PHNOM PENH – A three-and-a-half-year-old boy has died from avian influenza (H5N1) after a single day of hospitalization, the Cambodian Ministry of Health confirmed on March 23. This tragic case marks the third human death from the virus in the country this year.

The infection occurred in Preaek Ta Am village, Bos Leav commune, Chetr Borei district, Kratie province. On March 22, the National Institute of Public Health (NIPH) confirmed the boy's H5N1 diagnosis after he was transferred from the province in a severely weakened state. He presented with a high fever, cough, extreme fatigue, and difficulty breathing (dyspnea).

NIPH revealed from its findings that the boy's family raised chickens at home. Several chickens had died, and the family reportedly cooked and consumed some of the deceased birds. Other chickens in the flock were also displaying signs of illness.

In an effort to prevent further spread of the virus, the Ministry of Health, in collaboration with the provincial agriculture department and local authorities, has launched an investigation at the affected site. They are also carrying out contact-tracing – collecting samples from individuals who had contact with the deceased boy – and testing others exhibiting potential symptoms.

The Ministry has also distributed Tamiflu, an antiviral medication, to close contacts of the boy as a preventative measure. Additionally, they are conducting community outreach to educate residents on avian influenza prevention and proper sanitation practices, according to a press release issued on March 23.

From 2003 to January 2025, Cambodia has recorded 73 human cases of H5N1 influenza, with 44 fatalities. The first death of 2025 occurred in January, involving a 28-year-old man from Kampong Cham province. A 15-year-old girl from Prey Veng province died in early March, adding to the growing number of fatalities.

The Ministry of Health emphatically states that avian influenza (H5N1) remains a significant public health threat. The ministry strongly urges individuals who develop symptoms like fever, cough, fatigue, or shortness of breath within 14 days of contact with sick or dead poultry to seek immediate medical attention. 

The Ministry of Health also advises that individuals should refrain from any contact with poultry, wild birds, or mammals that appear ill or deceased. Thorough handwashing with soap and water is essential after any interaction with these animals, or after being present in their habitats. This preventative measure is crucial in minimizing the risk of infection.

In late 2023, as Cambodia experienced a sharp rise in human H5N1 cases, local scientists identified a novel reassortant virus. This strain combined genes from the older 2.3.2.1c clade, previously circulating in Southeast Asia, with internal genes from the newer 2.3.4.4b clade, which has spread globally, infecting various animal species. 

Currently, the 2020 H5N1 clade 2.3.4.4b variant has spread widely via wild birds, undergoing further genetic changes. Notably, it's infecting various mammals, including cows in the U.S., where it replicates efficiently in mammary glands, spreading through milking equipment. This novel infection in cows and the virus's high replication suggest adaptive mutations occurred during its transition from birds.

This fast-mutating H5N1 bird flu virus spreading across species, including humans, is raising fears of a new pandemic.

With additional reporting from Sonny Inbaraj Krishnan.