#19,125
With thanks for the head's up from @E_A_Karlsson, we have the following announcement from Cambodia's Ministry of Health on their 4th confirmed HPAI H5N1 human infection of 2026 - and 38th in just over 3 years - this time involving a 66 y.o. woman from Svay Rieng province who had recent contact with sick chickens and was confirmed positive on March April 21st.
(Translation)
Kingdom of Cambodia
Nation Religion King
Ministry of Health
Press ReleaseOn Bird flu case in 66-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 66-year-old woman who was confirmed to be positive for the H5N1 avian influenza virus on April 21, 2026 by the National Institute of Public Health. The patient is a resident of Trapaing Thkov village, Pong Teuk commune, Romduol district, Svay Rieng province. The patient has been placed in isolation at the hospital and is receiving intensive medical care. Investigations revealed that from April 2 to 13, there were sick and dead chickens in the village and the patient’s house, which were used for cooking.
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, as well as distribute Tamiflu to close contacts and conduct health education campaigns for citizens 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, runny nose, or difficulty breathing and have a history of contact with sick or dead chickens or ducks within 14 days before the onset of symptoms, do not go to gatherings or crowded places and seek consultation and examination and treatment at the nearest health center or hospital immediately. Avoid delaying this, which puts you at high risk of eventual death.
How it is transmitted: H5N1 bird flu is a type of flu that is usually spread from sick birds to other birds, but it can sometimes be spread from birds to humans through close contact with sick or dead birds. Bird flu in humans is a serious illness that requires prompt hospital treatment. Although it is not easily transmitted from person to person, if it mutates, it can be contagious, just like seasonal flu.
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Address: Lot No. 80, Samdech Pen Nut Street (289)
Sangkat Boeung Kak 2, Khan Toul Kork, Phnom Penh
Phone: (+855) 23 885 970
Email: info@moh.gov.kh
Website: www.moh.gov.kh
In February of 2023 an older clade of H5N1 (2.3.2.1.x) reemerged in Cambodia's population after a 9 year absence, spilling over into 6 humans in 2023, 10 people in 2024, and 18 people in 2025.
Cambodia's recent cases are due to a new reassortment of an older clade of the H5N1 virus (recently renamed 2.3.2.1e) - which appears to be spreading rapidly through both wild birds and local poultry.
Unlike the newer clade 2.3.4.4b H5Nx viruses - which have shown much lower mortality rates in the United States - this older clade has proved fatal in about 40% of the cases reported by Cambodia since 2023.
There is currently no evidence to suggest human-to-human transmission of this H5 virus, with most cases reporting recent contact with sick or dead poultry.
Among them were 4 `clusters' (Father/Daughter, two neighbors, 2 siblings, and 2 cousins living in the same household), 6 fatalities, and 12 cases < 18 years of age.
While human-to-human transmission was considered, the available evidence suggests a `shared' exposure instead, with infected poultry the most likely source of infection.
Due to copyright, I can only post the title and link, but I would urge you to go to the NEJM site to read it in its entirety.
Highly Recommended.
Resurgence of Zoonotic Highly Pathogenic Avian Influenza A(H5N1) Virus in Cambodia
Published October 22, 2025
N Engl J Med 2025;393:1650-1652
DOI: 10.1056/NEJMc2504302
VOL. 393 NO. 16 Copyright © 2025
