tetano
Editor, Senior Moderator
J Infect Dis. 2012 Aug 28. [Epub ahead of print]
Epidemiological dynamics and phylogeography of influenza in southern China.
Cheng X, Tan Y, He M, Lam TT, Lu X, Viboud C, He J, Zhang S, Lu J, Wu C, Fang S, Wang X, Xie X, Ma H, Nelson MI, Kung HF, Holmes EC, Cheng J.
Source
Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, Guangdong, China.
Abstract
Background. Understanding the epidemiological dynamics of influenza virus is central to viral surveillance and vaccine strain selection. It has been suggested that tropical and sub-tropical regions represent the global source of influenza epidemics. However, our understanding of the epidemiological dynamics of influenza virus in these regions is limited by a relative lack of long-time-period data.Methods. We analyzed influenza epidemiological and virological data over 15 years from the metropolitan city of Shenzhen in sub-tropical southern China. We used wavelet analysis to determine the periodicity of influenza epidemics and molecular phylogeographic analysis to investigate the role of Shenzhen and southern China in the global evolution of the influenza virus.Results. We show that southern China is unlikely to represent an epicenter of global influenza activity, as influenza activity in Shenzhen is characterized by significant annual cycles, multiple viral introductions every year, limited persistence across epidemic seasons, and viruses that generally are not positioned on the trunk of the global influenza phylogeny.Conclusions. We propose that novel influenza viruses emerge and evolve in multiple geographic localities and that the global evolution of influenza virus is complex and does not simply originate from a southern Chinese epicenter.
PMID:
22930808
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22930808
Epidemiological dynamics and phylogeography of influenza in southern China.
Cheng X, Tan Y, He M, Lam TT, Lu X, Viboud C, He J, Zhang S, Lu J, Wu C, Fang S, Wang X, Xie X, Ma H, Nelson MI, Kung HF, Holmes EC, Cheng J.
Source
Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, Guangdong, China.
Abstract
Background. Understanding the epidemiological dynamics of influenza virus is central to viral surveillance and vaccine strain selection. It has been suggested that tropical and sub-tropical regions represent the global source of influenza epidemics. However, our understanding of the epidemiological dynamics of influenza virus in these regions is limited by a relative lack of long-time-period data.Methods. We analyzed influenza epidemiological and virological data over 15 years from the metropolitan city of Shenzhen in sub-tropical southern China. We used wavelet analysis to determine the periodicity of influenza epidemics and molecular phylogeographic analysis to investigate the role of Shenzhen and southern China in the global evolution of the influenza virus.Results. We show that southern China is unlikely to represent an epicenter of global influenza activity, as influenza activity in Shenzhen is characterized by significant annual cycles, multiple viral introductions every year, limited persistence across epidemic seasons, and viruses that generally are not positioned on the trunk of the global influenza phylogeny.Conclusions. We propose that novel influenza viruses emerge and evolve in multiple geographic localities and that the global evolution of influenza virus is complex and does not simply originate from a southern Chinese epicenter.
PMID:
22930808
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22930808