Cambodia
Southeast Asian nation of 17 million; now central to the 2026 global H5N1 human-case picture.
Cambodia has logged five confirmed human H5N1 cases in 2026, more than any other country, most recently a nine-month-old girl in Phnom Penh confirmed on 9 July, driving most of this year's modest rise in the global case count.
Last refreshed: 31 July 2026 · Appears in 1 active topic
Why does Cambodia keep appearing in H5N1 reports when the US dairy story dominates?
Timeline for Cambodia
Supplied four of the world's seven new H5N1 cases
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Pandemics and BiosecurityLogged 3 H5N1 human cases in 2026 via poultry-contact pathway
Pandemics and Biosecurity: Bangladesh and Cambodia keep the poultry H5N1 lineBackground
Cambodia is a Southeast Asian country of around 17 million people, bordered by Thailand, Laos and Vietnam, with an economy built on rice, cassava and fishing. Smallholder poultry farming, where backyard ducks and chickens live in close proximity to households, is widespread across its rural provinces and is the structural reason the country keeps appearing in H5N1 case reports.
Its H5N1 human surveillance system dates to a 2004-06 cluster and was built with US CDC and WHO support, giving Cambodia markedly higher case-ascertainment sensitivity than most of its Mekong neighbours. The cases it detects trace to poultry-endemic clades that diverged from the lineage driving the US dairy-cattle outbreak years earlier, a separate surveillance thread rather than an extension of the American situation.
Regionally, Cambodian case data is used as a proxy for wider avian-influenza activity across the Mekong basin, and shared flyway routes give its poultry regions relevance to southern Chinese surveillance as well.
It leads the 2026 global case count
Cambodia's cases trace entirely to household poultry contact rather than the industrial dairy pathway driving the US outbreak, and four of its five 2026 cases fall inside the window ECDC used to record just seven new global cases between 16 February and 17 July, the most recent a nine-month-old girl in Phnom Penh, whose case the Institut Pasteur du Cambodge jointly verified with the National Institute of Public Health on 9 July.
The concentration reflects capability as much as exposure: Cambodia built its H5N1 human surveillance system with US CDC and WHO support after a 2004-06 cluster, giving it markedly higher case-ascertainment sensitivity than most of its Mekong neighbours, so its lead in the case count is a measure of how well it is looking, not necessarily how much worse its outbreak is.
Where was Cambodia's most recent H5N1 case confirmed?
How many H5N1 cases has Cambodia had in 2026?
Is Cambodia's H5N1 the same strain as the US dairy outbreak?
Why does Cambodia have so many bird flu cases?
How dangerous is bird flu for tourists visiting Cambodia?
