Highly pathogenic H5N1 avian influenza virus is an important Old World topic. This current study by Prof. Hongxuan He research group, appears novel and important data. Highly pathogenic avian influenza virus of type A of subtype H5N1(HPAI H5N1) is considered an avian disease, although there is some evidence of limited human-to-human transmission of the virus. A global effort is underway to control or eradicate HAPI H5N1 in poultry and prevent human exposure, both of which may also reduce the risk of pandemic emergence. avian influenza virus of type A of subtype H5N1(HPAI H5N1) is considered an avian disease, although there is some evidence of limited human-to-human transmission of the virus. A global effort is underway to control or eradicate HAPI H5N1 in poultry and prevent human exposure, both of which may also reduce the risk of pandemic emergence. Hemagglutinin gene (HA) sequences from 215 human cases of H5N1 were used to trace the source and dispersal pattern of human cases of H5N1 on a global scale. A mutation network and phylogenetic analyses of the HA shows that human H5N1 virus can be clearly divided into four clusters across geographic space. Based on the 100 and 170 N-glycosylation sites in the HA, human H5N1 viruses were also divided into three types. When combined with GIS data analysis, they found Southern China is often a common source of multiple H5N1 clusters and each cluster has different dispersal patterns and individual evolutionary features. In summary, the genetic evidence presented here provides clear evidence for multiple clusters of human H5N1 initially originating from southern China.

They propose that Southern China was the center of the HPAI H5N1 outbreak from where the virus radiated into Southeast Asia, western and northern China and a final, progressive spread across Eurasia into the Middle East and North Africa. An initial dispersal from southern China into the Indian subcontinent was followed by subsequent transmission to Indonesian islands. This strong phylogeographic structure provides an opportunity to trace the geographic origins of human cases of the HPAI H5N1 virus. In summary, the genetic evidence presented here provides a clear picture for multiple clusters of human HPAI H5N1 and that the source was southern China.

These research results have been published in Journal of Infectious Diseases: BinWu, Chengmin Wang, Guoying Dong, Yunhai Guo, Dale Louis Nolte, Thomas Jude Deliberto, Jianguo Xu,Mingxing Duan, Hongxuan He. New evidence suggests southern China as a common source of multiple clusters of highly pathogenic H5N1 avian influenza virus. The Journal of Infectious diseases, 2010，202:452–458.（IF=5.865）http://www.journals.uchicago.edu/doi/abs/10.1086/653709 .

This work was supported by grants from: This study was supported by grants from the National Key Basic Research and Development Program of China (9732007BC109103), the CAS Innovation Program (KSCX2-YW-N-063), USDA/APHIS/WS-IOZ CAS joint project (0760621234) and project supported by National Science and Technology Ministry(ID：2009BAI83B01)..

*Corresponding author：Tel：+86-10-64807118 E-mail：hehx@ioz.ac.cn (H.-X. He)