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EINet Alert ~ Dec 18, 2009
*****A free service of the APEC Emerging Infections Network*****
APEC EINet News Briefs offers the latest news, journal articles, and
notifications for emerging infections affecting the APEC member economies. It
was created to foster transparency, communication, and collaboration in emerging infectious diseases among health professionals, international business and commerce leaders, and policy makers in the Asia-Pacific region.
In this edition:
1. Influenza News
- 2009 Cumulative number of human cases of avian influenza A/H5N1
- WHO situation update on pandemic influenza H1N1
- Global: Three Asian countries top list to get donated H1N1 vaccine
- Egypt: Concerns regarding pandemic H1N1 infections and deaths
- Serbia: Schools closed to slow pandemic H1N1 spread
- UK: Pandemic H1N1 death rate similar to US's
- China & Thailand: Novel H1N1 in pigs and dogs
- China: Rise in flu deaths
- USA: Vaccine availability opens up as doses approach 100 million
- USA: FDA authorizes emergency use of portable flu PCR
- USA: Town offers zoo visits to prompt vaccination
- USA: USDA conditionally licenses vaccine for pigs
- USA: CDC Director reiterates H1N1 more severe in young people
- INFLUENZA A/H1N1
- AVIAN INFLUENZA
- Trial of influenza A (H1N1) 2009 monovalent MF59-adjuvanted vaccine
- Quantifying the risk of pandemic influenza in pregnancy and Indigenous people in Australia in 2009
- Influenza Circulation and the Burden of Invasive Pneumococcal Pneumonia during a Non-pandemic Period in the United States
- Neuraminidase inhibitors for preventing and treating influenza in healthy adults: systematic review and meta-analysis
- Evidence of Bias in Studies of Influenza Vaccine Effectiveness in Elderly Patients
- Modeling gene sequences over time in 2009 H1N1 Influenza A Virus populations
- Estimated epidemiologic parameters and morbidity associated with pandemic H1N1 influenza
- Pulmonary Pathologic Findings of Fatal 2009 Pandemic Influenza A/H1N1 Viral Infections
- International Symposium on Neglected Influenza Viruses
- 14th International Congress on Infectious Diseases (ICID)
- ISHEID Symposium on HIV and Emerging Infectious Diseases
- CDC 7th International Conference on Emerging Infectious Diseases
- Options for the Control of Influenza VII
- Updated influenza guidance and information from the US CDC
1. Influenza News
2009 Cumulative number of human cases of avian influenza A/H5N1
Economy / Cases (Deaths)
China/ 7 (4)
Egypt/ 38 (4)
Viet Nam/ 5 (5)
Total/ 50 (13)
***For data on human cases of avian influenza prior to 2009, go to: http://depts.washington.edu/einet/humanh5n1.html
Total no. of confirmed human cases of avian influenza A/(H5N1), Dec 2003 to present: 445 (263)
(WHO 12/11/09 http://www.who.int/csr/disease/avian_influenza/country/cases_table_2009_12_11/en/)
Avian influenza age distribution data from WHO/WPRO (last updated 9/10/09): http://www.wpro.who.int/sites/csr/data/data_Graphs.htm
WHO's map showing world's areas affected by H5N1 avian influenza (status as of 09/24/09): http://gamapserver.who.int/mapLibrary/Files/Maps/Global_H5N1Human_2009_FIMS_20090924.png.
WHO's timeline of important H5N1-related events (last updated 7/27/09): http://www.who.int/csr/disease/avian_influenza/ai_timeline/en/index.html
WHO situation update on pandemic influenza H1N1
As of 6 December 2009, worldwide more than 208 countries and overseas territories or communities have reported laboratory confirmed cases of pandemic influenza H1N1 2009, including at least 9,596 deaths. As many countries have stopped counting individual cases, particularly of milder illness, the case count is likely to be significantly lower than the actual number of cases that have occurred.
In United States and Canada, active influenza virus transmission persists but overall influenza-like illness (ILI) activity continues to decline for the 5th and 3rd consecutive weeks, respectively. In the US, after eight weeks of increases, proportional mortality due to pneumonia and influenza (P&I mortality) has begun to decrease but remains elevated above the epidemic threshold; weekly numbers of lab-confirmed hospitalizations and deaths have also recently begun to decline. So far, comparing transmission during the current winter season to transmission during the summer season, there appears to be 2-3 times more hospitalized cases and deaths in the United States and approximately 4-5 times more hospitalized cases and deaths in Canada during the winter season. However, the overall rate of hospitalization and death in the population is similar to that which was observed in temperate countries of the southern hemisphere during their winter. This would indicate that transmission of the virus has been much more widespread and intense during the winter, as predicted, but overall rates of severe illness have not changed compared to southern hemisphere. Similar to seasonal influenza, persons with certain underlying conditions (compared to those without) were at significantly increased risk of hospitalization and death associated with pandemic H1N1 2009 virus infection. During the current winter season in Canada, 52% of hospitalized cases, 60% of cases requiring ICU, and 67% of fatal cases, had an underlying chronic medical illness. Similar to the experience of many countries, the most common underlying conditions among fatal cases in Canada were asthma followed by chronic cardiac disease, immunosuppression, and diabetes.
In Europe, geographically widespread transmission of pandemic influenza virus continued to be observed across the continent. With the exception of France where ILI activity continues to increase, ILI activity has peaked or passed its peak in much of western Europe, including in Belgium, Iceland, Ireland, Netherlands, Spain, Portugal, Italy, and Germany. In northern Europe, intensity remains high, however activity has begun to decline in Norway, Sweden, and Denmark. Increasing activity continues to be observed in parts of central and southeastern Europe, including in Albania, the Czech Republic, Estonia, Greece, Hungary, Latvia, Poland, Romania, Montenegro, Slovenia, and Turkey. Further east, declining rates of ILI or ARI have been observed in Georgia, Bulgaria, and Ukraine. In the Russian Federation, influenza virus circulation remains active, but overall activity may have recently peaked. A high intensity of respiratory diseases activity was reported in Lithuania and Greece, and a moderate impact on the healthcare system was reported in France and in parts of northern and far eastern Europe. 99% of subtyped influenza A viruses in Europe were pandemic H1N1 2009. Of note, detections of RSV in Europe have increased over the past four weeks which may partially account for elevated ILI activity among young children.
In Western and Central Asia, influenza virus transmission remains active. ILI/ARI activity continues to increase in Kazakhstan and Kyrgyzstan, but may have peaked in Afghanistan, Israel, and Oman. Pandemic influenza virus continues to circulate in Iran, Iraq, Jordan, and in much of the surrounding region.
In East Asia, influenza transmission remains variable. Influenza activity continues to increase in Japan and has recently begun to increase in Hong Kong and Chinese Taipei both of which previously experienced a peak of transmission. Elevated but stable ILI activity has been reported in southern China, but declines in activity continue to be observed in northern China and Mongolia. In South Asia, influenza activity has begun to increase in the north-western parts of India and in Sri Lanka. Small number of seasonal influenza viruses continues to be detected in Asia but in decreasing amounts.
In the tropical region of Central and South America and the Caribbean, influenza transmission remains geographically widespread but overall disease activity has been declining in most areas.
In Africa, limited data suggest that pandemic H1N1 2009 virus continues to be detected from all parts of the continent (except South Africa where the winter season has passed). Pandemic H1N1 2009 virus appears to be the predominant influenza virus circulating in northern and eastern Africa.
In the temperate region of the southern hemisphere, sporadic cases of pandemic influenza have been reported in recent weeks but no sustained local transmission has been observed.
Global: Three Asian countries top list to get donated H1N1 vaccine
Afghanistan, Azerbaijan, and Mongolia will be the first three countries to receive donated supplies of pandemic H1N1 vaccine funneled through the World Health Organization, the WHO announced 17 December 2009 as it cautioned that it's too early to declare the pandemic over. The first shipments will go out considerably later than once projected. At a Sep 24 briefing, WHO officials predicted that developing countries would start getting their first doses in late October or in November. Dr. Keiji Fukuda, special assistant to the WHO director-general for pandemic flu, said logistical and regulatory hurdles make the task of providing the vaccine very complex. Countries that want doses must make a formal request, sign an agreement with the WHO, and develop a national vaccine deployment plan, he explained.
The WHO is currently focusing on an initial group of 35 countries, 34 of which have requested vaccine supplies, according to the written statement. Another 20 of the 35 countries have signed agreements, and just four have completed deployment plans.
[Detailed information available at http://www.who.int/csr/disease/swineflu/vaccines/h1n1_vaccination_deployment_update_20091217.pdf]
Egypt: Concerns regarding pandemic H1N1 infections and deaths
Egypt's Health Ministry has reported three new deaths from pandemic (H1N1) 2009 virus infection, bringing the death toll in the country to 59. Health officials are worried that the winter months could bring a higher number of infections and deaths. Since the virus first appeared in Egypt in June 2009, the country has reported more than 4,700 cases.
Serbia: Schools closed to slow pandemic H1N1 spread
Serbia's education ministry announced the country will close schools for the holiday break early, starting Dec 18, to slow the spread of pandemic flu. Classes will resume Jan 11. The measure was suggested by a working group monitoring flu developments in Serbia, where the vaccination campaign will begin 17 Dec 2009.
UK: Pandemic H1N1 death rate similar to US's
Pandemic H1N1 flu has killed fairly low numbers in the United Kingdom, British officials determined in a recently published study, but public health officials should stay vigilant and vaccination campaigns continue. The comprehensive analysis of data through 8 Nov 2009 revealed 26 H1N1 deaths in every 100,000 cases--a case-fatality rate (CFR) of 0.026%. On 10 December 2009 the CDC released figures indicating a US CFR of 0.021%.
China & Thailand: Novel H1N1 in pigs and dogs
Two countries recently confirmed novel H1N1 viruses in animals: Thailand in pigs and China in pigs and two dogs, according to reports filed with the World Organization for Animal Health (OIE). All cases were detected during enhanced surveillance. The Thai outbreak involved piglets at a farm in Saraburi province. In China the virus was detected in pigs at a slaughterhouse in Heilongjiang province and in dogs at an animal hospital in Beijing.
China: Rise in flu deaths
China's health ministry said on 16 December 2009 that flu deaths have risen by a third over the past few days to 442. This announcement comes soon after health officials warned that flu activity could rise during the upcoming Lunar New Year holiday, when millions of people travel and return home. Last week the health ministry said it would step up vaccination efforts to add to the 34 million in China that have already been vaccinated.
USA: Vaccine availability opens up as doses approach 100 million
The United States is reaching a new milestone in its fight against pandemic flu, with the number of vaccine doses expected to reach 100 million by 19 December 2009 and nearly half of states opening up immunization to anyone who wants it, federal officials said on 17 December 2009.
USA: FDA authorizes emergency use of portable flu PCR
The Food and Drug Administration (FDA) has issued an emergency use authorization (EUA) to the company DxNA for a rapid test for H1N1 influenza performed in a portable PCR device called GeneSTAT. The test-device combination speeds up flu detection by allowing small hospitals and other clinical sites to perform strain-specific testing themselves, rather than sending samples out to reference labs.
USA: Town offers zoo visits to prompt vaccination
To boost vaccine uptake in young people, the public health department in Norfolk, Va, is teaming up with the Virginia Zoo to offer free admission for those who come to the zoo tomorrow to receive their H1N1 shot. The campaign targets young people ages six months to 24 years and daycare providers. The groups are offering free parking and a tour of the zoo for all participants, along with a train ride for the first 500 children.
USA: USDA conditionally licenses vaccine for pigs
Pfizer Animal Health was granted a conditional license for an H1N1 flu vaccine for use in pigs, the US Department of Agriculture (USDA) announced 11 December 2009. It is the first H1N1 flu vaccine license issued by the USDA and is valid for a year. Under USDA regulations, a product shown to be pure and safe and deemed likely to be effective may be licensed while data on efficacy and potency are still being gathered. The vaccine can be used only by veterinarians.
USA: CDC Director reiterates H1N1 more severe in young people
"Many times more children and younger adults. . .have been hospitalized or killed by H1N1 influenza than happens in a usual flu season," stated Thomas R. Frieden, director of the US CDC, in a press briefing on 10 December 2009. He estimated that, through 14 November 2009, there have been 50 million cases, mostly in young adults and children, and more than 200,000 hospitalizations. There were also approximately 10,000 deaths including 1,100 children and 7,500 younger adults. Noting that five out of six Americans remain susceptible to H1N1 influenza infection, Frieden urged more people to take advantage of this "good window of opportunity to be vaccinated."
(CDC Media Briefing Transcript, 12/10/2009)
The following websites provide the most current information, surveillance, and guidance.
Influenza A/H1N1: http://www.who.int/csr/disease/swineflu/en/index.html
Influenza A/H1N1 frequently asked questions: http://www.who.int/csr/disease/swineflu/frequently_asked_questions/en/index.html
Pandemic Influenza Preparedness and Response - A WHO Guidance Document
International Health Regulations (IHR) at http://www.who.int/ihr/en/index.html.
- WHO regional offices
Eastern Mediterranean: http://www.emro.who.int/csr/h1n1/
Western Pacific: http://www.wpro.who.int/health_topics/h1n1/
- North America
US CDC: http://www.cdc.gov/flu/swine/investigation.htm
US pandemic emergency plan: http://www.flu.gov
MOH Mexico: http://portal.salud.gob.mx/index_eng.html
PHA of Canada: http://fightflu.ca
- Other useful sources
CIDRAP: Influenza A/H1N1 page: http://www.cidrap.umn.edu/cidrap/content/influenza/swineflu/biofacts/swinefluoverview.html
- UN: http://www.undp.org/mdtf/influenza/overview.shtml UNDP's web site for information on fund management and administrative services and includes the website of the Central Fund for Influenza Action. This site also includes a list of useful links.
- WHO: http://www.who.int/csr/disease/avian_influenza/en/.
- UN FAO: http://www.fao.org/avianflu/en/index.html. View the latest avian influenza outbreak maps, upcoming events, and key documents on avian influenza.
- OIE: http://www.oie.int/eng/info_ev/en_AI_avianinfluenza.htm. Link to the Communication Portal gives latest facts, updates, timeline, and more.
- US CDC: Visit "Pandemic Influenza Preparedness Tools for Professionals" at: http://www.cdc.gov/flu/pandemic/preparednesstools.htm. This site contains resources to help hospital administrators and state and local health officials prepare for the next influenza pandemic.
- The US government's website for pandemic/avian flu: http://www.flu.gov/. View archived Webcasts on influenza pandemic planning.
- CIDRAP: http://www.cidrap.umn.edu/
- PAHO: http://www.paho.org/English/AD/DPC/CD/influenza.htm Link to the Avian Influenza Portal at:
http://influenza.bvsalud.org/php/index.php?lang=en. The Virtual Health Library's Portal is a developing project for the operation of product networks and information services related to avian influenza.
- US National Wildlife Health Center: http://www.nwhc.usgs.gov/disease_information/avian_influenza/index.jsp Read about the latest news on H5N1 in wild birds and poultry.
Trial of influenza A (H1N1) 2009 monovalent MF59-adjuvanted vaccine
Clark TW, Pareek M, Hoschler K, et al. N Engl J Med. 17 December 2009;17;361(125):2424-35.
Available at http://content.nejm.org/cgi/content/full/361/25/2424.
Background. The 2009 pandemic influenza A (H1N1) virus has emerged to cause the first pandemic of the 21st century. Development of effective vaccines is a public health priority.
Methods. We conducted a single-center study, involving 176 adults, 18 to 50 years of age, to test the monovalent influenza A/California/2009 (H1N1) surface-antigen vaccine, in both MF59-adjuvanted and nonadjuvanted forms. Subjects were randomly assigned to receive two intramuscular injections of vaccine containing 7.5 µg of hemagglutinin on day 0 in each arm or one injection on day 0 and the other on day 7, 14, or 21; or two 3.75-µg doses of MF59-adjuvanted vaccine, or 7.5 or 15 µg of nonadjuvanted vaccine, administered 21 days apart. Antibody responses were measured by means of hemagglutination-inhibition assay and a microneutralization assay on days 0, 14, 21, and 42 after injection of the first dose.
Results. The most frequent local and systemic reactions were pain at the injection site and muscle aches, noted in 70% and 42% of subjects, respectively; reactions were more common with the MF59-adjuvanted vaccine than with nonadjuvanted vaccine. Three subjects reported fever, with a temperature of 38°C or higher, after either dose. Antibody titers, expressed as geometric means, were higher at day 21 among subjects who had received one dose of MF59-adjuvanted vaccine than among those who had received one dose of nonadjuvanted vaccine (P<0.001 by the microneutralization assay). By day 21, hemagglutination-inhibition and microneutralization antibody titers of 1:40 or more were seen in 77 to 96% and 92 to 100% of subjects receiving MF59-adjuvanted vaccine, respectively, and in 63 to 72% and 67 to 76% of those receiving nonadjuvanted vaccine, respectively. By day 42, after two doses of vaccine, hemagglutination-inhibition and microneutralization antibody titers of 1:40 or more were seen in 92 to 100% and 100% of recipients of MF59-adjuvanted vaccine, respectively, and in 74 to 79% and 78 to 83% of recipients of nonadjuvanted vaccine, respectively.
Conclusions. Monovalent 2009 influenza A (H1N1) MF59-adjuvanted vaccine generates antibody responses likely to be associated with protection after a single dose is administered. (ClinicalTrials.gov number, NCT00943358 [ClinicalTrials.gov] .)
Quantifying the risk of pandemic influenza in pregnancy and Indigenous people in Australia in 2009
Kelly H, Mercer GN, Cheng AC. Eurosurveillance. 17 December 2009;14(50):article 2.
Available at http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19441.
Abstract. An increased relative risk of infection with the 2009 pandemic H1N1 influenza virus associated with pregnancy and Indigenous status has been a common finding in many countries. Using publicly available data from May to October 2009 in Australia, we estimated the relative risk of hospitalisation, admission to intensive care unit and death as 5.2, 6.5 and 1.4 respectively for pregnant women, and as 6.6, 6.2 and 5.2, respectively for Indigenous Australians. Pregnancy and Indigenous status were associated with severe influenza. More complete analyses of risks in these groups are required to understand and prevent influenza morbidity and mortality.
Influenza Circulation and the Burden of Invasive Pneumococcal Pneumonia during a Non-pandemic Period in the United States
Walter ND, Taylor TH, Shay DK, et al. Clin Infect Dis. 16 December 2009; [Epub ahead of print].
Available at http://www.journals.uchicago.edu/doi/abs/10.1086/649208.
Background. Animal models and data from influenza pandemics suggest that influenza infection predisposes individuals to pneumococcal pneumonia. Influenza may contribute to high winter rates of pneumococcal pneumonia during non?pandemic periods, but the magnitude of this effect is unknown. With use of United States surveillance data during 1995-2006, we estimated the association between influenza circulation and invasive pneumococcal pneumonia rates.
Methods. Weekly invasive pneumococcal pneumonia incidence, defined by isolation of pneumococci from normally sterile sites in persons with clinical or radiographic pneumonia, was estimated from active population?based surveillance in 3 regions of the United States. We used influenza virus data collected by World Health Organization collaborating laboratories in the same 3 regions in seasonally adjusted negative binomial regression models to estimate the influenza?associated fraction of pneumococcal pneumonia.
Results. During 185 million person?years of surveillance, we observed 21,239 episodes of invasive pneumococcal pneumonia; 485,691 specimens were tested for influenza. Influenza circulation was associated with 11%-14% of pneumococcal pneumonia during periods of influenza circulation and 5%-6% overall. In 2 of 3 regions, the association was strongest when influenza circulation data were lagged by 1 week.
Conclusions. During recent seasonal influenza epidemics in the United States, a modest but potentially preventable fraction of invasive pneumococcal pneumonia was associated with influenza circulation.
Neuraminidase inhibitors for preventing and treating influenza in healthy adults: systematic review and meta-analysis
Jefferson T, Jones M, Doshi P, et al. BMJ. 8 December 2009; 339:b5106.
Available at http://www.bmj.com/cgi/content/full/339/dec07_2/b5106.
Objectives. To update a 2005 Cochrane review that assessed the effects of neuraminidase inhibitors in preventing or ameliorating the symptoms of influenza, the transmission of influenza, and complications from influenza in healthy adults, and to estimate the frequency of adverse effects.
Search strategy. An updated search of the Cochrane central register of controlled trials (Cochrane Library 2009, issue 2), which contains the Acute Respiratory Infections Group's specialised register, Medline (1950-Aug 2009), Embase (1980-Aug 2009), and post-marketing pharmacovigilance data and comparative safety cohorts.
Selection criteria. Randomised placebo controlled studies of neuraminidase inhibitors in otherwise healthy adults exposed to naturally occurring influenza.
Main outcome measures. Duration and incidence of symptoms; incidence of lower respiratory tract infections, or their proxies; and adverse events.
Data extraction. Two reviewers applied inclusion criteria, assessed trial quality, and extracted data.
Data analysis. Comparisons were structured into prophylaxis, treatment, and adverse events, with further subdivision by outcome and dose.
Results. 20 trials were included: four on prophylaxis, 12 on treatment, and four on postexposure prophylaxis. For prophylaxis, neuraminidase inhibitors had no effect against influenza-like illness or asymptomatic influenza. The efficacy of oral oseltamivir against symptomatic laboratory confirmed influenza was 61% (risk ratio 0.39, 95% confidence interval 0.18 to 0.85) at 75 mg daily and 73% (0.27, 0.11 to 0.67) at 150 mg daily. Inhaled zanamivir 10 mg daily was 62% efficacious (0.38, 0.17 to 0.85). Oseltamivir for postexposure prophylaxis had an efficacy of 58% (95% confidence interval 15% to 79%) and 84% (49% to 95%) in two trials of households. Zanamivir performed similarly. The hazard ratios for time to alleviation of influenza-like illness symptoms were in favour of treatment: 1.20 (95% confidence interval 1.06 to 1.35) for oseltamivir and 1.24 (1.13 to 1.36) for zanamivir. Eight unpublished studies on complications were ineligible and therefore excluded. The remaining evidence suggests oseltamivir did not reduce influenza related lower respiratory tract complications (risk ratio 0.55, 95% confidence interval 0.22 to 1.35). From trial evidence, oseltamivir induced nausea (odds ratio 1.79, 95% confidence interval 1.10 to 2.93). Evidence of rarer adverse events from pharmacovigilance was of poor quality or possibly under-reported.
Conclusion. Neuraminidase inhibitors have modest effectiveness against the symptoms of influenza in otherwise healthy adults. The drugs are effective postexposure against laboratory confirmed influenza, but this is a small component of influenza-like illness, so for this outcome neuraminidase inhibitors are not effective. Neuraminidase inhibitors might be regarded as optional for reducing the symptoms of seasonal influenza. Paucity of good data has undermined previous findings for oseltamivir's prevention of complications from influenza. Independent randomised trials to resolve these uncertainties are needed.
Evidence of Bias in Studies of Influenza Vaccine Effectiveness in Elderly Patients
Baxter R, Lee J, Fireman B. J Infect Dis. 08 December 2009; [Epub ahead of print].
Available at http://www.journals.uchicago.edu/doi/abs/10.1086/649568.
Abstract. Although studies have shown influenza vaccines to be effective in preventing death in the elderly population, these findings may be the result of selection bias. We examined the relationship between vaccination, age, underlying morbidity, and probability of death in the upcoming year. Vaccination coverage varied in a curvilinear fashion with age, morbidity, and risk of death. Forgoing vaccination predicted death in those who had received vaccinations in the previous 5 years, but it predicted survival in patients who had never before received a vaccination. We conclude that bias is inherent in studies of influenza vaccination and death among elderly patients.
Modeling gene sequences over time in 2009 H1N1 Influenza A Virus populations
Goñi N, Fajardo A, Moratorio G, et al. Virology Journal. 04 December 2009;6:215.
Available at http://www.virologyj.com/content/6/1/215.
Background. A sudden emergence of Influenza A Virus (IAV) infections with a new pandemic H1N1 IAV is taking place since April of 2009. In order to gain insight into the mode of evolution of these new H1N1 strains, we performed a Bayesian coalescent Markov chain Monte Carlo (MCMC) analysis of full-length neuraminidase (NA) gene sequences of 62 H1N1 IAV strains (isolated from March 30th to by July 28th, 2009).
Results. The results of these studies revealed that the expansion population growth model was the best to fit the sequence data. A mean of evolutionary change of 7.84 × 10-3 nucleotide substitutions per site per year (s/s/y) was obtained for the NA gene. A significant contribution of first codon position to this mean rate was observed. Maximum clade credibility trees revealed a rapid diversification of NA genes in different genetic lineages, all of them containing Oseltamivir-resistant viruses of very recent emergence. Mapping of naturally occurring amino acid substitutions in the NA protein from 2009 H1N1 IAV circulating in 62 different patients revealed that substitutions are distributed all around the surface of the molecule, leaving the hydrophobic core and the catalytic site essentially untouched.
Conclusion. High evolutionary rates and fast population growth have contributed to the initial transmission dynamics of 2009 H1N1 IAV. Naturally occurring substitutions are preferentially located at the protein surface and do not interfere with the NA active site. Antigenic regions relevant for vaccine development can differ from previous vaccine strains and vary among patients.
Estimated epidemiologic parameters and morbidity associated with pandemic H1N1 influenza
Tuite AR, Greer AL, Whelan M, et al. CMAJ. 03 December 2009; [Epub ahead of print].
Available at http://www.cmaj.ca/cgi/content/abstract/cmaj.091807v1.
Background. In the face of an influenza pandemic, accurate estimates of epidemiologic parameters are required to help guide decision-making. We sought to estimate epidemiologic parameters for pandemic H1N1 influenza using data from initial reports of laboratory-confirmed cases.
Methods. We obtained data on laboratory- confirmed cases of pandemic H1N1 influenza reported in the province of Ontario, Canada, with dates of symptom onset between Apr.13 and June 20, 2009. Incubation periods and duration of symptoms were estimated and fit to parametric distributions. We used competing-risk models to estimate risk of hospital admission and case-fatality rates. We used a Markov Chain Monte Carlo model to simulate disease transmission.
Results. The median incubation period was 4 days and the duration of symptoms was 7 days. Recovery was faster among patients less than 18 years old than among older patients (hazard ratio 1.23, 95% confidence interval 1.06-1.44). The risk of hospital admission was 4.5% (95% CI 3.8%-5.2%) and the case-fatality rate was 0.3% (95% CI 0.1%-0.5%). The risk of hospital admission was highest among patients less than 1 year old and those 65 years or older. Adults more than 50 years old comprised 7% of cases but accounted for 7 of 10 initial deaths (odds ratio 28.6, 95% confidence interval 7.3-111.2). From the simulation models, we estimated the following values (and 95% credible intervals): a mean basic reproductive number (Ro, the number of new cases created by a single primary case in a susceptible population) of 1.31 (1.25-1.38), a mean latent period of 2.62 (2.28-3.12) days and a mean duration of infectiousness of 3.38 (2.06-4.69) days. From these values we estimated a serial interval (the average time from onset of infectiousness in a case to the onset of infectiousness in a person infected by that case) of 4-5 days.
Interpretation. The low estimates for Ro indicate that effective mitigation strategies may reduce the final epidemic impact of pandemic H1N1 influenza.
Pulmonary Pathologic Findings of Fatal 2009 Pandemic Influenza A/H1N1 Viral Infections
Gill JR, Sheng Z, Ely SF, et al. Arch Pathol Lab Med. 2010;134:E1-E9.
Available at http://arpa.allenpress.com/pdf/i1543-2165-134-2-1.pdf.
Context. In March 2009, a novel swine-origin influenza A/H1N1 virus was identified. After global spread, the World Health Organization in June declared the first influenza pandemic in 41 years. Objective.-To describe the clinicopathologic characteristics of 34 people who died following confirmed A/ H1N1 infection with emphasis on the pulmonary pathology findings.
Design. We reviewed medical records, autopsy reports, microbiologic studies, and microscopic slides of 34 people who died between May 15 and July 9, 2009, and were investigated either by the New York City Office of Chief Medical Examiner (32 deaths) or through the consultation service of a coauthor (2 deaths).
Results. Most of the 34 decedents (62%) were between 25 and 49 years old (median, 41.5 years). Tracheitis, bronchiolitis, and diffuse alveolar damage were noted in most cases. Influenza viral antigen was observed most commonly in the epithelium of the tracheobronchial tree but also in alveolar epithelial cells and macrophages. Most cases were reverse transcription-polymerase chain reaction positive for influenza. Histologic and microbiologic autopsy evidence of bacterial pneumonia was detected in 55% of cases. Underlying medical conditions including cardiorespiratory diseases and immunosuppression were present in 91% of cases. Obesity (body mass index, .30) was noted in 72% of adult and adolescent cases.
Conclusions. The pulmonary pathologic findings in fatal disease caused by the novel pandemic influenza virus are similar to findings identified in past pandemics. Superimposed bacterial infections of the respiratory tract were common. Preexisting obesity, cardiorespiratory diseases, and other comorbidities also were prominent findings among the decedents.
International Symposium on Neglected Influenza Viruses
Amelia Island, Florida, 3-5 Feb 2010
The International Symposium on Neglected Influenza Viruses will bring together international scientists whose work focuses on mammalian influenza viruses from nonhuman/nonavian sources. You are invited to submit an abstract of original research in all areas related to nonhuman/nonavian influenza research for oral or poster presentation.
For a complete conference program, registration, and abstract submission information visit https://www.isirv.org/events/neglected-influenza/.
14th International Congress on Infectious Diseases (ICID)
Miami, Florida, 9-12 Mar 2010
Take advantage of reduced registration fees by registering on or before January 15, 2010.
Additional information and registration available at http://www.isid.org/14th_icid/.
ISHEID Symposium on HIV and Emerging Infectious Diseases
Marseille, France, 24-26 Mar 2010
Tackling each topic from basic science to clinical applications, this meeting will deal with issues of HIV/AIDS, Viral Hepatitis, Emerging Infectious Diseases, and welcome many Key Opinion Leaders.
Additional information and registration available at http://www.isheid.com/.
The ISHEID 2010 congress organizing office...
E-mail: firstname.lastname@example.org; Ph. : +33 1 44 64 15 15 - Fax : +33 1 44 64 15 16
CDC 7th International Conference on Emerging Infectious Diseases
Atlanta, Georgia, 11-14 Jul 2010
The 2010 International Conference on Emerging Infectious Diseases (ICEID) is the principal meeting for emerging infectious diseases organized by CDC. This conference includes plenary and panel sessions, as well as oral and poster presentations, and covers a broad spectrum of infectious diseases of public health relevance. ICEID 2010 will also focus on the impact of various intervention and preventive strategies that have been implemented to address emerging infectious disease threats.
Additional information is available at http://www.iceid.org/.
Options for the Control of Influenza VII
Hong Kong , 3-7 Sep 2010
Options for the Control of Influenza VII is the largest forum devoted to all aspects of the prevention, control, and treatment of influenza. As it has for over 20 years, Options VII will highlight the most recent advances in the science of influenza. The scientific program committee invites authors to submit original research in all areas related to influenza for abstract presentation. Accepted abstracts will be assigned for oral or poster presentation.
Additional information is available at http://www.controlinfluenza.com.
Updated influenza guidance and information from the US CDC
Updated Interim Recommendations: Special Considerations for Clinicians Regarding 2009 H1N1 Influenza in Severely Immunosuppressed Patients
Released 16 December 2009
Available at http://www.cdc.gov/h1n1flu/immunosuppression/index.htm.
Non-Safety-Related Voluntary Recall of Certain Lots of Sanofi Pasteur H1N1 Pediatric (0.25 mL, for 6-35 month olds) Vaccine in Pre-Filled Syringes Questions & Answers
Released 15 December 2009
Available at http://www.cdc.gov/h1n1flu/vaccination/syringes_qa.htm.
H1N1 Flu (Swine Flu): Resources for Obstetric Health Care Providers
Released 14 December 2009
Available at http://www.cdc.gov/h1n1flu/clinician_pregnant.htm.
In the News: Deaths related to 2009 H1N1 & American Indians and Alaskan Natives
Released 11 December 2009
Available at http://www.cdc.gov/h1n1flu/in_the_news/deaths_american_indians.htm.