Avian influenza subtype A(HxNy) normally spreads in birds but can also infect humans. Human infections are primarily acquired through direct contact with infected poultry or contaminated environments. While avian influenza viruses do not currently transmit easily from person to person, the ongoing circulation of these viruses in poultry is concerning, as these viruses can result in mild to severe illness and death, and also have the potential to mutate to become more contagious.

This weekly situation report will highlight the most recent developments in the regional response.

From 20 to 26 June 2025, three new cases of human infection with avian influenza A(H5N1) virus were reported to WHO in the Western Pacific Region, all from Cambodia. Two cases were reported in Takeo Province: a 65-year-old female with an onset date of 4 June and a 19-month-old male with an onset date of 7 June. The third case, a 52-year-old male, was reported in Svay Rieng Province, with an onset date of 14 June. Two of the three cases have died. All had a history of exposure to sick or dead poultry. From 1 January 2003 to 27 May 2025, a total of 466 cases of human infection with avian influenza A(H5N1) virus have been reported from six countries within the Western Pacific Region (Table 1). Of these cases, 313 were fatal, resulting in a case fatality rate (CFR) of 67.2%.