Avian influenza virus H9N2 seroprevalence and risk factors for infection in occupational poultry-exposed workers in Tai'an of China

To determine risk factor for H9N2 avian influenza virus (AIV) infection, a serological surveillance among both occupational poultry‐exposed (OPE) workers and general humans was carried out using both haemagglutination inhibition (HI) and microneutralization (MN) assays in Tai'an, China, between 2011 and 2013. At baseline, the positive rate of anti‐H9 antibody (HI and MN titers ≥40) among OPE workers (51/600, 8.5%) was significantly higher than that among the general population (11/600, 1.8%). The result indicated that occupational exposure to chicken flocks was an important risk factor for H9N2 AIV infection. J. Med. Virol. 88:1453–1456, 2016. © 2016 Wiley Periodicals, Inc.