Cambodia confirmed a human H5N1 bird flu case on 27 September in a poultry farmer in his forties in Oddar Meanchey, a north-western province bordering Thailand, its sixth of 2026. Hong Kong's Centre for Health Protection (CHP) counts 11 human cases and two deaths worldwide this year to 1 October, against 81 in 2024 and 30 in 20251. By country the 2026 count is Cambodia 6, Bangladesh 4 and India 1.
Severity has moved with geography. US farm workers with mostly mild eye infections dominated 2024's count, while this year's patients caught the virus from backyard poultry in South and South-East Asia. Cambodia had supplied four of seven new cases by July, and Bangladesh's cases include a child WHO died after household poultry contact in February. The global total since 2003, which passed 1,000 before August, stands at 1,002 cases and 478 deaths by the European Centre for Disease Prevention and Control's count2.
A quiet human year can mean less virus or less testing. The Pan American Health Organization counted mammal outbreaks in the Americas down 64.8% year on year to mid-July3, but poultry outbreaks resumed in September in France, Sweden, Bulgaria and Canada4.
Laboratory work also cut against alarm. A Nature Communications study led by Sriram Subramaniam of the University of British Columbia examined the virus from a critically ill British Columbia teenager in November 20245. Its two mutations weakened binding to both human-type and bird-type cell receptors, the molecules on cell surfaces the virus latches on to, according to the university. "To our surprise, the mutations did the opposite of what many expected," Subramaniam said; an independent preprint, not yet peer-reviewed, argues weaker binding could help the virus slip past mucus, so the question stays open.
