Objective To analyze the epidemiological characteristics of the first human case of avian influenza A(H5N6) virus infection in Beijing, so as to provide evidences for prevention and control of avian influenza A(H5N6) virus infection.

Methods The relatives of the case were interviewed to obtain data of disease onset, treatment process and information of close contacts. The respiratory tract samples of the case and the close contacts, poultry specimens frozen at homes of the case and persons of co-exposure were collected for nucleic acid testing and genome analysis.

Results The case had severe pneumonia. Before onset, the patient solely cooked the frozen chicken bought by the neighbour from one market in Human province. The samples of bronchoalveolar lavage fluid, sputum collected at the early stage of diseases were positive for the nucleic acid of avian influenza A(H5N6) virus. Genomic analysis indicated that the sequences obtained from bronchoalveolar lavage fluid and frozen poultry samples were highly similar. The Clade typing of HA gene showed the virus belonged to highly pathogenic avian influenza virus clade 2.3.4.4.

Conclusions Processing of frozen poultry products may also cause infection, suggesting that process of unquarantined frozen poultry products can also be risky.