Supply of neuraminidase inhibitors related to reduced influenza A (H1N1) mortality during the 2009-2010 H1N1 pandemic: an ecological study.

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Miller, Paula E; Rambachan, Aksharananda; Hubbard, Roderick J; Li, Jiabai; Meyer, Alison E; Stephens, Peter; Mounts, Anthony W; Rolfes, Melissa A; Penn, Charles R

2012-01-01

The influenza A (H1N1) pandemic swept across the globe from April 2009 to August 2010 affecting millions. Many WHO Member States relied on antiviral drugs, specifically neuraminidase inhibitors (NAIs) oseltamivir and zanamivir, to treat influenza patients in critical condition. Such drugs have been found to be effective in reducing severity and duration of influenza illness, and likely reduced morbidity during the pandemic. However, it is less clear whether NAIs used during the pandemic reduced H1N1 mortality. Country-level data on supply of oseltamivir and zanamivir were used to predict H1N1 mortality (per 100,000 people) from July 2009 to August 2010 in forty-two WHO Member States. Poisson regression was used to model the association between NAI supply and H1N1 mortality, with adjustment for economic, demographic, and health-related confounders. After adjustment for potential confounders, each 10% increase in kilograms of oseltamivir, per 100,000 people, was associated with a 1.6% reduction in H1N1 mortality over the pandemic period (relative rate (RR) = 0.84 per log increase in oseltamivir supply). While the supply of zanamivir was considerably less than that of oseltamivir in each Member State, each 10% increase in kilogram of active zanamivir, per 100,000, was associated with a 0.3% reduction in H1N1 mortality (RR = 0.97 per log increase). While there are limitations to the ecologic nature of these data, this analysis offers evidence of a protective relationship between antiviral drug supply and influenza mortality and supports a role for influenza antiviral use in future pandemics.

Pandemic H1N1 2009 ('swine flu'): diagnostic and other challenges.

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Burkardt, Hans-Joachim

2011-01-01

Pandemic H1N1 2009 ('swine flu') virus was 'the virus of the year 2009' because it affected the lives of many people in this year. H1N1 was first described in California in April 2009 and spread very rapidly all over the globe. The fast global penetration of the swine flu caused the WHO in Geneva to call the infection with H1N1 a new pandemic with a rapid escalation of the different pandemic phases that ended on 11 June 2009, with the declaration of phase 6 (full-blown pandemic). This had far-reaching consequences for the local health authorities in the different affected countries and created awareness in the public and fear in the experts and even more so in many lay people. The consequences were: setting up reliable diagnostic tests as soon as possible; enhanced production, distribution and stock creation of the few drugs that were available to treat newly infected persons; and development, production, distribution and stock creation of new and appropriate anti-H1N1 swine flu vaccines. This all resulted in enormous costs in the local healthcare systems and also required smart and diligent logistics, because demand for all this was, in most cases, much higher than availability. Fortunately, the pandemic ended quite quickly (there was no 'second wave' as had been anticipated by some experts) and the death toll was moderate, compared with other influenza pandemic in the past and even to the regular annual appearance of the seasonal flu. This favorable outcome, however, provoked some harsh criticism that the WHO and healthcare systems in general had over-reacted and by doing so, a lot of money was thrown out of the window. This article describes the history of the H1N1 pandemic, the diagnostic challenges and resolutions, touches on treatment and vaccination very briefly and also comments on the criticism and arguments that came up immediately at the end and following the termination of the pandemic situation.

1918 pandemic H1N1 DNA vaccine protects ferrets against 2007 H1N1 virus infection

DEFF Research Database (Denmark)

Bragstad, Karoline; Martel, Cyril Jean-Marie; Aasted, Bent

of the H1N1 pandemic virus from 1918 induce protection in ferrets against infection with a H1N1 (A/New Caledonia/20/99(H1N1)) virus which was included in the conventional vaccine for the 2006-2007 season. The viruses are separated by a time interval of 89 years and differ by 21.2% in the HA1 protein...

Efficacy of a pandemic (H1N1) 2009 virus vaccine in pigs against the pandemic influenza virus is superior to commercially available swine influenza vaccines.

NARCIS (Netherlands)

Loeffen, W.L.A.; Stockhofe-Zurwieden, N.; Weesendorp, E.; Zoelen-Bos, van D.J.; Heutink, R.; Quak, J.; Goovaerts, D.; Heldens, J.; Maas, H.A.; Moormann, R.J.M.; Koch, G.

2011-01-01

In April 2009 a new influenza A/H1N1 strain, currently named “pandemic (H1N1) influenza 2009¿ (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to

Novel pandemic influenza A(H1N1 viruses are potently inhibited by DAS181, a sialidase fusion protein.

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Gallen B Triana-Baltzer

2009-11-01

Full Text Available The recent emergence of a novel pandemic influenza A(H1N1 strain in humans exemplifies the rapid and unpredictable nature of influenza virus evolution and the need for effective therapeutics and vaccines to control such outbreaks. However, resistance to antivirals can be a formidable problem as evidenced by the currently widespread oseltamivir- and adamantane-resistant seasonal influenza A viruses (IFV. Additional antiviral approaches with novel mechanisms of action are needed to combat novel and resistant influenza strains. DAS181 (Fludase is a sialidase fusion protein in early clinical development with in vitro and in vivo preclinical activity against a variety of seasonal influenza strains and highly pathogenic avian influenza strains (A/H5N1. Here, we use in vitro, ex vivo, and in vivo models to evaluate the activity of DAS181 against several pandemic influenza A(H1N1 viruses.The activity of DAS181 against several pandemic influenza A(H1N1 virus isolates was examined in MDCK cells, differentiated primary human respiratory tract culture, ex-vivo human bronchi tissue and mice. DAS181 efficiently inhibited viral replication in each of these models and against all tested pandemic influenza A(H1N1 strains. DAS181 treatment also protected mice from pandemic influenza A(H1N1-induced pathogenesis. Furthermore, DAS181 antiviral activity against pandemic influenza A(H1N1 strains was comparable to that observed against seasonal influenza virus including the H274Y oseltamivir-resistant influenza virus.The sialidase fusion protein DAS181 exhibits potent inhibitory activity against pandemic influenza A(H1N1 viruses. As inhibition was also observed with oseltamivir-resistant IFV (H274Y, DAS181 may be active against the antigenically novel pandemic influenza A(H1N1 virus should it acquire the H274Y mutation. Based on these and previous results demonstrating DAS181 broad-spectrum anti-IFV activity, DAS181 represents a potential therapeutic agent for

Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus

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Ducatez MF

2011-07-01

Full Text Available Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1pdm09 viruses. However, as the A(H1N1pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1pdm09 and seasonal A(H1N1 or A(H3N2 viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1 pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation

ICU-treated influenza A(H1N1 pdm09 infections more severe post pandemic than during 2009 pandemic: a retrospective analysis

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Pekka Ylipalosaari

2017-11-01

Full Text Available Abstract Background We compared in a single mixed intensive care unit (ICU patients with influenza A(H1N1 pdm09 between pandemic and postpandemic periods. Methods Retrospective analysis of prospectively collected data in 2009–2016. Data are expressed as median (25th–75th percentile or number (percentile. Results Seventy-six influenza A(H1N1 pdm09 patients were admitted to the ICU: 16 during the pandemic period and 60 during the postpandemic period. Postpandemic patients were significantly older (60 years vs. 43 years, p < 0.001 and less likely to have epilepsy or other neurological diseases compared with pandemic patients (5 [8.3%] vs. 6 [38%], respectively; p = 0.009. Postpandemic patients were more likely than pandemic patients to have cardiovascular disease (24 [40%] vs. 1 [6%], respectively; p = 0.015, and they had higher scores on APACHE II (17 [13–22] vs. 14 [10–17], p = 0.002 and SAPS II (40 [31–51] vs. 31 [25–35], p = 0.002 upon admission to the ICU. Postpandemic patients had higher maximal SOFA score (9 [5–12] vs. 5 [4–9], respectively; p = 0.03 during their ICU stay. Postpandemic patients had more often septic shock (40 [66.7%] vs. 8 [50.0%], p = 0.042, and longer median hospital stays (15.0 vs. 8.0 days, respectively; p = 0.006. During 2015–2016, only 18% of the ICU- treated patients had received seasonal influenza vaccination. Conclusions Postpandemic ICU-treated A(H1N1 pdm09 influenza patients were older and developed more often septic shock and had longer hospital stays than influenza patients during the 2009 pandemic.

Comparison of temporal and spatial dynamics of seasonal H3N2, pandemic H1N1 and highly pathogenic avian influenza H5N1 virus infections in ferrets.

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Judith M A van den Brand

Full Text Available Humans may be infected by different influenza A viruses--seasonal, pandemic, and zoonotic--which differ in presentation from mild upper respiratory tract disease to severe and sometimes fatal pneumonia with extra-respiratory spread. Differences in spatial and temporal dynamics of these infections are poorly understood. Therefore, we inoculated ferrets with seasonal H3N2, pandemic H1N1 (pH1N1, and highly pathogenic avian H5N1 influenza virus and performed detailed virological and pathological analyses at time points from 0.5 to 14 days post inoculation (dpi, as well as describing clinical signs and hematological parameters. H3N2 infection was restricted to the nose and peaked at 1 dpi. pH1N1 infection also peaked at 1 dpi, but occurred at similar levels throughout the respiratory tract. H5N1 infection occurred predominantly in the alveoli, where it peaked for a longer period, from 1 to 3 dpi. The associated lesions followed the same spatial distribution as virus infection, but their severity peaked between 1 and 6 days later. Neutrophil and monocyte counts in peripheral blood correlated with inflammatory cell influx in the alveoli. Of the different parameters used to measure lower respiratory tract disease, relative lung weight and affected lung tissue allowed the best quantitative distinction between the virus groups. There was extra-respiratory spread to more tissues--including the central nervous system--for H5N1 infection than for pH1N1 infection, and to none for H3N2 infection. This study shows that seasonal, pandemic, and zoonotic influenza viruses differ strongly in the spatial and temporal dynamics of infection in the respiratory tract and extra-respiratory tissues of ferrets.

Pandemic influenza A/H1N1pdm in Italy: age, risk and population susceptibility.

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Stefano Merler

Full Text Available BACKGROUND: A common pattern emerging from several studies evaluating the impact of the 2009 A/H1N1 pandemic influenza (A/H1N1pdm conducted in countries worldwide is the low attack rate observed in elderly compared to that observed in children and young adults. The biological or social mechanisms responsible for the observed age-specific risk of infection are still to be deeply investigated. METHODS: The level of immunity against the A/H1N1pdm in pre and post pandemic sera was determined using left over sera taken for diagnostic purposes or routine ascertainment obtained from clinical laboratories. The antibody titres were measured by the haemagglutination inhibition (HI assay. To investigate whether certain age groups had higher risk of infection the presence of protective antibody (≥1∶40, was calculated using exact binomial 95% CI on both pre- and post- pandemic serological data in the age groups considered. To estimate age-specific susceptibility to infection we used an age-structured SEIR model. RESULTS: By comparing pre- and post-pandemic serological data in Italy we found age- specific attack rates similar to those observed in other countries. Cumulative attack rate at the end of the first A/H1N1pdm season in Italy was estimated to be 16.3% (95% CI 9.4%-23.1%. Modeling results allow ruling out the hypothesis that only age-specific characteristics of the contact network and levels of pre-pandemic immunity are responsible for the observed age-specific risk of infection. This means that age-specific susceptibility to infection, suspected to play an important role in the pandemic, was not only determined by pre-pandemic levels of H1N1pdm antibody measured by HI. CONCLUSIONS: Our results claim for new studies to better identify the biological mechanisms, which might have determined the observed pattern of susceptibility with age. Moreover, our results highlight the need to obtain early estimates of differential susceptibility with age in

Reassortant H1N1 influenza virus vaccines protect pigs against pandemic H1N1 influenza virus and H1N2 swine influenza virus challenge.

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Yang, Huanliang; Chen, Yan; Shi, Jianzhong; Guo, Jing; Xin, Xiaoguang; Zhang, Jian; Wang, Dayan; Shu, Yuelong; Qiao, Chuanling; Chen, Hualan

2011-09-28

Influenza A (H1N1) virus has caused human influenza outbreaks in a worldwide pandemic since April 2009. Pigs have been found to be susceptible to this influenza virus under experimental and natural conditions, raising concern about their potential role in the pandemic spread of the virus. In this study, we generated a high-growth reassortant virus (SC/PR8) that contains the hemagglutinin (HA) and neuraminidase (NA) genes from a novel H1N1 isolate, A/Sichuan/1/2009 (SC/09), and six internal genes from A/Puerto Rico/8/34 (PR8) virus, by genetic reassortment. The immunogenicity and protective efficacy of this reassortant virus were evaluated at different doses in a challenge model using a homologous SC/09 or heterologous A/Swine/Guangdong/1/06(H1N2) virus (GD/06). Two doses of SC/PR8 virus vaccine elicited high-titer serum hemagglutination inhibiting (HI) antibodies specific for the 2009 H1N1 virus and conferred complete protection against challenge with either SC/09 or GD/06 virus, with reduced lung lesions and viral shedding in vaccine-inoculated animals compared with non-vaccinated control animals. These results indicated for the first time that a high-growth SC/PR8 reassortant H1N1 virus exhibits properties that are desirable to be a promising vaccine candidate for use in swine in the event of a pandemic H1N1 influenza. Copyright © 2011 Elsevier B.V. All rights reserved.

Novel triple reassortant H1N2 influenza viruses bearing six internal genes of the pandemic 2009/H1N1 influenza virus were detected in pigs in China.

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Qiao, Chuanling; Liu, Liping; Yang, Huanliang; Chen, Yan; Xu, Huiyang; Chen, Hualan

2014-12-01

The pandemic A/H1N1 influenza viruses emerged in both Mexico and the United States in March 2009, and were transmitted efficiently in the human population. Transmissions of the pandemic 2009/H1N1 virus from humans to poultry and other species of mammals were reported from several continents during the course of the 2009 H1N1 pandemic. Reassortant H1N1, H1N2, and H3N2 viruses containing genes of the pandemic 2009/H1N1 viruses appeared in pigs in some countries. In winter of 2012, a total of 2600 nasal swabs were collected from healthy pigs in slaughterhouses located throughout 10 provinces in China. The isolated viruses were subjected to genetic and antigenic analysis. Two novel triple-reassortant H1N2 influenza viruses were isolated from swine in China in 2012, with the HA gene derived from Eurasian avian-like swine H1N1, the NA gene from North American swine H1N2, and the six internal genes from the pandemic 2009/H1N1 viruses. The two viruses had similar antigenic features and some significant changes in antigenic characteristics emerged when compared to the previously identified isolates. We inferred that the novel reassortant viruses in China may have arisen from the accumulation of the three types of influenza viruses, which further indicates that swine herds serve as "mixing vessels" for influenza viruses. Influenza virus reassortment is an ongoing process, and our findings highlight the urgent need for continued influenza surveillance among swine herds. Copyright © 2014 Elsevier B.V. All rights reserved.

Protection against H5N1 Highly Pathogenic Avian and Pandemic (H1N1) 2009 Influenza Virus Infection in Cynomolgus Monkeys by an Inactivated H5N1 Whole Particle Vaccine

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Nakayama, Misako; Shichinohe, Shintaro; Itoh, Yasushi; Ishigaki, Hirohito; Kitano, Mitsutaka; Arikata, Masahiko; Pham, Van Loi; Ishida, Hideaki; Kitagawa, Naoko; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Ichikawa, Takaya; Tsuchiya, Hideaki; Nakamura, Shinichiro; Le, Quynh Mai; Ito, Mutsumi; Kawaoka, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

2013-01-01

H5N1 highly pathogenic avian influenza virus (HPAIV) infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3), in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1) 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3. PMID:24376571

Protection against H5N1 highly pathogenic avian and pandemic (H1N1 2009 influenza virus infection in cynomolgus monkeys by an inactivated H5N1 whole particle vaccine.

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Misako Nakayama

Full Text Available H5N1 highly pathogenic avian influenza virus (HPAIV infection has been reported in poultry and humans with expanding clade designations. Therefore, a vaccine that induces immunity against a broad spectrum of H5N1 viruses is preferable for pandemic preparedness. We established a second H5N1 vaccine candidate, A/duck/Hokkaido/Vac-3/2007 (Vac-3, in our virus library and examined the efficacy of inactivated whole particles of this strain against two clades of H5N1 HPAIV strains that caused severe morbidity in cynomolgus macaques. Virus propagation in vaccinated macaques infected with either of the H5N1 HPAIV strains was prevented compared with that in unvaccinated macaques. This vaccine also prevented propagation of a pandemic (H1N1 2009 virus in macaques. In the vaccinated macaques, neutralization activity, which was mainly shown by anti-hemagglutinin antibody, against H5N1 HPAIVs in plasma was detected, but that against H1N1 virus was not detected. However, neuraminidase inhibition activity in plasma and T-lymphocyte responses in lymph nodes against H1N1 virus were detected. Therefore, cross-clade and heterosubtypic protective immunity in macaques consisted of humoral and cellular immunity induced by vaccination with Vac-3.

Supply of neuraminidase inhibitors related to reduced influenza A (H1N1) mortality during the 2009-2010 H1N1 pandemic: summary of an ecological study.

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Miller, Paula E; Rambachan, Aksharananda; Hubbard, Roderick J; Li, Jiabai; Meyer, Alison E; Stephens, Peter; Mounts, Anthony W; Rolfes, Melissa A; Penn, Charles R

2013-09-01

When the influenza A (H1N1) pandemic spread across the globe from April 2009 to August 2010, many WHO Member States used antiviral drugs, specifically neuraminidase inhibitors (NAIs) oseltamivir and zanamivir, to treat influenza patients in critical condition. Antivirals have been found to be effective in reducing severity and duration of influenza illness, and likely reduce morbidity; however, it is unclear whether NAIs used during the pandemic reduced H1N1 mortality. To assess the association between antivirals and influenza mortality, at an ecologic level, country-level data on supply of oseltamivir and zanamivir were compared to laboratory-confirmed H1N1 deaths (per 100 000 people) from July 2009 to August 2010 in 42 WHO Member States. From this analysis, it was found that each 10% increase in kilograms of oseltamivir, per 100 000 people, was associated with a 1·6% reduction in H1N1 mortality over the pandemic period [relative rate (RR) = 0·84 per log increase in oseltamivir supply]. Each 10% increase in kilogram of active zanamivir, per 100 000, was associated with a 0·3% reduction in H1N1 mortality (RR = 0·97 per log increase). While limitations exist in the inference that can be drawn from an ecologic evaluation, this analysis offers evidence of a protective relationship between antiviral drug supply and influenza mortality and supports a role for influenza antiviral use in future pandemics. This article summarises the original study described previously, which can be accessed through the following citation: Miller PE, Rambachan A, Hubbard RJ, Li J, Meyer AE, et al. (2012) Supply of Neuraminidase Inhibitors Related to Reduced Influenza A (H1N1) Mortality during the 2009-2010 H1N1 Pandemic: An Ecological Study. PLoS ONE 7(9): e43491. © 2013 Blackwell Publishing Ltd.

Adaptation of Pandemic H1N1 Influenza Viruses in Mice▿

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Ilyushina, Natalia A.; Khalenkov, Alexey M.; Seiler, Jon P.; Forrest, Heather L.; Bovin, Nicolai V.; Marjuki, Henju; Barman, Subrata; Webster, Robert G.; Webby, Richard J.

2010-01-01

The molecular mechanism by which pandemic 2009 influenza A viruses were able to sufficiently adapt to humans is largely unknown. Subsequent human infections with novel H1N1 influenza viruses prompted an investigation of the molecular determinants of the host range and pathogenicity of pandemic influenza viruses in mammals. To address this problem, we assessed the genetic basis for increased virulence of A/CA/04/09 (H1N1) and A/TN/1-560/09 (H1N1) isolates, which are not lethal for mice, in a new mammalian host by promoting their mouse adaptation. The resulting mouse lung-adapted variants showed significantly enhanced growth characteristics in eggs, extended extrapulmonary tissue tropism, and pathogenicity in mice. All mouse-adapted viruses except A/TN/1-560/09-MA2 grew faster and to higher titers in cells than the original strains. We found that 10 amino acid changes in the ribonucleoprotein (RNP) complex (PB2 E158G/A, PA L295P, NP D101G, and NP H289Y) and hemagglutinin (HA) glycoprotein (K119N, G155E, S183P, R221K, and D222G) controlled enhanced mouse virulence of pandemic isolates. HA mutations acquired during adaptation affected viral receptor specificity by enhancing binding to α2,3 together with decreasing binding to α2,6 sialyl receptors. PB2 E158G/A and PA L295P amino acid substitutions were responsible for the significant enhancement of transcription and replication activity of the mouse-adapted H1N1 variants. Taken together, our findings suggest that changes optimizing receptor specificity and interaction of viral polymerase components with host cellular factors are the major mechanisms that contribute to the optimal competitive advantage of pandemic influenza viruses in mice. These modulators of virulence, therefore, may have been the driving components of early evolution, which paved the way for novel 2009 viruses in mammals. PMID:20592084

Streptococcus pneumoniae Coinfection Is Correlated with the Severity of H1N1 Pandemic Influenza

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Cisterna, Daniel; Savji, Nazir; Bussetti, Ana Valeria; Kapoor, Vishal; Hui, Jeffrey; Tokarz, Rafal; Briese, Thomas; Baumeister, Elsa; Lipkin, W. Ian

2009-01-01

Background Initial reports in May 2009 of the novel influenza strain H1N1pdm estimated a case fatality rate (CFR) of 0.6%, similar to that of seasonal influenza. In July 2009, however, Argentina reported 3056 cases with 137 deaths, representing a CFR of 4.5%. Potential explanations for increased CFR included virus reassortment or genetic drift, or infection of a more vulnerable population. Virus genomic sequencing of 26 Argentinian samples representing both severe and mild disease indicated no evidence of reassortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence. Furthermore, no evidence was found for increased frequency of risk factors for H1N1pdm disease. Methods/Principal Findings We examined nasopharyngeal swab samples (NPS) from 199 cases of H1N1pdm infection from Argentina with MassTag PCR, testing for 33 additional microbial agents. The study population consisted of 199 H1N1pdm-infected subjects sampled between 23 June and 4 July 2009. Thirty-nine had severe disease defined as death (n = 20) or hospitalization (n = 19); 160 had mild disease. At least one additional agent of potential pathogenic importance was identified in 152 samples (76%), including Streptococcus pneumoniae (n = 62); Haemophilus influenzae (n = 104); human respiratory syncytial virus A (n = 11) and B (n = 1); human rhinovirus A (n = 1) and B (n = 4); human coronaviruses 229E (n = 1) and OC43 (n = 2); Klebsiella pneumoniae (n = 2); Acinetobacter baumannii (n = 2); Serratia marcescens (n = 1); and Staphylococcus aureus (n = 35) and methicillin-resistant S. aureus (MRSA, n = 6). The presence of S. pneumoniae was strongly correlated with severe disease. S. pneumoniae was present in 56.4% of severe cases versus 25% of mild cases; more than one-third of H1N1pdm NPS with S. pneumoniae were from subjects with severe disease (22 of 62 S. pneumoniae-positive NPS, p = 0

Pre-admission statin use and in-hospital severity of 2009 pandemic influenza A(H1N1 disease.

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Stephen J Brett

2011-04-01

Full Text Available Statins are drugs that are used to lower plasma cholesterol levels. Recently, contradictory claims have been made about possible additional effects of statins on progression of a variety of inflammatory disorders, including infections. We therefore examined the clinical course of patients admitted to hospital with 2009 pandemic influenza A(H1N1, who were or weren't taking statins at time of admission.A retrospective case-control study was performed using the United Kingdom Influenza Clinical Information Network (FLU-CIN database, containing detailed information on 1,520 patients admitted to participating hospitals with confirmed 2009 pandemic influenza A(H1N1 infection between April 2009 and January 2010. We confined our analysis to those aged over 34 years. Univariate analysis was used to calculate unadjusted odds ratios (OR and 95 percent confidence intervals (95%CI for factors affecting progression to severe outcome (high dependency or intensive care unit level support or death (cases; two multivariable logistic regression models were then established for age and sex, and for age, sex, obesity and "indication for statin" (e.g., heart disease or hypercholesterolaemia.We found no statistically significant association between pre-admission statin use and severity of outcome after adjustment for age and sex [adjusted OR: 0.81 (95% CI: 0.46-1.38; n = 571]. After adjustment for age, sex, obesity and indication for statin, the association between pre-admission statin use and severe outcome was not statistically significant; point estimates are compatible with a small but clinically significant protective effect of statin use [adjusted OR: 0.72 (95% CI: 0.38-1.33].In this group of patients hospitalized with pandemic influenza, a significant beneficial effect of pre-admission statin use on the in-hospital course of illness was not identified. Although the database from which these observations are derived represents the largest available suitable

Treatment and Prevention of Pandemic H1N1 Influenza.

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Rewar, Suresh; Mirdha, Dashrath; Rewar, Prahlad

2015-01-01

Swine influenza is a respiratory infection common to pigs worldwide caused by type A influenza viruses, principally subtypes H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3. Swine influenza viruses also can cause moderate to severe illness in humans and affect persons of all age groups. People in close contact with swine are at especially high risk. Until recently, epidemiological study of influenza was limited to resource-rich countries. The World Health Organization declared an H1N1 pandemic on June 11, 2009, after more than 70 countries reported 30,000 cases of H1N1 infection. In 2015, incidence of swine influenza increased substantially to reach a 5-year high. In India in 2015, 10,000 cases of swine influenza were reported with 774 deaths. The Centers for Disease Control and Prevention recommend real-time polymerase chain reaction as the method of choice for diagnosing H1N1. Antiviral drugs are the mainstay of clinical treatment of swine influenza and can make the illness milder and enable the patient to feel better faster. Antiviral drugs are most effective when they are started within the first 48 hours after the clinical signs begin, although they also may be used in severe or high-risk cases first seen after this time. The Centers for Disease Control and Prevention recommends use of oseltamivir (Tamiflu, Genentech) or zanamivir (Relenza, GlaxoSmithKline). Prevention of swine influenza has 3 components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans. Because of limited treatment options, high risk for secondary infection, and frequent need for intensive care of individuals with H1N1 pneumonia, environmental control, including vaccination of high-risk populations and public education are critical to control of swine influenza out breaks. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Identification of swine H1N2/pandemic H1N1 reassortant influenza virus in pigs, United States.

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Ali, Ahmed; Khatri, Mahesh; Wang, Leyi; Saif, Yehia M; Lee, Chang-Won

2012-07-06

In October and November 2010, novel H1N2 reassortant influenza viruses were identified from pigs showing mild respiratory signs that included cough and depression. Sequence and phylogenetic analysis showed that the novel H1N2 reassortants possesses HA and NA genes derived from recent H1N2 swine isolates similar to those isolated from Midwest. Compared to the majority of reported reassortants, both viruses preserved human-like host restrictive and putative antigenic sites in their HA and NA genes. The four internal genes, PB2, PB1, PA, and NS were similar to the contemporary swine triple reassortant viruses' internal genes (TRIG). Interestingly, NP and M genes of the novel reassortants were derived from the 2009 pandemic H1N1. The NP and M proteins of the two isolates demonstrated one (E16G) and four (G34A, D53E, I109T, and V313I) amino acid changes in the M2 and NP proteins, respectively. Similar amino acid changes were also noticed upon incorporation of the 2009 pandemic H1N1 NP in other reassortant viruses reported in the U.S. Thus the role of those amino acids in relation to host adaptation need to be further investigated. The reassortments of pandemic H1N1 with swine influenza viruses and the potential of interspecies transmission of these reassortants from swine to other species including human indicate the importance of systematic surveillance of swine population to determine the origin, the prevalence of similar reassortants in the U.S. and their impact on both swine production and public health. Copyright © 2012 Elsevier B.V. All rights reserved.

Transmission of Hemagglutinin D222G Mutant Strain of Pandemic (H1N1) 2009 Virus

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Facchini, Marzia; Spagnolo, Domenico; De Marco, Maria A.; Calzoletti, Laura; Zanetti, Alessandro; Fumagalli, Roberto; Tanzi, Maria L.; Cassone, Antonio; Rezza, Giovanni; Donatelli, Isabella

2010-01-01

A pandemic (H1N1) 2009 virus strain carrying the D222G mutation was identified in a severely ill man and was transmitted to a household contact. Only mild illness developed in the contact, despite his obesity and diabetes. The isolated virus reacted fully with an antiserum against the pandemic vaccine strain. PMID:20409386

Cytokine response patterns in severe pandemic 2009 H1N1 and seasonal influenza among hospitalized adults.

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Nelson Lee

Full Text Available BACKGROUND: Studying cytokine/chemokine responses in severe influenza infections caused by different virus subtypes may improve understanding on pathogenesis. METHODS: Adults hospitalized for laboratory-confirmed seasonal and pandemic 2009 A/H1N1 (pH1N1 influenza were studied. Plasma concentrations of 13 cytokines/chemokines were measured at presentation and then serially, using cytometric-bead-array with flow-cytometry and ELISA. PBMCs from influenza patients were studied for cytokine/chemokine expression using ex-vivo culture (Whole Blood Assay,±PHA/LPS stimulation. Clinical variables were prospectively recorded and analyzed. RESULTS: 63 pH1N1 and 53 seasonal influenza patients were studied. pH1N1 patients were younger (mean±S.D. 42.8±19.2 vs 70.5±16.7 years, and fewer had comorbidities. Respiratory/cardiovascular complications were common in both groups (71.4% vs 81.1%, although severe pneumonia with hypoxemia (54.0% vs 28.3% and ICU admissions (25.4% vs 1.9% were more frequent with pH1N1. Hyperactivation of the proinflammatory cytokines IL-6, CXCL8/IL-8, CCL2/MCP-1 and sTNFR-1 was found in pH1N1 pneumonia (2-15 times normal and in complicated seasonal influenza, but not in milder pH1N1 infections. The adaptive-immunity (Th1/Th17-related CXCL10/IP-10, CXCL9/MIG and IL-17A however, were markedly suppressed in severe pH1N1 pneumonia (2-27 times lower than seasonal influenza; P-values<0.01. This pattern was further confirmed with serial measurements. Hypercytokinemia tended to be sustained in pH1N1 pneumonia, associated with a slower viral clearance [PCR-negativity: day 3-4, 55% vs 85%; day 6-7, 67% vs 100%]. Elevated proinflammatory cytokines, particularly IL-6, predicted ICU admission (adjusted OR 12.6, 95%CI 2.6-61.5, per log(10unit increase; P = 0.002, and correlated with fever, tachypnoea, deoxygenation, and length-of-stay (Spearman's rho, P-values<0.01 in influenza infections. PBMCs in seasonal influenza patients were activated and

Mannose-binding lectin contributes to deleterious inflammatory response in pandemic H1N1 and avian H9N2 infection.

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Ling, Man To; Tu, Wenwei; Han, Yan; Mao, Huawei; Chong, Wai Po; Guan, Jing; Liu, Ming; Lam, Kwok Tai; Law, Helen K W; Peiris, J S Malik; Takahashi, K; Lau, Yu Lung

2012-01-01

Mannose-binding lectin (MBL) is a pattern-recognition molecule, which functions as a first line of host defense. Pandemic H1N1 (pdmH1N1) influenza A virus caused massive infection in 2009 and currently circulates worldwide. Avian influenza A H9N2 (H9N2/G1) virus has infected humans and has the potential to be the next pandemic virus. Antiviral function and immunomodulatory role of MBL in pdmH1N1 and H9N2/G1 virus infection have not been investigated. In this study, MBL wild-type (WT) and MBL knockout (KO) murine models were used to examine the role of MBL in pdmH1N1 and H9N2/G1 virus infection. Our study demonstrated that in vitro, MBL binds to pdmH1N1 and H9N2/G1 viruses, likely via the carbohydrate recognition domain of MBL. Wild-type mice developed more severe disease, as evidenced by a greater weight loss than MBL KO mice during influenza virus infection. Furthermore, MBL WT mice had enhanced production of proinflammatory cytokines and chemokines compared with MBL KO mice, suggesting that MBL could upregulate inflammatory responses that may potentially worsen pdmH1N1 and H9N2/G1 virus infections. Our study provided the first in vivo evidence that MBL may be a risk factor during pdmH1N1 and H9N2/G1 infection by upregulating proinflammatory response.

Pulmonary function in patients with pandemic H1N1

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Soraia Koppe

Full Text Available Abstract Introduction: The influenza A (H1N1 was responsible for the 2009 pandemic, especially with severe pulmonary complications. Objective: To describe characteristics of patients in a university hospital in Curitiba - PR with laboratory diagnosis of influenza A (H1N1 and its post hospital discharge in the 2009 lung function pandemic. Methodology: A retrospective observational study. It was used as a data source the institution Epidemiology Service (SEPIH and spirometry tests of patients who were admitted in 2009, 18 years without lung disease associated and non-pregnant. Descriptive statistics were used and applied Fisher's exact test for relationship between comorbidity and spirometry tests. Results: There were 84 confirmed cases, of these 11 were eligible for the study with a mean age of 44.27 years (± 9.63 and 63.63% males. 54.54% of the 11 patients had comorbidities associated with systemic arterial hypertension (54.54%, diabetes (18.18% and late postoperative period of kidney transplantation (18.18% were the most frequent. Most patients (81.81% had BMI ≥ 25kg / m². The Spirometry test was performed approximately 40.09 (± 15.27 days after discharge, of these, 5 had restrictive pattern and all had abnormal chest radiograph results. There was no statistically significant difference between the results of Spirometry and comorbidities (p=0.24. Conclusions: The group evaluated in this research did not show a direct relationship between Spirometry and comorbidities, but changes in Spirometry in some patients after hospital discharge stood out, suggesting changes in lung function due to influenza A (H1N1.

Value for Money in H1N1 Influenza: A Systematic Review of the Cost-Effectiveness of Pandemic Interventions.

Science.gov (United States)

Pasquini-Descomps, Hélène; Brender, Nathalie; Maradan, David

2017-06-01

The 2009 A/H1N1 influenza pandemic generated additional data and triggered new studies that opened debate over the optimal strategy for handling a pandemic. The lessons-learned documents from the World Health Organization show the need for a cost estimation of the pandemic response during the risk-assessment phase. Several years after the crisis, what conclusions can we draw from this field of research? The main objective of this article was to provide an analysis of the studies that present cost-effectiveness or cost-benefit analyses for A/H1N1 pandemic interventions since 2009 and to identify which measures seem most cost-effective. We reviewed 18 academic articles that provide cost-effectiveness or cost-benefit analyses for A/H1N1 pandemic interventions since 2009. Our review converts the studies' results into a cost-utility measure (cost per disability-adjusted life-year or quality-adjusted life-year) and presents the contexts of severity and fatality. The existing studies suggest that hospital quarantine, vaccination, and usage of the antiviral stockpile are highly cost-effective, even for mild pandemics. However, school closures, antiviral treatments, and social distancing may not qualify as efficient measures, for a virus like 2009's H1N1 and a willingness-to-pay threshold of $45,000 per disability-adjusted life-year. Such interventions may become cost-effective for severe crises. This study helps to shed light on the cost-utility of various interventions, and may support decision making, among other criteria, for future pandemics. Nonetheless, one should consider these results carefully, considering these may not apply to a specific crisis or country, and a dedicated cost-effectiveness assessment should be conducted at the time. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

H1N1 pandemic preparedness and business continuity plan

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-10-15

SaskPower's H1N1 pandemic preparedness and business continuity plan was designed to prepare SaskPower employees for elevated levels of absenteeism during a potential pandemic. Emergency management and business continuity will be facilitated if critical duties and essential services are maintained without interruption. A layered approach was used to develop a range of response measures designed to meet a range of possible pandemic threats. The plan identified essential activities, tasks and functions and outlined methods of mitigating supply disruptions and possible shortages. Methods of minimizing illness in employees were discussed, as well as methods of maintaining a safe and secure work environment. The measures were developed in accordance with the World Health Organization (WHO) 6 phases of pandemic alert. The plan was also designed to be read by SaskPower's key suppliers in order to ensure their pandemic readiness. 5 tabs.

Replication, Pathogenesis and Transmission of Pandemic (H1N1) 2009 Virus in Non-Immune Pigs

DEFF Research Database (Denmark)

Brookes, Sharon M; Nunez, Alejandor; Choudhury, Bhudipa

2010-01-01

The declaration of the human influenza A pandemic (H1N1) 2009 (H1N1/09) raised important questions, including origin and host range [1,2]. Two of the three pandemics in the last century resulted in the spread of virus to pigs (H1N1, 1918; H3N2, 1968) with subsequent independent establishment...... and evolution within swine worldwide [3]. A key public and veterinary health consideration in the context of the evolving pandemic is whether the H1N1/09 virus could become established in pig populations [4]. We performed an infection and transmission study in pigs with A/California/07/09. In combination......, with clearly demonstrable pulmonary pathology, there was apparent selection of a virus variant with glycine (225G). These findings provide potential clues to the existence and biological significance of viral receptor-binding variants with 225D and 225G during the 1918 pandemic [5]....

Heterogeneous virulence of pandemic 2009 influenza H1N1 virus in mice

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Farooqui Amber

2012-06-01

Full Text Available Abstract Background Understanding the pathogenesis of influenza infection is a key factor leading to the prevention and control of future outbreaks. Pandemic 2009 Influenza H1N1 infection, although frequently mild, led to a severe and fatal form of disease in certain cases that make its virulence nature debatable. Much effort has been made toward explaining the determinants of disease severity; however, no absolute reason has been established. Results This study presents the heterogeneous virulence of clinically similar strains of pandemic 2009 influenza virus in human alveolar adenocarcinoma cells and mice. The viruses were obtained from patients who were admitted in a local hospital in China with a similar course of infection and recovered. The A/Nanchang/8002/2009 and A/Nanchang/8011/2009 viruses showed efficient replication and high lethality in mice while infection with A/Nanchang/8008/2009 was not lethal with impaired viral replication, minimal pathology and modest proinflammatory activity in lungs. Sequence analysis displayed prominent differences between polymerase subunits (PB2 and PA of viral genomes that might correlate with their different phenotypic behavior. Conclusions The study confirms that biological heterogeneity, linked with the extent of viral replication, exists among pandemic H1N1 strains that may serve as a benchmark for future investigations on influenza pathogenesis.

Pandemic Influenza A (N1H1: what to learn from it?

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Cristina Rolim Neumann

2009-09-01

Full Text Available Influenza pandemics are natural events that occur periodically. The pandemic’s current agent, Influenza virus A (H1N1 was first identified in Mexico in April 2009, spread rapidly and has caused deaths mainly among young adults. The objective of this manuscript is to present the biological aspects involved in the outbreak of this pandemic, as well as population-control strategies for pandemic influenza. In addition to the population mitigation measures, whose efficacy has been described by theoretical models, today we also have drugs with efficacy valued in some patient groups. These drugs reduce moderately the duration and severity of symptoms, as long as they are started early. This pandemic, with a large number of cases, but caused by a virus of low lethality, could be managed preferably in Units of Primary Health Care, that would treat the wild cases and forward the severe ones to the hospitals. However, what occurred in numerous cities was the burden on emergency care with triage situations, forcing managers to improvise field hospitals, tents and containers to house the extra work in services that were already at the limit of physical infrastructure and human resources. Pandemic Influenza exposed the fragility of our network of primary care and lack of ICU beds.

A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus

OpenAIRE

Kang, Xiao-ping; Jiang, Tao; Li, Yong-qiang; Lin, Fang; Liu, Hong; Chang, Guo-hui; Zhu, Qing-yu; Qin, E-de; Qin, Cheng-feng; Yang, Yin-hui

2010-01-01

Abstract A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009) influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose) for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same a...

Hospitalizations for Pandemic (H1N1) 2009 among Maori and Pacific Islanders, New Zealand

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Verrall, Ayesha; Norton, Katherine; Rooker, Serena; Dee, Stephen; Olsen, Leeanne; Tan, Chor Ee; Paull, Sharon; Allen, Richard

2010-01-01

Community transmission of influenza A pandemic (H1N1) 2009 was followed by high rates of hospital admissions in the Wellington region of New Zealand, particularly among Maori and Pacific Islanders. These findings may help health authorities anticipate the effects of pandemic (H1N1) 2009 in other communities. PMID:20031050

A duplex real-time RT-PCR assay for detecting H5N1 avian influenza virus and pandemic H1N1 influenza virus

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Qin E-de

2010-06-01

Full Text Available Abstract A duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR assay was improved for simultaneous detection of highly pathogenic H5N1 avian influenza virus and pandemic H1N1 (2009 influenza virus, which is suitable for early diagnosis of influenza-like patients and for epidemiological surveillance. The sensitivity of this duplex real-time RT-PCR assay was 0.02 TCID50 (50% tissue culture infective dose for H5N1 and 0.2 TCID50 for the pandemic H1N1, which was the same as that of each single-target RT-PCR for pandemic H1N1 and even more sensitive for H5N1 with the same primers and probes. No cross reactivity of detecting other subtype influenza viruses or respiratory tract viruses was observed. Two hundred and thirty-six clinical specimens were tested by comparing with single real-time RT-PCR and result from the duplex assay was 100% consistent with the results of single real-time RT-PCR and sequence analysis.

Antivirals Use During the Pandemic H1N1 2009 Outbreak

Centers for Disease Control (CDC) Podcasts

2012-01-23

Charisma Atkins, CDC public health analyst, discusses antiviral use during the 2009 H1N1 pandemic flu outbreak.  Created: 1/23/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/23/2012.

A home health agency's pandemic preparedness and experience with the 2009 H1N1 pandemic.

Science.gov (United States)

Rebmann, Terri; Citarella, Barbara; Subramaniam, Divya S; Subramaniam, Dipti P

2011-11-01

Adequate pandemic preparedness is imperative for home health agencies. A 23-item pandemic preparedness survey was administered to home health agencies in the spring of 2010. The Kruskal-Wallis (KW) test was used to evaluate the relationships between agency size and preparedness indicators. Significant findings were further analyzed by the Mann-Whitney (MW) U post hoc test. The response rate was 25% (526/2,119). Approximately one-third of respondents (30.4%; n = 131) reported experiencing trouble obtaining supplies during the 2009 H1N1 pandemic. Small agencies were significantly more likely (Krusal-Wallis [KW] = 9.2; P agency pandemic preparedness, including surge capacity and participation in disaster drills, that need to be addressed. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Hospitalizations Associated with Pandemic Influenza A (H1N1) 2009 in Asthmatic Children in Japan

OpenAIRE

Toshio Katsunuma; Takehiko Matsui; Tsutomu Iwata; Mitsuhiko Nambu; Naomi Kondo

2012-01-01

Background: The pandemic influenza A (H1N1) 2009 [pdm (H1N1) 2009] spread through the world in 2009, producing a serious epidemic in Japan. Since it was suggested early that asthma is a risk factor for an increased severity of the infection, the Japanese Society of Pediatric Allergy and Clinical Immunology (JSPACI) organized a working group for countermeasures, and investigated asthmatic children admitted to the hospitals for pdm (H1N1) 2009 infection. Methods: An appeal was made on the ho...

Spatial and temporal characteristics of the 2009 A/H1N1 influenza pandemic in Peru.

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Chowell, Gerardo; Viboud, Cécile; Munayco, Cesar V; Gómez, Jorge; Simonsen, Lone; Miller, Mark A; Tamerius, James; Fiestas, Victor; Halsey, Eric S; Laguna-Torres, Victor A

2011-01-01

Highly refined surveillance data on the 2009 A/H1N1 influenza pandemic are crucial to quantify the spatial and temporal characteristics of the pandemic. There is little information about the spatial-temporal dynamics of pandemic influenza in South America. Here we provide a quantitative description of the age-specific morbidity pandemic patterns across administrative areas of Peru. We used daily cases of influenza-like-illness, tests for A/H1N1 influenza virus infections, and laboratory-confirmed A/H1N1 influenza cases reported to the epidemiological surveillance system of Peru's Ministry of Health from May 1 to December 31, 2009. We analyzed the geographic spread of the pandemic waves and their association with the winter school vacation period, demographic factors, and absolute humidity. We also estimated the reproduction number and quantified the association between the winter school vacation period and the age distribution of cases. The national pandemic curve revealed a bimodal winter pandemic wave, with the first peak limited to school age children in the Lima metropolitan area, and the second peak more geographically widespread. The reproduction number was estimated at 1.6-2.2 for the Lima metropolitan area and 1.3-1.5 in the rest of Peru. We found a significant association between the timing of the school vacation period and changes in the age distribution of cases, while earlier pandemic onset was correlated with large population size. By contrast there was no association between pandemic dynamics and absolute humidity. Our results indicate substantial spatial variation in pandemic patterns across Peru, with two pandemic waves of varying timing and impact by age and region. Moreover, the Peru data suggest a hierarchical transmission pattern of pandemic influenza A/H1N1 driven by large population centers. The higher reproduction number of the first pandemic wave could be explained by high contact rates among school-age children, the age group most affected

Spatial and Temporal Characteristics of the 2009 A/H1N1 Influenza Pandemic in Peru

Science.gov (United States)

Chowell, Gerardo; Viboud, Cécile; Munayco, Cesar V.; Gómez, Jorge; Simonsen, Lone; Miller, Mark A.; Tamerius, James; Fiestas, Victor; Halsey, Eric S.; Laguna-Torres, Victor A.

2011-01-01

Background Highly refined surveillance data on the 2009 A/H1N1 influenza pandemic are crucial to quantify the spatial and temporal characteristics of the pandemic. There is little information about the spatial-temporal dynamics of pandemic influenza in South America. Here we provide a quantitative description of the age-specific morbidity pandemic patterns across administrative areas of Peru. Methods We used daily cases of influenza-like-illness, tests for A/H1N1 influenza virus infections, and laboratory-confirmed A/H1N1 influenza cases reported to the epidemiological surveillance system of Peru's Ministry of Health from May 1 to December 31, 2009. We analyzed the geographic spread of the pandemic waves and their association with the winter school vacation period, demographic factors, and absolute humidity. We also estimated the reproduction number and quantified the association between the winter school vacation period and the age distribution of cases. Results The national pandemic curve revealed a bimodal winter pandemic wave, with the first peak limited to school age children in the Lima metropolitan area, and the second peak more geographically widespread. The reproduction number was estimated at 1.6–2.2 for the Lima metropolitan area and 1.3–1.5 in the rest of Peru. We found a significant association between the timing of the school vacation period and changes in the age distribution of cases, while earlier pandemic onset was correlated with large population size. By contrast there was no association between pandemic dynamics and absolute humidity. Conclusions Our results indicate substantial spatial variation in pandemic patterns across Peru, with two pandemic waves of varying timing and impact by age and region. Moreover, the Peru data suggest a hierarchical transmission pattern of pandemic influenza A/H1N1 driven by large population centers. The higher reproduction number of the first pandemic wave could be explained by high contact rates among school

Impact of antiviral treatment and hospital admission delay on risk of death associated with 2009 A/H1N1 pandemic influenza in Mexico

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Chowell Gerardo

2012-04-01

Full Text Available Abstract Background Increasing our understanding of the factors affecting the severity of the 2009 A/H1N1 influenza pandemic in different regions of the world could lead to improved clinical practice and mitigation strategies for future influenza pandemics. Even though a number of studies have shed light into the risk factors associated with severe outcomes of 2009 A/H1N1 influenza infections in different populations (e.g., [1-5], analyses of the determinants of mortality risk spanning multiple pandemic waves and geographic regions are scarce. Between-country differences in the mortality burden of the 2009 pandemic could be linked to differences in influenza case management, underlying population health, or intrinsic differences in disease transmission [6]. Additional studies elucidating the determinants of disease severity globally are warranted to guide prevention efforts in future influenza pandemics. In Mexico, the 2009 A/H1N1 influenza pandemic was characterized by a three-wave pattern occurring in the spring, summer, and fall of 2009 with substantial geographical heterogeneity [7]. A recent study suggests that Mexico experienced high excess mortality burden during the 2009 A/H1N1 influenza pandemic relative to other countries [6]. However, an assessment of potential factors that contributed to the relatively high pandemic death toll in Mexico are lacking. Here, we fill this gap by analyzing a large series of laboratory-confirmed A/H1N1 influenza cases, hospitalizations, and deaths monitored by the Mexican Social Security medical system during April 1 through December 31, 2009 in Mexico. In particular, we quantify the association between disease severity, hospital admission delays, and neuraminidase inhibitor use by demographic characteristics, pandemic wave, and geographic regions of Mexico. Methods We analyzed a large series of laboratory-confirmed pandemic A/H1N1 influenza cases from a prospective surveillance system maintained by the

Differential host determinants contribute to the pathogenesis of 2009 pandemic H1N1 and human H5N1 influenza A viruses in experimental mouse models.

Science.gov (United States)

Otte, Anna; Sauter, Martina; Alleva, Lisa; Baumgarte, Sigrid; Klingel, Karin; Gabriel, Gülsah

2011-07-01

Influenza viruses are responsible for high morbidities in humans and may, eventually, cause pandemics. Herein, we compared the pathogenesis and host innate immune responses of a seasonal H1N1, two 2009 pandemic H1N1, and a human H5N1 influenza virus in experimental BALB/c and C57BL/6J mouse models. We found that both 2009 pandemic H1N1 isolates studied (A/Hamburg/05/09 and A/Hamburg/NY1580/09) were low pathogenic in BALB/c mice [log mouse lethal dose 50 (MLD(50)) >6 plaque-forming units (PFU)] but displayed remarkable differences in virulence in C57BL/6J mice. A/Hamburg/NY1580/09 was more virulent (logMLD(50) = 3.5 PFU) than A/Hamburg/05/09 (logMLD(50) = 5.2 PFU) in C57BL/6J mice. In contrast, the H5N1 influenza virus was more virulent in BALB/c mice (logMLD(50) = 0.3 PFU) than in C57BL/6J mice (logMLD(50) = 1.8 PFU). Seasonal H1N1 influenza revealed marginal pathogenicity in BALB/c or C57BL/6J mice (logMLD(50) >6 PFU). Enhanced susceptibility of C57BL/6J mice to pandemic H1N1 correlated with a depressed cytokine response. In contrast, enhanced H5N1 virulence in BALB/c mice correlated with an elevated proinflammatory cytokine response. These findings highlight that host determinants responsible for the pathogenesis of 2009 pandemic H1N1 influenza viruses are different from those contributing to H5N1 pathogenesis. Our results show, for the first time to our knowledge, that the C57BL/6J mouse strain is more appropriate for the evaluation and identification of intrinsic pathogenicity markers of 2009 pandemic H1N1 influenza viruses that are "masked" in BALB/c mice. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Detection of extensive cross-neutralization between pandemic and seasonal A/H1N1 Influenza Viruses using a pseudotype neutralization assay.

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Béatrice Labrosse

Full Text Available BACKGROUND: Cross-immunity between seasonal and pandemic A/H1N1 influenza viruses remains uncertain. In particular, the extent that previous infection or vaccination by seasonal A/H1N1 viruses can elicit protective immunity against pandemic A/H1N1 is unclear. METHODOLOGY/PRINCIPAL FINDINGS: Neutralizing titers against seasonal A/H1N1 (A/Brisbane/59/2007 and against pandemic A/H1N1 (A/California/04/2009 were measured using an HIV-1-based pseudovirus neutralization assay. Using this highly sensitive assay, we found that a large fraction of subjects who had never been exposed to pandemic A/H1N1 express high levels of pandemic A/H1N1 neutralizing titers. A significant correlation was seen between neutralization of pandemic A/H1N1 and neutralization of a standard seasonal A/H1N1 strain. Significantly higher pandemic A/H1N1 neutralizing titers were measured in subjects who had received vaccination against seasonal influenza in 2008-2009. Higher pandemic neutralizing titers were also measured in subjects over 60 years of age. CONCLUSIONS/SIGNIFICANCE: Our findings reveal that the extent of protective cross-immunity between seasonal and pandemic A/H1N1 influenza viruses may be more important than previously estimated. This cross-immunity could provide a possible explanation of the relatively mild profile of the recent influenza pandemic.

Genetic diversity of the 2009 pandemic influenza A(H1N1 viruses in Finland.

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Niina Ikonen

Full Text Available BACKGROUND: In Finland, the first infections caused by the 2009 pandemic influenza A(H1N1 virus were identified on May 10. During the next three months almost all infections were found from patients who had recently traveled abroad. In September 2009 the pandemic virus started to spread in the general population, leading to localized outbreaks and peak epidemic activity was reached during weeks 43-48. METHODS/RESULTS: The nucleotide sequences of the hemagglutinin (HA and neuraminidase (NA genes from viruses collected from 138 patients were determined. The analyzed viruses represented mild and severe infections and different geographic regions and time periods. Based on HA and NA gene sequences, the Finnish pandemic viruses clustered in four groups. Finnish epidemic viruses and A/California/07/2009 vaccine virus strain varied from 2-8 and 0-5 amino acids in HA and NA molecules, respectively, giving a respective maximal evolution speed of 1.4% and 1.1%. Most amino acid changes in HA and NA molecules accumulated on the surface of the molecule and were partly located in antigenic sites. Three severe infections were detected with a mutation at HA residue 222, in two viruses with a change D222G, and in one virus D222Y. Also viruses with change D222E were identified. All Finnish pandemic viruses were sensitive to oseltamivir having the amino acid histidine at residue 275 of the neuraminidase molecule. CONCLUSIONS: The Finnish pandemic viruses were quite closely related to A/California/07/2009 vaccine virus. Neither in the HA nor in the NA were changes identified that may lead to the selection of a virus with increased epidemic potential or exceptionally high virulence. Continued laboratory-based surveillance of the 2009 pandemic influenza A(H1N1 is important in order to rapidly identify drug resistant viruses and/or virus variants with potential ability to cause severe forms of infection and an ability to circumvent vaccine-induced immunity.

‘Presenting CXR phenotype of H1N1’ flu compared with contemporaneous non-H1N1, community acquired pneumonia, during pandemic and post-pandemic outbreaks’

International Nuclear Information System (INIS)

Minns, F.C.; Nimhuineachain, A; Beek, E.J.R. van; Ritchie, G.; Hill, A.; Murchison, J.T.

2015-01-01

Highlights: • Patients with H1N1 pneumonia demonstrated more opacified zones on chest x-ray than patients with non-H1N1 pneumonias. • A particular ‘phenotype’ of chest x-ray changes was identified in H1N1 patients. • This H1N1 ‘phenotype’ was the same for the two evaluated ‘flu seasons, during both pandemic and post pandemic stages. - Abstract: Aims: To review, phenotype and assess potential prognostic value of initial chest X-ray findings in patients with H1N1 influenza during seasonal outbreaks of 2009 and 2010, in comparison with non-H1N1, community acquired pneumonia (CAP). Methods: We retrospectively identified 72 patients admitted to hospital with pneumonia during the seasons of 2009 and 2010. H1N1 cases were confirmed by virology PCR. Presenting chest X-rays were jointly read by 2 radiologists, who were ‘blinded’ to further patient details and divided into 6 zones. Total number of opacified zones, the pattern and distribution of changes and length of hospital stay were recorded. Results: Patients with H1N1 demonstrated more opacified zones (mean of 2.9 compared with 2.0; p = 0.006), which were bilateral in two-thirds compared with a quarter of those with non-H1N1 CAP (p = 0.001). H1N1 radiographs were more likely to be ‘patchy’ versus ‘confluent’ changes of non-H1N1 CAP (p = 0.03) and more often demonstrated peripheral distribution (p = 0.01). H1N1 patients tended to stay in hospital longer (not significant; p = 0.08). A positive correlation existed between number of affected zones and length of inpatient stay, which was statistically significant for the cohorts combined (p = 0.02). The findings were the same for the two evaluated seasons. Conclusion: H1N1 patients demonstrated more extensive disease, which was more likely bilateral, ‘patchy’, and peripheral in distribution. With increasing global cases of H1N1, knowledge of the typical findings of the H1N1 presenting chest X-ray may assist with early triage of patients

‘Presenting CXR phenotype of H1N1’ flu compared with contemporaneous non-H1N1, community acquired pneumonia, during pandemic and post-pandemic outbreaks’

Energy Technology Data Exchange (ETDEWEB)

Minns, F.C., E-mail: Fiona.Minns@nhslothian.scot.nhs.uk [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Nimhuineachain, A, E-mail: draideen@gmail.com [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Beek, E.J.R. van, E-mail: Edwin-vanbeek@ed.ac.uk [Clinical Research Imaging Centre, University of Edinburgh, 47 Little France Crescent, Edinburgh, Midlothian EH16 4TJ (United Kingdom); Ritchie, G., E-mail: drgillritchie@hotmail.com [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Hill, A., E-mail: adam.hill318@nhs.net [Department of Respiratory Medicine, New Royal Infirmary, Edinburgh (United Kingdom); Murchison, J.T., E-mail: john.murchison@nhslothian.scot.nhs.uk [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom)

2015-09-15

Highlights: • Patients with H1N1 pneumonia demonstrated more opacified zones on chest x-ray than patients with non-H1N1 pneumonias. • A particular ‘phenotype’ of chest x-ray changes was identified in H1N1 patients. • This H1N1 ‘phenotype’ was the same for the two evaluated ‘flu seasons, during both pandemic and post pandemic stages. - Abstract: Aims: To review, phenotype and assess potential prognostic value of initial chest X-ray findings in patients with H1N1 influenza during seasonal outbreaks of 2009 and 2010, in comparison with non-H1N1, community acquired pneumonia (CAP). Methods: We retrospectively identified 72 patients admitted to hospital with pneumonia during the seasons of 2009 and 2010. H1N1 cases were confirmed by virology PCR. Presenting chest X-rays were jointly read by 2 radiologists, who were ‘blinded’ to further patient details and divided into 6 zones. Total number of opacified zones, the pattern and distribution of changes and length of hospital stay were recorded. Results: Patients with H1N1 demonstrated more opacified zones (mean of 2.9 compared with 2.0; p = 0.006), which were bilateral in two-thirds compared with a quarter of those with non-H1N1 CAP (p = 0.001). H1N1 radiographs were more likely to be ‘patchy’ versus ‘confluent’ changes of non-H1N1 CAP (p = 0.03) and more often demonstrated peripheral distribution (p = 0.01). H1N1 patients tended to stay in hospital longer (not significant; p = 0.08). A positive correlation existed between number of affected zones and length of inpatient stay, which was statistically significant for the cohorts combined (p = 0.02). The findings were the same for the two evaluated seasons. Conclusion: H1N1 patients demonstrated more extensive disease, which was more likely bilateral, ‘patchy’, and peripheral in distribution. With increasing global cases of H1N1, knowledge of the typical findings of the H1N1 presenting chest X-ray may assist with early triage of patients

Clinical characteristics and outcomes among pediatric patients hospitalized with pandemic influenza A/H1N1 2009 infection

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Eun Lee

2011-08-01

Full Text Available Purpose : The purpose of this article is to describe the clinical and epidemiologic features and outcomes among children hospitalized with pandemic influenza A/H1N1 2009 infection. Methods : We retrospectively reviewed the charts of hospitalized pediatric patients (&lt;18 years diagnosed with pandemic influenza A/H1N1 2009 infection by reverse-transcriptase polymerase chain reaction at a tertiary hospital in Seoul, Korea, between September 2009 and February 2010. Results : A total of 72 children were hospitalized with pandemic influenza A/H1N1 2009 infection (median age, 6.0 years; range, 2 months to 18 years. A total of 40% had at least 1 underlying medical condition, including asthma (17%, malignancies (19%, and heart diseases (17%. Of the 72 patients, 54 (76% children admitted with H1N1 infection showed radiographic alterations compatible with pneumonia. There was no significant difference in pre-existing conditions between pandemic influenza A/H1N1 infected patients with or without pneumonia. Children with pandemic influenza A/ H1N1 pneumonia were more likely to have a lower lymphocyte ratio (P=0.02, higher platelet count (P=0.02, and higher level of serum glucose (P=0.003, and more commonly presented with dyspnea than did those without pneumonia (P=0.04. Conclusion : No significant differences in age, sex, or presence of preexisting conditions were found between children hospitalized with pandemic influenza A/H1N1 H1N1 influenza infection with pneumonia and those without pneumonia. Higher leukocyte count, higher glucose level, and a lower lymphocyte ratio were associated with the development of pandemic A/H1N1 2009 influenza pneumonia.

Inpatient capacity at children's hospitals during pandemic (H1N1) 2009 outbreak, United States.

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Sills, Marion R; Hall, Matthew; Fieldston, Evan S; Hain, Paul D; Simon, Harold K; Brogan, Thomas V; Fagbuyi, Daniel B; Mundorff, Michael B; Shah, Samir S

2011-09-01

Quantifying how close hospitals came to exhausting capacity during the outbreak of pandemic influenza A (H1N1) 2009 can help the health care system plan for more virulent pandemics. This ecologic analysis used emergency department (ED) and inpatient data from 34 US children's hospitals. For the 11-week pandemic (H1N1) 2009 period during fall 2009, inpatient occupancy reached 95%, which was lower than the 101% occupancy during the 2008-09 seasonal influenza period. Fewer than 1 additional admission per 10 inpatient beds would have caused hospitals to reach 100% occupancy. Using parameters based on historical precedent, we built 5 models projecting inpatient occupancy, varying the ED visit numbers and admission rate for influenza-related ED visits. The 5 scenarios projected median occupancy as high as 132% of capacity. The pandemic did not exhaust inpatient bed capacity, but a more virulent pandemic has the potential to push children's hospitals past their maximum inpatient capacity.

Susceptibility of turkeys to pandemic-H1N1 virus by reproductive tract insemination

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Suarez David L

2010-02-01

Full Text Available Abstract The current pandemic influenza A H1N1 2009 (pH1N1 was first recognized in humans with acute respiratory diseases in April 2009 in Mexico, in swine in Canada in June, 2009 with respiratory disease, and in turkeys in Chile in June 2009 with a severe drop in egg production. Several experimental studies attempted to reproduce the disease in turkeys, but failed to produce respiratory infection in turkeys using standard inoculation routes. We demonstrated that pH1N1 virus can infect the reproductive tract of turkey hens after experimental intrauterine inoculation, causing decreased egg production. This route of exposure is realistic in modern turkey production because turkey hens are handled once a week for intrauterine insemination in order to produce fertile eggs. This understanding of virus exposure provides an improved understanding of the pathogenesis of the disease and can improve poultry husbandry to prevent disease outbreaks.

Pandemic influenza--including a risk assessment of H5N1.

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Taubenberger, J K; Morens, D M

2009-04-01

Influenza pandemics and epidemics have apparently occurred since at least the Middle Ages. When pandemics appear, 50% or more of an affected population can be infected in a single year, and the number of deaths caused by influenza can dramatically exceed what is normally expected. Since 1500, there appear to have been 13 or more influenza pandemics. In the past 120 years there were undoubted pandemics in 1889, 1918, 1957, 1968, and 1977. Although most experts believe we will face another influenza pandemic, it is impossible to predict when it will appear, where it will originate, or how severe it will be. Nor is there agreement about the subtype of influenza virus most likely to cause the next pandemic. The continuing spread of H5N1 highly pathogenic avian influenza viruses has heightened interest in pandemic prediction. Despite uncertainties in the historical record of the pre-virology era, study of previous pandemics may help guide future pandemic planning and lead to a better understanding of the complex ecobiology underlying the formation of pandemic strains of influenza A viruses.

A monoclonal antibody-based ELISA for differential diagnosis of 2009 pandemic H1N1

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The swine-origin 2009 pandemic H1N1 virus (pdmH1N1) is genetically related to North American swine H1 influenza viruses and unrelated to human seasonal H1 viruses. Currently, specific diagnosis of pdmH1N1 relies on RT-PCR. In order to develop an assay that does not rely in amplification of the viral...

Anti-pandemic influenza A (H1N1) virus potential of catechin and gallic acid.

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You, Huey-Ling; Huang, Chao-Chun; Chen, Chung-Jen; Chang, Cheng-Chin; Liao, Pei-Lin; Huang, Sheng-Teng

2018-05-01

The pandemic influenza A (H1N1) virus has spread worldwide and infected a large proportion of the human population. Discovery of new and effective drugs for the treatment of influenza is a crucial issue for the global medical community. According to our previous study, TSL-1, a fraction of the aqueous extract from the tender leaf of Toonasinensis, has demonstrated antiviral activities against pandemic influenza A (H1N1) through the down-regulation of adhesion molecules and chemokine to prevent viral attachment. The aim of the present study was to identify the active compounds in TSL-1 which exert anti-influenza A (H1N1) virus effects. XTT assay was used to detect the cell viability. Meanwhile, the inhibitory effect on the pandemic influenza A (H1N1) virus was analyzed by observing plaque formation, qRT-PCR, neuraminidase activity, and immunofluorescence staining of influenza A-specific glycoprotein. Both catechin and gallic acid were found to be potent inhibitors in terms of influenza virus mRNA replication and MDCK plaque formation. Additionally, both compounds inhibited neuraminidase activities and viral glycoprotein. The 50% effective inhibition concentration (EC 50 ) of catechin and gallic acid for the influenza A (H1N1) virus were 18.4 μg/mL and 2.6 μg/mL, respectively; whereas the 50% cytotoxic concentrations (CC 50 ) of catechin and gallic acid were >100 μg/mL and 22.1 μg/mL, respectively. Thus, the selectivity indexes (SI) of catechin and gallic acid were >5.6 and 22.1, respectively. The present study demonstrates that catechin might be a safe reagent for long-term use to prevent influenza A (H1N1) virus infection; whereas gallic acid might be a sensitive reagent to inhibit influenza virus infection. We conclude that these two phyto-chemicals in TSL-1 are responsible for exerting anti-pandemic influenza A (H1N1) virus effects. Copyright © 2017. Published by Elsevier Taiwan LLC.

Pandemic influenza A/H1N1 virus incursion into Africa: countries ...

African Journals Online (AJOL)

Pandemic influenza A/H1N1 virus incursion into Africa: countries, hosts and ... features are important for planning control measures between countries and to ... in humans, infections in pigs earlier reported in America, Europe and Asia were ...

Mortality attributable to pandemic influenza A (H1N1) 2009 in San Luis Potosí, Mexico

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Comas‐García, Andreu; García‐Sepúlveda, Christian A.; Méndez‐de Lira, José J.; Aranda‐Romo, Saray; Hernández‐Salinas, Alba E.; Noyola, Daniel E.

2010-01-01

Please cite this paper as: Comas‐García et al. (2011) Mortality attributable to pandemic influenza A (H1N1) 2009 in San Luis Potosí, Mexico. Influenza and Other Respiratory Viruses 5(2), 76–82. Background  Acute respiratory infections are a leading cause of morbidity and mortality worldwide. Starting in 2009, pandemic influenza A(H1N1) 2009 virus has become one of the leading respiratory pathogens worldwide. However, the overall impact of this virus as a cause of mortality has not been clearly defined. Objectives  To determine the impact of pandemic influenza A(H1N1) 2009 on mortality in a Mexican population. Methods  We assessed the impact of pandemic influenza virus on mortality during the first and second outbreaks in San Luis Potosí, Mexico, and compared it to mortality associated with seasonal influenza and respiratory syncytial virus (RSV) during the previous winter seasons. Results  We estimated that, on average, 8·1% of all deaths that occurred during the 2003–2009 seasons were attributable to influenza and RSV. During the first pandemic influenza A(H1N1) 2009 outbreak, there was an increase in mortality in persons 5–59 years of age, but not during the second outbreak (Fall of 2009). Overall, pandemic influenza A (H1N1) 2009 outbreaks had similar effects on mortality to those associated with seasonal influenza virus epidemics. Conclusions  The impact of influenza A(H1N1) 2009 virus on mortality during the first year of the pandemic was similar to that observed for seasonal influenza. The establishment of real‐time surveillance systems capable of integrating virological, morbidity, and mortality data may result in the timely identification of outbreaks so as to allow for the institution of appropriate control measures to reduce the impact of emerging pathogens on the population. PMID:21306570

Epidemiological characteristics of the influenza A(H1N1 2009 pandemic in the Western Pacific Region

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Lisa McCallum

2010-12-01

Full Text Available The first laboratory-confirmed cases of infection with pandemic influenza A(H1N1 2009 in the Western Pacific Region were reported on 28 April 2009. By 11 June 2009, the day the pandemic was declared by the World Health Organization, nine Western Pacific Region countries and areas had reported laboratory-confirmed pandemic influenza A(H1N1 2009 cases. From April 2009 to July 2010, more than 250 000 cases and 1800 deaths from laboratory-confirmed pandemic influenza A(H1N1 2009 were reported from 34 countries and areas in the Region. By age group region-wide, 8.6%, 41.9%, 48.3%, and 1.2% of cases were in the < 5 years, 5–14 years, 15–64 years, and 65+ years age groups, respectively; the overall crude case fatality ratio in the Western Pacific Region was 0.5%. The pandemic demonstrated that region-wide disease reporting was possible. Countries and areas of the Western Pacific Region should take this opportunity to strengthen the systems established during the pandemic to develop routine disease reporting.

Low adherence to influenza vaccination campaigns: is the H1N1 virus pandemic to be blamed?

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Trivellin Valeria

2011-11-01

Full Text Available Abstract Background Over the last few months, debates about the handling of the influenza virus A (H1N1 pandemic took place, in particular regarding the change of the WHO pandemic definition, economic interests, the dramatic communication style of mass media. The activation of plans to reduce the virus diffusion resulted in an important investment of resources. Were those investments proportionate to the risk? Was the pandemic overrated? The workload of the Pediatric Emergency Room (P.E.R. at a teaching hospital in Varese (Northern Italy was investigated in order to evaluate the local diffusion and severity of the new H1N1 influenza epidemic. Discussion A 100% increase of the number of P.E.R. visits, particularly for influenza-like illness, was recorded during weeks 42-46 of 2009 (October, 17 to November, 2; the low rate of hospitalization and the mild presentation of the infection gave rise to the conclusion that the pandemic risk was overrated. Mass media communications concerning the new virus created a disproportionate fear in the population that significantly enhanced the burden of cares at the hospital. In the absence of generally implemented measures for etiological diagnosis, the actual incidence of the H1N1 infection could not be estimated. Virus identification, in fact, was limited to children showing severe symptoms after consultancy with an infectious disease specialist. The alarming nature of the communication campaign and the choice to limit etiologic diagnosis to severe cases created a climate of uncertainty which significantly contributed to the massive admissions to the P.E.R.. Summary The communication strategy adopted by the mass media was an important element during the pandemic: the absence of clarity contributed to the spread of a pandemic phobia that appeared to result more from the sensationalism of the campaign than from infection with the novel influenza A variant of human, avian, swine origin virus. One relevant effect

Nosocomial Pandemic (H1N1) 2009, United Kingdom, 2009–2010

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Myles, Puja R.; Openshaw, Peter J.M.; Gadd, Elaine M.; Lim, Wei Shen; Semple, Malcolm G.; Read, Robert C.; Taylor, Bruce L.; McMenamin, James; Armstrong, Colin; Bannister, Barbara; Nicholson, Karl G.; Nguyen-Van-Tam, Jonathan S.

2011-01-01

To determine clinical characteristics of patients hospitalized in the United Kingdom with pandemic (H1N1) 2009, we studied 1,520 patients in 75 National Health Service hospitals. We characterized patients who acquired influenza nosocomially during the pandemic (H1N1) 2009 outbreak. Of 30 patients, 12 (80%) of 15 adults and 14 (93%) of 15 children had serious underlying illnesses. Only 12 (57%) of 21 patients who received antiviral therapy did so within 48 hours after symptom onset, but 53% needed escalated care or mechanical ventilation; 8 (27%) of 30 died. Despite national guidelines and standardized infection control procedures, nosocomial transmission remains a problem when influenza is prevalent. Health care workers should be routinely offered influenza vaccine, and vaccination should be prioritized for all patients at high risk. Staff should remain alert to the possibility of influenza in patients with complex clinical problems and be ready to institute antiviral therapy while awaiting diagnosis during influenza outbreaks. PMID:21470446

The influence of climatic conditions on the transmission dynamics of the 2009 A/H1N1 influenza pandemic in Chile.

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Chowell, Gerardo; Towers, Sherry; Viboud, Cécile; Fuentes, Rodrigo; Sotomayor, Viviana; Simonsen, Lone; Miller, Mark A; Lima, Mauricio; Villarroel, Claudia; Chiu, Monica; Villarroel, Jose E; Olea, Andrea

2012-11-13

The role of demographic factors, climatic conditions, school cycles, and connectivity patterns in shaping the spatio-temporal dynamics of pandemic influenza is not clearly understood. Here we analyzed the spatial, age and temporal evolution of the 2009 A/H1N1 influenza pandemic in Chile, a southern hemisphere country covering a long and narrow strip comprising latitudes 17°S to 56°S. We analyzed the dissemination patterns of the 2009 A/H1N1 pandemic across 15 regions of Chile based on daily hospitalizations for severe acute respiratory disease and laboratory confirmed A/H1N1 influenza infection from 01-May to 31-December, 2009. We explored the association between timing of pandemic onset and peak pandemic activity and several geographical and demographic indicators, school vacations, climatic factors, and international passengers. We also estimated the reproduction number (R) based on the growth rate of the exponential pandemic phase by date of symptoms onset, estimated using maximum likelihood methods. While earlier pandemic onset was associated with larger population size, there was no association with connectivity, demographic, school or climatic factors. In contrast, there was a latitudinal gradient in peak pandemic timing, representing a 16-39-day lag in disease activity from the southern regions relative to the northernmost region (P humidity explained 68.5% of the variability in peak timing (P = 0.01). In addition, there was a decreasing gradient in reproduction number from south to north Chile (P humidity. The latitudinal gradient in timing of pandemic activity was accompanied by a gradient in reproduction number (P < 0.0001). Intensified surveillance strategies in colder and drier southern regions could lead to earlier detection of pandemic influenza viruses and improved control outcomes.

The seroprevalence of pandemic influenza H1N1 (2009 virus in China.

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Cuiling Xu

2011-04-01

Full Text Available Mainland China experienced pandemic influenza H1N1 (2009 virus (pH1N1 with peak activity during November-December 2009. To understand the geographic extent, risk factors, and attack rate of pH1N1 infection in China we conducted a nationwide serological survey to determine the prevalence of antibodies to pH1N1.Stored serum samples (n = 2,379 collected during 2006-2008 were used to estimate baseline serum reactogenicity to pH1N1. In January 2010, we used a multistage-stratified random sampling method to select 50,111 subjects who met eligibility criteria and collected serum samples and administered a standardized questionnaire. Antibody response to pH1N1 was measured using haemagglutination inhibition (HI assay and the weighted seroprevalence was calculated using the Taylor series linearization method. Multivariable logistic regression analyses were used to examine risk factors for pH1N1 seropositivity. Baseline seroprevalence of pH1N1 antibody (HI titer ≥40 was 1.2%. The weighted seroprevalence of pH1N1 among the Chinese population was 21.5%(vaccinated: 62.0%; unvaccinated: 17.1%. Among unvaccinated participants, those aged 6-15 years (32.9% and 16-24 years (30.3% had higher seroprevalence compared with participants aged 25-59 years (10.7% and ≥60 years (9.9%, P<0.0001. Children in kindergarten and students had higher odds of seropositivity than children in family care (OR: 1.36 and 2.05, respectively. We estimated that 207.7 million individuals (15.9% experienced pH1N1 infection in China.The Chinese population had low pre-existing immunity to pH1N1 and experienced a relatively high attack rate in 2009 of this virus. We recommend routine control measures such as vaccination to reduce transmission and spread of seasonal and pandemic influenza viruses.

Compliance with recommendations for pandemic influenza H1N1 2009: the role of trust and personal beliefs.

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Prati, Gabriele; Pietrantoni, Luca; Zani, Bruna

2011-10-01

To investigate the relationship between risk perception, worry, control, trust, exposure to an educational campaign, media exaggeration with recommendations for pandemic influenza H1N1 2009. Cross sectional telephone survey using random digit dialing. A total of 1010 adult Italians were interviewed by telephone between 16 and 19 February 2010. The survey instrument included demographic data, measures on risk perception, worry, trust and compliance with recommendations for pandemic influenza H1N1 2009. Controlling for socio-demographic variables, compliance with all the recommended behaviors was associated with media trust, trust in the Ministry of Health, worry and perceived severity of illness. Perceptions that the risk of catching pandemic influenza H1N1 2009 is high, that the authorities are acting in the public's best interest in dealing with it, that the media had exaggerated the risks of catching it and that people can control their risk of catching it were associated with compliance with some recommended behaviors even after considering effects of socio-demographic characteristics. The results underscore the importance of building public trust and to consider the influence of risk perception and affective response in promoting compliance with recommended behaviors.

Fulminant hemophagocytic lymphohistiocytosis induced by pandemic A (H1N1 influenza: a case report

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Wacrenier Agnès

2011-07-01

Full Text Available Abstract Introduction Hemophagocytic lymphohistiocytosis induced by viral diseases is a well recognized entity. Severe forms of H5N1 influenza are known to be associated with symptoms very similar to a reactive hemophagocytic syndrome. We report a case of fulminant lymphohistiocytosis associated with the pandemic A (H1N1 variant. Case presentation A 42-year-old Caucasian woman developed a syndrome of fatal hemophagocytic lymphohistiocytosis shortly after H1N1 influenza. Initial symptoms of the viral disease were unusual, with acute abdominal involvement. Our patient's course was complicated by diffuse skin rash and ileal ischemia. Our patient died of refractory shock and multi-organ failure. Skin, ileum and colon histology was consistent with an acute apoptosis combined with an increased cellular regeneration. Conclusions Influenza may be complicated by severe forms of hemophagocytic lymphohistiocytosis. To ensure early recognition and treatment, physicians should be aware of the possible induction of the syndrome by the novel H1N1 variant. The rapid occurrence of a multi-organ involvement with evocative biological features of macrophage activation should alert clinicians.

Reasons for Low Pandemic H1N1 2009 Vaccine Acceptance within a College Sample

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Russell D. Ravert

2012-01-01

Full Text Available This study examined health beliefs associated with novel influenza A (H1N1 immunization among US college undergraduates during the 2009-2010 pandemic. Undergraduates (ages 18–24 years from a large Midwestern University were invited to complete an online survey during March, 2010, five months after H1N1 vaccines became available. Survey items measured H1N1 vaccine history and H1N1-related attitudes based on the health belief literature. Logistic regression was used to identify attitudes associated with having received an H1N1 vaccine, and thematic analysis of student comments was conducted to further understand influences on vaccine decisions. Among the 296 students who participated in the survey, 15.2% reported having received an H1N1 vaccine. In regression analysis, H1N1 immunization was associated with seasonal flu vaccine history, perceived vaccine effectiveness, perceived obstacles to vaccination, and vaccine safety concerns. Qualitative results illustrate the relationship of beliefs to vaccine decisions, particularly in demonstrating that students often held concerns that vaccine could cause H1N1 or side effects. Vaccine safety, efficacy, and obstacles to immunization were major considerations in deciding whether to accept the H1N1 pandemic vaccine. Therefore, focusing on those aspects might be especially useful in future vaccine efforts within the college population.

Household transmission of influenza A(H1N1pdm09 in the pandemic and post-pandemic seasons.

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Itziar Casado

Full Text Available The transmission of influenza viruses occurs person to person and is facilitated by contacts within enclosed environments such as households. The aim of this study was to evaluate secondary attack rates and factors associated with household transmission of laboratory-confirmed influenza A(H1N1pdm09 in the pandemic and post-pandemic seasons.During the 2009-2010 and 2010-2011 influenza seasons, 76 sentinel physicians in Navarra, Spain, took nasopharyngeal and pharyngeal swabs from patients diagnosed with influenza-like illness. A trained nurse telephoned households of those patients who were laboratory-confirmed for influenza A(H1N1pdm09 to ask about the symptoms, risk factors and vaccination status of each household member.In the 405 households with a patient laboratory-confirmed for influenza A(H1N1pdm09, 977 susceptible contacts were identified; 16% of them (95% CI 14-19% presented influenza-like illness and were considered as secondary cases. The secondary attack rate was 14% in 2009-2010 and 19% in the 2010-2011 season (p=0.049, an increase that mainly affected persons with major chronic conditions. In the multivariate logistic regression analysis, the risk of being a secondary case was higher in the 2010-2011 season than in the 2009-2010 season (adjusted odds ratio: 1.72; 95% CI 1.17-2.54, and in children under 5 years, with a decreasing risk in older contacts. Influenza vaccination was associated with lesser incidence of influenza-like illness near to statistical significance (adjusted odds ratio: 0.29; 95% CI 0.08-1.03.The secondary attack rate in households was higher in the second season than in the first pandemic season. Children had a greater risk of infection. Preventive measures should be maintained in the second pandemic season, especially in high-risk persons.

Genetic Characterization of Influenza A (H1N1) Pandemic 2009 Virus Isolates from Mumbai.

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Gohil, Devanshi; Kothari, Sweta; Shinde, Pramod; Meharunkar, Rhuta; Warke, Rajas; Chowdhary, Abhay; Deshmukh, Ranjana

2017-08-01

Pandemic influenza A (H1N1) 2009 virus was first detected in India in May 2009 which subsequently became endemic in many parts of the country. Influenza A viruses have the ability to evade the immune response through its ability of antigenic variations. The study aims to characterize influenza A (H1N1) pdm 09 viruses circulating in Mumbai during the pandemic and post-pandemic period. Nasopharyngeal swabs positive for influenza A (H1N1) pdm 09 viruses were inoculated on Madin-Darby canine kidney cell line for virus isolation. Molecular and phylogenetic analysis of influenza A (H1N1) pdm 09 isolates was conducted to understand the evolution and genetic diversity of the strains. Nucleotide and amino acid sequences of the HA gene of Mumbai isolates when compared to A/California/07/2009-vaccine strain revealed 14 specific amino acid differences located at the antigenic sites. Amino acid variations in HA and NA gene resulted in changes in the N-linked glycosylation motif which may lead to immune evasion. Phylogenetic analysis of the isolates revealed their evolutionary position with vaccine strain A/California/07/2009 but had undergone changes gradually. The findings in the present study confirm genetic variability of influenza viruses and highlight the importance of continuous surveillance during influenza outbreaks.

Seasonal influenza vaccine and protection against pandemic (H1N1 2009-associated illness among US military personnel.

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Matthew C Johns

Full Text Available INTRODUCTION: A novel A/H1N1 virus is the cause of the present influenza pandemic; vaccination is a key countermeasure, however, few data assessing prior seasonal vaccine effectiveness (VE against the pandemic strain of H1N1 (pH1N1 virus are available. MATERIALS AND METHODS: Surveillance of influenza-related medical encounter data of active duty military service members stationed in the United States during the period of April-October 2009 with comparison of pH1N1-confirmed cases and location and date-matched controls. Crude odds ratios (OR and VE estimates for immunized versus non-immunized were calculated as well as adjusted OR (AOR controlling for sex, age group, and history of prior influenza vaccination. Separate stratified VE analyses by vaccine type (trivalent inactivated [TIV] or live attenuated [LAIV], age groups and hospitalization status were also performed. For the period of April 20 to October 15, 2009, a total of 1,205 cases of pH1N1-confirmed cases were reported, 966 (80% among males and over one-half (58% under 25 years of age. Overall VE for service members was found to be 45% (95% CI, 33 to 55%. Immunization with prior season's TIV (VE = 44%, 95% CI, 32 to 54% as well as LAIV (VE = 24%, 95% CI, 6 to 38% were both found to be associated with protection. Of significance, VE against a severe disease outcome was higher (VE = 62%, 95% CI, 14 to 84% than against milder outcomes (VE = 42%, 95% CI, 29 to 53%. CONCLUSION: A moderate association with protection against clinically apparent, laboratory-confirmed Pandemic (H1N1 2009-associated illness was found for immunization with either TIV or LAIV 2008-09 seasonal influenza vaccines. This association with protection was found to be especially apparent for severe disease as compared to milder outcome, as well as in the youngest and older populations. Prior vaccination with seasonal influenza vaccines in 2004-08 was also independently associated with protection.

Pandemic H1N1 2009 virus in Norwegian pigs naïve to influenza A viruses

DEFF Research Database (Denmark)

Germundsson, A.; Gjerset, B.; Hjulsager, Charlotte Kristiane

In March-April 2009, a novel pandemic influenza A (H1N1) virus (pH1N1-09v) emerged in the human population. The first case of pH1N1v infection in pigs was reported from Canada in May 2009. In Norway, pH1N1v infection was recorded in a swine herd on the 10th of October of 2009. Here, we report...... isolated from a confirmed human case at the farm. The majority of the positive herds had a history of contact with humans that were diagnosed with pandemic influenza or with ILI. This suggests that infected humans are the most likely source for introduction of pH1N1-09v to the Norwegian pig herds...

Pandemic influenza – including a risk assessment of H5N1

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Taubenberger, J.K.; Morens, D.M.

2009-01-01

Summary Influenza pandemics and epidemics have apparently occurred since at least the Middle Ages. When pandemics appear, 50% or more of an affected population can be infected in a single year, and the number of deaths caused by influenza can dramatically exceed what is normally expected. Since 1500, there appear to have been 13 or more influenza pandemics. In the past 120 years there were undoubted pandemics in 1889, 1918, 1957, 1968, and 1977. Although most experts believe we will face another influenza pandemic, it is impossible to predict when it will appear, where it will originate, or how severe it will be. Nor is there agreement about the subtype of influenza virus most likely to cause the next pandemic. The continuing spread of H5N1 highly pathogenic avian influenza viruses has heightened interest in pandemic prediction. Despite uncertainties in the historical record of the pre-virology era, study of previous pandemics may help guide future pandemic planning and lead to a better understanding of the complex ecobiology underlying the formation of pandemic strains of influenza A viruses. PMID:19618626

Healthcare workers as parents: attitudes toward vaccinating their children against pandemic influenza A/H1N1

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Torun Fuat

2010-10-01

Full Text Available Abstract Background Both the health care workers (HCWs and children are target groups for pandemic influenza vaccination. The coverage of the target populations is an important determinant for impact of mass vaccination. The objective of this study is to determine the attitudes of HCWs as parents, toward vaccinating their children with pandemic influenza A/H1N1 vaccine. Methods A cross-sectional questionnaire survey was conducted with health care workers (HCWs in a public hospital during December 2009 in Istanbul. All persons employed in the hospital with or without a health-care occupation are accepted as HCW. The HCWs who are parents of children 6 months to 18 years of age were included in the study. Pearson's chi-square test and logistic regression analysis was applied for the statistical analyses. Results A total of 389 HCWs who were parents of children aged 6 months-18 years participated study. Among all participants 27.0% (n = 105 reported that themselves had been vaccinated against pandemic influenza A/H1N1. Two third (66.1% of the parents answered that they will not vaccinate their children, 21.1% already vaccinated and 12.9% were still undecided. Concern about side effect was most reported reason among who had been not vaccinated their children and among undecided parents. The second reason for refusing the pandemic vaccine was concerns efficacy of the vaccine. Media was the only source of information about pandemic influenza in nearly one third of HCWs. Agreement with vaccine safety, self receipt of pandemic influenza A/H1N1 vaccine, and trust in Ministry of Health were found to be associated with the positive attitude toward vaccinating their children against pandemic influenza A/H1N1. Conclusions Persuading parents to accept a new vaccine seems not be easy even if they are HCWs. In order to overcome the barriers among HCWs related to pandemic vaccines, determination of their misinformation, attitudes and behaviors regarding the

Healthcare workers as parents: attitudes toward vaccinating their children against pandemic influenza A/H1N1.

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Torun, Sebahat D; Torun, Fuat; Catak, Binali

2010-10-10

Both the health care workers (HCWs) and children are target groups for pandemic influenza vaccination. The coverage of the target populations is an important determinant for impact of mass vaccination. The objective of this study is to determine the attitudes of HCWs as parents, toward vaccinating their children with pandemic influenza A/H1N1 vaccine. A cross-sectional questionnaire survey was conducted with health care workers (HCWs) in a public hospital during December 2009 in Istanbul. All persons employed in the hospital with or without a health-care occupation are accepted as HCW. The HCWs who are parents of children 6 months to 18 years of age were included in the study. Pearson's chi-square test and logistic regression analysis was applied for the statistical analyses. A total of 389 HCWs who were parents of children aged 6 months-18 years participated study. Among all participants 27.0% (n = 105) reported that themselves had been vaccinated against pandemic influenza A/H1N1. Two third (66.1%) of the parents answered that they will not vaccinate their children, 21.1% already vaccinated and 12.9% were still undecided. Concern about side effect was most reported reason among who had been not vaccinated their children and among undecided parents. The second reason for refusing the pandemic vaccine was concerns efficacy of the vaccine. Media was the only source of information about pandemic influenza in nearly one third of HCWs. Agreement with vaccine safety, self receipt of pandemic influenza A/H1N1 vaccine, and trust in Ministry of Health were found to be associated with the positive attitude toward vaccinating their children against pandemic influenza A/H1N1. Persuading parents to accept a new vaccine seems not be easy even if they are HCWs. In order to overcome the barriers among HCWs related to pandemic vaccines, determination of their misinformation, attitudes and behaviors regarding the pandemic influenza vaccination is necessary. Efforts for orienting

Clinical outcomes of seasonal influenza and pandemic influenza A (H1N1 in pediatric inpatients

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Budd Alicia

2010-10-01

Full Text Available Abstract Background In April 2009, a novel influenza A H1N1 (nH1N1 virus emerged and spread rapidly worldwide. News of the pandemic led to a heightened awareness of the consequences of influenza and generally resulted in enhanced infection control practices and strengthened vaccination efforts for both healthcare workers and the general population. Seasonal influenza (SI illness in the pediatric population has been previously shown to result in significant morbidity, mortality, and substantial hospital resource utilization. Although influenza pandemics have the possibility of resulting in considerable illness, we must not ignore the impact that we can experience annually with SI. Methods We compared the outcomes of pediatric patients ≤18 years of age at a large urban hospital with laboratory confirmed influenza and an influenza-like illness (ILI during the 2009 pandemic and two prior influenza seasons. The primary outcome measure was hospital length of stay (LOS. All variables potentially associated with LOS based on univariable analysis, previous studies, or hypothesized relationships were included in the regression models to ensure adjustment for their effects. Results There were 133 pediatric cases of nH1N1 admitted during 2009 and 133 cases of SI admitted during the prior 2 influenza seasons (2007-8 and 2008-9. Thirty-six percent of children with SI and 18% of children with nH1N1 had no preexisting medical conditions (p = 0.14. Children admitted with SI had 1.73 times longer adjusted LOS than children admitted for nH1N1 (95% CI 1.35 - 2.13. There was a trend towards more children with SI requiring mechanical ventilation compared with nH1N1 (16 vs.7, p = 0.08. Conclusions This study strengthens the growing body of evidence demonstrating that SI results in significant morbidity in the pediatric population. Pandemic H1N1 received considerable attention with strong media messages urging people to undergo vaccination and encouraging improved

Effect of priming with H1N1 influenza viruses of variable antigenic distances on challenge with 2009 pandemic H1N1 virus.

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O'Donnell, Christopher D; Wright, Amber; Vogel, Leatrice N; Wei, Chih-Jen; Nabel, Gary J; Subbarao, Kanta

2012-08-01

Compared to seasonal influenza viruses, the 2009 pandemic H1N1 (pH1N1) virus caused greater morbidity and mortality in children and young adults. People over 60 years of age showed a higher prevalence of cross-reactive pH1N1 antibodies, suggesting that they were previously exposed to an influenza virus or vaccine that was antigenically related to the pH1N1 virus. To define the basis for this cross-reactivity, ferrets were infected with H1N1 viruses of variable antigenic distance that circulated during different decades from the 1930s (Alaska/35), 1940s (Fort Monmouth/47), 1950s (Fort Warren/50), and 1990s (New Caledonia/99) and challenged with 2009 pH1N1 virus 6 weeks later. Ferrets primed with the homologous CA/09 or New Jersey/76 (NJ/76) virus served as a positive control, while the negative control was an influenza B virus that should not cross-protect against influenza A virus infection. Significant protection against challenge virus replication in the respiratory tract was observed in ferrets primed with AK/35, FM/47, and NJ/76; FW/50-primed ferrets showed reduced protection, and NC/99-primed ferrets were not protected. The hemagglutinins (HAs) of AK/35, FM/47, and FW/50 differ in the presence of glycosylation sites. We found that the loss of protective efficacy observed with FW/50 was associated with the presence of a specific glycosylation site. Our results suggest that changes in the HA occurred between 1947 and 1950, such that prior infection could no longer protect against 2009 pH1N1 infection. This provides a mechanistic understanding of the nature of serological cross-protection observed in people over 60 years of age during the 2009 H1N1 pandemic.

Characterizing the epidemiology of the 2009 influenza A/H1N1 pandemic in Mexico.

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Gerardo Chowell

2011-05-01

Full Text Available BACKGROUND: Mexico's local and national authorities initiated an intense public health response during the early stages of the 2009 A/H1N1 pandemic. In this study we analyzed the epidemiological patterns of the pandemic during April-December 2009 in Mexico and evaluated the impact of nonmedical interventions, school cycles, and demographic factors on influenza transmission. METHODS AND FINDINGS: We used influenza surveillance data compiled by the Mexican Institute for Social Security, representing 40% of the population, to study patterns in influenza-like illness (ILIs hospitalizations, deaths, and case-fatality rate by pandemic wave and geographical region. We also estimated the reproduction number (R on the basis of the growth rate of daily cases, and used a transmission model to evaluate the effectiveness of mitigation strategies initiated during the spring pandemic wave. A total of 117,626 ILI cases were identified during April-December 2009, of which 30.6% were tested for influenza, and 23.3% were positive for the influenza A/H1N1 pandemic virus. A three-wave pandemic profile was identified, with an initial wave in April-May (Mexico City area, a second wave in June-July (southeastern states, and a geographically widespread third wave in August-December. The median age of laboratory confirmed ILI cases was ∼ 18 years overall and increased to ∼ 31 years during autumn (p<0.0001. The case-fatality ratio among ILI cases was 1.2% overall, and highest (5.5% among people over 60 years. The regional R estimates were 1.8-2.1, 1.6-1.9, and 1.2-1.3 for the spring, summer, and fall waves, respectively. We estimate that the 18-day period of mandatory school closures and other social distancing measures implemented in the greater Mexico City area was associated with a 29%-37% reduction in influenza transmission in spring 2009. In addition, an increase in R was observed in late May and early June in the southeast states, after mandatory school

Humoral and cell-mediated immunity to pandemic H1N1 influenza in a Canadian cohort one year post-pandemic: implications for vaccination.

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Lisa E Wagar

Full Text Available We evaluated a cohort of Canadian donors for T cell and antibody responses against influenza A/California/7/2009 (pH1N1 at 8-10 months after the 2nd pandemic wave by flow cytometry and microneutralization assays. Memory CD8 T cell responses to pH1N1 were detectable in 58% (61/105 of donors. These responses were largely due to cross-reactive CD8 T cell epitopes as, for those donors tested, similar recall responses were obtained to A/California 2009 and A/PR8 1934 H1N1 Hviruses. Longitudinal analysis of a single infected individual showed only a small and transient increase in neutralizing antibody levels, but a robust CD8 T cell response that rose rapidly post symptom onset, peaking at 3 weeks, followed by a gradual decline to the baseline levels seen in a seroprevalence cohort post-pandemic. The magnitude of the influenza-specific CD8 T cell memory response at one year post-pandemic was similar in cases and controls as well as in vaccinated and unvaccinated donors, suggesting that any T cell boosting from infection was transient. Pandemic H1-specific antibodies were only detectable in approximately half of vaccinated donors. However, those who were vaccinated within a few months following infection had the highest persisting antibody titers, suggesting that vaccination shortly after influenza infection can boost or sustain antibody levels. For the most part the circulating influenza-specific T cell and serum antibody levels in the population at one year post-pandemic were not different between cases and controls, suggesting that natural infection does not lead to higher long term T cell and antibody responses in donors with pre-existing immunity to influenza. However, based on the responses of one longitudinal donor, it is possible for a small population of pre-existing cross-reactive memory CD8 T cells to expand rapidly following infection and this response may aid in viral clearance and contribute to a lessening of disease severity.

Why do I need it? I am not at risk! Public perceptions towards the pandemic (H1N1 2009 vaccine

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Ward Kirsten F

2010-04-01

Full Text Available Abstract Background On the 30th September 2009, the pandemic (H1N1 2009 influenza vaccine was made available to adults and children aged 10 years and over, in Australia. Acceptance of a novel vaccine is influenced by perceptions of risk including risk of infection, risk of death or severe illness and risk of serious vaccine side-effects. We surveyed a sample of residents from Sydney, Australia to ascertain their risk perception, attitudes towards the pandemic and willingness to accept the pandemic (H1N1 2009 influenza vaccine. Methods We sampled residents using a cross-sectional intercept design during the WHO Phase 6. Members of the public were approached in shopping and pedestrian malls to undertake the survey during September and October 2009. The survey measured perceived risk, seriousness of disease, recent behavioural changes, likely acceptance of the pandemic (H1N1 2009 vaccine and issues relating to uptake and perceived safety. Results Of the 627 respondents, the majority felt that they had a "very low to low" (332/627, 52.9% risk of acquiring H1N1. 24.5% (154/627 of respondents believed that the disease would "very seriously or extremely" affect their health. Nearly half (305/627, 48.6% reported that in response to the "swine flu" outbreak they had undertaken one or more of the investigated behavioural changes. Overall, the self-reported likelihood of accepting vaccination against novel H1N1 was 54.7% (343/627. Conclusions While, most participants did not believe they were at high risk of acquiring pandemic H1N1 2009, over half of the sample indicated that they would accept the vaccine. Participants who were vaccinated against the seasonal influenza were more likely to receive the H1N1 vaccine. Concerns about safety, the possibility of side effects and the vaccine development process need to be addressed.

Pandemic (H1N1) 2009: clinical and laboratory findings of the first fifty cases in Singapore.

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Chan, Monica; Chen, Mark I; Chow, Angela; Lee, Caroline P S; Tan, Adriana S H; Lye, David Chien; Leo, Yee Sin

2010-04-01

Since the fi rst imported case on 26 May 2009, pandemic (H1N1) 2009 has spread from travellers and has resulted in sustained community transmission. Singapore began with a strict containment policy where all suspected and confirmed cases of pandemic (H1N1) 2009 were admitted for testing. We describe here the clinical and laboratory characteristics of the fi rst 50 adult cases with confirmed pandemic (H1N1) 2009. A review was conducted of medical notes of adult patients with confirmed pandemic (H1N1) 2009 by polymerase chain reaction assay from combined nasal and throat swabs admitted to the Communicable Disease Centre, Tan Tock Seng Hospital. From 26 May to 18 June 2009, 50 patients with a median age of 27 years old were admitted at a median of 3 days from illness onset. Half were male and all were travellers arriving in Singapore. Non-Singaporean citizens (38%) and other ethnic groups (40%) were over-represented. History of fever was reported in 90% and respiratory symptoms in 92%. Gastrointestinal symptoms were uncommon, present in 4% only. Temperatures on presentation of >or=38.0 degrees C, >or=37.8 degrees C and >or=37.5 degrees C were present in 48%, 56% and 76%, respectively. Only 46% of patients met the United States Centers for Disease Control and Prevention (US CDC) case definition of influenza-like illness (ILI). Clinical and laboratory findings were unremarkable for the majority. All cases were treated with oseltamivir and had uncomplicated recovery. Pandemic (H1N1) 2009 had mild clinical and laboratory findings in immunocompetent patients. Use of the US CDC ILI criteria alone would have detected less than half of confirmed cases.

Entry and exit screening of airline travellers during the A(H1N1) 2009 pandemic: a retrospective evaluation.

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Khan, Kamran; Eckhardt, Rose; Brownstein, John S; Naqvi, Raza; Hu, Wei; Kossowsky, David; Scales, David; Arino, Julien; MacDonald, Michael; Wang, Jun; Sears, Jennifer; Cetron, Martin S

2013-05-01

To evaluate the screening measures that would have been required to assess all travellers at risk of transporting A(H1N1)pdm09 out of Mexico by air at the start of the 2009 pandemic. Data from flight itineraries for travellers who flew from Mexico were used to estimate the number of international airports where health screening measures would have been needed, and the number of travellers who would have had to be screened, to assess all air travellers who could have transported the H1N1 influenza virus out of Mexico during the initial stages of the 2009 A(H1N1) pandemic. Exit screening at 36 airports in Mexico, or entry screening of travellers arriving on direct flights from Mexico at 82 airports in 26 other countries, would have resulted in the assessment of all air travellers at risk of transporting A(H1N1)pdm09 out of Mexico at the start of the pandemic. Entry screening of 116 travellers arriving from Mexico by direct or connecting flights would have been necessary for every one traveller at risk of transporting A(H1N1)pdm09. Screening at just eight airports would have resulted in the assessment of 90% of all air travellers at risk of transporting A(H1N1)pdm09 out of Mexico in the early stages of the pandemic. During the earliest stages of the A(H1N1) pandemic, most public health benefits potentially attainable through the screening of air travellers could have been achieved by screening travellers at only eight airports.

Molecular characterization of a novel reassortant H1N2 influenza virus containing genes from the 2009 pandemic human H1N1 virus in swine from eastern China.

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Peng, Xiuming; Wu, Haibo; Xu, Lihua; Peng, Xiaorong; Cheng, Linfang; Jin, Changzhong; Xie, Tiansheng; Lu, Xiangyun; Wu, Nanping

2016-06-01

Pandemic outbreaks of H1N1 swine influenza virus have been reported since 2009. Reassortant H1N2 viruses that contain genes from the pandemic H1N1 virus have been isolated in Italy and the United States. However, there is limited information regarding the molecular characteristics of reassortant H1N2 swine influenza viruses in eastern China. Active influenza surveillance programs in Zhejiang Province identified a novel H1N2 influenza virus isolated from pigs displaying clinical signs of influenza virus infection. Whole-genome sequencing was performed and this strain was compared with other influenza viruses available in GenBank. Phylogenetic analysis suggested that the novel strain contained genes from the 2009 pandemic human H1N1 and swine H3N2 viruses. BALB/c mice were infected with the isolated virus to assess its virulence in mice. While the novel H1N2 isolate replicated well in mice, it was found to be less virulent. These results provide additional evidence that swine serve as intermediate hosts or 'mixing vessels' for novel influenza viruses. They also emphasize the importance of surveillance in the swine population for use as an early warning system for influenza outbreaks in swine and human populations.

Contextual generalized trust and immunization against the 2009 A(H1N1 pandemic in the American states: A multilevel approach

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Björn Rönnerstrand

2016-12-01

Full Text Available The aim of the study was to investigate the association between contextual generalized trust and individual-level 2009 A(H1N1 pandemic immunization acceptance. A second aim was to investigate whether knowledge about the A(H1N1 pandemic mediated the association between contextual generalized trust and A(H1N1 immunization acceptance. Data from the National 2009 H1N1 Flu Survey was used. To capture contextual generalized trust, data comes from an aggregation of surveys measuring generalized trust in the American states. To investigate the association between contextual generalized trust and immunization acceptance, while taking potential individual-level confounders into account, multilevel logistic regression was used. The investigation showed contextual generalized trust to be significantly associated with immunization acceptance. However, controlling for knowledge about the A(H1N1 pandemic did not substantially affect the association between contextual generalized trust and immunization acceptance. In conclusion, contextual state-level generalized trust was associated with A(H1N1 immunization, but knowledge about A(H1N1 was not mediating this association. Keywords: Generalized trust, Social capital, Immunization, A(H1N1 pandemic, American states

The early days of pandemic (H1N1 2009 virus infection in the central region of Portugal

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V. Duque

2010-11-01

period for the for pandemic (H1N1 2009 virus infection was 2 days. The length of the clinical manifestations until the patients sough for medical observation had a median time of 2 days. All the cases were of mild to moderate severity. No deaths were observed. Conclusions: The early days of pandemic (H1N1 2009 virus infection were characterized by cases of disease of mild to moderate severity, in our region. Most affected patients were young adults, with the extreme ages of life being spared. An early diagnosis, strict isolation and treatment procedures could have slowed the spread of the infection. Resumo: Introdução: O primeiro caso de infecção pelo vírus da gripe pandémica (H1N1 2009, foi diagnosticado na região centro de Portugal no dia 16 de Junho de 2009, numa mulher infectada no Canadá. Métodos: O nosso estudo tem por objectivos, em primeiro lugar caracterizar os aspectos clínicos e epidemiológicos de todos os doentes que tiveram manifestações clínicas incluídas na definição de caso para investigação com amostras submetidas para diagnóstico da infecção pelo vírus da gripe pandémica (H1N1 2009; em segundo lugar, avaliar a precisão da definição de caso para investigação de acordo com a presença ou ausência de febre no momento da observação clínica. Efectuámos a revisão dos registos médicos de todos os doentes classificados como caso para investigação e analisaram-se os primeiros casos de doentes infectados com o novo vírus da gripe pandémica (H1N1 2009, diagnosticados na região centro de Portugal durante o período pandémico compreendido entre Junho e Agosto de 2009. Foi utilizado o método da reacção em cadeia da polimerase de retrotranscripção em tempo real para confirmação da infecção pelo vírus da gripe pandémica (H1N1 2009. A colheita de dados foi efectuada de forma padronizada em suporte de papel de acordo com as normas da Direcção Geral de Saúde. Resultados e discussão: A infecção pelo vírus da gripe

Pandemic H1N1 2009 virus in Danish pigs: Diagnosis and lack of surveillance

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Larsen, Lars Erik; Nielsen, L. P.; Breum, Solvej Østergaard

In March-April 2009, a novel pandemic H1N1 virus (H1N1v) of likely swine origin emerged in the human population globally. The first case in pigs was reported from Canada in May 2009 and presently almost all countries with pig production have reported cases. The emergence of a new influenza subtype...

An Analysis of 332 Fatalities Infected with Pandemic 2009 Influenza A (H1N1) in Argentina

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Balanzat, Ana M.; Hertlein, Christian; Apezteguia, Carlos; Bonvehi, Pablo; Cámera, Luis; Gentile, Angela; Rizzo, Oscar; Gómez-Carrillo, Manuel; Coronado, Fatima; Azziz-Baumgartner, Eduardo; Chávez, Pollyanna R.; Widdowson, Marc-Alain

2012-01-01

Background The apparent high number of deaths in Argentina during the 2009 pandemic led to concern that the influenza A H1N1pdm disease was different there. We report the characteristics and risk factors for influenza A H1N1pdm fatalities. Methods We identified laboratory-confirmed influenza A H1N1pdm fatalities occurring during June-July 2009. Physicians abstracted data on age, sex, time of onset of illness, medical history, clinical presentation at admission, laboratory, treatment, and outcomes using standardize questionnaires. We explored the characteristics of fatalities according to their age and risk group. Results Of 332 influenza A H1N1pdm fatalities, 226 (68%) were among persons aged Argentina, though timeliness of antiviral treatment improved during the pandemic. PMID:22506006

Cost-effective strategies for mitigating a future influenza pandemic with H1N1 2009 characteristics.

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Nilimesh Halder

Full Text Available BACKGROUND: We performed an analysis of the cost-effectiveness of pandemic intervention strategies using a detailed, individual-based simulation model of a community in Australia together with health outcome data of infected individuals gathered during 2009-2010. The aim was to examine the cost-effectiveness of a range of interventions to determine the most cost-effective strategies suitable for a future pandemic with H1N1 2009 characteristics. METHODOLOGY/PRINCIPAL FINDINGS: Using transmissibility, age-stratified attack rates and health outcomes determined from H1N1 2009 data, we determined that the most cost-effective strategies involved treatment and household prophylaxis using antiviral drugs combined with limited duration school closure, with costs ranging from $632 to $777 per case prevented. When school closure was used as a sole intervention we found the use of limited duration school closure to be significantly more cost-effective compared to continuous school closure, a result with applicability to countries with limited access to antiviral drugs. Other social distancing strategies, such as reduced workplace attendance, were found to be costly due to productivity losses. CONCLUSION: The mild severity (low hospitalisation and case fatality rates and low transmissibility of H1N1 2009 meant that health treatment costs were dominated by the higher productivity losses arising from workplace absence due to illness and childcare requirements following school closure. Further analysis for higher transmissibility but with the same, mild severity had no effect on the overall findings.

Reassortant swine influenza viruses isolated in Japan contain genes from pandemic A(H1N1) 2009.

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Kanehira, Katsushi; Takemae, Nobuhiro; Uchida, Yuko; Hikono, Hirokazu; Saito, Takehiko

2014-06-01

In 2013, three reassortant swine influenza viruses (SIVs)-two H1N2 and one H3N2-were isolated from symptomatic pigs in Japan; each contained genes from the pandemic A(H1N1) 2009 virus and endemic SIVs. Phylogenetic analysis revealed that the two H1N2 viruses, A/swine/Gunma/1/2013 and A/swine/Ibaraki/1/2013, were reassortants that contain genes from the following three distinct lineages: (i) H1 and nucleoprotein (NP) genes derived from a classical swine H1 HA lineage uniquely circulating among Japanese SIVs; (ii) neuraminidase (NA) genes from human-like H1N2 swine viruses; and (iii) other genes from pandemic A(H1N1) 2009 viruses. The H3N2 virus, A/swine/Miyazaki/2/2013, comprised genes from two sources: (i) hemagglutinin (HA) and NA genes derived from human and human-like H3N2 swine viruses and (ii) other genes from pandemic A(H1N1) 2009 viruses. Phylogenetic analysis also indicated that each of the reassortants may have arisen independently in Japanese pigs. A/swine/Miyazaki/2/2013 were found to have strong antigenic reactivities with antisera generated for some seasonal human-lineage viruses isolated during or before 2003, whereas A/swine/Miyazaki/2/2013 reactivities with antisera against viruses isolated after 2004 were clearly weaker. In addition, antisera against some strains of seasonal human-lineage H1 viruses did not react with either A/swine/Gunma/1/2013 or A/swine/Ibaraki/1/2013. These findings indicate that emergence and spread of these reassortant SIVs is a potential public health risk. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

Factors associated with 2009 pandemic influenza A (H1N1 vaccination acceptance among university students from India during the post-pandemic phase

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Thejaswini Venkatesh

2011-07-01

Full Text Available Abstract Background There was a low adherence to influenza A (H1N1 vaccination program among university students and health care workers during the pandemic influenza in many parts of the world. Vaccination of high risk individuals is one of the recommendations of World Health Organization during the post-pandemic period. It is not documented about the student's knowledge, attitude and willingness to accept H1N1 vaccination during the post-pandemic period. We aimed to analyze the student's knowledge, attitude and willingness to accept H1N1 vaccination during the post-pandemic period in India. Methods Vaccine against H1N1 was made available to the students of Vellore Institute of Technology, India from September 2010. The data are based on a cross-sectional study conducted during October 2010 to January 2011 using a self-administered questionnaire with a representative sample of the student population (N = 802. Results Of the 802 respondents, only 102/802 (12.7% had been vaccinated and 105/802 (13% planned to do so in the future, while 595/802 (74% would probably or definitely not get vaccinated in the future. The highest coverage was among the female (65/102, 63.7% and non-compliance was higher among men in the group (384/595; 64.5% (p Conclusions Our study shows that the vaccination coverage among university students remains very low in the post-pandemic period and doubts about the safety and effectiveness of the vaccine are key elements in their rejection. Our results indicate a need to provide accessible information about the vaccine safety by scientific authorities and fill gaps and confusions in this regard.

Functional Evolution of Influenza Virus NS1 Protein in Currently Circulating Human 2009 Pandemic H1N1 Viruses.

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Clark, Amelia M; Nogales, Aitor; Martinez-Sobrido, Luis; Topham, David J; DeDiego, Marta L

2017-09-01

In 2009, a novel H1N1 influenza virus emerged in humans, causing a global pandemic. It was previously shown that the NS1 protein from this human 2009 pandemic H1N1 (pH1N1) virus was an effective interferon (IFN) antagonist but could not inhibit general host gene expression, unlike other NS1 proteins from seasonal human H1N1 and H3N2 viruses. Here we show that the NS1 protein from currently circulating pH1N1 viruses has evolved to encode 6 amino acid changes (E55K, L90I, I123V, E125D, K131E, and N205S) with respect to the original protein. Notably, these 6 residue changes restore the ability of pH1N1 NS1 to inhibit general host gene expression, mainly by their ability to restore binding to the cellular factor CPSF30. This is the first report describing the ability of the pH1N1 NS1 protein to naturally acquire mutations that restore this function. Importantly, a recombinant pH1N1 virus containing these 6 amino acid changes in the NS1 protein (pH1N1/NSs-6mut) inhibited host IFN and proinflammatory responses to a greater extent than that with the parental virus (pH1N1/NS1-wt), yet virus titers were not significantly increased in cell cultures or in mouse lungs, and the disease was partially attenuated. The pH1N1/NSs-6mut virus grew similarly to pH1N1/NSs-wt in mouse lungs, but infection with pH1N1/NSs-6mut induced lower levels of proinflammatory cytokines, likely due to a general inhibition of gene expression mediated by the mutated NS1 protein. This lower level of inflammation induced by the pH1N1/NSs-6mut virus likely accounts for the attenuated disease phenotype and may represent a host-virus adaptation affecting influenza virus pathogenesis. IMPORTANCE Seasonal influenza A viruses (IAVs) are among the most common causes of respiratory infections in humans. In addition, occasional pandemics are caused when IAVs circulating in other species emerge in the human population. In 2009, a swine-origin H1N1 IAV (pH1N1) was transmitted to humans, infecting people then and up

THE A (H1N1 INFLUENZA. SYMBOLIC DIMENSIONS OF A PANDEMIC ARTEFACT

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Andrés G. Seguel

2013-01-01

Full Text Available The aim of the present paper is to present the symbolic features that are exposed by the concept of artefact in the context of a pandemic alarm, such as the A (H1N1 influenza. The symbolic qualities entailed by the notion of artefact are well-known within the Social Sciences: Sociology, Anthropology, Archaeology, and Linguistics. The artefact is basically not an object, but an action aimed at designing, simulating or creating a simile by means of material, technological or linguistic structures. The purpose of the present work is to unveil the symbolic dimensions that are activated by the A (H1N1 influenza as a Pandemic Artefact: a the assumption of separating information from matter; b the need for a material support to enable the exchange; c the sociological reflexivity of the artefact and its agency; d the arbitrariness of its social use, that detaches it from the design as intention.

Surveillance of hospitalizations with pandemic A(H1N1 2009 influenza infection in Queensland, Australia

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Frances Birrell

2011-05-01

Full Text Available Objective : To describe the demographic and clinical characteristics of patients hospitalized with pandemic A(H1N1 2009 infection in Queensland, Australia between 25 May and 3 October 2009 and to examine the relationship between timing of antiviral treatment and severity of illness.Method: Using data from the Queensland Health EpiLog information system, descriptive analysis and logistic regression modelling were used to describe and model factors which influence patient outcomes (death, admission to intensive care unit and/or special care unit. Data on patients admitted to hospital in Queensland with confirmed pandemic A(H1N1 2009 infection were included in this analysis.Results: 1236 patients with pandemic A(H1N1 2009 infection were admitted to hospitals in Queensland during the study period. Of the total group: 15% were admitted to an intensive care unit or special care unit; 3% died; 34% were under the age of 18 years and 8% were 65 years of age or older; and 55% had at least one underlying medical condition. Among the 842 patients for whom data were available regarding the use of antiviral drugs, antiviral treatment was initiated in 737 (87.5% patients with treatment commencing at a median of one day (range 1–33 days after onset of illness. Admission to an intensive care unit or special care unit (ICU/SCU or death was significantly associated with increased age, lack of timeliness of antiviral treatment, chronic renal disease and morbid obesity.Discussion: Early antiviral treatment was significantly associated with lower likelihood of ICU/SCU admission or death. Early antiviral treatment for influenza cases may therefore have important public health implications.

Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus.

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Busquets, Núria; Segalés, Joaquim; Córdoba, Lorena; Mussá, Tufaria; Crisci, Elisa; Martín-Valls, Gerard E; Simon-Grifé, Meritxell; Pérez-Simó, Marta; Pérez-Maíllo, Monica; Núñez, Jose I; Abad, Francesc X; Fraile, Lorenzo; Pina, Sonia; Majó, Natalia; Bensaid, Albert; Domingo, Mariano; Montoya, María

2010-01-01

The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains. © INRA, EDP Sciences, 2010.

Risk factors for death from pandemic (H1N1) 2009, southern Brazil.

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Yokota, Renata T C; Skalinski, Lacita M; Igansi, Cristine N; de Souza, Libia R O; Iser, Betine P M; Reis, Priscilleyne O; Barros, Eliana N C; Macário, Eduardo M; Bercini, Marilina A; Ranieri, Tani M S; Araújo, Wildo N

2011-08-01

To identify risk factors for death from pandemic (H1N1) 2009, we obtained data for 157 hospitalized patients with confirmed cases of this disease. Multivariate analysis showed that diabetes and class III obesity were associated with death. These findings helped define priority vaccination groups in Brazil.

An assessment of H1N1 influenza-associated acute respiratory distress syndrome severity after adjustment for treatment characteristics.

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Brent P Riscili

2011-03-01

Full Text Available Pandemic influenza caused significant increases in healthcare utilization across several continents including the use of high-intensity rescue therapies like extracorporeal membrane oxygenation (ECMO or high-frequency oscillatory ventilation (HFOV. The severity of illness observed with pandemic influenza in 2009 strained healthcare resources. Because lung injury in ARDS can be influenced by daily management and multiple organ failure, we performed a retrospective cohort study to understand the severity of H1N1 associated ARDS after adjustment for treatment. Sixty subjects were identified in our hospital with ARDS from "direct injury" within 24 hours of ICU admission over a three month period. Twenty-three subjects (38.3% were positive for H1N1 within 72 hours of hospitalization. These cases of H1N1-associated ARDS were compared to non-H1N1 associated ARDS patients. Subjects with H1N1-associated ARDS were younger and more likely to have a higher body mass index (BMI, present more rapidly and have worse oxygenation. Severity of illness (SOFA score was directly related to worse oxygenation. Management was similar between the two groups on the day of admission and subsequent five days with respect to tidal volumes used, fluid balance and transfusion practices. There was, however, more frequent use of "rescue" therapy like prone ventilation, HFOV or ECMO in H1N1 patients. First morning set tidal volumes and BMI were significantly associated with increased severity of lung injury (Lung injury score, LIS at presentation and over time while prior prescription of statins was protective. After assessment of the effect of these co-interventions LIS was significantly higher in H1N1 patients. Patients with pandemic influenza-associated ARDS had higher LIS both at presentation and over the course of the first six days of treatment when compared to non-H1N1 associated ARDS controls. The difference in LIS persisted over the duration of observation in patients

Will the community nurse continue to function during H1N1 influenza pandemic: a cross-sectional study of Hong Kong community nurses?

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Wong, Eliza L Y; Wong, Samuel Y S; Kung, Kenny; Cheung, Annie W L; Gao, Tiffany T; Griffiths, Sian

2010-04-30

Healthcare workers have been identified as one of the high risk groups for being infected with influenza during influenza pandemic. Potential levels of absenteeism among healthcare workers in hospital settings are high. However, there was no study to explore the attitudes of healthcare workers in community setting towards the preparedness to the novel H1N1 influenza pandemic. The aim of this study was to explore the willingness of community nurses in Hong Kong to work during H1N1 influenza pandemic. A cross-sectional survey was conducted among all 401 community nurses employed by the Hospital Authority in Hong Kong when the WHO pandemic alert level was 6. The response rate of this study was 66.6%. 76.9% participants reported being "not willing" (33.3%) or "not sure" (43.6%) to take care of patients during H1N1 influenza pandemic. The self-reported reasons for being unwilling to report to duty during H1N1 influenza pandemic were psychological stress (55.0%) and fear of being infected H1N1 influenza (29.2%). The reported unwillingness to report to duty was marginally significantly associated with the request for further training of using infection control clinical guideline (OR: 0.057; CI: 0.25-1.02). Those who reported unwillingness or not being sure about taking care of the patients during H1N1 influenza pandemic were more depressed (p work more emotionally stressful (p < 0.001). Interventions to provide infection control training and address community nurses' psychological needs might increase their willingness to provide care to patients in the community during H1N1 influenza pandemic. This would help to ensure an effective and appropriate health system response during the H1N1 influenza pandemic.

Will the community nurse continue to function during H1N1 influenza pandemic: a cross-sectional study of Hong Kong community nurses?

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Gao Tiffany T

2010-04-01

Full Text Available Abstract Background Healthcare workers have been identified as one of the high risk groups for being infected with influenza during influenza pandemic. Potential levels of absenteeism among healthcare workers in hospital settings are high. However, there was no study to explore the attitudes of healthcare workers in community setting towards the preparedness to the novel H1N1 influenza pandemic. The aim of this study was to explore the willingness of community nurses in Hong Kong to work during H1N1 influenza pandemic. Methods A cross-sectional survey was conducted among all 401 community nurses employed by the Hospital Authority in Hong Kong when the WHO pandemic alert level was 6. Results The response rate of this study was 66.6%. 76.9% participants reported being "not willing" (33.3% or "not sure" (43.6% to take care of patients during H1N1 influenza pandemic. The self-reported reasons for being unwilling to report to duty during H1N1 influenza pandemic were psychological stress (55.0% and fear of being infected H1N1 influenza (29.2%. The reported unwillingness to report to duty was marginally significantly associated with the request for further training of using infection control clinical guideline (OR: 0.057; CI: 0.25-1.02. Those who reported unwillingness or not being sure about taking care of the patients during H1N1 influenza pandemic were more depressed (p Conclusions Interventions to provide infection control training and address community nurses' psychological needs might increase their willingness to provide care to patients in the community during H1N1 influenza pandemic. This would help to ensure an effective and appropriate health system response during the H1N1 influenza pandemic.

Outbreak of H3N2 influenza at a US military base in Djibouti during the H1N1 pandemic of 2009.

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Cosby, Michael T; Pimentel, Guillermo; Nevin, Remington L; Fouad Ahmed, Salwa; Klena, John D; Amir, Ehab; Younan, Mary; Browning, Robert; Sebeny, Peter J

2013-01-01

Influenza pandemics have significant operational impact on deployed military personnel working in areas throughout the world. The US Department of Defense global influenza-like illness (ILI) surveillance network serves an important role in establishing baseline trends and can be leveraged to respond to outbreaks of respiratory illness. We identified and characterized an operationally unique outbreak of H3N2 influenza at Camp Lemonnier, Djibouti occurring simultaneously with the H1N1 pandemic of 2009 [A(H1N1)pdm09]. Enhanced surveillance for ILI was conducted at Camp Lemonnier in response to local reports of a possible outbreak during the A(H1N1)pdm09 pandemic. Samples were collected from consenting patients presenting with ILI (utilizing a modified case definition) and who completed a case report form. Samples were cultured and analyzed using standard real-time reverse transcriptase PCR (rt-RT-PCR) methodology and sequenced genetic material was phylogenetically compared to other published strains. rt-RT-PCR and DNA sequencing revealed that 25 (78%) of the 32 clinical samples collected were seasonal H3N2 and only 2 (6%) were A(H1N1)pdm09 influenza. The highest incidence of H3N2 occurred during the month of May and 80% of these were active duty military personnel. Phylogenetic analysis revealed that sequenced H3N2 strains were genetically similar to 2009 strains from the United States of America, Australia, and South east Asia. This outbreak highlights challenges in the investigation of influenza among deployed military populations and corroborates the public health importance of maintaining surveillance systems for ILI that can be enhanced locally when needed.

The 2009 A (H1N1) influenza virus pandemic: A review.

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Girard, Marc P; Tam, John S; Assossou, Olga M; Kieny, Marie Paule

2010-07-12

In March and early April 2009 a new swine-origin influenza virus (S-OIV), A (H1N1), emerged in Mexico and the USA. The virus quickly spread worldwide through human-to-human transmission. In view of the number of countries and communities which were reporting human cases, the World Health Organization raised the influenza pandemic alert to the highest level (level 6) on June 11, 2009. The propensity of the virus to primarily affect children, young adults and pregnant women, especially those with an underlying lung or cardiac disease condition, and the substantial increase in rate of hospitalizations, prompted the efforts of the pharmaceutical industry, including new manufacturers from China, Thailand, India and South America, to develop pandemic H1N1 influenza vaccines. All currently registered vaccines were tested for safety and immunogenicity in clinical trials on human volunteers. All were found to be safe and to elicit potentially protective antibody responses after the administration of a single dose of vaccine, including split inactivated vaccines with or without adjuvant, whole-virion vaccines and live-attenuated vaccines. The need for an increased surveillance of influenza virus circulation in swine is outlined. Copyright 2010. Published by Elsevier Ltd.

[Technical report on the 2009 influenza A (H1N1) pandemic].

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2010-01-01

Since its appearance in April 2009, the influenza A (H1N1) pandemic has been a subject of continued attention by national and international health authorities, as well as in the communication media. It has been six months since the first cases were published and the winter season has just ended in the southern hemisphere. Therefore, we now have quite extensive knowledge on the behaviour of the disease, its severity and the way it manifests itself in the child/adolescent population. The Spanish Paediatric Association commissioned its Evidence Based Medicine Working Group to prepare a technical report on the influenza pandemic. This report has been prepared following the highly structured working methodology proposed by the so-called Evidence Based Medicine (EBM). This methodology requires formulating clinical questions, carrying out a systematic review of the literature looking for research works that could answer them, the critical reading of these, evaluating their methodology quality and clinical importance and finally, establishing recommendations based on those studies considered valid and important as well as on good clinical judgement. The present report approaches all aspects of the influenza pandemic considered to be of interest: extent of the disease, clinical and laboratory diagnosis, physical prevention measures, vaccination and pharmacological treatment. The target population of the report are children and adolescents. Many of the considerations made may also be applied to other age groups. The primary objective of this report is to establish a group of recommendations which may serve as a generic framework for the prevention, diagnosis and treatment of the pandemic influenza in children and adolescents. The final targets of the report are paediatricians and also general/family doctors and nurses who look after children and adolescents. Copyright (c) 2009 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Genetic divergence of influenza A NS1 gene in pandemic 2009 H1N1 isolates with respect to H1N1 and H3N2 isolates from previous seasonal epidemics

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Campanini Giulia

2010-09-01

Full Text Available Abstract Background The Influenza A pandemic sustained by a new H1N1 variant (H1N1v started in Mexico and the USA at the end of April 2009 spreading worldwide in a few weeks. In this study we investigate the variability of the NS1 gene of the pandemic H1N1v strain with respect to previous seasonal strains circulating in humans and the potential selection of virus variants through isolation in cell culture. Methods During the period April 27th 2009-Jan 15th 2010, 1633 potential 2009 H1N1v cases have been screened at our center using the CDC detection and typing realtime RT-PCR assays. Virus isolation on MDCK cells was systematically performed in 1/10 positive cases. A subset of 51 H1N1v strains isolated in the period May-September 2009 was selected for NS1 gene sequencing. In addition, 15 H1N1 and 47 H3N2 virus isolates from three previous seasonal epidemics (2006-2009 were analyzed in parallel. Results A low variability in the NS1 amino acid (aa sequence among H1N1v isolates was shown (aa identity 99.5%. A slightly higher NS1 variability was observed among H1N1 and H3N2 strains from previous epidemics (aa identity 98.6% and 98.9%, respectively. The H1N1v strains were closely related (aa identity 92.1% to swine reference strain (A/swine/Oklahoma/042169/2008. In contrast, substantial divergence (aa identity 83.4% with respect to human reference strain A/Brevig Mission/1/1918 and previous epidemic strains H1N1 and H3N2 (aa identity 78.9% and 77.6%, respectively was shown. Specific sequence signatures of uncertain significance in the new virus variant were a C-terminus deletion and a T215P substitution. Conclusions The H1N1v NS1 gene was more conserved than that of previous epidemic strains. In addition, a closer genetic identity of H1N1v with the swine than the human reference strains was shown. Hot-spots were shown in the H1N1v NS1 aa sequence whose biologic relevance remains to be investigated.

Community-based measures for mitigating the 2009 H1N1 pandemic in China.

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Sanyi Tang

Full Text Available Since the emergence of influenza A/H1N1 pandemic virus in March-April 2009, very stringent interventions including Fengxiao were implemented to prevent importation of infected cases and decelerate the disease spread in mainland China. The extent to which these measures have been effective remains elusive. We sought to investigate the effectiveness of Fengxiao that may inform policy decisions on improving community-based interventions for management of on-going outbreaks in China, in particular during the Spring Festival in mid-February 2010 when nationwide traveling will be substantially increased. We obtained data on initial laboratory-confirmed cases of H1N1 in the province of Shaanxi and used Markov-chain Monte-Carlo (MCMC simulations to estimate the reproduction number. Given the estimates for the exposed and infectious periods of the novel H1N1 virus, we estimated a mean reproduction number of 1.68 (95% CI 1.45-1.92 and other A/H1N1 epidemiological parameters. Our results based on a spatially stratified population dynamical model show that the early implementation of Fengxiao can delay the epidemic peak significantly and prevent the disease spread to the general population but may also, if not implemented appropriately, cause more severe outbreak within universities/colleges, while late implementation of Fengxiao can achieve nothing more than no implementation. Strengthening local control strategies (quarantine and hygiene precaution is much more effective in mitigating outbreaks and inhibiting the successive waves than implementing Fengxiao. Either strong mobility or high transport-related transmission rate during the Spring Festival holiday will not reverse the ongoing outbreak, but both will result in a large new wave. The findings suggest that Fengxiao and travel precautions should not be relaxed unless strict measures of quarantine, isolation, and hygiene precaution practices are put in place. Integration and prompt implementation of

Clinical features and risk factors for severe and critical pregnant women with 2009 pandemic H1N1 influenza infection in China

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Zhang Peng-jun

2012-02-01

Full Text Available Abstract Background 2009 pandemic H1N1 (pH1N1 influenza posed an increased risk of severe illness among pregnant women. Data on risk factors associated with death of pregnant women and neonates with pH1N1 infections are limited outside of developed countries. Methods Retrospective observational study in 394 severe or critical pregnant women admitted to a hospital with pH1N1 influenza from Sep. 1, 2009 to Dec. 31, 2009. rRT-PCR testing was used to confirm infection. In-hospital mortality was the primary endpoint of this study. Univariable logistic analysis and multivariate logistic regression analysis were used to investigate the potential factors on admission that might be associated with the maternal and neonatal mortality. Results 394 pregnant women were included, 286 were infected with pH1N1 in the third trimester. 351 had pneumonia, and 77 died. A PaO2/FiO2 ≤ 200 (odds ratio (OR, 27.16; 95% confidence interval (CI, 2.64-279.70 and higher BMI (i.e. ≥ 30 on admission (OR, 1.26; 95% CI, 1.09 to 1.47 were independent risk factors for maternal death. Of 211 deliveries, 146 neonates survived. Premature delivery (OR, 4.17; 95% CI, 1.19-14.56 was associated neonatal mortality. Among 186 patients who received mechanical ventilation, 83 patients were treated with non-invasive ventilation (NIV and 38 were successful with NIV. The death rate was lower among patients who initially received NIV than those who were initially intubated (24/83, 28.9% vs 43/87, 49.4%; p = 0.006. Septic shock was an independent risk factor for failure of NIV. Conclusions Severe hypoxemia and higher BMI on admission were associated with adverse outcomes for pregnant women. Preterm delivery was a risk factor for neonatal death among pregnant women with pH1N1 influenza infection. NIV may be useful in selected pregnant women without septic shock.

Morbid obesity as a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1 disease.

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Oliver W Morgan

Full Text Available BACKGROUND: Severe illness due to 2009 pandemic A(H1N1 infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1, independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP to increase the risk of influenza-related complications. METHODOLOGY/PRINCIPAL FINDINGS: We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1 influenza occurring between April-July, 2009, with a cohort of the U.S. population estimated from the 2003-2006 National Health and Nutrition Examination Survey (NHANES; pregnant women and children or=20 year olds, hospitalization was associated with being morbidly obese (BMI>or=40 for individuals with ACIP-recognized chronic conditions (OR = 4.9, 95% CI 2.4-9.9 and without ACIP-recognized chronic conditions (OR = 4.7, 95%CI 1.3-17.2. Among 2-19 year olds, hospitalization was associated with being underweight (BMIor=20 years without ACIP-recognized chronic medical conditions death was associated with obesity (OR = 3.1, 95%CI: 1.5-6.6 and morbid obesity (OR = 7.6, 95%CI 2.1-27.9. CONCLUSIONS/SIGNIFICANCE: Our findings support observations that morbid obesity may be associated with hospitalization and possibly death due to 2009 pandemic H1N1 infection. These complications could be prevented by early antiviral therapy and vaccination.

Adoption of Preventive Measures and Attitudes toward the H1N1 Influenza Pandemic in Schools

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Pérez, Anna; Rodríguez, Tània; López, Maria José; Continente, Xavier; Nebot, Manel

2016-01-01

Background: This study describes the perceived impact of H1N1 influenza and the adoption of the recommended measures to address the pandemic in schools. Methods: A cross-sectional self-reported survey was conducted in 433 schools in Barcelona addressed to the school principal or the H1N1 influenza designated person. A descriptive analysis was…

Outbreak of H3N2 influenza at a US military base in Djibouti during the H1N1 pandemic of 2009.

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Michael T Cosby

Full Text Available BACKGROUND: Influenza pandemics have significant operational impact on deployed military personnel working in areas throughout the world. The US Department of Defense global influenza-like illness (ILI surveillance network serves an important role in establishing baseline trends and can be leveraged to respond to outbreaks of respiratory illness. OBJECTIVE: We identified and characterized an operationally unique outbreak of H3N2 influenza at Camp Lemonnier, Djibouti occurring simultaneously with the H1N1 pandemic of 2009 [A(H1N1pdm09]. METHODS: Enhanced surveillance for ILI was conducted at Camp Lemonnier in response to local reports of a possible outbreak during the A(H1N1pdm09 pandemic. Samples were collected from consenting patients presenting with ILI (utilizing a modified case definition and who completed a case report form. Samples were cultured and analyzed using standard real-time reverse transcriptase PCR (rt-RT-PCR methodology and sequenced genetic material was phylogenetically compared to other published strains. RESULTS: rt-RT-PCR and DNA sequencing revealed that 25 (78% of the 32 clinical samples collected were seasonal H3N2 and only 2 (6% were A(H1N1pdm09 influenza. The highest incidence of H3N2 occurred during the month of May and 80% of these were active duty military personnel. Phylogenetic analysis revealed that sequenced H3N2 strains were genetically similar to 2009 strains from the United States of America, Australia, and South east Asia. CONCLUSIONS: This outbreak highlights challenges in the investigation of influenza among deployed military populations and corroborates the public health importance of maintaining surveillance systems for ILI that can be enhanced locally when needed.

Specific Inhibitory Effect of κ-Carrageenan Polysaccharide on Swine Pandemic 2009 H1N1 Influenza Virus.

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Qiang Shao

Full Text Available The 2009 influenza A H1N1 pandemic placed unprecedented demands on antiviral drug resources and the vaccine industry. Carrageenan, an extractive of red algae, has been proven to inhibit infection and multiplication of various enveloped viruses. The aim of this study was to examine the ability of κ-carrageenan to inhibit swine pandemic 2009 H1N1 influenza virus to gain an understanding of antiviral ability of κ-carrageenan. It was here demonstrated that κ-carrageenan had no cytotoxicity at concentrations below 1000 μg/ml. Hemagglutination, 50% tissue culture infectious dose (TCID50 and cytopathic effect (CPE inhibition assays showed that κ-carrageenan inhibited A/Swine/Shandong/731/2009 H1N1 (SW731 and A/California/04/2009 H1N1 (CA04 replication in a dose-dependent fashion. Mechanism studies show that the inhibition of SW731 multiplication and mRNA expression was maximized when κ-carrageenan was added before or during adsorption. The result of Hemagglutination inhibition assay indicate that κ-carrageenan specifically targeted HA of SW731 and CA04, both of which are pandemic H1N/2009 viruses, without effect on A/Pureto Rico/8/34 H1N1 (PR8, A/WSN/1933 H1N1 (WSN, A/Swine/Beijing/26/2008 H1N1 (SW26, A/Chicken/Shandong/LY/2008 H9N2 (LY08, and A/Chicken/Shandong/ZB/2007 H9N2 (ZB07 viruses. Immunofluorescence assay and Western blot showed that κ-carrageenan also inhibited SW731 protein expression after its internalization into cells. These results suggest that κ-carrageenan can significantly inhibit SW731 replication by interfering with a few replication steps in the SW731 life cycles, including adsorption, transcription, and viral protein expression, especially interactions between HA and cells. In this way, κ-carrageenan might be a suitable alternative approach to therapy meant to address anti-IAV, which contains an HA homologous to that of SW731.

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...

Lessons from pandemic influenza A(H1N1): the research-based vaccine industry's perspective.

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Abelin, Atika; Colegate, Tony; Gardner, Stephen; Hehme, Norbert; Palache, Abraham

2011-02-01

As A(H1N1) influenza enters the post-pandemic phase, health authorities around the world are reviewing the response to the pandemic. To ensure this process enhances future preparations, it is essential that perspectives are included from all relevant stakeholders, including vaccine manufacturers. This paper outlines the contribution of R&D-based influenza vaccine producers to the pandemic response, and explores lessons that can be learned to improve future preparedness. The emergence of 2009 A(H1N1) influenza led to unprecedented collaboration between global health authorities, scientists and manufacturers, resulting in the most comprehensive pandemic response ever undertaken, with a number of vaccines approved for use three months after the pandemic declaration. This response was only possible because of the extensive preparations undertaken during the last decade. During this period, manufacturers greatly increased influenza vaccine production capacity, and estimates suggest a further doubling of capacity by 2014. Producers also introduced cell-culture technology, while adjuvant and whole virion technologies significantly reduced pandemic vaccine antigen content. This substantially increased pandemic vaccine production capacity, which in July 2009 WHO estimated reached 4.9 billion doses per annum. Manufacturers also worked with health authorities to establish risk management plans for robust vaccine surveillance during the pandemic. Individual producers pledged significant donations of vaccine doses and tiered-pricing approaches for developing country supply. Based on the pandemic experience, a number of improvements would strengthen future preparedness. Technical improvements to rapidly select optimal vaccine viruses, and processes to speed up vaccine standardization, could accelerate and extend vaccine availability. Establishing vaccine supply agreements beforehand would avoid the need for complex discussions during a period of intense time pressure. Enhancing

The impact of the pandemic influenza A(H1N1) 2009 virus on seasonal influenza A viruses in the southern hemisphere, 2009.

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Blyth, C C; Kelso, A; McPhie, K A; Ratnamohan, V M; Catton, M; Druce, J D; Smith, D W; Williams, S H; Huang, Q S; Lopez, L; Schoub, B D; Venter, M; Dwyer, D E

2010-08-05

Data collected over winter 2009 by five World Health Organisation National Influenza Centres in the southern hemisphere were used to examine the circulation of pandemic and seasonal influenza A strains during the first pandemic wave in the southern hemisphere.There is compelling evidence that the pandemic influenza A(H1N1) 2009 virus significantly displaced seasonal influenza A(H1N1) and, to a lesser extent, A(H3N2) viruses circulating in the southern hemisphere. Complete replacement of seasonal influenza A strains, however, was not observed during the first pandemic wave.

Framing risk: communication messages in the Australian and Swedish print media surrounding the 2009 H1N1 pandemic.

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Sandell, Tiffany; Sebar, Bernadette; Harris, Neil

2013-12-01

Australia and Sweden have similar immunisation rates. However, during the 2009 H1N1 pandemic the uptake of immunisation was 60% in Sweden and 18% in Australia. During pandemics, perceptions of risk are largely formed by media communication which may influence the public's response. The study aimed to compare the differences in how the media framed the 2009 H1N1 pandemic message and the associated public perceptions of risk as expressed through the uptake of vaccinations in Australia and Sweden. A qualitative content analysis was conducted on 81 articles from the Australian and Swedish print media: 45 and 36, respectively. The risk of H1N1 was communicated similarly in Australia and Sweden. However, major differences were found in how the Australian and Swedish media framed the pandemic in terms of responsibility, self-efficacy, and uncertainty. In Australia, responsibility was predominantly reported negatively, blaming various organisations for a lack of information, compared to Sweden where responsibility was placed on the community to help protect public health. Furthermore, there was limited self-efficacy measures reported in the Australian media compared to Sweden and Sweden's media was more transparent about the uncertainties of the pandemic. This study affirms the association between the framing of health messages in the media and the public's perception of risk and related behaviour. Governments need to actively incorporate the media into pandemic communication planning.

Whole genome characterization of human influenza A(H1N1)pdm09 viruses isolated from Kenya during the 2009 pandemic.

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Gachara, George; Symekher, Samuel; Otieno, Michael; Magana, Japheth; Opot, Benjamin; Bulimo, Wallace

2016-06-01

An influenza pandemic caused by a novel influenza virus A(H1N1)pdm09 spread worldwide in 2009 and is estimated to have caused between 151,700 and 575,400 deaths globally. While whole genome data on new virus enables a deeper insight in the pathogenesis, epidemiology, and drug sensitivities of the circulating viruses, there are relatively limited complete genetic sequences available for this virus from African countries. We describe herein the full genome analysis of influenza A(H1N1)pdm09 viruses isolated in Kenya between June 2009 and August 2010. A total of 40 influenza A(H1N1)pdm09 viruses isolated during the pandemic were selected. The segments from each isolate were amplified and directly sequenced. The resulting sequences of individual gene segments were concatenated and used for subsequent analysis. These were used to infer phylogenetic relationships and also to reconstruct the time of most recent ancestor, time of introduction into the country, rates of substitution and to estimate a time-resolved phylogeny. The Kenyan complete genome sequences clustered with globally distributed clade 2 and clade 7 sequences but local clade 2 viruses did not circulate beyond the introductory foci while clade 7 viruses disseminated country wide. The time of the most recent common ancestor was estimated between April and June 2009, and distinct clusters circulated during the pandemic. The complete genome had an estimated rate of nucleotide substitution of 4.9×10(-3) substitutions/site/year and greater diversity in surface expressed proteins was observed. We show that two clades of influenza A(H1N1)pdm09 virus were introduced into Kenya from the UK and the pandemic was sustained as a result of importations. Several closely related but distinct clusters co-circulated locally during the peak pandemic phase but only one cluster dominated in the late phase of the pandemic suggesting that it possessed greater adaptability. Copyright © 2016 Elsevier B.V. All rights reserved.

Transmission dynamics of pandemic influenza A(H1N1)pdm09 virus in humans and swine in backyard farms in Tumbes, Peru.

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Tinoco, Yeny O; Montgomery, Joel M; Kasper, Mathew R; Nelson, Martha I; Razuri, Hugo; Guezala, Maria C; Azziz-Baumgartner, Eduardo; Widdowson, Marc-Alain; Barnes, John; Gilman, Robert H; Bausch, Daniel G; Gonzalez, Armando E

2016-01-01

We aimed to determine the frequency of pH1N1 transmission between humans and swine on backyard farms in Tumbes, Peru. Two-year serial cross-sectional study comprising four sampling periods: March 2009 (pre-pandemic), October 2009 (peak of the pandemic in Peru), April 2010 (1st post-pandemic period), and October 2011 (2nd post-pandemic period). Backyard swine serum, tracheal swabs, and lung sample were collected during each sampling period. We assessed current and past pH1N1 infection in swine through serological testing, virus culture, and RT-PCR and compared the results with human incidence data from a population-based active surveillance cohort study in Peru. Among 1303 swine sampled, the antibody prevalence to pH1N1 was 0% pre-pandemic, 8% at the peak of the human pandemic (October 2009), and 24% in April 2010 and 1% in October 2011 (post-pandemic sampling periods). Trends in swine seropositivity paralleled those seen in humans in Tumbes. The pH1N1 virus was isolated from three pigs during the peak of the pandemic. Phylogenetic analysis revealed that these viruses likely represent two separate human-to-swine transmission events in backyard farm settings. Our findings suggest that human-to-swine pH1N1 transmission occurred during the pandemic among backyard farms in Peru, emphasizing the importance of interspecies transmission in backyard pig populations. Continued surveillance for influenza viruses in backyard farms is warranted. © 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Epidemiology of Travel-associated Pandemic (H1N1) 2009 Infection in 116 Patients, Singapore

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Mukherjee, Pratik; Lim, Poh Lian; Chow, Angela; Barkham, Timothy; Seow, Eillyne; Win, Mar Kyaw; Chua, Arlene; Leo, Yee Sin; Chen, Mark I-Cheng

2010-01-01

In June 2009, during Singapore?s pandemic influenza plan containment phase, pandemic (H1N1) 2009 was introduced into the country through imported cases. To understand how travel patterns affected the initial outbreak, we examined epidemiologic and travel data for the first 116 case-patients admitted to Tan Tock Seng Hospital, Singapore, with travel-associated infection. Sixty-one percent and 54% of patients, respectively, met US Centers for Disease Control and Prevention and World Health Orga...

Immune protection induced on day 10 following administration of the 2009 A/H1N1 pandemic influenza vaccine.

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Yizhuo Sun

Full Text Available BACKGROUND: The 2009 swine-origin influenza virus (S-OIV H1N1 pandemic has caused more than 18,000 deaths worldwide. Vaccines against the 2009 A/H1N1 influenza virus are useful for preventing infection and controlling the pandemic. The kinetics of the immune response following vaccination with the 2009 A/H1N1 influenza vaccine need further investigation. METHODOLOGY/PRINCIPAL FINDINGS: 58 volunteers were vaccinated with a 2009 A/H1N1 pandemic influenza monovalent split-virus vaccine (15 µg, single-dose. The sera were collected before Day 0 (pre-vaccination and on Days 3, 5, 10, 14, 21, 30, 45 and 60 post vaccination. Specific antibody responses induced by the vaccination were analyzed using hemagglutination inhibition (HI assay and enzyme-linked immunosorbent assay (ELISA. After administration of the 2009 A/H1N1 influenza vaccine, specific and protective antibody response with a major subtype of IgG was sufficiently developed as early as Day 10 (seroprotection rate: 93%. This specific antibody response could maintain for at least 60 days without significant reduction. Antibody response induced by the 2009 A/H1N1 influenza vaccine could not render protection against seasonal H1N1 influenza (seroconversion rate: 3% on Day 21. However, volunteers with higher pre-existing seasonal influenza antibody levels (pre-vaccination HI titer ≥1∶40, Group 1 more easily developed a strong antibody protection effect against the 2009 A/H1N1 influenza vaccine as compared with those showing lower pre-existing seasonal influenza antibody levels (pre-vaccination HI titer <1∶40, Group 2. The titer of the specific antibody against the 2009 A/H1N1 influenza was much higher in Group 1 (geometric mean titer: 146 on Day 21 than that in Group 2 (geometric mean titer: 70 on Day 21. CONCLUSIONS/SIGNIFICANCE: Recipients could gain sufficient protection as early as 10 days after vaccine administration. The protection could last at least 60 days. Individuals with a

Whole Genome Characterization, Phylogenetic and Genome Signature Analysis of Human Pandemic H1N1 Virus in Thailand, 2009–2012

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Makkoch, Jarika; Suwannakarn, Kamol; Payungporn, Sunchai; Prachayangprecha, Slinporn; Cheiocharnsin, Thaweesak; Linsuwanon, Piyada; Theamboonlers, Apiradee; Poovorawan, Yong

2012-01-01

Background Three waves of human pandemic influenza occurred in Thailand in 2009–2012. The genome signature features and evolution of pH1N1 need to be characterized to elucidate the aspects responsible for the multiple waves of pandemic. Methodology/Findings Forty whole genome sequences and 584 partial sequences of pH1N1 circulating in Thailand, divided into 1st, 2nd and 3rd wave and post-pandemic were characterized and 77 genome signatures were analyzed. Phylogenetic trees of concatenated whole genome and HA gene sequences were constructed calculating substitution rate and dN/dS of each gene. Phylogenetic analysis showed a distinct pattern of pH1N1 circulation in Thailand, with the first two isolates from May, 2009 belonging to clade 5 while clades 5, 6 and 7 co-circulated during the first wave of pH1N1 pandemic in Thailand. Clade 8 predominated during the second wave and different proportions of the pH1N1 viruses circulating during the third wave and post pandemic period belonged to clades 8, 11.1 and 11.2. The mutation analysis of pH1N1 revealed many adaptive mutations which have become the signature of each clade and may be responsible for the multiple pandemic waves in Thailand, especially with regard to clades 11.1 and 11.2 as evidenced with V731I, G154D of PB1 gene, PA I330V, HA A214T S160G and S202T. The substitution rate of pH1N1 in Thailand ranged from 2.53×10−3±0.02 (M2 genes) to 5.27×10−3±0.03 per site per year (NA gene). Conclusions All results suggested that this virus is still adaptive, maybe to evade the host's immune response and tends to remain in the human host although the dN/dS were under purifying selection in all 8 genes. Due to the gradual evolution of pH1N1 in Thailand, continuous monitoring is essential for evaluation and surveillance to be prepared for and able to control future influenza activities. PMID:23251479

Continued dominance of pandemic A(H1N1 2009 influenza in Victoria, Australia in 2010

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James E. Fielding

2011-08-01

Full Text Available The 2010 Victorian influenza season was characterized by normal seasonal influenza activity and the dominance of the pandemic A(H1N1 2009 strain. General Practice Sentinel Surveillance rates peaked at 9.4 ILI cases per 1000 consultations in week 36 for metropolitan practices, and at 10.5 ILI cases per 1000 in the following week for rural practices. Of the 678 ILI cases, 23% were vaccinated, a significantly higher percentage than in previous years. A significantly higher percentage of ILI patients were swabbed in 2010 compared to 2003–2008, but similar to 2009, with a similar percentage being positive for influenza as in previous years. Vaccination rates increased with patient age. Melbourne Medical Deputising Service rates peaked in week 35 at 19.1 ILI cases per 1000 consultations. Of the 1914 cases of influenza notified to the Department of Health, Victoria, 1812 (95% were influenza A infections - 1001 (55% pandemic A(H1N1 2009, 4 (<1% A(H3N2 and 807 (45% not subtyped; 88 (5% were influenza B; and 14 (< 1% were influenza A and B co-infections. The World Health Organization Collaborating Centre for Reference and Research on Influenza tested 403 isolates of which 261 were positive for influenza, 250 of which were influenza A and 11 were influenza B. Ninety-two per cent of the influenza A viruses were pandemic A(H1N1 2009, and following antigenic analysis all of these were found to be similar to the current vaccine strain. Three viruses (0.9% were found to be oseltamivir resistant due to an H275Y mutation in the neuraminidase gene.

Economic Evaluation of Individual School Closure Strategies: The Hong Kong 2009 H1N1 Pandemic.

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Zoie Shui-Yee Wong

Full Text Available School closures as a means of containing the spread of disease have received considerable attention from the public health community. Although they have been implemented during previous pandemics, the epidemiological and economic effects of the closure of individual schools remain unclear.This study used data from the 2009 H1N1 pandemic in Hong Kong to develop a simulation model of an influenza pandemic with a localised population structure to provide scientific justifications for and economic evaluations of individual-level school closure strategies.The estimated cost of the study's baseline scenario was USD330 million. We found that the individual school closure strategies that involved all types of schools and those that used a lower threshold to trigger school closures had the best performance. The best scenario resulted in an 80% decrease in the number of cases (i.e., prevention of about 830,000 cases, and the cost per case prevented by this intervention was USD1,145; thus, the total cost was USD1.28 billion.This study predicts the effects of individual school closure strategies on the 2009 H1N1 pandemic in Hong Kong. Further research could determine optimal strategies that combine various system-wide and district-wide school closures with individual school triggers across types of schools. The effects of different closure triggers at different phases of a pandemic should also be examined.

Estimation of the burden of pandemic(H1N12009 in developing countries: experience from a tertiary care center in South India.

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Mahesh Moorthy

Full Text Available The burden of the pandemic (H1N1 2009 influenza might be underestimated if detection of the virus is mandated to diagnose infection. Using an alternate approach, we propose that a much higher pandemic burden was experienced in our institution.Consecutive patients (n = 2588 presenting to our hospital with influenza like illness (ILI or severe acute respiratory infection (SARI during a 1-year period (May 2009-April 2010 were prospectively recruited and tested for influenza A by real-time RT-PCR. Analysis of weekly trends showed an 11-fold increase in patients presenting with ILI/SARI during the peak pandemic period when compared with the pre-pandemic period and a significant (P<0.001 increase in SARI admissions during the pandemic period (30 ± 15.9 admissions/week when compared with pre-pandemic (7 ± 2.5 and post-pandemic periods (5 ± 3.8. However, Influenza A was detected in less than one-third of patients with ILI/SARI [699 (27.0%]; a majority of these (557/699, 79.7% were Pandemic (H1N12009 virus [A/H1N1/09]. An A/H1N1/09 positive test was correlated with shorter symptom duration prior to presentation (p = 0.03. More ILI cases tested positive for A/H1N1/09 when compared with SARI (27.4% vs. 14.6%, P = 0.037. When the entire study population was considered, A/H1N1/09 positivity was associated with lower risk of hospitalization (p<0.0001 and ICU admission (p = 0.013 suggesting mild self-limiting illness in a majority.Analysis of weekly trends of ILI/SARI suggest a higher burden of the pandemic attributable to A/H1N1/09 than estimates assessed by a positive PCR test alone. The study highlights methodological consideration in the estimation of burden of pandemic influenza in developing countries using hospital-based data that may help assess the impact of future outbreaks of respiratory illnesses.

A Predictable Unpredictability. The 2009 H1N1 pandemic and the concept of “strategic uncertainty” within global public health

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Theresa MacPhail

2010-12-01

Full Text Available This essay will examine the seemingly new paradigm shift within global public health from the use of a scientific “certainty” to a biological and situational “uncertainty” as one of the foundations of response to infectious disease outbreaks. During the recent 2009 H1N1 influenza outbreak, national and international public health officials often referred directly to the “uncertainty” surrounding both the virus itself and of the course, duration and severity of the pandemic. The vague and flexible concept of “uncertainty” – especially as it was employed by top virologists and epidemiologists in relationship to questions about the predictability of the influenza virus – provided the scientific foundation for much of the rationale behind both national and international health responses to the global pandemic. Public health officials, epidemiologists, and scientists often deployed a type of “strategic uncertainty” as an effective tool for gaining or retaining trust and scientific authority during the H1N1 pandemic.

Pandemic influenza A (H1N1 2009: epidemiological analysis of cases in a tropical/semi-arid region of Brazil

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Roberto da Justa Pires Neto

2013-04-01

Full Text Available Introduction The year 2009 marked the beginning of a pandemic caused by a new variant of influenza A (H1N1. After spreading through North America, the pandemic influenza virus (H1N1 2009 spread rapidly throughout the world. The aim of this study was to describe the clinical and epidemiological characteristics of cases of pandemic influenza in a tropical/semi-arid region of Brazil. Methods A retrospective study analyzed all suspected cases of pandemic influenza (H1N1 2009 reported in the Ceará State through the National Information System for Notifiable Diseases during the pandemic period between 28 April, 2009 and November 25, 2010. Results A total of 616 suspected cases were notified, 58 (9.4% in the containment phase and 558 (90.6% in the mitigation phase. Most cases were of affected young people resident in the City of Fortaleza, the largest urban center in the State of Ceará. The most frequent symptoms presented by the cases with confirmed infection were fever, cough, myalgia, arthralgia, and nasal congestion. Mortality rate was 0.0009/1,000 inhabitants and lethality was 5.6%. Deaths were observed only in the mitigation phase. Mortality rates were similar for both sexes but were higher in the age group under 5 years. Conclusions The study suggests that the influenza A (H1N1 pandemic in this tropical/semi-arid region had a lower magnitude when compared to states in the Southern and Southeastern regions of Brazil.

Determination of preventive behaviors for pandemic influenza A/H1N1 based on protection motivation theory among female high school students in Isfahan, Iran

OpenAIRE

Sharifirad, Gholamreza; Yarmohammadi, Parastoo; Sharifabad, Mohammad Ali Morowati; Rahaei, Zohreh

2014-01-01

Introduction: Influenza A/H1N1 pandemic has recently threatened the health of world's population more than ever. Non-pharmaceutical measures are important to prevent the spread of influenza A/H1N1 and to prevent a pandemic. Effective influenza pandemic management requires understanding of the factors influencing preventive behavioral. This study reports on predictors of students’ preventive behaviors for pandemic influenza A/H1N1 using variables based on the protection motivation theory (PMT)...

A metagenomic analysis of pandemic influenza A (2009 H1N1 infection in patients from North America.

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Alexander L Greninger

2010-10-01

Full Text Available Although metagenomics has been previously employed for pathogen discovery, its cost and complexity have prevented its use as a practical front-line diagnostic for unknown infectious diseases. Here we demonstrate the utility of two metagenomics-based strategies, a pan-viral microarray (Virochip and deep sequencing, for the identification and characterization of 2009 pandemic H1N1 influenza A virus. Using nasopharyngeal swabs collected during the earliest stages of the pandemic in Mexico, Canada, and the United States (n = 17, the Virochip was able to detect a novel virus most closely related to swine influenza viruses without a priori information. Deep sequencing yielded reads corresponding to 2009 H1N1 influenza in each sample (percentage of aligned sequences corresponding to 2009 H1N1 ranging from 0.0011% to 10.9%, with up to 97% coverage of the influenza genome in one sample. Detection of 2009 H1N1 by deep sequencing was possible even at titers near the limits of detection for specific RT-PCR, and the percentage of sequence reads was linearly correlated with virus titer. Deep sequencing also provided insights into the upper respiratory microbiota and host gene expression in response to 2009 H1N1 infection. An unbiased analysis combining sequence data from all 17 outbreak samples revealed that 90% of the 2009 H1N1 genome could be assembled de novo without the use of any reference sequence, including assembly of several near full-length genomic segments. These results indicate that a streamlined metagenomics detection strategy can potentially replace the multiple conventional diagnostic tests required to investigate an outbreak of a novel pathogen, and provide a blueprint for comprehensive diagnosis of unexplained acute illnesses or outbreaks in clinical and public health settings.

Spreading patterns of the influenza A (H1N1 pandemic.

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Sergio de Picoli Junior

Full Text Available We investigate the dynamics of the 2009 influenza A (H1N1/S-OIV pandemic by analyzing data obtained from World Health Organization containing the total number of laboratory-confirmed cases of infections--by country--in a period of 69 days, from 26 April to 3 July, 2009. Specifically, we find evidence of exponential growth in the total number of confirmed cases and linear growth in the number of countries with confirmed cases. We also find that, i at early stages, the cumulative distribution of cases among countries exhibits linear behavior on log-log scale, being well approximated by a power law decay; ii for larger times, the cumulative distribution presents a systematic curvature on log-log scale, indicating a gradual change to lognormal behavior. Finally, we compare these empirical findings with the predictions of a simple stochastic model. Our results could help to select more realistic models of the dynamics of influenza-type pandemics.

Bayesian estimation of the dynamics of pandemic (H1N1) 2009 influenza transmission in Queensland: A space-time SIR-based model.

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Huang, Xiaodong; Clements, Archie C A; Williams, Gail; Mengersen, Kerrie; Tong, Shilu; Hu, Wenbiao

2016-04-01

A pandemic strain of influenza A spread rapidly around the world in 2009, now referred to as pandemic (H1N1) 2009. This study aimed to examine the spatiotemporal variation in the transmission rate of pandemic (H1N1) 2009 associated with changes in local socio-environmental conditions from May 7-December 31, 2009, at a postal area level in Queensland, Australia. We used the data on laboratory-confirmed H1N1 cases to examine the spatiotemporal dynamics of transmission using a flexible Bayesian, space-time, Susceptible-Infected-Recovered (SIR) modelling approach. The model incorporated parameters describing spatiotemporal variation in H1N1 infection and local socio-environmental factors. The weekly transmission rate of pandemic (H1N1) 2009 was negatively associated with the weekly area-mean maximum temperature at a lag of 1 week (LMXT) (posterior mean: -0.341; 95% credible interval (CI): -0.370--0.311) and the socio-economic index for area (SEIFA) (posterior mean: -0.003; 95% CI: -0.004--0.001), and was positively associated with the product of LMXT and the weekly area-mean vapour pressure at a lag of 1 week (LVAP) (posterior mean: 0.008; 95% CI: 0.007-0.009). There was substantial spatiotemporal variation in transmission rate of pandemic (H1N1) 2009 across Queensland over the epidemic period. High random effects of estimated transmission rates were apparent in remote areas and some postal areas with higher proportion of indigenous populations and smaller overall populations. Local SEIFA and local atmospheric conditions were associated with the transmission rate of pandemic (H1N1) 2009. The more populated regions displayed consistent and synchronized epidemics with low average transmission rates. The less populated regions had high average transmission rates with more variations during the H1N1 epidemic period. Copyright © 2016 Elsevier Inc. All rights reserved.

Protection from the 2009 H1N1 pandemic influenza by an antibody from combinatorial survivor-based libraries.

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Arun K Kashyap

2010-07-01

Full Text Available Influenza viruses elude immune responses and antiviral chemotherapeutics through genetic drift and reassortment. As a result, the development of new strategies that attack a highly conserved viral function to prevent and/or treat influenza infection is being pursued. Such novel broadly acting antiviral therapies would be less susceptible to virus escape and provide a long lasting solution to the evolving virus challenge. Here we report the in vitro and in vivo activity of a human monoclonal antibody (A06 against two isolates of the 2009 H1N1 pandemic influenza virus. This antibody, which was obtained from a combinatorial library derived from a survivor of highly pathogenic H5N1 infection, neutralizes H5N1, seasonal H1N1 and 2009 "Swine" H1N1 pandemic influenza in vitro with similar potency and is capable of preventing and treating 2009 H1N1 influenza infection in murine models of disease. These results demonstrate broad activity of the A06 antibody and its utility as an anti-influenza treatment option, even against newly evolved influenza strains to which there is limited immunity in the general population.

Signal Immune Reactions of Macrophages Differentiated from THP-1 Monocytes to Infection with Pandemic H1N1PDM09 Virus and H5N2 and H9N2 Avian Influenza A Virus.

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Sokolova, T M; Poloskov, V V; Shuvalov, A N; Rudneva, I A; Timofeeva, T A

2018-03-01

In culture of THP-1 cells differentiated into macrophages with PMA (THP-PMA macrophages) infected with influenza viruses of subtypes H1, H5 and H9, we measured the expression of TLR7 and RIG1 receptor genes, sensors of viral RNA and ribonucleoprotein, and the levels of production of inflammatory cytokines IL-1β, TNFα, IL-10, and IFNα. The sensitivity and inflammatory response of THP-PMA macrophages to pandemic influenza A virus H1N1pdm09 and avian influenza H5N2 and H9N2 viruses correlate with the intracellular level of their viral RNA and activation of the RIG1 gene. Abortive infection is accompanied by intensive macrophage secretion of TNFα, IL-1β, and toxic factors inducing cell death. Activity of endosomal TLR7 receptor gene changed insignificantly in 24 h after infection and significantly decreased in 48 and 72 h under the action of H5N2 and H9N2, which correlated with manifestation of the cytopathogenic effect of these viruses. H5N2 and H9N2 avian viruses in THP-PMA macrophages are strong activators of the expression of the gene of the cytoplasmic RIG1 receptor 24 and 48 h after infection, and the pandemic virus H1N1pdm09 is a weak stimulator of RIG1 gene. Avian influenza H5N2 and H9N2 viruses are released by rapid induction of the inflammatory response in macrophages. At the late stages of infection, we observed a minor increase in IL-10 secretion in macrophages and, probably, the polarization of a part of the population in type M2. The studied influenza A viruses are weak inductors of IFN in THP-PMA macrophages. In the culture medium of THP-PMA macrophages infected with H9N2 and H5N2 viruses, MTT test revealed high levels of toxic factors causing the death of Caco-2 cells. In contrast to avian viruses, pandemic virus H1N1pdm09 did not induce production of toxic factors.

An analysis of 332 fatalities infected with pandemic 2009 influenza A (H1N1 in Argentina.

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Ana M Balanzat

Full Text Available The apparent high number of deaths in Argentina during the 2009 pandemic led to concern that the influenza A H1N1pdm disease was different there. We report the characteristics and risk factors for influenza A H1N1pdm fatalities.We identified laboratory-confirmed influenza A H1N1pdm fatalities occurring during June-July 2009. Physicians abstracted data on age, sex, time of onset of illness, medical history, clinical presentation at admission, laboratory, treatment, and outcomes using standardize questionnaires. We explored the characteristics of fatalities according to their age and risk group.Of 332 influenza A H1N1pdm fatalities, 226 (68% were among persons aged <50 years. Acute respiratory failure was the leading cause of death. Of all cases, 249 (75% had at least one comorbidity as defined by Advisory Committee on Immunization Practices. Obesity was reported in 32% with data and chronic pulmonary disease in 28%. Among the 40 deaths in children aged <5 years, chronic pulmonary disease (42% and neonatal pathologies (35% were the most common co-morbidities. Twenty (6% fatalities were among pregnant or postpartum women of which only 47% had diagnosed co-morbidities. Only 13% of patients received antiviral treatment within 48 hours of symptom onset. None of children aged <5 years or the pregnant women received antivirals within 48 h of symptom onset. As the pandemic progressed, the time from symptom-onset to medical care and to antiviral treatment decreased significantly among case-patients who subsequently died (p<0.001.Persons with co-morbidities, pregnant and who received antivirals late were over-represented among influenza A H1N1pdm deaths in Argentina, though timeliness of antiviral treatment improved during the pandemic.

School illness absenteeism during 2009 influenza A (H1N1) pandemic--South Dakota, 2009-2010.

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Kightlinger, Lon; Horan, Vickie

2013-05-01

Schools are important amplification settings of influenza virus transmission. We demonstrated correlation of school absenteeism (due to any illness) with other influenza A (H1N1) activity surveillance data during the 2009 pandemic. We collected nonspecific illness student absenteeism data from August 17, 2009 through April 3, 2010 from 187 voluntarily participating South Dakota schools using weekly online surveys. Relative risks (RR) were calculated as the ratio of the probability of absenteeism during elevated weeks versus the probability of absenteeism during the baseline weeks (RR = 1.89). We used Pearson correlation to associate absenteeism with laboratory-confirmed influenza cases, influenza cases diagnosed by rapid tests, influenza-associated hospitalizations and deaths reported in South Dakota during the 2009 H1N1 pandemic period. School-absenteeism data correlated strongly with data from these other influenza surveillance sources.

Evidence of cross-reactive immunity to 2009 pandemic influenza A virus in workers seropositive to swine H1N1 influenza viruses circulating in Italy.

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Maria A De Marco

Full Text Available BACKGROUND: Pigs play a key epidemiologic role in the ecology of influenza A viruses (IAVs emerging from animal hosts and transmitted to humans. Between 2008 and 2010, we investigated the health risk of occupational exposure to swine influenza viruses (SIVs in Italy, during the emergence and spread of the 2009 H1N1 pandemic (H1N1pdm virus. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples from 123 swine workers (SWs and 379 control subjects (Cs, not exposed to pig herds, were tested by haemagglutination inhibition (HI assay against selected SIVs belonging to H1N1 (swH1N1, H1N2 (swH1N2 and H3N2 (swH3N2 subtypes circulating in the study area. Potential cross-reactivity between swine and human IAVs was evaluated by testing sera against recent, pandemic and seasonal, human influenza viruses (H1N1 and H3N2 antigenic subtypes. Samples tested against swH1N1 and H1N1pdm viruses were categorized into sera collected before (n. 84 SWs; n. 234 Cs and after (n. 39 SWs; n. 145 Cs the pandemic peak. HI-antibody titers ≥10 were considered positive. In both pre-pandemic and post-pandemic peak subperiods, SWs showed significantly higher swH1N1 seroprevalences when compared with Cs (52.4% vs. 4.7% and 59% vs. 9.7%, respectively. Comparable HI results were obtained against H1N1pdm antigen (58.3% vs. 7.7% and 59% vs. 31.7%, respectively. No differences were found between HI seroreactivity detected in SWs and Cs against swH1N2 (33.3% vs. 40.4% and swH3N2 (51.2 vs. 55.4% viruses. These findings indicate the occurrence of swH1N1 transmission from pigs to Italian SWs. CONCLUSION/SIGNIFICANCE: A significant increase of H1N1pdm seroprevalences occurred in the post-pandemic peak subperiod in the Cs (p<0.001 whereas SWs showed no differences between the two subperiods, suggesting a possible occurrence of cross-protective immunity related to previous swH1N1 infections. These data underline the importance of risk assessment and occupational health surveillance activities aimed

The Influenza A(H1N1)v Pandemic : An Exploratory System Dynamics Approach

NARCIS (Netherlands)

Pruyt, E.; Hamarat, C.

2010-01-01

This paper presents a small exploratory System Dynamics model related to the dynamics of the 2009 flu pandemic, also known as the Mexican flu, swine flu, or A(H1N1)v. The model was developed in May 2009 in order to quickly foster understanding about the possible dynamics of this new flu variant and

From press release to news: mapping the framing of the 2009 H1N1 A influenza pandemic.

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Lee, Seow Ting; Basnyat, Iccha

2013-01-01

Pandemics challenge conventional assumptions about health promotion, message development, community engagement, and the role of news media. To understand the use of press releases in news coverage of pandemics, this study traces the development of framing devices from a government public health agency's press releases to news stories about the 2009 H1N1 A influenza pandemic. The communication management of the H1N1 pandemic, an international news event with local implications, by the Singapore government is a rich locus for understanding the dynamics of public relations, health communication, and journalism. A content analysis shows that the evolution of information from press release to news is marked by significant changes in media frames, including the expansion and diversification in dominant frames and emotion appeals, stronger thematic framing, more sources of information, conversion of loss frames into gain frames, and amplification of positive tone favoring the public health agency's position. Contrary to previous research that suggests that government information subsidies passed almost unchanged through media gatekeepers, the news coverage of the pandemic reflects journalists' selectivity in disseminating the government press releases and in mediating the information flow and frames from the press releases.

Twitter influence on vaccination and antiviral uptake during the 2009 H1N1 pandemic.

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Andrew eMcNeill

2016-02-01

Full Text Available ObjectiveInformation exchange via Twitter and other forms of social media make public health communication more complex as citizens play an increasingly influential role in shaping acceptable or desired health behaviours. Taking the case of the 2009-10 H1N1 pandemic, we explore in detail the dissemination of H1N1-related advice in the UK through Twitter to see how it was used to discourage or encourage vaccine and antiviral uptake.MethodsIn three stages we conducted (1 an analysis of general content, retweeting patterns and URL sharing, (2 a discourse analysis of the public evaluation of press releases and (3 a template analysis of conversations around vaccine and antiviral uptake, using Protection Motivation Theory (PMT as a way of understanding how the public weighed the costs and benefits.ResultsNetwork analysis of retweets showed that information from official sources predominated. Analysing the spread of significant messages through Twitter showed that most content was descriptive but there was some criticism of health authorities. A detailed analysis of responses to press releases revealed some scepticism over the economic beneficiaries of vaccination, that served to undermine public trust. Finally, the conversational analysis showed the influence of peers when weighing up the risks and benefits of medication.ConclusionsMost tweets linked to reliable sources, however Twitter was used to discuss both individual and health authority motivations to vaccinate. The PMT framework describes the ways individuals assessed the threat of the H1N1 pandemic, weighing this against the perceived cost of taking medication. These findings offer some valuable insights for social media communication practices in future pandemics.

US school morbidity and mortality, mandatory vaccination, institution closure, and interventions implemented during the 2009 influenza A H1N1 pandemic.

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Rebmann, Terri; Elliott, Michael B; Swick, Zachary; Reddick, David

2013-03-01

The 2009 H1N1 pandemic disproportionately affected school-aged children, but only school-based outbreak case studies have been conducted. The purposes of this study were to evaluate US academic institutions' experiences during the 2009 H1N1 pandemic in terms of infection prevention interventions implemented and to examine factors associated with school closure during the pandemic. An online survey was sent to school nurses in May through July 2011. Hierarchical logistic regressions were used to determine predictive models for having a mandatory H1N1 vaccination policy for school nurses and school closure. In all, 1,997 nurses from 26 states participated. Very few nurses (3.3%, n=65) reported having a mandatory H1N1 influenza vaccination policy; nurses were more likely than all other school employees (pnurse employed by a public health agency or hospital, and being a private school. The most commonly implemented interventions included encouraging staff and students to exercise hand hygiene and increasing classroom cleaning; least commonly implemented interventions included discouraging face-to-face meetings, training staff on H1N1 influenza and/or respiratory hygiene, and discouraging handshaking. Schools should develop and continue to improve their pandemic plans, including collaborating with community response agencies.

Oseltamivir-resistant pandemic (H1N12009 in Yemen - case report

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Al-Kohlani Abdulhakeem

2010-05-01

Full Text Available Abstract Background During the influenza season of 2007-08, oseltamivir-resistant influenza A (H1N1 viruses emerged in several countries in Europe, North America, and Asia. Despite substantial prevalence of oseltamivir-resistant viruses, few data are available on the clinical profile of subjects infected with these viruses. Objectives: to describe the first oseltamivir-resistant (H1N1 influenza virus pandemic 2009 from the Eastern Mediterranean Region including Yemen and to determine the evidence by clinical presentation of children infected with these oseltamivir - resistant viruses. Methodology History, physical examination and laboratory investigations including Complete Blood Count, chest x-ray, blood cultures, CSF examination, LFTs, RFTs, blood for sugar, H1N1 test and oseltamivir resistance test. Results Nasal swabs indicated positivity on both H1N1 test and the RNP gene (Human R Nase P gene that serves as internal positive control for Human RNA. Both clinical specimens presented the mutation S31N in the M2 gene associated with resistance to adamantanes and H274Y in NA gene associated with resistance to oseltamivir. This was the first diagnosed case of resistance to oseltamivir in Yemen and also it is the first reported case of oseltamivir resistance virus in the Eastern Mediterranean Region. Conclusion The pattern of resistance found in the oseltamivir resistant isolate collected from Yemen is the same as has been reported elsewhere in other WHO regions. Clinical description and outcomes are not different from what is described elsewhere.

Seasonal Influenza A H1N1pdm09 Virus and Severe Outcomes: A Reason for Broader Vaccination in Non-Elderly, At-Risk People.

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Elisa Minchole

Full Text Available Recent pandemics of influenza A H1N1pdm09 virus have caused severe illness, especially in young people. Very few studies on influenza A H1N1pdm09 in post-pandemic periods exist, and there is no information on the severity of both seasonal influenza A(H1N1 and A(H3N2 from the same season, adjusting for potential confounders, including vaccine.We performed a retrospective observational study of adults hospitalized during the 2014 season with influenza A(H1N1 or A(H3N2. All patients underwent the same diagnostic and therapeutic protocol in a single hospital, including early Oseltamivir therapy. We included 234 patients: 146 (62.4% influenza A(H1N1 and 88 (37.6% A(H3N2. A(H1N1 patients were younger (p<0.01, developed more pneumonia (p<0.01, respiratory complications (p = 0.015, ARDS (p = 0.047, and septic shock (p = 0.049, were more frequently admitted to the ICU (p = 0.022, required IMV (p = 0.049, and were less frequently vaccinated (p = 0.008. After adjusting for age, comorbidities, time from onset of illness, and vaccine status, influenza A(H1N1 (OR, 2.525, coinfection (OR, 2.821, and no vaccination (OR, 3.086 were independent risk factors for severe disease.Hospitalized patients with influenza A(H1N1 were more than twice as likely to have severe influenza. They were younger and most had not received the vaccine. Our findings suggest that seasonal influenza A(H1N1 maintains some features of pandemic viruses, and recommend wider use of vaccination in younger adult high-risk patients.

Pediatric Healthcare Response to Pandemic (H1N1) 2009 Influenza Stakeholder Meeting - Summary of Proceedings

Energy Technology Data Exchange (ETDEWEB)

HCTT CHE

2010-01-01

The goal of the meeting was to bring together subject matter experts to develop tools and resources for use by the pediatric healthcare community in response to 2009 (H1N1) pandemic influenza activity during the 2009 influenza season.

Central nervous system manifestations in pediatric patients with influenza A H1N1 infection during the 2009 pandemic.

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Wilking, Ashley N; Elliott, Elizabeth; Garcia, Melissa N; Murray, Kristy O; Munoz, Flor M

2014-09-01

A novel H1N1 influenza A virus (A(H1N1)pdm09) particularly affected individuals central nervous system complications associated with pandemic influenza in the pediatric population. Retrospective review of patients with laboratory-confirmed influenza A(H1N1)pdm09 infection and central nervous system manifestations at Texas Children's Hospital between April 2009 and June 2010. Among 365 patients with influenza A(H1N1)pdm09, 32 (8.8%) had central nervous system manifestations at a median age of 4 years. Eight (25.0%) were previously healthy, and 12 (37.5%) had neurological pre-existing conditions. Of the 32 cases of influenza with neurological complications, seizure (n = 17; 53.1%) was the most common central nervous system manifestation, followed by encephalitis (n = 4; 12.5%), meningitis (n = 4; 12.5%), encephalopathy (n = 3; 9.4%), meningismus (n = 3; 9.4%), focal hemorrhagic brain lesions (n = 2; 6.3%), brain infarction (n = 1; 3.1%), and sensorineural hearing loss (n = 1; 3.1%). Two patients demonstrated two or more types of central nervous system complications. One patient had abnormal cerebrospinal fluid with pleocytosis. Almost two thirds of the children with central nervous system manifestations required intensive care unit admission and nearly half required mechanical ventilation. There were no deaths. Patients with pre-existing neurological conditions were at greater risk for central nervous system manifestations during pandemic influenza infection. Patients with central nervous system manifestations were more likely to experience severe illness, characterized by intensive care unit admission and mechanical ventilation, although overall outcomes were good. Influenza prevention in patients with underlying medical conditions, particularly those with neurological conditions, is important. Copyright © 2014 Elsevier Inc. All rights reserved.

Transmisibilidad y gravedad de la pandemia de gripe A(H1N12009 en España Transmissibility and severity of the pandemic influenza A (H1N1 2009 virus in Spain

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Lorena Simón Méndez

2011-08-01

veces el promedio anual ajustado de las temporadas interpandémicas de comparación (1.802. Conclusiones: Los valores estimados de R0 durante la fase de crecimiento de la onda pandémica se encuentran en el rango inferior de estimaciones de ese parámetro en pandemias anteriores. Los indicadores de mortalidad calculados en el periodo pandémico señalan un aumento de las defunciones, en comparación con temporadas interpándemicas previas, más acusado en edades jóvenes.Objectives: To estimate the value of the basic reproduction number for the pandemic wave of influenza A (H1N1 2009 in Spain and to assess its impact on morbidity and mortality in the Spanish population compared with those in the previous influenza season. Methods: Data on the incidence of influenza and viral detections were obtained from the Spanish Influenza Surveillance System. Deaths from pandemic influenza were obtained from the Coordinating Center for Health Alerts and Emergencies of the Spanish Ministry of Health and Social Policy, and deaths from seasonal influenza during the period 2003-2008 were obtained from the National Statistics Institute. The reproduction number was estimated by two methods: firstly, by using the growth rate of the cumulative incidence of influenza during the exponential growth phase of the pandemic wave, and secondly (maximum likelihood estimation, through analysis the dates of onset of symptoms observed in pairs of cases based on generation time distribution. We calculated the fatality rate and mortality from influenza by comparing potential years of life lost in the pandemic season with those in previous interpandemic seasons. Results: The start of the pandemic wave occurred in Spain earlier in week 40/2009 (from 4 to 10 October, with an absolute predominance of the new strain in the pattern of circulating viruses. The value of R0 in the growth phase of the wave was 1.29 (95% CI: 1.25-1.33, estimated with the first method, and was 1.01 (95% CI: 0.99-1.03 with the second

Transmission characteristics of the 2009 H1N1 influenza pandemic: comparison of 8 Southern hemisphere countries.

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Lulla Opatowski

2011-09-01

Full Text Available While in Northern hemisphere countries, the pandemic H1N1 virus (H1N1pdm was introduced outside of the typical influenza season, Southern hemisphere countries experienced a single wave of transmission during their 2009 winter season. This provides a unique opportunity to compare the spread of a single virus in different countries and study the factors influencing its transmission. Here, we estimate and compare transmission characteristics of H1N1pdm for eight Southern hemisphere countries/states: Argentina, Australia, Bolivia, Brazil, Chile, New Zealand, South Africa and Victoria (Australia. Weekly incidence of cases and age-distribution of cumulative cases were extracted from public reports of countries' surveillance systems. Estimates of the reproduction numbers, R(0, empirically derived from the country-epidemics' early exponential phase, were positively associated with the proportion of children in the populations (p = 0.004. To explore the role of demography in explaining differences in transmission intensity, we then fitted a dynamic age-structured model of influenza transmission to available incidence data for each country independently, and for all the countries simultaneously. Posterior median estimates of R₀ ranged 1.2-1.8 for the country-specific fits, and 1.29-1.47 for the global fits. Corresponding estimates for overall attack-rate were in the range 20-50%. All model fits indicated a significant decrease in susceptibility to infection with age. These results confirm the transmissibility of the 2009 H1N1 pandemic virus was relatively low compared with past pandemics. The pattern of age-dependent susceptibility found confirms that older populations had substantial--though partial--pre-existing immunity, presumably due to exposure to heterologous influenza strains. Our analysis indicates that between-country-differences in transmission were at least partly due to differences in population demography.

In vitro reassortment between endemic H1N2 and 2009 H1N1 pandemic swine influenza viruses generates attenuated viruses.

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Ben M Hause

Full Text Available The pandemic H1N1 (pH1N1 influenza virus was first reported in humans in the spring of 2009 and soon thereafter was identified in numerous species, including swine. Reassortant viruses, presumably arising from the co-infection of pH1N1 and endemic swine influenza virus (SIV, were subsequently identified from diagnostic samples collected from swine. In this study, co-infection of swine testicle (ST cells with swine-derived endemic H1N2 (MN745 and pH1N1 (MN432 yielded two reassortant H1N2 viruses (R1 and R2, both possessing a matrix gene derived from pH1N1. In ST cells, the reassortant viruses had growth kinetics similar to the parental H1N2 virus and reached titers approximately 2 log(10 TCID(50/mL higher than the pH1N1 virus, while in A549 cells these viruses had similar growth kinetics. Intranasal challenge of pigs with H1N2, pH1N1, R1 or R2 found that all viruses were capable of infecting and transmitting between direct contact pigs as measured by real time reverse transcription PCR of nasal swabs. Lung samples were also PCR-positive for all challenge groups and influenza-associated microscopic lesions were detected by histology. Interestingly, infectious virus was detected in lung samples for pigs challenged with the parental H1N2 and pH1N1 at levels significantly higher than either reassortant virus despite similar levels of viral RNA. Results of our experiment suggested that the reassortant viruses generated through in vitro cell culture system were attenuated without gaining any selective growth advantage in pigs over the parental lineages. Thus, reassortant influenza viruses described in this study may provide a good system to study genetic basis of the attenuation and its mechanism.

Mutation analysis of 2009 pandemic influenza A(H1N1 viruses collected in Japan during the peak phase of the pandemic.

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Jean-Étienne Morlighem

Full Text Available BACKGROUND: Pandemic influenza A(H1N1 virus infection quickly circulated worldwide in 2009. In Japan, the first case was reported in May 2009, one month after its outbreak in Mexico. Thereafter, A(H1N1 infection spread widely throughout the country. It is of great importance to profile and understand the situation regarding viral mutations and their circulation in Japan to accumulate a knowledge base and to prepare clinical response platforms before a second pandemic (pdm wave emerges. METHODOLOGY: A total of 253 swab samples were collected from patients with influenza-like illness in the Osaka, Tokyo, and Chiba areas both in May 2009 and between October 2009 and January 2010. We analyzed partial sequences of the hemagglutinin (HA and neuraminidase (NA genes of the 2009 pdm influenza virus in the collected clinical samples. By phylogenetic analysis, we identified major variants of the 2009 pdm influenza virus and critical mutations associated with severe cases, including drug-resistance mutations. RESULTS AND CONCLUSIONS: Our sequence analysis has revealed that both HA-S220T and NA-N248D are major non-synonymous mutations that clearly discriminate the 2009 pdm influenza viruses identified in the very early phase (May 2009 from those found in the peak phase (October 2009 to January 2010 in Japan. By phylogenetic analysis, we found 14 micro-clades within the viruses collected during the peak phase. Among them, 12 were new micro-clades, while two were previously reported. Oseltamivir resistance-related mutations, i.e., NA-H275Y and NA-N295S, were also detected in sporadic cases in Osaka and Tokyo.

Molecular characterization of pandemic H1N1 influenza viruses isolated from turkeys and pathogenicity of a human pH1N1 isolate in turkeys.

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Berhane, Yohannes; Ojkic, Davor; Neufeld, James; Leith, Marsha; Hisanaga, Tamiko; Kehler, Helen; Ferencz, Arpad; Wojcinski, Helen; Cottam-Birt, Colleen; Suderman, Matthew; Handel, Katherine; Alexandersen, Soren; Pasick, John

2010-12-01

Suspected human-to-animal transmission of the 2009 pandemic H1N1 (pH1N1) virus has been reported in several animal species, including pigs, dogs, cats, ferrets, and turkeys. In this study we describe the genetic characterization of pH1N1 viruses isolated from breeder turkeys that was associated with a progressive drop in egg production. Sequence analysis of all eight gene segments from three viruses isolated from this outbreak demonstrated homology with other human and swine pH1N1 isolates. The susceptibility of turkeys to a human pH1N1 isolate was further evaluated experimentally. The 50% turkey infectious dose (TID50) for the human isolate A/Mexico/LnDRE/4487/2009 was determined by inoculating groups of 8-10-week-old turkeys with serial 10-fold dilutions of virus by oronasal and cloacal routes. We estimated the TID50 to be between 1 x 10(5) and 1 x 10(6) TCID50. The pathogenesis of pH1N1 in oronasally or cloacally inoculated juvenile turkeys was also examined. None of the turkeys exhibited clinical signs, and no significant difference in virus shedding or seroconversion was observed between the two inoculation groups. More than 50% of the turkeys in both oronasal and cloacal groups shed virus beginning at 2 days postinoculation (dpi). All birds that actively shed virus seroconverted by 14 dpi. Virus antigen was demonstrated by immunohistochemistry in the cecal tonsils and bursa of Fabricius in two of the birds that were infected by the cloacal route. Virus transmission to naive contact turkeys was at best doubtful. This report provides additional evidence that pH1N1 can cross the species barrier and cause disease outbreaks in domestic turkeys. However, it appears that the reproductive status of the host as well as environmental factors such as concurrent infections, stress, the presence or absence of litter, and stocking density may also contribute to efficient infection and transmission of this agent.

Determination of preventive behaviors for pandemic influenza A/H1N1 based on protection motivation theory among female high school students in Isfahan, Iran.

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Sharifirad, Gholamreza; Yarmohammadi, Parastoo; Sharifabad, Mohammad Ali Morowati; Rahaei, Zohreh

2014-01-01

Influenza A/H1N1 pandemic has recently threatened the health of world's population more than ever. Non-pharmaceutical measures are important to prevent the spread of influenza A/H1N1 and to prevent a pandemic. Effective influenza pandemic management requires understanding of the factors influencing preventive behavioral. This study reports on predictors of students' preventive behaviors for pandemic influenza A/H1N1 using variables based on the protection motivation theory (PMT). In a cross-sectional study, multiple-stage randomized sampling was used to select 300 female students in Isfahan who completed a questionnaire in December 2009. Data were collected using a self-report questionnaire based on PMT. The statistical analysis of the data included bivariate correlations, Mann-Whitney, Kruskal-Wallis, and linear regression. The mean age of participants was 15.62 (SE = 1.1) years old. Majority of participants were aware regarding pandemic influenza A/H1N1 (87.3%, 262 out of 300). Results showed that, protection motivation was highly significant relationship with preventive behavior and predicted 34% of its variance. We found all of the variables with the exception of perceived susceptibility, perceived severity, and response cost were related with protection motivation and explained 22% of its variance. Promotion of students' self-efficacy, and intention to protect themselves from a health threat should be priorities of any programs aimed at promoting preventive behaviors among students. It is also concluded that the protection motivation theory may be used in developing countries, like Iran, as a framework for prevention interventions in an attempt to improve the preventive behaviors of students.

Determinants of non-vaccination against pandemic 2009 H1N1 influenza in pregnant women: a prospective cohort study.

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Romain Freund

Full Text Available BACKGROUND: In October 2009, the French government organized a national-wide, free of charge vaccination campaign against pandemic H1N1 influenza virus, especially targeting pregnant women, a high risk group for severe illness. The study objective was to evaluate pandemic flu vaccine uptake and factors associated with non-vaccination in a population of pregnant women. METHODOLOGY/PRINCIPAL FINDINGS: In a prospective cohort conducted in 3 maternity hospitals in Paris, 882 pregnant women were randomly included between October 12, 2009 and February 3, 2010, with the aim to study characteristics of pandemic influenza during pregnancy. At inclusion, socio-demographic, medical, obstetrical factors and those associated with a higher risk of flu exposition and disease-spreading were systematically collected. Pandemic flu vaccine uptake was checked until delivery. 555 (62.9% women did not get vaccinated. Determinants associated with non-vaccination in a multivariate logistic regression were: geographic origin (Sub-Saharan African origin, adjusted Odd Ratio aOR = 5.4[2.3-12.7], North African origin, aOR = 2.5[1.3-4.7] and Asian origin, aOR = 2.1[1.7-2.6] compared to French and European origin and socio-professional categories (farmers, craftsmen and tradesmen, aOR = 2.3[2.0-2.6], intermediate professionals, aOR = 1.3[1.0-1.6], employees and manual workers, aOR = 2.5[1.4-4.4] compared to managers and intellectual professionals. The probability of not receiving pandemic flu vaccine was lower among women vaccinated against seasonal flu in the previous 5 years (aOR = 0.6[0.4-0.8] and among those who stopped smoking before or early during pregnancy (aOR = 0.6[0.4-0.8]. Number of children less than 18 years old living at home, work in contact with children or in healthcare area, or professional contact with the public, were not associated with a higher vaccine uptake. CONCLUSIONS/SIGNIFICANCE: In this cohort of pregnant women, vaccine coverage against pandemic

The H1N1 influenza pandemic: need for solutions to ethical problems.

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Bhatia, Prateek

2013-01-01

The rapid spread of the novel influenza virus of H1N1 swine origin led to widespread fear, panic and unrest among the public and healthcare personnel. The pandemic not only tested the world's health preparedness, but also brought up new ethical issues which need to be addressed as soon as possible. This article highlights these issues and suggests ethical answers to the same. The main areas that require attention are the distribution of scarce resources, prioritisation of antiviral drugs and vaccines, obligations of healthcare workers, and adequate dissemination and proper communication of information related to the pandemic. It is of great importance to plan in advance how to confront these issues in an ethical manner. This is possible only if a comprehensive contingency plan is prepared with the involvement of and in consultation with all the stakeholders concerned.

Did pandemic preparedness aid the response to pandemic (H1N1) 2009? A qualitative analysis in seven countries within the WHO European Region.

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Hashim, Ahmed; Jean-Gilles, Lucie; Hegermann-Lindencrone, Michala; Shaw, Ian; Brown, Caroline; Nguyen-Van-Tam, Jonathan

2012-08-01

Although the 2009-2010 influenza A (H1N1) pandemic was of low severity compared with other pandemics of the 20th century, this pandemic was the first opportunity for countries to implement a real-life pandemic response. The aim of the project was to review the extent to which these plans and planning activities proved useful and to identify areas of pandemic planning that require further strengthening. We randomly selected seven countries within the WHO European Region to participate in a comprehensive, qualitative study to evaluate the pandemic preparedness activities undertaken prior to March 2009 compared with the subsequent pandemic responses mounted from May 2009 onwards. Research teams visited each country and interviewed stakeholders from health and civil response ministries, national public health authorities, regional authorities and family and hospital doctors. The following six consistent themes were identified as essential elements of successful pandemic preparedness activities: communication, coordination, capacity building, adaptability/flexibility, leadership and mutual support. Regarding future pandemic preparedness activities, an emphasis on these areas should be retained and planning for the following activities should be improved: communication (i.e., with the public and health professionals); coordination of vaccine procurement and logistics; flexibility of response and hospital surveillance. Pandemic preparedness activities were successfully undertaken in the WHO European Region prior to the 2009 pandemic. These activities proved to be effective and were generally appropriate for the response provided in 2009. Nevertheless, consistent themes also emerged regarding specific areas of under planning that were common to most of the surveyed countries. Copyright © 2012 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

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Hu, Weibin [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Chen, Aizhong [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Miao, Yi [Shanghai Xuhui Central Hospital, Shanghai 200031 (China); Xia, Shengli [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Ling, Zhiyang; Xu, Ke; Wang, Tongyan [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Shu, Yuelong [Chinese Center for Disease Control and Prevention, Beijing 102206 (China); Ma, Xiaowei [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Xu, Bianli; Zhang, Jin [Center for Disease Control and Prevention of Henan Province, Zhengzhou 450016 (China); Lin, Xiaojun, E-mail: linxiaojun@hualan.com [Hualan Biological Bacterin Company, Xinxiang 453003 (China); Bian, Chao, E-mail: cbian@sibs.ac.cn [Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China); Sun, Bing, E-mail: bsun@sibs.ac.cn [Molecular Virus Unit, Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Key Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

2013-01-20

Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient

International Nuclear Information System (INIS)

Hu, Weibin; Chen, Aizhong; Miao, Yi; Xia, Shengli; Ling, Zhiyang; Xu, Ke; Wang, Tongyan; Xu, Ying; Cui, Jun; Wu, Hongqiang; Hu, Guiyu; Tian, Lin; Wang, Lingling; Shu, Yuelong; Ma, Xiaowei; Xu, Bianli; Zhang, Jin; Lin, Xiaojun; Bian, Chao; Sun, Bing

2013-01-01

Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

A novel monoclonal antibody effective against lethal challenge with swine-lineage and 2009 pandemic H1N1 influenza viruses in mice

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The HA protein of the 2009 pandemic H1N1viruses (14 H1N1pdm) is antigenically closely related to the HA of classical North American swine H1N1 influenza viruses (cH1N1). Since 1998, through reassortment and incorporation of HA genes from human H3N2 and H1N1 influenza viruses, swine influenza strains...

PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1 Virus Impairs the Human T Cell Response

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Nuriban Valero-Pacheco

2013-01-01

Full Text Available PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1pdm09, and its effects on the T cell response have not been widely explored. We found that A(H1N1pdm09 virus induced PD-L1 expression on human dendritic cells (DCs and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1pdm09 by promoting CD8+ T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+ T cells correlated inversely with T cell proportions in patients infected with A(H1N1pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1pdm09 virus.

A seroepidemiological study of pandemic A/H1N1(2009) influenza in a rural population of Mali.

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Koita, O A; Sangare, L; Poudiougou, B; Aboubacar, B; Samake, Y; Coulibaly, T; Pronyk, P; Salez, N; Kieffer, A; Ninove, L; Flahault, A; de Lamballerie, X

2012-10-01

The swine-origin H1N1 influenza A virus (pH1N1(2009)) started to circulate worldwide in 2009, and cases were notified in a number of sub-Saharan African countries. However, no epidemiological data allowing estimation of the epidemic burden were available in this region, preventing comprehensive comparisons with other parts of the world. The CoPanFlu-Mali programme studied a cohort of 202 individuals living in the rural commune of Dioro (southern central Mali). Pre-pandemic and post-pandemic paired sera (sampled in 2006 and April 2010, respectively) were tested by the haemagglutination inhibition (HI) method. Different estimates of pH1N1(2009) infection during the 2009 first epidemic wave were used (increased prevalence of HI titre of ≥1/40 or ≥1/80, seroconversions) and provided convergent attack rate values (12.4-14.9%), the highest values being observed in the 0-19-year age group (16.0-18.4%). In all age groups, pre-pandemic HI titres of ≥1/40 were associated with complete absence of seroconversion; and geometric mean titres were 20 in others. Important variations in seroconversion rate existed among the different villages investigated. Despite limitations resulting from the size and composition of the sample analysed, this study provides strong evidence that the impact of the pH1N1(2009) first wave was more important than previously believed, and that the determinants of the epidemic spread in sub-Saharan populations were quite different from those observed in developed countries. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Pandemic (H1N1) 2009 virus infection during pregnancy in South India.

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Pramanick, Angsumita; Rathore, Swati; Peter, John V; Moorthy, Mahesh; Lionel, Jessie

2011-04-01

To assess the clinical profile of pregnant/puerperal women from a semi-urban Indian population who were infected with pandemic (H1N1) 2009 virus (P[H1N1]2009v) and to evaluate their outcome. In a cross-sectional study, 566 women (79 pregnant/puerperal, 487 nonpregnant) who presented to a tertiary care hospital with influenza-like illness were tested for P(H1N1)2009v by real-time reverse transcriptase polymerase chain reaction. Outcomes measures were the maternal mortality and the perinatal mortality rate (PMR). Twenty (25%) pregnant/puerperal and 144 (30%) nonpregnant women tested positive for P(H1N1)2009v, with 5 pregnant and 3 postpartum women requiring admission to the intensive care unit (ICU). P(H1N1)2009v-related mortality was higher in pregnant than nonpregnant women (25% versus 8%; P=0.04). In the pregnant/puerperal cohort, factors associated with death included delayed presentation (median 6days versus 1.5days in survivors; P=0.007), need for ICU admission (P=0.004), need for ventilation (P=0.001), and renal failure (P=0.001). The PMR was 55.5/1000 births compared with 33.5/1000 births in the hospital overall during the study period. In a low-income country, P(H1N1)2009v infection in pregnancy is associated with considerable mortality. Delayed presentation to a tertiary care center, lack of awareness, and restricted access to treatment might have contributed to the high mortality. Copyright © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Low acceptability of A/H1N1 pandemic vaccination in French adult population: did public health policy fuel public dissonance?

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Michaël Schwarzinger

Full Text Available BACKGROUND: In July 2009, French public health authorities embarked in a mass vaccination campaign against A/H1N1 2009 pandemic-influenza. We explored the attitudes and behaviors of the general population toward pandemic vaccination. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional online survey among 2,253 French representative adults aged 18 to 64 from November 17 to 25, 2009 (completion rate: 93.8%. The main outcome was the acceptability of A/H1N1 vaccination as defined by previous receipt or intention to get vaccinated ("Yes, certainly", "Yes, probably". Overall 17.0% (CI 95%, 15.5% to 18.7% of respondents accepted A/H1N1 vaccination. Independent factors associated with acceptability included: male sex (p = .0001; older age (p = .002; highest or lowest level of education (p = .016; non-clerical occupation (p = .011; having only one child (p = .008; and having received seasonal flu vaccination in prior 3 years (p<.0001. Acceptability was also significantly higher among pregnant women (37.9% and other at risk groups with chronic diseases (34.8% (p = .002. Only 35.5% of respondents perceived A/H1N1 influenza illness as a severe disease and 12.7% had experienced A/H1N1 cases in their close relationships with higher acceptability (p<.0001 and p = .006, respectively. In comparison to 26.0% respondents who did not consult their primary care physician, acceptability was significantly higher among 8.0% respondents who were formally advised to get vaccinated, and lower among 63.7% respondents who were not advised to get vaccinated (respectively: 15.8%, 59.5% and 11.7%- p<.0001. Among respondents who refused vaccination, 71.2% expressed concerns about vaccine safety. CONCLUSIONS/SIGNIFICANCE: Our survey occurred one week before the peak of the pandemic in France. We found that alarming public health messages aiming at increasing the perception of risk severity were counteracted by daily personal experience which did not confirm the threat

A polyvalent influenza A DNA vaccine induces heterologous immunity and protects pigs against pandemic A(H1N1)pdm09 virus infection

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Bragstad, Karoline; Vinner, Lasse; Hansen, Mette Sif

2013-01-01

seasonal and emerging influenza viruses. We have developed an alternative influenza vaccine based on DNA expressing selected influenza proteins of pandemic and seasonal origin. In the current study, we investigated the protection of a polyvalent influenza DNA vaccine approach in pigs. We immunised pigs...... intradermally with a combination of influenza DNA vaccine components based on the pandemic 1918 H1N1 (M and NP genes), pandemic 2009 H1N1pdm09 (HA and NA genes) and seasonal 2005 H3N2 genes (HA and NA genes) and investigated the protection against infection with virus both homologous and heterologous to the DNA...... of this DNA vaccine to limit virus shedding may have an impact on virus spread among pigs which could possibly extend to humans as well, thereby diminishing the risk for epidemics and pandemics to evolve....

Radiological and Clinical Characteristics of a Military Outbreak of Pandemic H1N1 2009 Influenza Virus Infection

International Nuclear Information System (INIS)

Yun, Tae Jin; Kwon, Gu Jin; Oh, Mi Kyeong; Woo, Sung Koo; Park, Seung Hoon; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo; Yim, Jae Joon; Kim, Jong Sung; Park, Chang Min

2010-01-01

To describe detailed clinical and radiological features of the pandemic H1N1 2009 influenza viral infection among healthy young males in a semiclosed institutionalized setting. A total of 18 patients confirmed with the pandemic H1N1 2009 influenza virus infection from July 18 to July 30, 2009 were enrolled in this study. Each patient underwent an evaluation to determine detailed clinical and radiological features. All patients presented with high fever (> 38.0..C), with accompanying symptoms of cough, rhinorrhea, sore throat, myalgia and diarrhea, and increased C-reactive protein (CRP) values with no leukocytosis nor elevated erythrocyte sedimentation rate (ESR). All patients, including one patient who progressed into acute respiratory distress syndrome, were treated with oseltamivir phosphate and quickly recovered from their symptoms. Chest radiographs showed abnormalities of small nodules and lobar consolidation in only two out of 18 patients. However, six of 12 patients who underwent thin-section CT examinations showed abnormal findings for small ground-glass opacities (GGOs) in addition to poorly-defined nodules with upper lobe predominance. In a population of healthy young adults, elevated CRP with normal ESR and white blood cell levels combined with GGOs and nodules on thin section CT scans may indicate early signs of infection by the pandemic H1N1 2009 influenza virus

Phase 1 study of pandemic H1 DNA vaccine in healthy adults.

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Michelle C Crank

Full Text Available A novel, swine-origin influenza A (H1N1 virus was detected worldwide in April 2009, and the World Health Organization (WHO declared a global pandemic that June. DNA vaccine priming improves responses to inactivated influenza vaccines. We describe the rapid production and clinical evaluation of a DNA vaccine encoding the hemagglutinin protein of the 2009 pandemic A/California/04/2009(H1N1 influenza virus, accomplished nearly two months faster than production of A/California/07/2009(H1N1 licensed monovalent inactivated vaccine (MIV.20 subjects received three H1 DNA vaccinations (4 mg intramuscularly with Biojector at 4-week intervals. Eighteen subjects received an optional boost when the licensed H1N1 MIV became available. The interval between the third H1 DNA injection and MIV boost was 3-17 weeks. Vaccine safety was assessed by clinical observation, laboratory parameters, and 7-day solicited reactogenicity. Antibody responses were assessed by ELISA, HAI and neutralization assays, and T cell responses by ELISpot and flow cytometry.Vaccinations were safe and well-tolerated. As evaluated by HAI, 6/20 developed positive responses at 4 weeks after third DNA injection and 13/18 at 4 weeks after MIV boost. Similar results were detected in neutralization assays. T cell responses were detected after DNA and MIV. The antibody responses were significantly amplified by the MIV boost, however, the boost did not increased T cell responses induced by DNA vaccine.H1 DNA vaccine was produced quickly, was well-tolerated, and had modest immunogenicity as a single agent. Other HA DNA prime-MIV boost regimens utilizing one DNA prime vaccination and longer boost intervals have shown significant immunogenicity. Rapid and large-scale production of HA DNA vaccines has the potential to contribute to an efficient response against future influenza pandemics.Clinicaltrials.gov NCT00973895.

Maternal and neonatal outcomes among pregnant women with 2009 pandemic influenza A(H1N1 illness in Florida, 2009-2010: a population-based cohort study.

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Timothy J Doyle

Full Text Available Pregnant women have been identified as a high risk group for severe illness with 2009 pandemic influenza A(H1N1 virus infection (pH1N1. Obesity has also been identified as a risk factor for severe illness, though this has not been thoroughly assessed among pregnant women. The objectives of this study were to provide risk estimates for adverse maternal and neonatal outcomes associated with pH1N1 illness during pregnancy and to assess the role of obesity in these outcomes.We established a retrospective population-based cohort of all live births occurring in Florida during the first 15 months of the pandemic. Illness with pH1N1 during pregnancy was ascertained through record linkage with the Florida state notifiable disease surveillance database. Data from the birth record, including pre-pregnancy body mass index, were analyzed to assess risk of adverse outcomes associated with pH1N1 illness.A total of 194 women were identified through surveillance with pH1N1 illness during pregnancy. Children born to women with pH1N1 illness during pregnancy were at increased risk for low birth weight [OR (95%CI: 1.78 (1.11-2.860], premature birth [2.21 (1.47-3.330], and infant death [4.46 (1.80-11.00], after adjusting for other factors. Women with pH1N1 illness during pregnancy were at increased risk for severe outcomes including admission to an intensive care unit. Obesity was an observed risk factor, both for the more severe pH1N1 illness detected through surveillance, and for severe maternal outcomes.Case-patients in this analysis likely represent the most severely ill subset of all women infected with pH1N1 during pregnancy, limiting the generalizability of these findings to more severely ill patients rather than influenza infection in general. Nevertheless, these results suggest that more severe pH1N1 illness during pregnancy is associated with adverse neonatal outcomes and that pregnant women should continue to be targeted for appropriate prophylaxis and

Efficacy of a pandemic (H1N1) 2009 virus vaccine in pigs against the pandemic influenza virus is superior to commercially available swine influenza vaccines.

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Loeffen, W L A; Stockhofe, N; Weesendorp, E; van Zoelen-Bos, D; Heutink, R; Quak, S; Goovaerts, D; Heldens, J G M; Maas, R; Moormann, R J; Koch, G

2011-09-28

In April 2009 a new influenza A/H1N1 strain, currently named "pandemic (H1N1) influenza 2009" (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to reduce exposure of human contacts with infected pigs, thereby preventing cross-species transfer, but also to protect pigs themselves, should this virus cause damage in the pig population. Three swine influenza vaccines, two of them commercially available and one experimental, were therefore tested and compared for their efficacy against an H1N1v challenge. One of the commercial vaccines is based on an American classical H1N1 influenza strain, the other is based on a European avian H1N1 influenza strain. The experimental vaccine is based on reassortant virus NYMC X179A (containing the hemagglutinin (HA) and neuraminidase (NA) genes of A/California/7/2009 (H1N1v) and the internal genes of A/Puerto Rico/8/34 (H1N1)). Excretion of infectious virus was reduced by 0.5-3 log(10) by the commercial vaccines, depending on vaccine and sample type. Both vaccines were able to reduce virus replication especially in the lower respiratory tract, with less pathological lesions in vaccinated and subsequently challenged pigs than in unvaccinated controls. In pigs vaccinated with the experimental vaccine, excretion levels of infectious virus in nasal and oropharyngeal swabs, were at or below 1 log(10)TCID(50) per swab and lasted for only 1 or 2 days. An inactivated vaccine containing the HA and NA of an H1N1v is able to protect pigs from an infection with H1N1v, whereas swine influenza vaccines that are currently available are of limited efficaciousness. Whether vaccination of pigs against H1N1v will become opportune remains to be seen and will depend on future evolution of this strain in the pig population. Close monitoring of the pig population, focussing on presence and evolution of

Toward a method for tracking virus evolutionary trajectory applied to the pandemic H1N1 2009 influenza virus.

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Squires, R Burke; Pickett, Brett E; Das, Sajal; Scheuermann, Richard H

2014-12-01

In 2009 a novel pandemic H1N1 influenza virus (H1N1pdm09) emerged as the first official influenza pandemic of the 21st century. Early genomic sequence analysis pointed to the swine origin of the virus. Here we report a novel computational approach to determine the evolutionary trajectory of viral sequences that uses data-driven estimations of nucleotide substitution rates to track the gradual accumulation of observed sequence alterations over time. Phylogenetic analysis and multiple sequence alignments show that sequences belonging to the resulting evolutionary trajectory of the H1N1pdm09 lineage exhibit a gradual accumulation of sequence variations and tight temporal correlations in the topological structure of the phylogenetic trees. These results suggest that our evolutionary trajectory analysis (ETA) can more effectively pinpoint the evolutionary history of viruses, including the host and geographical location traversed by each segment, when compared against either BLAST or traditional phylogenetic analysis alone. Copyright © 2014 Elsevier B.V. All rights reserved.

Impact of Body Mass Index on Immunogenicity of Pandemic H1N1 Vaccine in Children and Adults

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Callahan, S. Todd; Wolff, Mark; Hill, Heather R.; Edwards, Kathryn M.; Keitel, Wendy; Atmar, Robert; Patel, Shital; Sahly, Hana El; Munoz, Flor; Paul Glezen, W.; Brady, Rebecca; Frenck, Robert; Bernstein, David; Harrison, Christopher; Jackson, Mary Anne; Swanson, Douglas; Newland, Jason; Myers, Angela; Livingston, Robyn A; Walter, Emmanuel; Dolor, Rowena; Schmader, Kenneth; Mulligan, Mark J.; Edupuganti, Srilatha; Rouphael, Nadine; Whitaker, Jennifer; Spearman, Paul; Keyserling, Harry; Shane, Andi; Eckard, Allison Ross; Jackson, Lisa A.; Frey, Sharon E.; Belshe, Robert B.; Graham, Irene; Anderson, Edwin; Englund, Janet A.; Healy, Sara; Winokur, Patricia; Stapleton, Jack; Meier, Jeffrey; Kotloff, Karen; Chen, Wilbur; Hutter, Julia; Stephens, Ina; Wooten, Susan; Wald, Anna; Johnston, Christine; Edwards, Kathryn M.; Buddy Creech, C.; Todd Callahan, S.

2014-01-01

Obesity emerged as a risk factor for morbidity and mortality related to 2009 pandemic influenza A (H1N1) infection. However, few studies examine the immune responses to H1N1 vaccine among children and adults of various body mass indices (BMI). Pooling data from 3 trials of unadjuvanted split-virus H1N1 A/California/07/2009 influenza vaccines, we analyzed serologic responses of participants stratified by BMI grouping. A single vaccine dose produced higher hemagglutination inhibition antibody titers at day 21 in obese compared to nonobese adults, but there were no significant differences in responses to H1N1 vaccine among children or adults of various BMI following 2 doses. PMID:24795475

Radiologic Review of an Outbreak of the Pandemic (H1N1) 2009 Virus Infection at a University Hospital in Seoul, Korea

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Choi, Seung Hee; Kang, Eun Young; Kim, Yoon Kyung; Woo, Ok Hee; Yong, Hwan Seok; Oh, Yu Whan; Kim, Jang Su

2011-01-01

To assess the frequency of radiologic abnormalities and investigate the radiologic findings of patients with a pandemic (H1N1) 2009 virus infection at a University hospital in Seoul, Korea. In November 2009, 9,427 patients were tested for pandemic (H1N1) 2009 virus and 3,849 (41%) were positive. Among them, only 338 (9%) underwent chest radiographs and 13 (0.3%) received chest CT. Two radiologists retrospectively reviewed all the radiologic images. Among the 338 patients, 287 (85%) were normal and 51 (15%) showed abnormalities. The frequency of abnormalities was significantly higher in children (41/212=19%) than in adults (10/126=8%) (p = 0.005). Of them, 42 (82%) patients had airspace pneumonia, whereas the remaining patients showed a bronchopneumonia pattern. Unilateral (82%) involvement was more common than bilateral (18%) involvement. Among patients who received chest CT, 12 (92%) showed abnormalities, with bilateral (67%) and random (75%) involvement being more common. Ground-glass opacity (67%) and centrilobular nodules (58%) were the more common CT findings. Only a small number of patients were critically ill enough to undergo further radiologic evaluation as a result of pandemic (H1N1) 2009 virus infection, and most patients had normal chest radiographs. Unilateral airspace pneumonia was the most common abnormality in patients infected with pandemic (H1N1) 2009 virus.

Pandemic (H1N1) 2009 Outbreak at Camp for Children with Hematologic and Oncologic Conditions

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Morrison, Cori; Maurtua-Neumann, Paola; Myint, Myo Thwin; Drury, Stacy S.

2011-01-01

An outbreak of influenza A pandemic (H1N1) 2009 occurred among campers and staff at a summer camp attended by children with hematologic and oncologic conditions. The overall attack rate was 36% and was highest among children and adolescents (43%), persons with cancer (48%), and persons with sickle cell disease (82%). PMID:21192861

Identification and Epidemiology of Severe Respiratory Disease due to Novel Swine-Origin Influenza A (H1N1 Virus Infection in Alberta

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George Zahariadis

2010-01-01

Full Text Available BACKGROUND: In March 2009, global surveillance started detecting cases of influenza-like illness in Mexico. By mid-April 2009, two pediatric patients were identified in the United States who were confirmed to be infected by a novel influenza A (H1N1 strain. The present article describes the first identified severe respiratory infection and the first death associated with pandemic H1N1 (pH1N1 in Canada.

Community-acquired pneumonia due to pandemic A(H1N12009 influenzavirus and methicillin resistant Staphylococcus aureus co-infection.

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Ronan J Murray

Full Text Available BACKGROUND: Bacterial pneumonia is a well described complication of influenza. In recent years, community-onset methicillin-resistant Staphylococcus aureus (cMRSA infection has emerged as a contributor to morbidity and mortality in patients with influenza. Since the emergence and rapid dissemination of pandemic A(H1N12009 influenzavirus in April 2009, initial descriptions of the clinical features of patients hospitalized with pneumonia have contained few details of patients with bacterial co-infection. METHODOLOGY/PRINCIPAL FINDINGS: Patients with community-acquired pneumonia (CAP caused by co-infection with pandemic A(H1N12009 influenzavirus and cMRSA were prospectively identified at two tertiary hospitals in one Australian city during July to September 2009, the period of intense influenza activity in our region. Detailed characterization of the cMRSA isolates was performed. 252 patients with pandemic A(H1N12009 influenzavirus infection were admitted at the two sites during the period of study. Three cases of CAP due to pandemic A(H1N12009/cMRSA co-infection were identified. The clinical features of these patients were typical of those with S. aureus co-infection or sequential infection following influenza. The 3 patients received appropriate empiric therapy for influenza, but inappropriate empiric therapy for cMRSA infection; all 3 survived. In addition, 2 fatal cases of CAP caused by pandemic A(H1N12009/cMRSA co-infection were identified on post-mortem examination. The cMRSA infections were caused by three different cMRSA clones, only one of which contained genes for Panton-Valentine Leukocidin (PVL. CONCLUSIONS/SIGNIFICANCE: Clinicians managing patients with pandemic A(H1N12009 influenzavirus infection should be alert to the possibility of co-infection or sequential infection with virulent, antimicrobial-resistant bacterial pathogens such as cMRSA. PVL toxin is not necessary for the development of cMRSA pneumonia in the setting of pandemic

The H1N1 pandemic: media frames, stigmatization and coping.

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McCauley, Michael; Minsky, Sara; Viswanath, Kasisomayajula

2013-12-03

Throughout history, people have soothed their fear of disease outbreaks by searching for someone to blame. Such was the case with the April 2009 H1N1 flu outbreak. Mexicans and other Latinos living in the US were quickly stigmatized by non-Latinos as carriers of the virus, partly because of news reports on the outbreak's alleged origin in Mexican pig farms. In this exploratory study we examined the psychological processes of cue convergence and associative priming, through which many people likely conflated news of the H1N1 outbreak with pre-existing cognitive scripts that blamed Latino immigrants for a variety of social problems. We also used a transactional model of stress and coping to analyze the transcripts from five focus groups, in order to examine the ways in which a diverse collection of New England residents appraised the threat of H1N1, processed information about stereotypes and stigmas, and devised personal strategies to cope with these stressors. Twelve themes emerged in the final wave of coding, with most of them appearing at distinctive points in the stress and coping trajectories of focus group participants. Primary and secondary appraisals were mostly stressful or negative, with participants born in the USA reporting more stressful responses than those who were not. Latino participants reported no stressful primary appraisals, but spoke much more often than Whites or Non-Hispanic Blacks about negative secondary appraisals. When interactions between participants dealt with stigmas regarding Latinos and H1N1, Latinos in our focus groups reported using far more negative coping strategies than Whites or Non-Hispanic Blacks. When discussions did not focus on stereotypes or stigmas, Latino participants spoke much more often about positive coping strategies compared to members of these same groups. Participants in all five focus groups went through a similar process of stress and coping in response to the threat of H1N1, though individual responses

Clinical and radiological features of pandemic H1N1 2009 influenza virus infection manifesting as acute febrile respiratory illness at their initial presentations: comparison with contemporaneous non-H1N1 patients

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Yun, Tae Jin; Park, Chang Min; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo; Kwon, Gu Jin; Woo, Sung Koo; Park, Seung Hoon

2011-01-01

Background Since the first outbreak caused by the pandemic H1N1 2009 influenza in Mexico, the virus has spread widely across the world with meaningful morbidity and mortality. However, there are few data on the comparative investigations to assess the clinical and radiological features between the H1N1 patient and non-H1N1 patients. Purpose To assess the clinical and radiological features of patients infected by the pandemic H1N1 2009 flu virus at their initial presentation and to compare them with contemporaneous non-H1N1 patients with acute febrile respiratory illness. Material and Methods This retrospective study was approved by the ethics committee of the Armed Forces Medical Command, South Korea. From August to September 2009, 337 consecutive patients presented with an acute febrile respiratory illness in a tertiary military hospital. Reverse-transcriptase polymerase-chain-reaction tests were performed in 62 of these patients under the impression of H1N1 infection. Clinical and radiological features at their initial presentation were described for the H1N1 group (n = 35) and non-H1N1 group (n = 27) and compared between the two groups. Results Increased C-reactive protein level (97%) without leukocytosis (9%) or increased erythrocyte sedimentation rate (0%) was common in the H1N1 group at their initial presentation. On chest radiographs, 12 of 35 (34%) H1N1 patients had abnormal findings; nodules in 10 patients (83%) and consolidations in two (17%). Of the 28 H1N1 patients who underwent thin-section CT 16 patients (57%) showed abnormal findings; ground-glass opacities (GGOs) in 15 (94%), and nodules in 13 (81%). However, there were no significant differences between the H1N1 group and non-H1N1 group in terms of symptoms, laboratory results, or radiological findings (P > 0.05). Conclusion Patients with H1N1 infection show consistent clinical and radiological features at their initial presentation, however, clinical and radiological features of the H1N1 group are

Clinical and radiological features of pandemic H1N1 2009 influenza virus infection manifesting as acute febrile respiratory illness at their initial presentations: comparison with contemporaneous non-H1N1 patients

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Yun, Tae Jin (Dept. of Radiology, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of); Dept. of Radiology, Seoul National Univ. Hospital, Seoul (Korea, Republic of)); Park, Chang Min; Choi, Seung Hong; Lee, Hyun Ju; Goo, Jin Mo (Dept. of Radiology, Seoul National Univ. Hospital, Seoul (Korea, Republic of)), email: cmpark@radiol.snu.ac.kr; Kwon, Gu Jin (Dept. of Family Medicine, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of); Dept. of Family Medicine, Gangneung Asan Hospital, Gangneung (Korea, Republic of)); Woo, Sung Koo (Dept. of Radiology, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of)); Park, Seung Hoon (Dept. of Internal Medicine, Armed Force Byukjae Hospital, Gyeonggi-do (Korea, Republic of))

2011-05-15

Background Since the first outbreak caused by the pandemic H1N1 2009 influenza in Mexico, the virus has spread widely across the world with meaningful morbidity and mortality. However, there are few data on the comparative investigations to assess the clinical and radiological features between the H1N1 patient and non-H1N1 patients. Purpose To assess the clinical and radiological features of patients infected by the pandemic H1N1 2009 flu virus at their initial presentation and to compare them with contemporaneous non-H1N1 patients with acute febrile respiratory illness. Material and Methods This retrospective study was approved by the ethics committee of the Armed Forces Medical Command, South Korea. From August to September 2009, 337 consecutive patients presented with an acute febrile respiratory illness in a tertiary military hospital. Reverse-transcriptase polymerase-chain-reaction tests were performed in 62 of these patients under the impression of H1N1 infection. Clinical and radiological features at their initial presentation were described for the H1N1 group (n = 35) and non-H1N1 group (n = 27) and compared between the two groups. Results Increased C-reactive protein level (97%) without leukocytosis (9%) or increased erythrocyte sedimentation rate (0%) was common in the H1N1 group at their initial presentation. On chest radiographs, 12 of 35 (34%) H1N1 patients had abnormal findings; nodules in 10 patients (83%) and consolidations in two (17%). Of the 28 H1N1 patients who underwent thin-section CT 16 patients (57%) showed abnormal findings; ground-glass opacities (GGOs) in 15 (94%), and nodules in 13 (81%). However, there were no significant differences between the H1N1 group and non-H1N1 group in terms of symptoms, laboratory results, or radiological findings (P > 0.05). Conclusion Patients with H1N1 infection show consistent clinical and radiological features at their initial presentation, however, clinical and radiological features of the H1N1 group are

Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case–control study

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Morales-García Guadalupe

2012-11-01

Full Text Available Abstract Background Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Methods Case–control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR and the 95% confidence interval (95% CI were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Results Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07–1248.77; LTA rs909253 AG (OR = 4.33, 95% CI = 1.82–10.32; TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48–12.64; additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13. Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05; those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05. The IL1B rs16944 AA

Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case-control study.

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Morales-García, Guadalupe; Falfán-Valencia, Ramcés; García-Ramírez, Román Alejandro; Camarena, Ángel; Ramirez-Venegas, Alejandra; Castillejos-López, Manuel; Pérez-Rodríguez, Martha; González-Bonilla, César; Grajales-Muñíz, Concepción; Borja-Aburto, Víctor; Mejía-Aranguré, Juan Manuel

2012-11-13

Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Case-control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR) and the 95% confidence interval (95% CI) were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07-1248.77); LTA rs909253 AG (OR = 4.33, 95% CI = 1.82-10.32); TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48-12.64); additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13). Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05); those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05). The IL1B rs16944 AA genotype was associated with an elevated number of

Pandemic influenza A/H1N1 virus infection and TNF, LTA, IL1B, IL6, IL8, and CCL polymorphisms in Mexican population: a case–control study

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2012-01-01

Background Some patients have a greater response to viral infection than do others having a similar level of viral replication. Hypercytokinemia is the principal immunopathological mechanism that contributes to a severer clinical course in cases of influenza A/H1N1. The benefit produced, or damage caused, by these cytokines in severe disease is not known. The genes that code for these molecules are polymorphic and certain alleles have been associated with susceptibility to various diseases. The objective of the present study was to determine whether there was an association between polymorphisms of TNF, LTA, IL1B, IL6, IL8, and CCL1 and the infection and severity of the illness caused by the pandemic A/H1N1 in Mexico in 2009. Methods Case–control study. The cases were patients confirmed with real time PCR with infection by the A/H1N1 pandemic virus. The controls were patients with infection like to influenza and non-familial healthy contacts of the patients with influenza. Medical history and outcome of the disease was registered. The DNA samples were genotyped for polymorphisms TNF rs361525, rs1800629, and rs1800750; LTA rs909253; IL1B rs16944; IL6 rs1818879; IL8 rs4073; and CCL1 rs2282691. Odds ratio (OR) and the 95% confidence interval (95% CI) were calculated. The logistic regression model was adjusted by age and severity of the illness in cases. Results Infection with the pandemic A/H1N1 virus was associated with the following genotypes: TNF rs361525 AA, OR = 27.00; 95% CI = 3.07–1248.77); LTA rs909253 AG (OR = 4.33, 95% CI = 1.82–10.32); TNF rs1800750 AA (OR = 4.33, 95% CI = 1.48–12.64); additionally, LTA rs909253 AG showed a limited statistically significant association with mortality (p = 0.06, OR = 3.13). Carriers of the TNF rs1800629 GA genotype were associated with high levels of blood urea nitrogen (p = 0.05); those of the TNF rs1800750 AA genotype, with high levels of creatine phosphokinase (p=0.05). The IL1B rs16944 AA genotype was associated

Factors associated with household transmission of pandemic (H1N1 2009 among self-quarantined patients in Beijing, China.

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Daitao Zhang

Full Text Available As the pandemic (H1N1 2009 progressed, the Ministry of Health of China advised cases with mild symptoms to remain home for isolation and observation, which may have increased the risk for infection among other household members. Describing the transmission characteristics of this novel virus is indispensable to effectively controlling the spread of disease; thus, the aim of this study was to assess risk factors associated with household transmission of pandemic H1N1 from self-quarantined patients in Beijing, the capital city of China. A 1:2 case-control study with 54 case households and 108 control households was conducted between August 1 and September 30, 2009 in Beijing. Cases were households with a self-quarantined index patient and a secondary case, while controls were households with a self-quarantined index patient and a close contact. Controls were also matched to cases for sex and age of index case-patient. A structured interview guide was used to collect the data. Conditional logistical models were employed to estimate Odds Ratios (OR with 95% confidence intervals (95% CI. Results indicated that higher education level (OR 0.42; 95% CI 0.22-0.83, sharing room with an index case-patient (OR 3.29; 95%CI 1.23-8.78, daily room ventilation (OR 0.28; 95%CI 0.08-0.93, and hand washing ≥ 3/d (OR 0.71; 95%CI 0.48-0.94 were related to the household transmission of pandemic H1N1 from self-quarantined patients. These results highlight that health education, as well as the quarantine of the index case-patient immediately after infection, frequent hand hygiene, and ventilation are critical to mitigating household spread of pandemic H1N1 virus and minimizing its impact. Household contacts should be educated to promote these in-home practices to contain transmission, particularly when household members are quarantined at home.

Pandemic (H1N1 2009 Influenza Virus Infection in A Survivor who has recovered from severe H7N9 Virus Infection, China

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Shan-Hui Chen

2016-10-01

Full Text Available We firstly report a patient who presented with severe complications after infection with influenza A(H1N1 pdm2009, more than one year after recovery from severe H7N9 virus infections. The population of patients who recovered from severe H7N9 infections might be at a higher risk to suffer severe complications after seasonal influenza infections, and they should be included in the high-risk populations recommended to receive seasonal influenza vaccination.

Major incidents in rural areas: managing a pandemic A/H1N1/2009 cluster.

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Stark, Cameron; Garman, Elaine; McMenamin, Jim; McCormick, Duncan; Oates, Ken

2010-01-01

Pandemic Influenza (A/H1N1/2009) caused worldwide concern because of its potential to spread rapidly in human populations. In Scotland, Government policy had been to seek to contain the spread of the virus for as long as possible in order to allow time for service preparations, and for vaccine development and supply. The first major Scottish outbreak of pandemic A/H1N1/2009 was in the rural area of Cowal and Bute. After two initial cases were identified, contact tracing found a cluster of cases associated with a football supporters' bus. Within 3 weeks, 130 cases had been identified in the area. Rapid provision of treatment doses of anti-viral medication to cases and prophylactic treatment of asymptomatic close contacts, advice on self-isolation and, where required, interruption of transmission by temporary school closure, were successful in containing the outbreak. Pre-existing Major Incident and Pandemic Flu plans were used and adapted to the particular circumstances of the outbreak and the area. Supporting operational decision-making as close to the cases as possible allowed for speed and flexibility of response. Contact tracing and tracking of cases and results was performed by specialist public health staff who were geographically removed from the cases. This was possible because of effective use of existing telephone conferencing facilities, clarity of roles, and frequent communication among staff working on all areas of the response. Basing the work on established plans, staff experience of rural areas and rural service provision was successful.

University life and pandemic influenza: Attitudes and intended behaviour of staff and students towards pandemic (H1N1 2009

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MacIntyre C Raina

2010-03-01

Full Text Available Abstract Background In a pandemic young adults are more likely to be infected, increasing the potential for Universities to be explosive disease outbreak centres. Outbreak management is essential to reduce the impact in both the institution and the surrounding community. Through the use of an online survey, we aimed to measure the perceptions and responses of staff and students towards pandemic (H1N1 2009 at a major university in Sydney, Australia. Methods The survey was available online from 29 June to 30 September 2009. The sample included academic staff, general staff and students of the University. Results A total of 2882 surveys were completed. Nearly all respondents (99.6%, 2870/2882 were aware of the Australian pandemic situation and 64.2% (1851/2882 reported either "no anxiety" or "disinterest." Asian-born respondents were significantly (p Conclusions Responses to a pandemic are subject to change in its pre-, early and mid-outbreak stages. Lessons for these institutions in preparation for a second wave and future disease outbreaks include the need to promote positive public health behaviours amongst young people and students.

Occupational health impact of the 2009 H1N1 flu pandemic: surveillance of sickness absence.

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Torá-Rocamora, Isabel; Delclos, George L; Martínez, José Miguel; Jardí, Josefina; Alberti, Constança; Manzanera, Rafael; Yasui, Yutaka; Clèries, Ramón; Tobías, Aurelio; Benavides, Fernando G

2012-03-01

Workplace absences due to illness can disrupt usual operations and increase costs for businesses. This study of sickness absence due to influenza and influenza-related illness presents a unique opportunity to characterise and measure the impact of the 2009 (H1N1) pandemic, by comparing trends during the pandemic to those of previous years, and adding this information to that obtained by traditional epidemiological surveillance systems. We compared the numbers of cases of sickness absence due to illness caused by influenza and influenza-related illness in 2007-2009, and in the first 3 months of 2010 in Catalonia (n=811 940) using a time series approach. Trends were examined by economic activity, age and gender. The weekly endemic-epidemic index (EEI) was calculated and its 95% CI obtained with the delta method, with observed and expected cases considered as independent random variables. Influenza activity peaked earlier in 2009 and yielded more cases than in previous years. Week 46 (in November 2009) had the highest number of new cases resulting in sickness absence (EEI 20.99; 95% CI 9.44 to 46.69). Women and the 'education, health and other social activities' sector were the most affected. Results indicate that the new H1N1 pandemic had a significant impact on business, with shifts in the timing of peak incidence, a doubling in the number of cases, and changes in the distribution of cases by economic activity sector and gender. Traditional epidemiological surveillance systems could benefit from the addition of information based on sickness absence data.

Antiviral therapy and outcomes of patients with pneumonia caused by influenza A pandemic (H1N1 virus.

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Shi-gui Yang

Full Text Available BACKGROUND: There is limited data on the clinical outcome of patients with pandemic H1N1 (pH1N1 pneumonia who received oseltamivir treatment, especially when the treatment was administered more than 48 hours after symptom onset. METHODS: During the pandemic in 2009, a cohort of pH1N1 influenza pneumonia was built in China, and their clinical information was collected systematically, and analyzed with Cox models. RESULTS: 920 adults and 541 children with pneumonia who didn't receive corticosteroids were analyzed. In-hospital mortality was higher in adults who did not receive antiviral therapy (18.2% than those with who received oseltamivir ≤ 2 days (2.9%, between 2-5 days (4.6% and >5 days after illness onset (4.9%, p5 days, respectively. For males patients, aged ≥ 14 years and baseline PaO(2/FiO(23.8 mg/kg/d did not improve clinical outcome (mortality, higher dose 2.5% vs standard dose 2.8%, p>0.05. CONCLUSIONS: Antiviral therapy might reduce mortality of patients with pH1N1 pneumonia, even when initiated more than 48 hours after onset of illness. Greater protective effects might be in males, patients aged 14-60 years, and patients with PaO(2/FiO(2<200.

Impact of cytokine in type 1 narcolepsy: Role of pandemic H1N1 vaccination ?

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Lecendreux, Michel; Libri, Valentina; Jaussent, Isabelle; Mottez, Estelle; Lopez, Régis; Lavault, Sophie; Regnault, Armelle; Arnulf, Isabelle; Dauvilliers, Yves