#18,768
After going nearly a decade without reporting a human H5N1 case, Cambodia reported two cases in February of 2023, followed 4 more cases in October -November.In 2024 they reported 10 cases. Already in 2025, Cambodia has reported 7 cases, with 4 of those coming since the end of May.
Unlike the milder 2.3.4.4b clade circulating in the United States, Europe, and much of the rest of the world, recent cases from Cambodia and Vietnam have stemmed from a resurgent older, and more virulent, clade (formerly clade 2.3.2.1c but recently redubbed as 2.3.2.1e).
Like many cases we've seen from Cambodia, this patient reportedly had contact with sick and dead chickens prior to falling ill. Despite concerted public health messaging, the sharing, and cooking, of sick or dying poultry remains a common practice in Cambodia.
The announcement (see screen shot below) was made overnight on the Cambodian MOH Facebook page. I've provided a translation (emphasis mine).
(Translation)
Kingdom of Cambodia
Ministry of Health
Press Release
A case of bird flu in a 41-year-old woman
The Ministry of Health of the Kingdom of Cambodia would like to inform the public that there is 1 case of bird flu in a 41-year-old woman who was confirmed positive for the H5N1 avian influenza virus by the National Institute of Public Health on June 23, 2025, residing in Lwek village, Daun Kao commune, Puok district, Siem Reap province.
The patient has symptoms of fever, cough, shortness of breath, and difficulty breathing. The patient is currently in critical condition and is receiving close medical care. Investigations revealed that there were sick and dead chickens in the patient’s home and in the homes of neighbors, and the patient had handled and handled the sick and dead chickens and cooked them for consumption 5 days before the patient started feeling sick.
The emergency response teams of the national and sub-national ministries of health have been collaborating with the provincial agriculture departments and local authorities at all levels to actively investigate the outbreak of bird flu and respond according to technical methods and protocols, find sources of transmission in both animals and humans, and search for suspected cases and contacts to prevent further transmission in the community. They have also distributed Tamiflu to close contacts and conducted health education campaigns among residents in the affected villages.
The Ministry of Health would like to remind all citizens to always pay attention to and be vigilant about bird flu because H5N1 bird flu continues to threaten the health of our citizens. We would also like to inform you that if you have a fever, cough, sputum discharge, or difficulty breathing and have a history of contact with sick or dead chickens or ducks within 14 days before the start of the symptoms, do not go to gatherings or crowded places and seek consultation and treatment at the nearest health center or hospital immediately. Avoid delaying this, which puts you at high risk of eventual death.
Currently the clade 2.3.2.1x H5N1 virus appears to be geographically limited to the Cambodia, Vietnam, Laos regions of Southeast Asia, but it continues to reassort with the newer clade 2.3.4.4b virus (see FAO Statement On Reassortment Between H5N1 Clade 2.3.4.4b & Clade 2.3.2.1c Viruses In Mekong Delta Region).
A reminder that the growing array of H5Nx viruses circulating around the globe continue to evolve, and anything we say about any given subtype, clade or genotype today, may not hold true tomorrow.
