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 inves...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.展开更多
The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have ca...The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have caused five waves of human infection, with almost half of the total number of human cases(766 of 1,567) being reported in the fifth wave, raising concerns that even more human infections could occur in the sixth wave. In September 2017, an H5/H7 bivalent inactivated vaccine for chickens was introduced, and the H7 N9 virus isolation rate in poultry dropped by 93.3% after vaccination. More importantly,only three H7 N9 human cases were reported between October 1, 2017 and September 30, 2018, indicating that vaccination of poultry successfully eliminated human infection with H7 N9 virus. These facts emphasize that active control of animal disease is extremely important for zoonosis control and human health protection.展开更多
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
Since the first case of novel H7N9 infection was reported,China has experienced five epidemics of H7N9.During the fifth wave,a highly pathogenic H7N9 strain emerged.Meanwhile,the H7N9 virus continues to accumulate mut...Since the first case of novel H7N9 infection was reported,China has experienced five epidemics of H7N9.During the fifth wave,a highly pathogenic H7N9 strain emerged.Meanwhile,the H7N9 virus continues to accumulate mutations,and its affinity for the human respiratory epithelial sialic acid 2-6 receptor has increased.Therefore,a pandemic is still possible.In the past 6 years,we have accumulated rich experience in dealing with H7N9,especially in terms of virus tracing,epidemiological research,key site mutation monitoring,critical disease mechanisms,clinical treatment,and vaccine development.In the research fields above,significant progress has been made to effectively control the spread of the epidemic and reduce the fatality rate.To fully document the research progress concerning H7N9,we reviewed the clinical and epidemiological characteristics of H7N9,the key gene mutations of the virus,and H7N9 vaccine,thus providing a scientific basis for further monitoring and prevention of H7N9 influenza epidemics.展开更多
Background Rapidly progressive pneumonia infection with H7N9 virus is a novel disease,and limited information is available concerning serial chest radiographic and computed tomography （CT） findings.The aim of this s...Background Rapidly progressive pneumonia infection with H7N9 virus is a novel disease,and limited information is available concerning serial chest radiographic and computed tomography （CT） findings.The aim of this study was to evaluate the changes in serial radiologic findings in patients with H7N9 pneumonia.Methods The two institutional ethics review boards approved this retrospective study.This study included 10 patients with H7N9 pneumonia.All patients underwent chest radiologic examinations at different time points.Serial radiologic images were systematically analyzed.Results All patients showed abnormal results on initial chest radiography and CT.The initial radiographic abnormalities were unilateral （n=9） and bilateral （n=1）,including ground-glass opacities （GGOs） （n=5） and consolidation （n=5）.The initial CT findings consisted of unilateral （n=6） and bilateral （n=4）,including consolidation （n=10）,GGOs （n=10）,reticular opacities （n=2）,and pleural effusion （n=3）.Follow-up radiologic findings showed rapid development of consolidation or GGOs within two weeks after illness onset.Pneumomediastinum with secondary subcutaneous emphysema and pneumothorax were noted in two patients.Follow-up high resolution computed tomography （HRCT） after two weeks showed slow improvement in both size and opacity of the lesions.On HRCT after discharge,patients had substantial residual lesions such as irregular linear opacities,reticular opacities,parenchymal bands,traction bronchiectasis,and cystic lesions.Conclusions The most common radiologic findings at presentation are multifocal or diffuse areas of consolidation and GGOs in H7N9 pneumonia.HRCT in sequence can show more changes in rapid progression of disease and a slow decrease of both size and opacity of the lesions plays an important role in the evaluation of H7N9 pneumonia.展开更多
基金supported by the National Basic Research Program of China,the China Agricultural Research System (CARS-42-G08)the National Science and Technology Major Project (2012ZX10004214)
文摘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.
基金supported by the National Key R&D Program of China (2016YFD0500201, 2016YFD0500203)the National Natural Science Foundation of China (31521005)+1 种基金the China Agriculture Research System (CARS-41-G12)the US NIH CEIRS contract HHSN272201400004C
文摘The H7 N9 viruses that emerged in China in 2013 were nonpathogenic in chickens but mutated to a highly pathogenic form in early 2017 and caused severe disease outbreaks in chickens. The H7 N9 influenza viruses have caused five waves of human infection, with almost half of the total number of human cases(766 of 1,567) being reported in the fifth wave, raising concerns that even more human infections could occur in the sixth wave. In September 2017, an H5/H7 bivalent inactivated vaccine for chickens was introduced, and the H7 N9 virus isolation rate in poultry dropped by 93.3% after vaccination. More importantly,only three H7 N9 human cases were reported between October 1, 2017 and September 30, 2018, indicating that vaccination of poultry successfully eliminated human infection with H7 N9 virus. These facts emphasize that active control of animal disease is extremely important for zoonosis control and human health protection.
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supported by the State Project of Essential Drug Research and Development(No.2015ZX09101044).
文摘Since the first case of novel H7N9 infection was reported,China has experienced five epidemics of H7N9.During the fifth wave,a highly pathogenic H7N9 strain emerged.Meanwhile,the H7N9 virus continues to accumulate mutations,and its affinity for the human respiratory epithelial sialic acid 2-6 receptor has increased.Therefore,a pandemic is still possible.In the past 6 years,we have accumulated rich experience in dealing with H7N9,especially in terms of virus tracing,epidemiological research,key site mutation monitoring,critical disease mechanisms,clinical treatment,and vaccine development.In the research fields above,significant progress has been made to effectively control the spread of the epidemic and reduce the fatality rate.To fully document the research progress concerning H7N9,we reviewed the clinical and epidemiological characteristics of H7N9,the key gene mutations of the virus,and H7N9 vaccine,thus providing a scientific basis for further monitoring and prevention of H7N9 influenza epidemics.
文摘Background Rapidly progressive pneumonia infection with H7N9 virus is a novel disease,and limited information is available concerning serial chest radiographic and computed tomography （CT） findings.The aim of this study was to evaluate the changes in serial radiologic findings in patients with H7N9 pneumonia.Methods The two institutional ethics review boards approved this retrospective study.This study included 10 patients with H7N9 pneumonia.All patients underwent chest radiologic examinations at different time points.Serial radiologic images were systematically analyzed.Results All patients showed abnormal results on initial chest radiography and CT.The initial radiographic abnormalities were unilateral （n=9） and bilateral （n=1）,including ground-glass opacities （GGOs） （n=5） and consolidation （n=5）.The initial CT findings consisted of unilateral （n=6） and bilateral （n=4）,including consolidation （n=10）,GGOs （n=10）,reticular opacities （n=2）,and pleural effusion （n=3）.Follow-up radiologic findings showed rapid development of consolidation or GGOs within two weeks after illness onset.Pneumomediastinum with secondary subcutaneous emphysema and pneumothorax were noted in two patients.Follow-up high resolution computed tomography （HRCT） after two weeks showed slow improvement in both size and opacity of the lesions.On HRCT after discharge,patients had substantial residual lesions such as irregular linear opacities,reticular opacities,parenchymal bands,traction bronchiectasis,and cystic lesions.Conclusions The most common radiologic findings at presentation are multifocal or diffuse areas of consolidation and GGOs in H7N9 pneumonia.HRCT in sequence can show more changes in rapid progression of disease and a slow decrease of both size and opacity of the lesions plays an important role in the evaluation of H7N9 pneumonia.
