocus sequence typing (MLST. We found a variety of sequence types (ST among the isolates, which did not substantially differ from the MLST patterns of colonizing strains from Germany. However serotype III, which is often seen in colonizing strains and invasive infections was rare among CF patients. The emergence of S. agalactiae in the respiratory tract of CF patients may represent the adaptation to a novel host environment, supported by the altered surfactant composition in older CF patients.

The Airborne Transmission of Infection Between Flats in High-rise Residential Buildings

DEFF Research Database (Denmark)

Gao, N.P.; Niu, J. L.; Perino, M.

2008-01-01

Airborne transmission of infectious respiratory diseases in indoor environments has drawn our attention for decades, and this issue is revitalized with the outbreak of severe acute respiratory syndrome (SARS). One of the concerns is that there may be multiple transmission routes across households...... in high-rise residential buildings, one of which is the natural ventilative airflow through open windows between flats, caused by buoyancy effects. Our early on-site measurement using tracer gases confirmed qualitatively and quantitatively that the re-entry of the exhaust-polluted air from the window...... of the lower floor into the adjacent upper floor is a fact. This study presents the modeling of this cascade effect using computational fluid dynamics (CFD) technique. It is found that the presence of the pollutants generated in the lower floor is generally lower in the immediate upper floor by two orders...

Surveillance of low pathogenic avian influenza in layer chickens: risk factors, transmission and early detection

NARCIS (Netherlands)

Gonzales Rojas, J.L.

2012-01-01

Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly pathogenic avian influenza virus (HPAIv), which are lethal for most poultry species, can cause large epidemics and are a serious threat to public health. Thus, circulation of these LPAIv in poultry is

The retrotrapezoid nucleus neurons expressing Atoh1 and Phox2b are essential for the respiratory response to CO₂

DEFF Research Database (Denmark)

Ruffault, Pierre Louis; D’Autréaux, Fabien; Hayes, John A.

2015-01-01

. Photostimulation of these neurons entrains the respiratory rhythm. Conversely, abrogating expression of Atoh1 or Phox2b or glutamatergic transmission in these cells curtails the phrenic nerve response to low pH in embryonic preparations and abolishes the respiratory chemoreflex in behaving animals. Thus, the RTN...

Respiratory syncytial virus infection facilitates acute colonization of Pseudomonas aeruginosa in mice

DEFF Research Database (Denmark)

de Vrankrijker, Angélica M M; Wolfs, Tom F W; Ciofu, Oana

2009-01-01

virus infections in facilitating colonization and infection with P. aeruginosa. A study was undertaken to determine whether respiratory syncytial virus (RSV) infection could facilitate the initiation of an acute infection with P. aeruginosa in vivo. Balb/c mice were infected intranasally with P......Pseudomonas aeruginosa causes opportunistic infections in immunocompromised individuals and patients ventilated mechanically and is the major pathogen in patients with cystic fibrosis, in which it causes chronic infections. Epidemiological, in vitro and animal data suggest a role for respiratory....... These results suggest that RSV can facilitate the initiation of acute P. aeruginosa infection without the RSV infection being clinically apparent. This could have implications for treatment strategies to prevent opportunistic P. aeruginosa lung infection....

Respiratory effects of kynurenic acid microinjected into the ventromedullary surface of the rat

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F.P. Tolentino-Silva

1998-10-01

Full Text Available Several studies demonstrate that, within the ventral medullary surface (VMS, excitatory amino acids are necessary components of the neural circuits involved in the tonic and reflex control of respiration and circulation. In the present study we investigated the cardiorespiratory effects of unilateral microinjections of the broad spectrum glutamate antagonist kynurenic acid (2 nmol/200 nl along the VMS of urethane-anesthetized rats. Within the VMS only one region was responsive to this drug. This area includes most of the intermediate respiratory area, partially overlapping the rostral ventrolateral medulla (IA/RVL. When microinjected into the IA/RVL, kynurenic acid produced a respiratory depression, without changes in mean arterial pressure or heart rate. The respiratory depression observed was characterized by a decrease in ventilation, tidal volume and mean inspiratory flow and an increase in respiratory frequency. Therefore, the observed respiratory depression was entirely due to a reduction in the inspiratory drive. Microinjections of vehicle (200 nl of saline into this area produced no significant changes in breathing pattern, blood pressure or heart rate. Respiratory depression in response to the blockade of glutamatergic receptors inside the rostral VMS suggests that neurons at this site have an endogenous glutamatergic input controlling the respiratory cycle duration and the inspiratory drive transmission.

Transmission of Influenza A Viruses

Science.gov (United States)

Neumann, Gabriele; Kawaoka, Yoshihiro

2015-01-01

Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

Relationship between respiratory and food allergy and evaluation of preventive measures.

Science.gov (United States)

Vega, F; Panizo, C; Dordal, M T; González, M L; Velázquez, E; Valero, A; Sánchez, M C; Rondón, C; Montoro, J; Matheu, V; Lluch-Bernal, M; González, R; Fernández-Parra, B; Del Cuvillo, A; Dávila, I; Colás, C; Campo, P; Antón, E; Navarro, A M

2016-01-01

Food allergy and respiratory allergy are two frequently associated diseases and with an increasing prevalence. Several reports show the presence of respiratory symptoms in patients with food allergy, while certain foods may be related to the development or exacerbation of allergic rhinitis and asthma. The present update focuses on this relationship, revealing a pathogenic and clinical association between food and respiratory allergy. This association is even more intense when the food hypersensitivity is persistent or starts in the early years of life. Food allergy usually precedes respiratory allergy and may be a risk factor for allergic rhinitis and asthma, becoming a relevant clinical marker for severe atopic asthma. Furthermore, the presence of co-existing asthma may enhance life-threatening symptoms occurring during a food allergic reaction. Recommendations for dietary restrictions during pregnancy and breastfeeding to prevent the development of respiratory allergy are controversial and not supported by consistent scientific data. Current recommendations from medical societies propose exclusive breastfeeding during the first four months of life, with the introduction of solid food in the fourth to the seventh month period of life. A delayed introduction of solid food after this period may increase the risk of developing subsequent allergic conditions. Further studies are encouraged to avoid unjustified recommendations involving useless dietary restrictions. Copyright © 2015 SEICAP. Published by Elsevier Espana. All rights reserved.

Adaptation of H9N2 AIV in guinea pigs enables efficient transmission by direct contact and inefficient transmission by respiratory droplets

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Sang, Xiaoyu; Wang, Airong; Ding, Jie; Kong, Huihui; Gao, Xiaolong; Li, Lin; Chai, Tongjie; Li, Yuanguo; Zhang, Kun; Wang, Chengyu; Wan, Zhonghai; Huang, Geng; Wang, Tiecheng; Feng, Na; Zheng, Xuexing; Wang, Hualei; Zhao, Yongkun; Yang, Songtao; Qian, Jun; Hu, Guixue; Gao, Yuwei; Xia, Xianzhu

2015-01-01

H9N2 avian influenza viruses circulate worldwide in poultry and have sporadically infected humans, raising concern whether H9N2 viruses have pandemic potential. Here, we use a guinea pig model to examine whether serial passage results in adaptive viral changes that confer a transmissible phenotype to a wild-type H9N2 virus. After nine serial passages of an H9N2 virus through guinea pigs, productive transmission by direct contact occurred in 2/3 guinea pig pairs. The efficiency of transmission by direct contact increased following the fifteenth passage and occurred in 3/3 guinea pig pairs. In contrast, airborne transmission of the passaged virus was less efficient and occurred in 1/6 guinea pig pairs and 0/6 ferret pairs after the fifteenth passage. Three amino acid substitutions, HA1-Q227P, HA2-D46E, and NP-E434K, were sufficient for contact transmission in guinea pigs (2/3 pairs). The two HA amino acid substitutions enhanced receptor binding to α2,3-linked sialic acid receptors. Additionally, the HA2-D46E substitution increased virus thermostability whereas the NP-E434K mutation enhanced viral RNA polymerase activity in vitro. Our findings suggest that adaptive changes that enhance viral receptor binding, thermostability, and replicative capacity in mammalian cells can collectively enhance the transmissibility of H9N2 AIVs by direct contact in the guinea pig model. PMID:26552719

Genetics, receptor binding property, and transmissibility in mammals of naturally isolated H9N2 Avian Influenza viruses.

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Xuyong Li

2014-11-01

Full Text Available H9N2 subtype influenza viruses have been detected in different species of wild birds and domestic poultry in many countries for several decades. Because these viruses are of low pathogenicity in poultry, their eradication is not a priority for animal disease control in many countries, which has allowed them to continue to evolve and spread. Here, we characterized the genetic variation, receptor-binding specificity, replication capability, and transmission in mammals of a series of H9N2 influenza viruses that were detected in live poultry markets in southern China between 2009 and 2013. Thirty-five viruses represented 17 genotypes on the basis of genomic diversity, and one specific "internal-gene-combination" predominated among the H9N2 viruses. This gene combination was also present in the H7N9 and H10N8 viruses that have infected humans in China. All of the 35 viruses preferentially bound to the human-like receptor, although two also retained the ability to bind to the avian-like receptor. Six of nine viruses tested were transmissible in ferrets by respiratory droplet; two were highly transmissible. Some H9N2 viruses readily acquired the 627K or 701N mutation in their PB2 gene upon infection of ferrets, further enhancing their virulence and transmission in mammals. Our study indicates that the widespread dissemination of H9N2 viruses poses a threat to human health not only because of the potential of these viruses to cause an influenza pandemic, but also because they can function as "vehicles" to deliver different subtypes of influenza viruses from avian species to humans.

Resistance development of cystic fibrosis respiratory pathogens when exposed to fosfomycin and tobramycin alone and in combination under aerobic and anaerobic conditions.

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McCaughey, Gerard; Diamond, Paul; Elborn, J Stuart; McKevitt, Matt; Tunney, Michael M

2013-01-01

Although antibiotics from different classes are frequently prescribed in combination to prevent the development of resistance amongst Cystic Fibrosis (CF) respiratory pathogens, there is a lack of data as to the efficacy of this approach. We have previously shown that a 4:1 (w/w) combination of fosfomycin and tobramycin (F:T) has excellent activity against CF pathogens with increased activity under physiologically relevant anaerobic conditions. Therefore, the aim of this study was to determine whether F:T could delay or prevent the onset of resistance compared to either fosfomycin or tobramycin alone under aerobic and anaerobic conditions. The frequency of spontaneous mutants arising following exposure to fosfomycin, tobramycin and F:T was determined for clinical Pseudomonas aeruginosa and MRSA isolates under aerobic and anaerobic conditions. The effect of sub-inhibitory concentrations of fosfomycin, tobramycin and F:T on the induction of resistance was also investigated, with the stability of resistance and fitness cost associated with resistance assessed if it developed. P. aeruginosa and MRSA isolates had a lower frequency of spontaneous mutants to F:T compared to fosfomycin and tobramycin under both aerobic and anaerobic conditions. There was a maximum two-fold increase in F:T MICs when P. aeruginosa and MRSA isolates were passaged in sub-inhibitory F:T for 12 days. In contrast, sequential resistance to fosfomycin and tobramycin developed quickly (n = 3 days for both) after passage in sub-inhibitory concentrations. Once developed, both fosfomycin and tobramycin resistance was stable and not associated with a biological fitness cost to either P. aeruginosa or MRSA isolates. The results of this study suggest that F:T may prevent the development of resistance compared to fosfomycin or tobramycin alone under aerobic and physiologically relevant anaerobic conditions. F:T may be a potential treatment option in CF patients chronically colonised by MRSA and/or P

Occurrence and diversity of arthropod-transmitted pathogens in red foxes (Vulpes vulpes) in western Austria, and possible vertical (transplacental) transmission of Hepatozoon canis.

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Hodžić, Adnan; Mrowietz, Naike; Cézanne, Rita; Bruckschwaiger, Pia; Punz, Sylvia; Habler, Verena Elisabeth; Tomsik, Valentina; Lazar, Judit; Duscher, Georg G; Glawischnig, Walter; Fuehrer, Hans-Peter

2018-03-01

Red fox (Vulpes vulpes) is the most abundant wild canid species in Austria, and it is a well-known carrier of many pathogens of medical and veterinary concern. The main aim of the present study was to investigate the occurrence and diversity of protozoan, bacterial and filarial parasites transmitted by blood-feeding arthropods in a red fox population in western Austria. Blood (n = 351) and spleen (n = 506) samples from foxes were examined by PCR and sequencing and the following pathogens were identified: Babesia canis, Babesia cf. microti (syn. Theileria annae), Hepatozoon canis, Anaplasma phagocytophilum, Candidatus Neoehrlichia sp. and Bartonella rochalimae. Blood was shown to be more suitable for detection of Babesia cf. microti, whilst the spleen tissue was better for detection of H. canis than blood. Moreover, extremely low genetic variability of H. canis and its relatively low prevalence rate observed in this study may suggest that the parasite has only recently been introduced in the sampled area. Furthermore, the data presented here demonstrates, for the first time, the possible vertical transmission of H. canis from an infected vixen to the offspring, and this could explain the very high prevalence in areas considered free of its main tick vector(s).

Pathogen Presence in European Starlings Inhabiting Commercial Piggeries in South Australia.

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Pearson, Hayley E; Lapidge, Steven J; Hernández-Jover, Marta; Toribio, Jenny-Ann L M L

2016-06-01

The majority of bacterial diarrhea-causing illnesses in domestic pigs result from infection with Escherichia coli, Salmonella spp., or Campylobacter spp. These bacterial enteropathogens also correspond with the most-common bacteria isolated from wild birds. Additionally, viral pathogens such as avian influenza virus (AIV), West Nile virus (WNV, including Kunjin disease), and Newcastle disease virus (NDV) may also be carried and transmitted by birds in Australia. Introduced European starlings (Sturnus vulgarus) are one of the most-frequently reported birds on piggeries in Australia. The presence of the three bacterial pathogens, Salmonella spp., Campylobacter spp., and Escherichia coli , as well as the three viral pathogens AIV, WNV, and NDV, were evaluated in starlings captured on four commercial piggeries in South Australia. A total of 473 starlings were captured on the four piggeries in 2008 and 2009. A cloacal swab was taken from each bird and cultured for bacterial identification, with follow-up serotyping of any positives, whilst fifty samples were analyzed by PCR for the three target viral pathogens. There was no AIV, WNV, or NDV detected in the 50 starlings sampled. Escherichia coli was found to be present in the starling populations on all four piggeries whilst Salmonella spp. and Campylobacter jejuni were found to be present only in the starling population sampled on one piggery. Serotyping identified pig-pathogenic strains of the bacteria. The prevalence of these production-limiting bacterial pathogens in starlings, coupled with the large starling populations often found inside piggeries during daylight hours in the summer months, presents a disease transmission risk and jeopardizes piggery disease management. Removal of starlings from agricultural enterprises (as shown by international studies), or prevention of starling access to animal feed and water, could substantially reduce the risk of transmission of enterobacterial pathogens from starlings to