Genetic changes of reemerged influenza A(H7N9) viruses, China.
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ABSTRACT:
SUBMITTER: Lu J
PROVIDER: S-EPMC4178397 | biostudies-literature | 2014 Sep
REPOSITORIES: biostudies-literature
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Genetic changes of reemerged influenza A(H7N9) viruses, China.
Lu Jing J Wu Jie J Guan Dawei D Yi Lina L Zeng Xianqiao X Zou Lirong L Liang Lijun L Ni Hanzhong H Zhang Xin X Lin Jinyan J Ke Changwen C
Emerging infectious diseases 20140901 9
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Project description:UnlabelledDue to enzootic infections in poultry and persistent human infections in China, influenza A (H7N9) virus has remained a public health threat. The Yangtze River Delta region, which is located in eastern China, is well recognized as the original source for H7N9 outbreaks. Based on the evolutionary analysis of H7N9 viruses from all three outbreak waves since 2013, we identified the Pearl River Delta region as an additional H7N9 outbreak source. H7N9 viruses are repeatedly introduced from these two sources to the other areas, and the persistent circulation of H7N9 viruses occurs in poultry, causing continuous outbreak waves. Poultry movements may contribute to the geographic expansion of the virus. In addition, the AnH1 genotype, which was predominant during wave 1, was replaced by JS537, JS18828, and AnH1887 genotypes during waves 2 and 3. The establishment of a new source and the continuous evolution of the virus hamper the elimination of H7N9 viruses, thus posing a long-term threat of H7N9 infection in humans. Therefore, both surveillance of H7N9 viruses in humans and poultry and supervision of poultry movements should be strengthened.ImportanceSince its occurrence in humans in eastern China in spring 2013, the avian H7N9 viruses have been demonstrating the continuing pandemic threat posed by the current influenza ecosystem in China. As the viruses are silently circulated in poultry, with potentially severe outcomes in humans, H7N9 virus activity in humans in China is very important to understand. In this study, we identified a newly emerged H7N9 outbreak source in the Pearl River Delta region. Both sources in the Yangtze River Delta region and the Pearl River Delta region have been established and found to be responsible for the H7N9 outbreaks in mainland China.
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