The A(H7N9) virusInfluenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. Although some H7 viruses (H7N2, H7N3 and H7N7) have occasionally been found to infect humans, no human infections with H7N9 viruses have been reported until March 2013, when three urban residents of Shanghai or Anhui, China, presented with rapidly progressing lower respiratory tract infections and were found to be infected with a novel reassortant avian-origin influenza A (H7N9) virus.
Developing a vaccineThere is currently no vaccine for the prevention of avian influenza A(H7N9) infections. "However, viruses have already been isolated and characterized from the initial cases. The first step in development of a vaccine is the selection of candidate viruses that could go into a vaccine. WHO, in collaboration with partners, will continue to characterize available avian influenza A(H7N9) viruses to identify the best candidate viruses. These candidate vaccine viruses can then be used for the manufacture of vaccine if this step becomes necessary." (WHO 30 April 2013)
WHO Avian influenza A(H7N9) virus
This webpage lists up-to-date information on the developing H7N9 situation. It includes updates on human infection caused by the avian influenza A(H7N9) virus, numbers of confirmed human cases reported to the WHO, technical guidance and frequently asked questions.
Avian Influenza A(H7N9) Response:An Investment in Public Health Preparedness
Hong Kong Centre for Health Protection (CHP)
Chinese Center for Disease Control and Prevention
Dr Ian M Mackay Avian influenza A virus H7N9...
Virology Down Under, University of Queensland, Australia
Influenza Specialist Group, Australia
Spatial and temporal analysis of human infection with avian influenza A(H7N9) virus in China, 2013
Liu W. et al. Euro Surveill 2013 Nov 21;18(47):pii=20640
Origin and characteristics of internal genes affect infectivity of the novel avian-origin influenza A (H7N9) virus
Feng Y. et al. PLoS One 2013 (published online Nov 22)
A novel pyrosequencing assay for the detection of neuraminidase inhibitor resistance-conferring mutations among clinical isolates of avian H7N9 influenza virus.
Qi Y. et al. Virus Res. 2013 Nov 5. pii: S0168-1702(13)00373-0. doi: 10.1016/j.virusres.2013.10.026. [Epub ahead of print]
Virological, Serological, and Antiviral Studies in an Imported Human Case of Avian Influenza A(H7N9) Virus in Taiwan.
Lin PH. et al. Clin Infect Dis. 2013 Nov 15. [Epub ahead of print]
Serological survey in close contacts with a confirmed case of H7N9 influenza in Taiwan.
Hsieh SM. et al. J Infect. 2013 Nov;67(5):494-5. doi: 10.1016/j.jinf.2013.08.003. Epub 2013 Aug 9.
Mild illness in avian influenza A(H7N9) virus–infected poultry worker, Huzhou, China, April 2013.
Huakun Lv et al. Emerg Infect Dis 2013 Nov
Geographic co-distribution of influenza virus subtypes H7N9 and H5N1 in humans, China
Wang L et al. Emerg Infect Dis 2013
Evolution of Influenza A Virus H7 and N9 Subtypes, Eastern Asia
Camille Lebarbenchon, Justin D. Brown, and David E. Stallknecht Emerging Infectious Diseases Volume 19, Number 10—October 2013
Surveillance for avian influenza A(H7N9), Beijing, China, 2013.
Yang P. et al. Emerg Infect Dis 2013 Dec
Use of national pneumonia surveillance to describe influenza A(H7N9) virus epidemiology, China, 2004–2013.
Xiang N. et al. Emerg Infect Dis 2013 Nov
Effect of closure of live poultry markets on poultry-to-person transmission of avian influenza A H7N9 virus: an ecological study
Hongjie Yu et al. The Lancet, Early Online Publication, 31 October 2013
Inhibition of Influenza H7 Hemagglutinin-Mediated Entry
Antanasijevic A. et al. PLoS ONE 8(10): e76363. doi:10.1371/journal.pone.0076363
Adaptation of novel H7N9 influenza A virus to human receptors.
Dortmans JC. et al. Sci Rep. 2013 Oct 28;3:3058. doi: 10.1038/srep03058.
The emergence of H7N9 viruses: a chance to redefine correlates of protection for influenza virus vaccines.
Krammer F, Cox RJ. Expert Rev Vaccines. 2013 Oct 25. [Epub ahead of print]
A new piece in the puzzle of the novel avian-origin influenza a (H7N9) virus.
Lee RT. et al. Biol Direct. 2013 Oct 26;8(1):26. [Epub ahead of print]
A Detailed Epidemiological and Clinical Description of 6 Human Cases of Avian-Origin Influenza A (H7N9) Virus Infection in Shanghai.
Shi J. et al. PLoS One. 2013 Oct 15;8(10):e77651. doi: 10.1371/journal.pone.0077651.
Surveillance of the first case of human avian influenza A (H7N9) virus in Beijing, China.
Song R et al. Infection. 2013 Oct 16. [Epub ahead of print]
Laboratory findings in patients with avian-origin influenza A (H7N9) virus infections.
Zhang J, Zhao Y, Chen Y. J Med Virol. 2013 Oct 11. doi: 10.1002/jmv.23780. [Epub ahead of print]
Development of dual-function ELISA for effective antigen and antibody detection against H7 avian influenza virus.
He F. et al. BMC Microbiol. 2013 Oct 2;13(1):219. [Epub ahead of print]
Novel Avian-Origin Influenza A (H7N9) Virus Attaches to Epithelium in Both Upper and Lower Respiratory Tract of Humans.
van Riel D. et al. Am J Pathol. 2013 Oct;183(4):1137-43. doi: 10.1016/j.ajpath.2013.06.011. Epub 2013 Sep 10.
A detailed epidemiological and clinical description of 6 human cases of avian-origin influenza A (H7N9) virus infection in Shanghai
Shi J. et al. PLoS One 2013 Oct 15;8(10):e77651
Screening for H7N9 influenza A by matrix gene-based real-time reverse-transcription PCR
Hackett H. et al. J Virol Methods 2013 (published online Oct 14)
The novel human influenza A(H7N9) virus is naturally adapted to efficient growth in human lung tissue
Knepper J. et al. mBio 2013 Oct 8;4(5):e00601-13
Transmission potential of influenza A/H7N9
Chowell G. et al.February to May 2013, China. BMC Medicine 2013 (published online Oct 2)
Sequential reassortments underlie diverse influenza H7N9 genotypes in China
Wu A. et al. Cell Host Microbe 2013 Published online Sep 19
Detection of antibodies against avian influenza virus subtypes H7 and H9 among veterinarians in Guangdong province, China
Shuo Su et al. Journal of Clinical Microbiology Published ahead of print 18 September 2013,
Clinical Features and Factors Associated with Outcomes of Patients Infected with a Novel Influenza A (H7N9) Virus: A Preliminary Study.
Chen X. et al. PLoS ONE 8(9): e73362. September 17, 2013
R292K Substitution and Drug Susceptibility of Influenza A(H7N9) Viruses
Katrina Sleeman et al. Emerging Infectious Diseases Volume 19, Number 9—September 2013
Inactivation of the novel avian influenza A (H7N9) virus under physical conditions or chemical agents treatment
Zou S. et al. Virol J 2013 Published online Sep 15
Age-Specific and Sex-Specific Morbidity and Mortality from Avian Influenza A(H7N9)
Joseph P. Dudley and Ian M. Mackay Journal of Clinical Virology Available online 12 September 2013
Structures and Receptor Binding of Hemagglutinins from Human-Infecting H7N9 Influenza Viruses
Yi Shi et al. Science Published Online September 5 2013
The first patient infected with avian influenza A (H7N9) virus appearing in summer, China
Peng Yang et al. Sept 3 2013 Journal of Infection
Cytokine and chemokine levels in patients infected with the novel avian influenza A (H7N9) virus in China
Chi U. et al. J Infect Dis 2013 Published online Aug 29
Detection of Influenza H7N9: All Molecular Tests are Not Equal
Todd F. Hatchette et al. Journal of Clinical Microbiology 21 August 2013
Full genome of influenza A (H7N9) virus derived by direct sequencing without culture.
Ren X. et al. Emerg Infect Dis 2013 Nov
The genesis and source of the H7N9 influenza viruses causing human infections in China
Tommy Tsan-Yuk Lam et al. Nature 21 August 2013
Clinical, virological, and histopathological manifestations of fatal human infections by avian influenza A(H7N9) virus
Liang Yu et al. Clinical Infectious Diseases 13 August
Monitoring avian influenza A(H7N9) virus through national influenza-like illness surveillance, China.
Xu C. et al. Emerg Infect Dis Volume 19, Number 8—August 2013
Rapid and Sensitive Detection of Novel Avian-Origin Influenza A (H7N9) Virus by Reverse Transcription Loop-Mediated Isothermal Amplification Combined with a Lateral-Flow Device.
Ge Y. et al. PLoS ONE 8(8): August 1, 2013
Avian flu: Gain-of-function experiments on H7N9
Ron A. M. Fouchier,et al. Nature 500, 150–151 (08 August 2013)
Avian flu: Extra oversight for H7N9 experiments
Harold W. Jaffe, Amy P. Patterson, Nicole Lurie Nature 500, 151 (08 August 2013)
Handle with care
Editorial Nature 07 August 2013
Limited airborne transmission of H7N9 influenza A virus between ferrets
Mathilde Richardet et al. Nature Published online 07 August 2013
Human H7N9 avian influenza virus infection: a review and pandemic risk assessment
Kang Yiu Lai et al. Emerging Microbes and Infections (2013) 2, Published online 7 August 2013
Human to human transmission of H7N9
James W Rudge, Richard Coker. BMJ 2013; 347 (Published 6 August 2013)
Influenza A (H7N9) and the Importance of Digital Epidemiology
Marcel Salathé, et al N Engl J Med 2013; 369:401-404 August 1, 2013
Probable person to person transmission of novel avian influenza A (H7N9) virus in Eastern China, 2013: epidemiological investigation.
Qi X et al. BMJ 2013;347 (early online release)
H7N9 influenza: The emerging infectious disease
Viroj Wiwanitkit North American Journal of Medical Sciences 2013 Volume : 5 Issue : 7 Page : 395-398
Age distribution of cases caused by different influenza viruses
Guus F Rimmelzwaan, Ron AM Fouchier, Albert DME Osterhaus The Lancet Infectious Diseases, Volume 13, Issue 8, Pages 646 - 647, August 2013
The first patient recovered from avian influenza A H7N9 viral infection: A case report and review of the literature
Yanchao He, et al. Respiratory Medicine Case Reports 31 July 2013 Volume 10, 2013, Pages 23–26
Compiling of comprehensive data of human infections with novel influenza A (H7N9) virus
Ying Wu, George F. Gao Frontiers of Medicine July 2013
Tropism and innate host responses of a novel avian influenza A H7N9 virus: an analysis of ex-vivo and in-vitro cultures of the human respiratory tract
Michael CW Chan et al. The Lancet Respiratory Medicine, Early Online Publication, 25 July 2013
Tropism of H7N9 influenza viruses in the human respiratory tract
Jessica A Belser, Terrence M Tumpey The Lancet Respiratory Medicine, Early Online Publication, 25 July 2013
H7N9 Influenza Viruses Are Transmissible in Ferrets by Respiratory Droplet
Qianyi Zang et al. Science Published Online July 18 2013Abstract
Resistance to Neuraminidase Inhibitors Conferred by an R292K Mutation in a Human Influenza Virus H7N9 Isolate Can Be Masked by a Mixed R/K Viral Population
HL Yen et al. mBio 4(4):e00396-13. doi:10.1128/mBio.00396-13.
Mild infection of a novel H7N9 avian influenza virus in children in Shanghai
Xuelian Yu et al. Emerging Microbes and Infections (2013) 2, e41; doi:10.1038/emi.2013.41 Published online 10 July 2013Full text
Characterization of H7N9 influenza A viruses isolated from humans, letter
Watanabe T, Kiso M, Fukuyama S, et al. Nature 2013 Jul 10
Pathogenesis and transmission of avian influenza A (H7N9) virus in ferrets and mice, letter.
Belser JA, Gustin KM, Pearce MB, et al.Nature 2013 Jul 10
H7N9 avian influenza and the perpetual challenge of potential human pandemicity.
Morens DM et al. mBio DOI: 10.1128/mBio.00445-13 (2013).Published 9 July.Full text
Public perceptions and reactions to H7N9 in Mainland China
Robin Goodwin and Shaojing Sun, Journal of Infection, published online 08 July 2013.
Biological features of novel avian influenza A (H7N9) virus
Jaing Zhou et al. Nature (2013) doi:10.1038/nature12379 Published online 3 July 2013
Influenza A (H7N9) and the importance of digital epidemiology, perspective.
Salathe M. N Engl J Med 3 Jul 2013
Emerging H7N9 Influenza A (Novel Reassortant Avian-Origin) Pneumonia: Radiologic Findings
Qingle Wang et al Radiology Published online before print July 2, 2013, doi: 10.1148/radiol.13130988
Case-control study of risk factors for human infection with influenza A(H7N9) virus in Jiangsu Province, China, 2013
J Ai et al. Eurosurveillance, Volume 18, Issue 26, 27 June 2013
Human infection with avian influenza A H7N9 virus: an assessment of clinical severity
Hongjie Yu et al. The Lancet, Early Online Publication, 24 June 2013
Comparative epidemiology of human infections with avian influenza A H7N9 and H5N1 viruses in China: a population-based study of laboratory-confirmed cases
Benjamin J Cowling et al. The Lancet, Early Online Publication, 24 June 2013
Detection of mild to moderate influenza A/H7N9 infection by China’s national sentinel surveillance system for influenza-like illness: case series
Dennis KM Ip et al. BMJ 2013; 346 Published 24 June 2013
The Outbreak of Avian Influenza A (H7N9) in China: Current Status and Future Prospects.
Lu L, He B, Jiang S. Biomed J 2013 Jun 17;36:96-7.
Human co-infection with novel avian influenza A H7N9 and influenza A H3N2 viruses in Jiangsu province, China
Yefei Zhu et al. The Lancet 15 June 2013 (Vol. 381, Issue 9883, Page 2134)
Is avian influenza A (H7N9) virus staggering its way to humans?
Guang-Wu Chen, et al. Journal of the Formosan Medical Association 05 June 2013
Taiwan faces challenges on the emerging avian influenza A (H7N9) virus in China
Ho-Sheng Wu, Jen-Hsiang Chuang, Feng-Yee Chang Journal of the Formosan Medical Association 05 June 2013
Pandemic Influenza Viruses — Hoping for the Road Not Taken
David M. Morens. et al. New England Journal of Medicine June 5, 2013DOI: 10.1056/NEJMp1307009
Deaths Associated with Avian Influenza A(H7N9) Virus in China
Yuehua Ke et al. Ann Intern Med. Published online 4 June 2013 doi:10.7326/0003-4819-159-2-201307160-00669
Avian influenza A(H7N9): information-sharing through government web sites in the Western Pacific Region.
Harada N et al. Western Pacific Surveillance and Response Journal, 4(2). doi:10.5365/wpsar.2013.4.2.010
Association between adverse clinical outcome in human disease caused by novel influenza A H7N9 virus and sustained viral shedding and emergence of antiviral resistance
Yunwen Hu The Lancet Corrected Proof, 29 May 2013 10.1016/S0140-6736(13)61125-3
Serologic study for influenza A (H7N9) among high-risk groups in China
N Engl J Med, published online May 29
Interim Guidance for Antiviral Prophylaxis and Treatment of Influenza Illness due to Avian Influenza A(H7N9) Virus.
AAMI, Canada. Gerald A. Evans Released: May 27, 2013
Infectivity, transmission, and pathology of human H7N9 influenza in ferrets and pigs
H Zhu Science, published online May 23
A comparison of rapid point-of-care tests for the detection of avian influenza A(H7N9) virus, 2013
C. Baas et al. Euro Surveill Eurosurveillance, Volume 18, Issue 21, 23 May 2013
Clinical findings in 111 cases of influenza A (H7N9) virus infection
Hai-Nv Gao et al. N Engl J Med, published online May 22
China's H7N9 outbreak slows but experts remain wary
Ted Alcorn The Lancet Respiratory Medicine, Early Online Publication, 17 May 2013
Population-level antibody estimates to novel influenza A/H7N9
MF Boni et al. Journal of Infectious Diseases published online 17 May 2013
Epidemiological link between exposure to poultry and all influenza A(H7N9) confirmed cases in Huzhou city, China, March to May 2013
J Han et al. Eurosurveillance, Volume 18, Issue 20, 16 May 2013
Surveillance of avian influenza A(H7N9) virus infection in humans and detection of the first imported human case in Taiwan, 3 April to 10 May 2013
Y C Lo et al. Eurosurveillance, Volume 18, Issue 20, 16 May 2013
Risk assessment on the epidemics of human infection with a novel avian influenza A (H7N9) virus in Jiangsu Province, China
Wendong Liu et al. J Biomed Res 16 May 2013
Influenza A (H7N9): from anxiety to preparedness
Andrew T. Pavia Ann Intern Med published online May 14
A proportionate response to H7N9
Editorial from Lancet Infect Dis, published online May 14
Reducing exposure to avian influenza H7N9
Jianguo Xu et al. The Lancet, Early Online Publication, 10 May 2013
Molecular Detection of Human H7N9 Influenza A Virus Causing Outbreaks in China
Chloe KS Wong et al. Clinical Chemistry 10 May 2013
Exposure to avian influenza H7N9 in farms and wet markets.
Shui Shan Lee, Ngai Sze Wong, Chi Chiu Leung The Lancet 10.1016/S0140-6736(13)60949-6, 10 May 2013
Major Challenges in Providing an Effective and Timely Pandemic Vaccine for Influenza A(H7N9)
Michael T. Osterholm, Katie S. Ballering, Nicholas S. Kelley. JAMA. 2013;():1-2. doi:10.1001/jama.2013.6589. Published online May 9, 2013
Preliminary inferences on the age-specific seriousness of human disease caused by avian influenza A(H7N9) infections in China, March to April 2013
B J Cowling et al. Eurosurveillance, Volume 18, Issue 19, 09 May 2013
Monitoring Avian Influenza A(H7N9) Virus through National Influenza-like Illness Surveillance, China
Cuiling Xu et al. Emerg Infect Dis, published online May 8
An overview of the recent outbreaks of the avian-origin influenza A (H7N9) virus in the human
Ren-Bin Tang and Hui-Lan Chen Journal of the Chinese Medical Association 4 May 2013
Clinical Findings for Early Human Cases of Influenza A(H7N9) Virus Infection, Shanghai, China
Shuihua Lu et al. Emerging Infectious Diseases published online May 3
The Novel H7N9 Influenza A Virus: Its Present Impact and Indeterminate Future
Robert E. Kahn and Juergen A. Richt Vector-Borne and Zoonotic Diseases, 30 April 2013
Clinical presentation and sequence analyses of HA and NA antigens of the novel H7N9 viruses
Jiankang Han et al. Emerging Microbes and Infections (2013) 2, e23; doi:10.1038/emi.2013.28 Published online 1 May 2013
Origin and diversity of novel avian influenza A H7N9 viruses causing human infection: phylogenetic, structural, and coalescent analyses
Di Lui et al the Lancet, Early Online Publication, 1 May 2013 doi:10.1016/S0140-6736(13)60938-1
Avian Influenza A(H7N9) Virus Infections, Shanghai, China
Letter from Emerging Infectious Diseases, published online 1 May 2013
Emergence of Avian Influenza A(H7N9) Virus Causing Severe Human Illness — China, February–April 2013
Morbidity and Mortality Weekly Report May 1, 2013 / 62(Early Release);1-6
The first case of H7N9 influenza in Taiwan
Sui-Yuan Chang et al. Lancet 29 April 2013
We report here the first case of H7N9 infection outside mainland China
Epidemiological and risk analysis of the H7N9 subtype influenza outbreak in China at its early stage
QingYe Zhuang et al. Chinese Science Bulletin 29 April 2013
Dozens of human cases infected with H7N9 subtype avian influenza virus (AIV) have been confirmed in China since March, 2013. Distribution data of sexes, ages, professions and regions of the cases were analyzed in this report. The results showed that the elderly cases, especially the male elderly, were significantly more than expected, which is different from human cases of H5N1 avian influenza and human cases of the pandemic H1N1 influenza. The outbreak was rated as a Grade III (severe) outbreak, and it would evolve into a Grade IV (very severe) outbreak soon, using a method reported previously. The H7N9 AIV will probably circulate in humans, birds and pigs for years. Moreover, with the driving force of natural selection, the virus will probably evolve into highly pathogenic AIV in birds, and into a deadly pandemic influenza virus in humans. Therefore, the H7N9 outbreak has been assumed severe, and it is likely to become very or extremely severe in the future, highlighting the emergent need of forceful scientific measures to eliminate any infected animal flocks. We also described two possible mild scenarios of the future evolution of the outbreak.
Isolation and characterization of H7N9 viruses from live poultry markets—Implication of the source of current H7N9 infection in humans
JianZhong Shi et al. Chinese Science Bulletin 27 April 2013
On March 31, 2013, the National Health and Family Planning Commission announced that human infections with a previously undescribed influenza A (H7N9) virus had occurred in Shanghai and Anhui Province, China. To investigate the possible origins of the H7N9 viruses causing these human infections, we collected 970 samples, including drinking water, soil, and cloacal and tracheal swabs of poultry from live poultry markets and poultry farms in Shanghai and Anhui Province. Twenty samples were positive for the H7N9 influenza virus. Notably, all 20 viruses were isolated from samples collected from live poultry markets in Shanghai. Phylogenetic analyses showed that the six internal genes of these novel human H7N9 viruses were derived from avian H9N2 viruses, but the ancestor of their HA and NA genes is uncertain. When we examined the phylogenetic relationship between the H7N9 isolates from live poultry markets and the viruses that caused the human infections, we found that they shared high homology across all eight gene segments. We thus identified the direct avian origin of the H7N9 influenza viruses that caused the human infections. Importantly, we observed that the H7N9 viruses isolated from humans had acquired critical mutations that made them more “human-like”. It is therefore imperative to take strong measures to control the spread of H7N9 viruses in birds and humans to prevent further threats to human health.
Influenza.Despite large research effort, H7N9 continues to baffle.
Hvistendahl M. Science. 2013 Apr 26;340(6131):414-5. doi: 10.1126/science.340.6131.414.
Preliminary Report: Epidemiology of the Avian Influenza A (H7N9) Outbreak in China.
Li Q. et al. N Engl J Med. 2013 Apr 24. [Epub ahead of print]
Background The first identified cases of avian influenza A (H7N9) virus infection in humans occurred in China during February and March 2013. We analyzed data obtained from field investigations to characterize the epidemiologic characteristics of H7N9 cases in China as of April 17, 2013. Methods Field investigations were conducted for each confirmed case of H7N9 virus infection. A patient was considered to have a confirmed case if the presence of the H7N9 virus was verified by means of real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR), viral isolation, or serologic testing. Information on demographic characteristics, exposure history, and illness timelines was obtained from patients with confirmed cases. Close contacts were monitored for 7 days for symptoms of illness. Throat swabs were obtained from contacts in whom symptoms developed and were tested for the presence of the H7N9 virus testing by means of real-time RT-PCR. Results Among 82 persons with confirmed H7N9 virus infection, the median age was 63 years (range, 2 to 89), 73% were male, and 84% were urban residents. Confirmed cases occurred in six areas of China. Of 77 persons with available data, 4 were poultry workers, and 77% had a history of exposure to live animals, including chickens (76%). A total of 17 persons (21%) died after a median duration of illness of 11 days, 60 remain critically ill, and 4 with clinically mild cases were discharged from the hospital; 1 pediatric patient was not admitted to the hospital. In two family clusters, human-to-human transmission of H7N9 virus could not be ruled out. A total of 1251 of the 1689 close contacts of case patients completed the monitoring period; respiratory symptoms developed in 19 of them (1.5%), all of whom tested negative for the H7N9 virus. Conclusions Most persons with confirmed H7N9 virus infection were critically ill and epidemiologically unrelated. Laboratory-confirmed human-to-human H7N9 virus transmission was not documented among close contacts, but such transmission could not be ruled out in two families.
Analysis of the clinical characteristics and treatment of two patients with avian influenza virus (H7N9).
Lu S.H.et al. Biosci Trends. 2013 Apr;7(2):109-12.
Avian influenza is one of the most dangerous contagions in poultry worldwide, and avian influenza A viruses are the major pathogens responsible. Outbreaks of H7N9, a strain of the avian influenza A virus H7 subtype, have increasingly been reported in several countries since 2007. This spring, H7N9 broke out in China and has thus far caused 24 cases of infection and 7 deaths. Recently, we treated two patients with H7N9 infection. The infection was characterized by respiratory symptoms, fever, rapid progression, and significant hypoxemia. Laboratory tests showed a low level or decrease in leukocytes, a drop in blood platelets, and an increase in myocardial enzymes and aspartate aminotransferase. Oseltamivir, anti-infective drugs, and immunoglobulin were administered. Supplemental oxygen or non-invasive mechanical ventilation helped to relieve symptoms. This report provides information on the clinical characteristics and treatment of two Chinese patients with H7N9.
Specific detection by real-time reverse-transcription PCR assays of a novel avian influenza A(H7N9) strain associated with human spillover infections in China.
Corman V. et al. Euro Surveill. 2013 Apr 18;18(16). pii: 20461.
Emerging risk of H7N9 influenza in China.
Wu S, Wu F. Lancet. 2013 Apr 18. pii: S0140-6736(13)60767-9. doi: 10.1016/S0140-6736(13)60767-9. [Epub ahead of print]
Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013.
Kageyama T. et al. Euro Surveill. 2013 Apr 11;18(15). pii: 20453.
Novel influenza A(H7N9) virus linked to human disease in China, April 2013.
Eurosurveillance editorial team. Euro Surveill. 2013 Apr 4;18(14). pii: 20445.
H7N9 Incident, immune status, the elderly and a warning of an influenza pandemic.
Guan Y. et al. J Infect Dev Ctries. 2013 Apr 17;7(4):302-7. doi: 10.3855/jidc.3675.
The novel re-assortment A influenza H7N9 (nrH7N9) emerged in humans in the Shanghai and surrounding provinces of China in late February and early March. Three infected index patients developed severe viral pneumonia with acute respiratory distress syndrome (ARDS) and resulted in fatal outcome. As of 15 April 2013 there were reported 60 confirmed nrH7N9 infections with 13 fatalities. Human-to-human transmission has not been observed, but zoonotic infections of nrH7N9 from birds to humans appear to be associated with live poultry markets. Elderly patients greater than 60 years of age accounted for 61% of the cases, indicating that the elderly may be at high risk for severe disease.
Influenza. New flu virus in China worries and confuses.
Cohen J. Science. 2013 Apr 12;340(6129):129-30. doi: 10.1126/science.340.6129.129.
Global Concerns Regarding Novel Influenza A (H7N9) Virus Infections.
Uyeki TM, Cox NJ. N Engl J Med. 2013 Apr 11. [Epub ahead of print]
Severe disease in humans caused by a novel influenza A virus that is distinct from circulating human influenza A viruses is a seminal event. It might herald sporadic human infections from an animal source - e.g., highly pathogenic avian influenza (HPAI) A (H5N1) virus; or it might signal the start of an influenza pandemic - e.g., influenza A(H1N1)pdm09 virus. Therefore, the discovery of novel influenza A (H7N9) virus infections in three critically ill patients reported in the Journal by Gao and colleagues is of major public health significance. Chinese scientists are to be congratulated for the apparent speed with which .
Human Infection with a Novel Avian-Origin Influenza A (H7N9) Virus.
Gao R. et al. N Engl J Med. 2013 Apr 11. [Epub ahead of print]
Background Infection of poultry with influenza A subtype H7 viruses occurs worldwide, but the introduction of this subtype to humans in Asia has not been observed previously. In March 2013, three urban residents of Shanghai or Anhui, China, presented with rapidly progressing lower respiratory tract infections and were found to be infected with a novel reassortant avian-origin influenza A (H7N9) virus. Methods We obtained and analyzed clinical, epidemiologic, and virologic data from these patients. Respiratory specimens were tested for influenza and other respiratory viruses by means of real-time reverse-transcriptase-polymerase-chain-reaction assays, viral culturing, and sequence analyses. Results A novel reassortant avian-origin influenza A (H7N9) virus was isolated from respiratory specimens obtained from all three patients and was identified as H7N9. Sequencing analyses revealed that all the genes from these three viruses were of avian origin, with six internal genes from avian influenza A (H9N2) viruses. Substitution Q226L (H3 numbering) at the 210-loop in the hemagglutinin (HA) gene was found in the A/Anhui/1/2013 and A/Shanghai/2/2013 virus but not in the A/Shanghai/1/2013 virus. A T160A mutation was identified at the 150-loop in the HA gene of all three viruses. A deletion of five amino acids in the neuraminidase (NA) stalk region was found in all three viruses. All three patients presented with fever, cough, and dyspnea. Two of the patients had a history of recent exposure to poultry. Chest radiography revealed diffuse opacities and consolidation. Complications included acute respiratory distress syndrome and multiorgan failure. All three patients died. Conclusions Novel reassortant H7N9 viruses were associated with severe and fatal respiratory disease in three patients. (Funded by the National Basic Research Program of China and others.).