A novel H7N9 influenza A virus has been discovered as the causative identity of the emerging acute respiratory infection cases in Shanghai,China.This virus has also been identified in cases of infection in the neighbo...A novel H7N9 influenza A virus has been discovered as the causative identity of the emerging acute respiratory infection cases in Shanghai,China.This virus has also been identified in cases of infection in the neighboring area Hangzhou City in Zhejiang Province.In this study,epidemiologic,clinical,and virological data from three patients in Hangzhou who were confirmed to be infected by the novel H7N9 influenza A virus were collected and analyzed.Human respiratory specimens and chicken feces from a contacted free market were tested for influenza virus by real-time reverse transcription PCR(RT-PCR) and sequencing.The clinical features of the three cases were similar featured with high fever and severe respiratory symptoms;however,only one of the patients died.A certain degree of diversity was observed among the three Hangzhou viruses sequenced from human samples compared with other reported H7N9 influenza A viruses.The sequences of the novel avian-origin H7N9 influenza viruses from Hangzhou City contained important amino acid substitutions related to human adaptation.One of the Hangzhou viruses had gained a novel amino acid substitution(Q226I) in the receptor binding region of hemagglutinin.More importantly,the virus sequenced from the chicken feces had a 627E substitution in the PB2 protein instead of the mammalian-adapted 627K substitution that was found in the PB2 proteins from the Hangzhou viruses from the three patients.Therefore,the newly-emerging H7N9 virus might be under adaptation pressure that will help it "jump" from avian to human hosts.The significance of these substitutions needs further exploration,with both laboratory experiments and extensive field surveillance.展开更多
All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortalit...All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties.展开更多
基金supported by The Research Grants Council of The HongKong SAR Government (7488/05M) the Research Fund for the Control of Infectious Diseases of the Health, Welfare and Food Bureauof the Hong Kong SAR Government, the Li Ka Shing Foundation+1 种基金the Providence Foundation in memory of The late Dr. Lui Hac Minhgrants from The National Natural Science Foundation of China(30571674, 30771988)~~
基金supported by the Hangzhou Key Medicine Discipline Fund for Public Health Laboratory sponsored by the Hangzhou government,National Basic Research Program of China (2010CB530303,2011-CB504703)an intramural special grant for influenza virus research from Chinese Academy of Sciences (KSZD-EW-Z-002)
文摘A novel H7N9 influenza A virus has been discovered as the causative identity of the emerging acute respiratory infection cases in Shanghai,China.This virus has also been identified in cases of infection in the neighboring area Hangzhou City in Zhejiang Province.In this study,epidemiologic,clinical,and virological data from three patients in Hangzhou who were confirmed to be infected by the novel H7N9 influenza A virus were collected and analyzed.Human respiratory specimens and chicken feces from a contacted free market were tested for influenza virus by real-time reverse transcription PCR(RT-PCR) and sequencing.The clinical features of the three cases were similar featured with high fever and severe respiratory symptoms;however,only one of the patients died.A certain degree of diversity was observed among the three Hangzhou viruses sequenced from human samples compared with other reported H7N9 influenza A viruses.The sequences of the novel avian-origin H7N9 influenza viruses from Hangzhou City contained important amino acid substitutions related to human adaptation.One of the Hangzhou viruses had gained a novel amino acid substitution(Q226I) in the receptor binding region of hemagglutinin.More importantly,the virus sequenced from the chicken feces had a 627E substitution in the PB2 protein instead of the mammalian-adapted 627K substitution that was found in the PB2 proteins from the Hangzhou viruses from the three patients.Therefore,the newly-emerging H7N9 virus might be under adaptation pressure that will help it "jump" from avian to human hosts.The significance of these substitutions needs further exploration,with both laboratory experiments and extensive field surveillance.
基金Acknowledgments We thank Susan Watson for editing the manuscript and those in our laboratories who contributed to the data cited in this review. We also thank Ryo Takano for the preparation of figures. Research in HC＇s group is supported by the Ministry of Science and Technology, China （2004BA519A-57, 2006BAD06A05）. Research in GFG＇s group is supported by the Ministry of Science and Technology, China （MOST, 2005CB523001 and 2006BAD06A01）, the National Natural Science Foundation of China （NSFC, Grant #3059934, #30525010） and the US National Institutes of Health （U19 AI051915-05S1）. Research in YS＇s group is supported by the Ministry of Science and Technology, China （MOST, 2005CB523006 and 2006BAD06A15）, and the National Natural Science Foundation of China （NSFC, Grant #30599433）. Research in YK＇s group is supported by National Institute of Allergy and Infectious Diseases Public Health Service research grants by CREST and ERATO （Japan Science and Technology Agency）, and by grants-in-aid and a contract research fund for the Program of Founding Research Centers for Emerging and Reemerging Infectious Diseases from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
文摘All known subtypes of influenza A viruses are maintained in wild waterfowl, the natural reservoir of these viruses. Influenza A viruses are isolated from a variety of animal species with varying morbidity and mortality rates. More importantly, influenza A viruses cause respiratory disease in humans with potentially fatal outcome. Local or global outbreaks in humans are typically characterized by excess hospitalizations and deaths. In 1997, highly pathogenic avian influenza viruses of the H5N1 subtype emerged in Hong Kong that transmitted to humans, resulting in the first documented cases of human death by avian influenza virus infection. A new outbreak started in July 2003 in poultry in Vietnam, Indonesia, and Thailand, and highly pathogenic avian H5N1 influenza viruses have since spread throughout Asia and into Europe and Africa. These viruses continue to infect humans with a high mortality rate and cause worldwide concern of a looming pandemic. Moreover, H5N1 virus outbreaks have had devastating effects on the poultry industries throughout Asia. Since H5N1 virus outbreaks appear to originate from Southern China, we here examine H5N1 influenza viruses in China, with an emphasis on their biological properties.
