Abstract
Human infections of H5N1 highly pathogenic avian influenza virus have continued to occur in China without corresponding outbreaks in poultry, and there is little conclusive evidence of the source of these infections. Seeking to identify the source of the human infections, we sequenced 31 H5N1 viruses isolated from humans in China (2005 to 2010). We found a number of viral genotypes, not all of which have similar known avian virus counterparts. Guided by patient questionnaire data, we also obtained environmental samples from live poultry markets and dwellings frequented by six individuals prior to disease onset (2008 and 2009). H5N1 viruses were isolated from 4 of the 6 live poultry markets sampled. In each case, the genetic sequences of the environmental and corresponding human isolates were highly similar, demonstrating a link between human infection and live poultry markets. Therefore, infection control measures in live poultry markets are likely to reduce human H5N1 infection in China.
Highlights
Human infections of H5N1 highly pathogenic avian influenza virus have continued to occur in China without corresponding outbreaks in poultry, and there is little conclusive evidence of the source of these infections
The questionnaire data showed that only 3 cases were associated with known H5N1 outbreaks in poultry, whereas 20 cases were associated with contact with sick or dead birds and 11 cases were associated with visits to live poultry markets (Table 1)
Our findings suggest that the live poultry markets of China are an important source of human infection with H5N1 highly pathogenic avian influenza (HPAI) viruses
Summary
Human infections of H5N1 highly pathogenic avian influenza virus have continued to occur in China without corresponding outbreaks in poultry, and there is little conclusive evidence of the source of these infections. Seeking to identify the source of the human infections, we sequenced 31 H5N1 viruses isolated from humans in China (2005 to 2010). The genetic sequences of the environmental and corresponding human isolates were highly similar, demonstrating a link between human infection and live poultry markets. There have been very few subsequent outbreaks detected on domestic poultry farms, but sporadic human H5N1 infections continued to occur in China. With the threat of a new pandemic strain caused by reassortment between H5N1 HPAIV and 2009 H1N1 pandemic viruses, it is important to identify the direct sources of the sporadic human H5N1 cases so that effective prevention and control can be developed. Yen et al, presented at the World Congress on Options for the Control of Influenza IV, Excerpta Medica, Amsterdam, The Netherlands, 2001)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
