Cambodia reports fourth fatal human case of H5N1 bird flu

Cambodia’s Ministry of Health has confirmed its fourth human fatality from H5N1 avian influenza in 2025, marking another alarming development in the country’s ongoing battle with the virus. The latest case involves an 11-year-old boy from Kampong Speu province in south-central Cambodia who died Tuesday after being hospitalized with severe respiratory symptoms.

According to a ministry statement translated by infectious disease blog Avian Flu Diary, the child had a high fever, cough, shortness of breath, and difficulty breathing upon arrival at the hospital. Despite emergency care, he succumbed to the illness the same day. Testing conducted by the Pasteur Institute of Cambodia confirmed the presence of H5N1 in his samples.

The ministry’s investigation found that poultry near the boy’s home — both chickens and ducks — had been ill or dying roughly a week before the child began showing symptoms. Officials believe this was the likely source of infection, consistent with Cambodia’s previous H5N1 cases this year, all of which involved exposure to sick or dead poultry.

The boy’s death follows the March case of a 3-year-old from Kratie province, who also died after contracting the virus. Cambodia has seen a steady rise in H5N1 infections since late 2023. Some cases have been linked to a novel genetic reassortment between older H5N1 strains common in Southeast Asia (clade 2.3.2.1c) and the newer globally circulating 2.3.4.4b clade, though the specific strain responsible for the latest case has not been identified.

In response, health officials have deployed emergency teams to Kampong Speu to trace the source of infection, monitor close contacts, and administer the antiviral drug Tamiflu as a preventive measure. Public health education campaigns are also underway in affected villages.

The ministry has urged residents to seek immediate medical care if they develop flu-like symptoms and have had contact with sick or dead poultry within the past two weeks. “Avoid delaying this, which puts you at high risk of eventual death,” the ministry warned.

So far in 2025, all four human H5N1 cases reported in Cambodia have been fatal. According to the World Health Organization, a total of 10 human H5N1 cases have been confirmed globally this year, with five resulting in death.

While human cases remain rare and the virus is not considered a food safety risk, its spread to mammals and persistent presence in poultry continue to raise concerns among scientists. They warn that the virus could eventually adapt to spread more easily between people, posing a potential pandemic threat.

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