In the last week of October, Japan’s agriculture ministry confirmed the country’s first cases of highly pathogenic avian influenza (HPAI) in poultry of the 2022-2023 season. So far, three outbreaks have been identified in poultry.
The first outbreak to be confirmed as H5N1 HPAI was at a farm with around 170,000 laying hens in the Kurashiki city area in Okayama prefecture. Within a few days, commercial birds tested positive near Atsuma town in Hokkaido, and then near Kanonji city in Kagawa prefecture. Affected were around 170,000 broiler chickens, and 40,000 laying hens at the two farms, respectively.
At each of the affected premises, first sign to be observed was a spike in mortality. As soon as HPAI was suspected, movements on and off the premises were halted voluntarily. Once confirmed, the ministry put in place the usual internationally accepted restriction zones around each outbreak.
This current HPAI season has begun unusually early, reports Japan Times. Previously, the earliest start date was in 2020, when the fist cases were detected on November 5.
Also noteworthy is that the three outbreaks in Japan so far are in widely dispersed regions — even on three different islands. Okayama is located in the Chugoku region in western Honshu (main island), while Hokkaido is the most northerly island and prefecture, and Kanagawa is part of the nation’s smallest main island, Shikoku, which lie off the south coast of Honshu.
Around one month ago, the World Organisation for Animal Health (WOAH) was notified of the nation’s first wild bird testing positive for the H5N1 virus variant. In early October, a second cases was detected and officially recorded with the organization.
Last season, Japan registered a total of 23 HPAI outbreaks linked to the H5N1 HPAI virus serotype between November 12, 2021 and mid-May of this year. Directly impacted were more than 1.7 million of the nation’s poultry.
South Korea registers season’s third outbreak
Over the past week, South Korea’s total outbreaks for the new HPAI season has risen to three.
This season's first cases were confirmed at a farm in Yecheon county in North Gyeongsang province in the east of the country in mid-October.
According to the WOAH notification, the virus detected is identified as the 2.3.4.4b clade of Eurasian origin.
Within a few days, a second outbreak was reported in Yecheon, this time in a flock of around 32,000 broiler breeders, according to the agriculture ministry.
Five days later, presence of the H5N1 HPAI virus was confirmed at the third location. This followed reports of increased deaths among around 17,750 meat ducks. Affected was a farm in Jincheon county in North Chungcheong. This province is located in south-central South Korea.
According to the ministry, the HPAI risk is now high for poultry across South Korea.
After inspections at affected farms revealed some common weaknesses in biosecurity procedures, the minister has ordered all vulnerable premises to be visited by November 9. First priority are farms with ducks or breeding poultry, followed by premises with laying hens, quails, or native chickens where biosecurity measures have been assessed as “weak.” Particular attention will be paid to strict controls on — and disinfection procedures for — visitors and vehicles, and maintenance of effective disinfectant concentrations.
The ministry states that fines of up to 10 million won (KRW; US$7,050) may be levied on farms where disease control procedures are found to be inadequate.
Latest update from the ministry confirms that the H5N1 HPAI virus has been detected at three locations in South Korea since the start of October. Samples testing positive for the virus have been collected from North Chungcheong, South Chungcheong in the west, and Gyeonggi province in the north-west of the country.
More cases in Vietnam village flocks
With WOAH, Vietnam’s animal health agency has recently registered 13 more HPAI outbreaks linked to the H5N1 virus serotype.
Earliest cases included in the report were detected at the start of June, and the most recent were confirmed in early October. Directly affected were a total of 20,272 poultry of unspecified type in village flocks, each with between 29 and 3,300 birds. These were spread over 11 provinces in five regions from Hanoi and the Red River Delta and North West regions in the north, to the South Central Coast.
They bring to 39 the number of outbreaks officially recorded in Vietnam since October of 2021. Directly impacted have been a total of around 95,000 poultry.
HPAI situation elsewhere in Asia
Poultry at two locations in eastern Russia have tested positive for the H5N1 virus, according to recent notifications to WOAH.
In the Far Eastern federal district, a three-month HPAI hiatus ended with the detection of the virus in a backyard flock in Magadan oblast. Of the 72 birds at the property, 45 died.
Within the past 10 days, Russia’s veterinary authority has declared to WOAH that the HPAI situation in Chelyabinsk has been “resolved.” In August, a single outbreak was registered in this region of the Urals federal district, affecting a village flock of more than 2,000 domestic ducks and geese.
In the Philippines, provincial officials in Ilocos Norte are warning local people to be alert for signs of HPAI. According to the Philippines News Agency, a number of free-range chickens donated to local farmers in October died of the disease within a few days. They said this indicated the virus continues to circulate in this area of northwestern Luzon.
Two new human cases of avian flu in Asia
Vietnam has recorded its first human case of influenza of avian origin for eight years.
According to VN Express, a five-year-old girl from the northern province of Phu Tho is the nation’s first avian influenza A(H5) case since 2014.
Source of the infection is not identified, and none of the patient’s contacts tested positive from the virus. Between 2003 and 2014, there were 128 human infections in Vietnam, all involving the H5N1 virus variant. Of these, 64 patients died.
In the Western Pacific region, one new infection with the avian influenza A(H5N6) virus serotype have been registered with the World Health Organization.
No details are given of the patient or his/her location. The case brings to 82 the number of lab-confirmed human infections with this virus serotype in the region since 2014. This includes 33 deaths.
View our continuing coverage of the global avian influenza situation.
