Detection of Clade 2.3.4.4b Avian Influenza A(H5N8) Virus in Cambodia, 2021

Institute in Cambodia have partnered with the Food and Agriculture Organization of the United Nations to enhance ongoing longitudinal AIV surveillance in live bird markets and poultry storage facilities throughout Cambodia. This active surveillance reveals high levels of AIV circulation with approximate to 30%-50% of ducks and approximate to 20%-40% of chickens testing positive for various influenza A subtypes. Most detected HPAIVs were H5N1 HA clade 1 viruses during 2005-2014 and H5N1 HA clade 2.3.2.1c viruses since 2014; H5N6 clades 2.3.4.4g and 2.3.4.4h were detected sporadically during 2018-2020 (Appendix 1 Table 1, https:// pdf). Other subtypes also circulate, including novel H7Nx low pathogenicity avian influenza viruses proval no. 149/NECHR/2020) in late 2021, domestic n = 1), Takmao (Kandal, n = 2), Chba Ampov (Phnom Penh, n = 1), and Takeo (Takeo, n = 1) tested positive for HPAIV H5 HA but negative for neuraminidase PCR (RT-PCR). We determined these samples were the H5N8 subtype after further RT-PCR analysis (Ap