Since mid-June, Cambodia’s veterinary authority has confirmed six further highly pathogenic avian influenza (HPAI) outbreaks in poultry flocks.
Based on official notifications to the World Organisation for Animal Health (WOAH), these bring the nation’s total outbreaks over the past 12 months to 16. Directly impacted have been close to 8,000 domestic birds.
In the recent outbreaks, village flocks affected ranged in size from 25 to more than 650 birds. Two were in Pursat — the first infections in this western province. There were also two outbreaks in each of Takeo and Siem Reap, which are located in the far south and northwest of the country, respectively.
Detection of the H5N1 serotype of the HPAI virus at one of the Takeo province outbreaks was confirmed after an infection was suspected in a resident of the village. Sick or dead poultry at the other locations raised suspicions of HPAI in the other village flocks.
2 more outbreaks in South Korean poultry
Over the past two weeks, HPAI outbreaks linked to the same virus variant have been confirmed in two poultry flocks. The first ended a near two-month hiatus in South Korea.
Testing positive for the virus in mid-June was a flock of around 28,000 birds at a farm in the central province of North Chungcheong, according to the latest WOAH notification.
According to the agriculture ministry, the infection was revealed in ducks as a result of routine pre-shipment testing.
Just last week, a flock of around 1,000 native chickens tested positive for the same virus at a premises in the southeastern province of South Gyeongsang.
The ministry reports that the farm was not authorized to keep livestock, and numerous biosecurity-related deficiencies emerged during the follow-up inspection there.
Following this latest development, the authorities have increased surveillance of native chicken flocks, as well as dealers and traditional markets that handle these birds. Furthermore, for a period of 14 days, the proportion of birds subject to pre-shipment testing will be raised from 10% to 30%.
The risk of further spread of HPAI in South Korea is not considered by the ministry to be high. This is based on experience from 2024, when just four outbreaks were reported in the country during the months of July and August.
These latest outbreaks bring South Korea’s total since October of 2024 to 49.
HPAI developments elsewhere in Asia-Pacific birds
Animal health agencies of Australia and Japan have recently declared to WOAH that earlier HPAI outbreak series in their respective countries have been “resolved.”
In Australia, a total of more than 596,000 poultry were directly impacted by the disease at four farms in the state of Victoria earlier this year. All these outbreaks started during the month of February, with birds testing positive for the H7N8 serotype of HPAI.
The H5N1 HPAI virus was detected at a total of 51 poultry farms in Japan between October of 2024 and January of this year. As a result, more than 9.2 million birds died or were culled and destroyed to prevent the further spread of the virus.
Among Japan’s wild birds, however, the HPAI situation is ongoing.
After a hiatus of more than two years, the H5N2 variant of HPAI was detected in a wild bird in April, according to a retrospective report to WOAH.
More than 100 wild birds have also tested positive for the H5N1 virus serotype in Japan over recent months, according to a separate notification.
Furthermore, the same virus variant was detected after three sea otters were found dead around the island of Hokkaido in early May.
Most recent disease update from the Department of Agriculture’s Bureau of Animal Industry (dated June 26) in the Philippines indicates no new HPAI cases in poultry since the end of April.
As of June 16, nine HPAI outbreaks had occurred in Vietnamese poultry so far this year, reported DanViet, citing agriculture ministry data. Across six provinces, more than 21,300 birds had died, and 25,200 had been culled in 2025 up to that point.
Compared with 2024, the number of provinces affected this year is lower, but more than twice as many poultry have been lost to the disease, according to this source.
Further human infections reported in Cambodia, China
Cambodia has been experiencing a recent spike in human infections with the avian influenza A(H5N1) virus.
A recent update by Avian Flu Diary puts the country’s total cases so far this year at seven. Of these, four have been confirmed during the month of June. This was the situation on June 24, based on data from the country’s health ministry.
As in previous cases in Cambodia, the latest patient is known to have had contact with sick and dead poultry.
The source notes that several of those people infected there have died. This is linked to the greater virulence of the virus circulating in the country — recently designated as clade 2.3.2.1e — than the clade 2.3.4.4b variant circulating elsewhere, including in the U.S. and Europe.
In recent weeks, four human infections with flu viruses of avian origin have been confirmed in China. These are covered in recent updates on the situation in the Western Pacific Region from the World Health Organization (WHO).
Three of these involved the H9N2 virus — one in each of the provinces of Henan, Hunan, and Sichuan. All started in mid-May following contact with poultry. Two adult patients required hospital treatment, but they and a six-year-old boy are reported to have recovered.
The fourth Chinese patient was a farmer from Shaanxi province who may have contracted an H10N3 infection while traveling in Inner Mongolia. While still under treatment in hospital, her condition was reported to be improving. This is the sixth confirmed human infection with this virus in the world.
View our continuing coverage of the global avian influenza situation in poultry, and on disease developments in the U.S. dairy sector.