Phylogenetic Analysis Reveals the Global Migration of Seasonal Influenza A Viruses

PLoS Pathogens

Martha I Nelson¹  Lone Simonsen²  Mark A Miller³  Edward C Holmes³  Cecile Viboud⁴ 

[1] Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, Pennsylvania, United States of America;Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America;Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America;National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America

关键词: Influenza viruses;    Australia;    New York;    New Zeal;    Phylogenetic analysis;    Animal migration;    Influenza;    Influenza A virus;   

DOI  :  10.1371/journal.ppat.0030131

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The winter seasonality of influenza A virus in temperate climates is one of the most widely recognized, yet least understood, epidemiological patterns in infectious disease. Central to understanding what drives the seasonal emergence of this important human pathogen is determining what becomes of the virus during the non-epidemic summer months. Herein, we take a step towards elucidating the seasonal emergence of influenza virus by determining the evolutionary relationship between populations of influenza A virus sampled from opposite hemispheres. We conducted a phylogenetic analysis of 487 complete genomes of human influenza A/H3N2 viruses collected between 1999 and 2005 from Australia and New Zealand in the southern hemisphere, and a representative sub-sample of viral genome sequences from 413 isolates collected in New York state, United States, representing the northern hemisphere. We show that even in areas as relatively geographically isolated as New Zealand's South Island and Western Australia, global viral migration contributes significantly to the seasonal emergence of influenza A epidemics, and that this migration has no clear directional pattern. These observations run counter to suggestions that local epidemics are triggered by the climate-driven reactivation of influenza viruses that remain latent within hosts between seasons or transmit at low efficiency between seasons. However, a complete understanding of the seasonal movements of influenza A virus will require greatly expanded global surveillance, particularly of tropical regions where the virus circulates year-round, and during non-epidemic periods in temperate climate areas.

【 授权许可】

CC BY