Spatial, temporal and genetic dynamics of highly p

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   Spatial, temporal and genetic dynamics of highly pathogenic avian influenza A (H5N1) virus in China

 The spatial spread of H5N1 avian influenza, significant ongoing mutations, and long-term persistence of the virus in some geographic regions has had an enormous impact on the poultry industry and presents a serious threat to human health. 

Methods: We applied phylogenetic analysis, geospatial techniques, and time series models to investigate the spatiotemporal pattern of H5N1 outbreaks in China and the effect of vaccination on virus evolution. 

Results: Results showed obvious spatial and temporal clusters of H5N1 outbreaks on different scales, which may have been associated with poultry and wild-bird transmission modes of H5N1 viruses. Lead?lag relationships were found among poultry and wild-bird outbreaks and human cases.

 Human cases were preceded by poultry outbreaks, and wild-bird outbreaks were led by human cases. Each clade has gained its own unique spatiotemporal and genetic dominance.

 Genetic diversity of the H5N1 virus decreased significantly between 1996 and 2011; presumably under strong selective pressure of vaccination. Mean evolutionary rates of H5N1 virus increased after vaccination was adopted in China.

 A clear signature of positively selected sites in the clade 2.3.2 virus was discovered and this may have resulted in the emergence of clade 2.3.2.1. 

Conclusions: Our study revealed two different transmission modes of H5N1 viruses in China, and indicated a significant role of poultry in virus dissemination. Furthermore, selective pressure posed by vaccination was found in virus evolution in the country.

Author: Huaiyu TianYujun CuiLu DongSen ZhouXiaowen LiShanqian HuangRuifu YangBing Xu
Credits/Source: BMC Infectious Diseases 2015, 15:54

http://7thspace.com/headlines/503911/spatial_temporal_and_genetic_dynamics_of_highly_pathogenic_avian_influenza_a_h5n1_virus_in_china.html

For original study see:

http://www.biomedcentral.com/1471-2334/15/54/abstract

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arirish Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: June 19 2013 Location: Arkansas Status: Offline Points: 39215	Post Options Post Reply Quote arirish Report Post Thanks(0) Quote Reply Topic: Spatial, temporal and genetic dynamics of highly p Posted: February 13 2015 at 1:30pm
	Spatial, temporal and genetic dynamics of highly pathogenic avian influenza A (H5N1) virus in China The spatial spread of H5N1 avian influenza, significant ongoing mutations, and long-term persistence of the virus in some geographic regions has had an enormous impact on the poultry industry and presents a serious threat to human health. Methods: We applied phylogenetic analysis, geospatial techniques, and time series models to investigate the spatiotemporal pattern of H5N1 outbreaks in China and the effect of vaccination on virus evolution. Results: Results showed obvious spatial and temporal clusters of H5N1 outbreaks on different scales, which may have been associated with poultry and wild-bird transmission modes of H5N1 viruses. Lead?lag relationships were found among poultry and wild-bird outbreaks and human cases. Human cases were preceded by poultry outbreaks, and wild-bird outbreaks were led by human cases. Each clade has gained its own unique spatiotemporal and genetic dominance. Genetic diversity of the H5N1 virus decreased significantly between 1996 and 2011; presumably under strong selective pressure of vaccination. Mean evolutionary rates of H5N1 virus increased after vaccination was adopted in China. A clear signature of positively selected sites in the clade 2.3.2 virus was discovered and this may have resulted in the emergence of clade 2.3.2.1. Conclusions: Our study revealed two different transmission modes of H5N1 viruses in China, and indicated a significant role of poultry in virus dissemination. Furthermore, selective pressure posed by vaccination was found in virus evolution in the country. Author: Huaiyu TianYujun CuiLu DongSen ZhouXiaowen LiShanqian HuangRuifu YangBing Xu Credits/Source: BMC Infectious Diseases 2015, 15:54 http://7thspace.com/headlines/503911/spatial_temporal_and_genetic_dynamics_of_highly_pathogenic_avian_influenza_a_h5n1_virus_in_china.html For original study see: http://www.biomedcentral.com/1471-2334/15/54/abstract
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