Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6142501 | Virus Research | 2014 | 7 Pages |
Abstract
In 2013, the novel reassortant avian-origin influenza A (H7N9) virus was reported in China. Through enhanced surveillance, infection by the H7N9 virus in humans was first identified in Zhejiang Province. Real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) was used to confirm the infection. Embryonated chicken eggs were used for virus isolation from pharyngeal swabs taken from infected human patients. The H7N9 isolates were first identified by the hemagglutination test and electron microscopy, then used for whole genome sequencing. Bioinformatics software was used to construct the phylogenetic tree and for computing the mean rate of evolution of the HA gene in H7Nx and NA in HxN9. Two novel H7N9 avian influenza A viruses (A/Zhejiang/1/2013 and A/Zhejiang/2/2013) were isolated from the positive infection cases. Substitutions were found in both Zhejiang isolates and were identified as human-type viruses. All phylogenetic results indicated that the novel reassortant in H7N9 originated in viruses that infected birds. The sequencing and phylogenetic analysis of the whole genome revealed the mean rate of evolution of the HA gene in H7NX to be 5.74Eâ3 (95% Highest posterior density: 3.8218Eâ3 to 7.7873Eâ3) while the NA gene showed 2.243Eâ3 (4.378Eâ4 to 3.79Eâ3) substitutions per nucleotide site per year. The novel reassortant H7N9 virus was confirmed by molecular methods to have originated in poultry, with the mutations occurring during the spread of the H7N9 virus infection. Live poultry markets played an important role in whole H7N9 circulation.
Keywords
Related Topics
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Immunology and Microbiology
Virology
Authors
Yanjun Zhang, Haiyan Mao, Juying Yan, Lei Zhang, Yi Sun, Xinying Wang, Yin Chen, Yiyu Lu, Enfu Chen, Huakun Lv, Liming Gong, Zhen Li, Jian Gao, Changping Xu, Yan Feng, Qiong Ge, Baoxiang Xu, Fang Xu, Shichang Xia,