tetano
Editor, Senior Moderator
BMC Infect Dis. 2015 Feb 13;15(1):54. doi: 10.1186/s12879-015-0770-x.
[h=1]Spatial, temporal and genetic dynamics of highly pathogenic avian influenza A (H5N1) virus in China.[/h] Tian H[SUP]1[/SUP], Cui Y[SUP]2[/SUP], Dong L[SUP]3[/SUP], Zhou S[SUP]4[/SUP], Li X[SUP]5,[/SUP][SUP]6[/SUP], Huang S[SUP]7[/SUP], Yang R[SUP]8[/SUP], Xu B[SUP]9,[/SUP][SUP]10,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] 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.
[h=4]METHODS:[/h] 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.
[h=4]RESULTS:[/h] 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.
[h=4]CONCLUSIONS:[/h] 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.
PMID: 25887370 [PubMed - in process] PMCID: PMC4329208
[h=1]Spatial, temporal and genetic dynamics of highly pathogenic avian influenza A (H5N1) virus in China.[/h] Tian H[SUP]1[/SUP], Cui Y[SUP]2[/SUP], Dong L[SUP]3[/SUP], Zhou S[SUP]4[/SUP], Li X[SUP]5,[/SUP][SUP]6[/SUP], Huang S[SUP]7[/SUP], Yang R[SUP]8[/SUP], Xu B[SUP]9,[/SUP][SUP]10,[/SUP][SUP]11[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] 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.
[h=4]METHODS:[/h] 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.
[h=4]RESULTS:[/h] 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.
[h=4]CONCLUSIONS:[/h] 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.
PMID: 25887370 [PubMed - in process] PMCID: PMC4329208