Live poultry feeding and trading network and the transmission of avian influenza A(H5N6) virus in a large city in China, 2014-2015

Objectives: To understand the transmission mechanism of avian influenza A(H5N6) virus.

Design: In this study, we explored the live poultry feeding and trading network (LPFTN) around Changsha city, China. Field epidemiological investigations were performed in Changsha to investigate the LPFTN with the environmental samples systematically collected during 2014 to 2015 to monitor and analyze the spread of A(H5N6) virus. Two surveillance systems were also applied to find possible human cases of A(H5N6) infection.

Result: We collected the information of all the 665 live poultry farming sites, 5 wholesale markets, and 223 retail markets in Changsha to investigate the LPFTN. Moreover, about 840 environmental samples were systematically collected from the LPFTN during 2014 to 2015 to monitor the spread of A(H5N6) virus, with 8.45% (71/840) positive for N6 subtype. Furthermore, the full genome sequences of 10 A(H5N6) viruses detected from the environmental samples were obtained, which were then characterized and phylogenetically analyzed with the corresponding gene segments of A(H5N6) virus obtained from GenBank, to determine the source of human infection.

Conclusion: It was demonstrated that the LPFTN provided a platform for the H5N6 transmission, and formed an infectious pool for the spread of the virus to human.