Detection and Molecular Characterization of the Avian Influenza A (H7N9) Virus in Eastern China in 2013

On March 31, 2013, human infections with a novel avian influenza A (H7N9) virus were firstly reported in China. By February 7, 2015, a total of 562 laboratory-confirmed human cases of H7N9 infection were reported in mainland China. This study aimed to determine whether there is a novel H7N9 virus infection in human and animals in Taizhou city, China, in 2013. In this study, we developed real-time reverse transcription-polymerase chain reaction (RT-PCR) assays to detect H7N9 virus infection in human and animals (chicken, pig, and pigeon) in Taizhou city in the beginning of H7N9 epidemics of 2013. Also, we studied the novel isolated H7N9 virus strain by using genome sequencing and phylogenetic analysis. Of 150 samples tested, 7 were detected to be H7N9 positive which all were collected from chickens. Also, a novel H7N9 virus strain (A/chicken/jiangsu/1021/2013) was isolated and studied. Phylogenetic analysis showed the novel isolated H7N9 virus had high identity to the four novel human H7N9 viruses (A/Shanghai/1/2013, A/Shanghai/2/2013, A/Anhui/1/2013, and A/Hangzhou/1/2013). Our results demonstrated a novel H7N9 virus in chickens in Taizhou city in 2013 that may pose a potential risk to public health.