Cambodia has a robust H5N1 surveillance system built after its 2004-06 outbreak, giving it higher case detection than many neighbours. Smallholder poultry farming means rural populations are regularly exposed. Cambodia finds cases; it is not necessarily worse off than countries with comparable exposure but weaker testing.Source: CIDRAP

Is Cambodia's H5N1 the same strain as the US dairy outbreak?

No. Cambodia's cases involve local poultry-endemic clades that diverged from the US dairy clade 2.3.4.4b years ago. They represent a separate longstanding surveillance thread, not an extension of the American outbreak.Source: CIDRAP

How dangerous is bird flu for tourists visiting Cambodia?

The risk to tourists visiting cities is very low. The risk concentrates in rural areas with backyard poultry exposure. WHO travel guidance advises avoiding contact with live poultry in markets and household settings.Source: WHO

Background

Cambodia is a Southeast Asian country of approximately 17 million people, bordered by Thailand, Laos, Vietnam, and the Gulf of Thailand. It is a constitutional monarchy with a predominantly agricultural economy; rice, cassava, and fishing are the main rural livelihoods. Smallholder poultry farming, in which backyard ducks and chickens live in close proximity to households, is widespread across rural provinces. Cambodia has a GDP per Capita of around $1,700, placing it in the lower-middle-income bracket, with health infrastructure concentrated in urban centres and unevenly distributed at district and commune level.

Cambodia logged three H5N1 human cases through 2026, all linked to traditional household poultry contact, taking the global 2026 H5N1 count outside the US dairy pathway to four. The Cambodian cases trace to local poultry-endemic clades that diverged from the clade 2.3.4.4b line driving the US dairy outbreak years ago; they are a structurally distinct surveillance thread, not an extension of the American situation. Cambodia built an H5N1 human surveillance system after the 2004-06 Cambodian cluster, with US CDC and WHO support, giving it higher case ascertainment sensitivity than many Mekong neighbours. This detection capacity is why Cambodia consistently appears in H5N1 case counts: the country finds cases that other low-surveillance states likely miss.

Source Material

WHO Cambodia country office Cambodia — Wikipedia

How the World Sees Them

ASEAN

Cambodia's longstanding H5N1 endemicity in poultry is monitored regionally as part of the Mekong basin surveillance network; neighbouring countries use Cambodian case data as a proxy for regional avian influenza activity.

China

Chinese authorities monitor Cambodian H5N1 case reports through bilateral WHO channels given the shared flyway routes between southern Chinese poultry regions and Cambodian wetlands.

United States

US CDC co-built Cambodia's H5N1 surveillance infrastructure and uses Cambodian sequencing data to monitor clade divergence from the US dairy-strain lineage.