Key facts
- On 28 September 2026, one laboratory-confirmed human case of avian influenza A(H5N1) virus infection was reported in Oddar Meanchey Province, Cambodia.
- The case is a man in his forties who was hospitalized and was confirmed positive on September 27, 2026.
- The patient is a poultry farmer with exposure to sick and dead poultry. An outbreak of avian influenza among poultry was confirmed on 23 September 2026.
- The investigation is ongoing to identify the source of infection, including contact tracing.
- Contacts that have been identified received prophylactic treatment with antivirals (oseltamivir).
- No evidence of human-to-human transmission has been detected to date.
- The overall risk related to zoonotic avian influenza due to A(H5N1) virus for the general population in the EU/EEA is considered very low.
Overview
Summary
On 27 September 2026, the Ministry of Health of Cambodia reported a laboratory-confirmed human case of avian influenza A(H5N1) in a man in his forties from Trapeang Prasat district, Oddar Meanchey Province, Cambodia.
Infection was confirmed by the National Institute of Public Health and the Institut Pasteur du Cambodge. The patient is a poultry farmer and reportedly had direct contact with sick and dead chickens. The poultry outbreak was confirmed as avian influenza on 23 September 2026 by the National Animal Health and Production Research Institute. The patient is currently hospitalised in isolation and receiving treatment. Public health investigations are ongoing to identify the source of infection, detect additional human cases, and trace contacts. National and sub-national health authorities are working in collaboration with agricultural authorities and local officials. Antiviral prophylaxis (oseltamivir) is being provided to close contacts, and risk communication and health education activities have been implemented in the affected community.
Background
This is the sixth human case of avian influenza A(H5N1) infection reported in Cambodia in 2026. Previously Cambodia reported sporadic human cases between 2003 and 2014 with exposure history to infected poultry or contaminated -environments. Human cases re-emerged in 2023. Overall, 40 laboratory-confirmed cases, including 15 deaths (CFR: 37.5%) have been reported in Cambodia.
Since 2003, there have been 1 002 human cases of avian influenza A(H5N1) infection worldwide*, including 478 deaths (CFR: 47.7%). These cases have been reported in 25 countries (Australia (exposure occurred in India), Azerbaijan, Bangladesh, Cambodia, Canada, Chile, China, Djibouti, Ecuador, Egypt, India, Indonesia, Iraq, Laos, Mexico, Myanmar, Nepal, Nigeria, Pakistan, Spain, Thailand, Türkiye, Viet Nam, the United Kingdom (UK), and the United States (US)). To date, no sustained human-to-human transmission has been detected.
* This includes detections due to suspected environmental contamination, with no evidence of infection, that were reported in 2022 and 2023 by Spain (two detections), the US (one), and the UK (four, one of which was inconclusive). Human cases of A(H5) epidemiologically linked to A(H5N1) outbreaks in poultry and dairy cattle in the US are included in the reported number of cases of A(H5N1).
ECDC assessment
Sporadic human cases of different avian influenza A(H5) subtypes have previously been reported around the world. Current virological evidence suggests that circulating A(H5N1) viruses retain genetic characteristics consistent with avian-adapted influenza viruses. Despite the widespread transmission of avian influenza viruses in animals, transmission to humans remains infrequent and no sustained transmission between humans has been observed.
Based on the currently available information, the overall risk related to zoonotic avian influenza due to A(H5N1) virus for the general population in the EU/EEA is considered very low.
Direct contact with birds and other infected animals, their secretions or a contaminated environment is the most likely source of infection. Application of personal protective measures in people exposed to infected animals or their environment can reduce the associated risk. The recent severe cases in Asia and the Americas in children and people exposed to infected, sick or dead backyard poultry underline the risk of unprotected contact with infected birds in backyard farm settings. This underlines the importance of using appropriate personal protective equipment.
Actions
ECDC monitors avian influenza strains through its epidemic intelligence and disease network activities. Together with the European Food Safety Authority (EFSA) and the EU Reference Laboratory for Avian Influenza, ECDC produces a quarterly report on the avian influenza situation. The most recent report was published in June 2026.
