Avian influenza outbreaks in poultry in six Asian countries

Across Asia, it appears that the situation with highly pathogenic avian influenza (HPAI) is starting to decline seasonally as winter ends. However, further suspected or confirmed poultry outbreaks have been reported in Japan and the Republic of Korea, as have India, Nepal, the Philippines and Taiwan.

During the current HPAI "season" that began last October, outbreaks have been confirmed on 76 commercial farms in Japan.

The latest official notification from Japanese authorities to the World Organisation for Animal Health (WOAH) outlines 12 recent outbreaks. These start from January 25 to February 9.

More than 2.98 million birds were directly affected by the affected sites in seven different counties – all of which have reported outbreaks during the current wave of disease. Nine of the most recent outbreaks occurred in Kanto, the area around Tokyo. The rest of the outbreak occurred in the Kansai and Tohoku regions (also on the main island of Honshu), as well as on the southernmost main island of Kyushu.

In one of these recent outbreaks, there was an epidemiological link to a field in Kumamoto, where birds were also culled to prevent further spread of HPAI. This is the first time that this Kyushu region prefecture has been involved in the current wave of disease.

There are between 55,000 and 1.15 million chickens per flock, and five of the recently affected flocks are skinned hens. There are many more cases in commercial ducks, broilers, quail and two mixed groups. One of them includes some emus.

Since October 2022, more than 14.6 million Japanese poultry have been directly affected by highly pathogenic avian influenza outbreaks associated with H5N1 virus serotypes.

Variants of the H5N2 virus have also recently been identified in Japan. In mid-January, broiler chickens in commercial chickens in Kyushu tested positive for this serotype. No more cases have been reported in the country.

According to the WOAH notification, 1,225 wild birds in Japan have also tested positive for the H5N1 highly pathogenic avian influenza virus since January 2022.

South Korea has three new suspected outbreaks

In recent days, South Korea's Ministry of Agriculture has reported three suspected outbreaks of highly pathogenic avian influenza in poultry in South Korea.

Preliminary tests revealed the presence of the H5 virus in 43,000 laying hens in Gyeonggi Province, 42,500 native chickens in North Jeolla Province, and 110,000 quail in South Chungcheong-do. In the series that began in November 2021, outbreaks occurred in all three western provinces.

Since last October, as of January 12, 63 outbreaks associated with the H5N1 virus have been confirmed in South Korea. Of these, 25 affected meat ducks and 21 involved laying hens.

After a brief disruption, three recent outbreaks prompted the ministry to immediately suspend the movement of poultry and related shipments for 24 hours. This covers four metropolitan areas and five provinces, as well as Harim Co. The pause allows officials to check farms for signs of HPAI, conduct surveillance, and perform additional disinfection.

Three HPAI virus serotypes have been detected in Taiwan Province

Since early February, Taiwanese veterinary facilities have registered HPAI outbreaks in poultry associated with three virus serotypes.

After a 12-month hiatus, the H5N5 variant was detected on a farm in Chiayi County last month. Almost half of the 2,474 geese on the premises died, the rest have been destroyed. The source of the virus is unknown.

Between 25 and 31 December, the presence of the H5N1 virus serotype was confirmed in eight additional poultry flocks in four districts: Changhua, Yunlin, Chiayi and Tainan City. Each includes 4,677 to 61,620 native chickens, laying hens, quail, or meat ducks.

Since the outbreak in November 2022, 20 outbreaks have been reported to WOAH, directly affecting more than 325,700 commercial birds.

The current disease series involving the H5N2 HPAI virus variant began in November 2021. The virus has since been detected in 46 locations, affecting more than 587,500 poultry.

The most recent reported to WOAH are three outbreaks that began between 25 and 28 December. A total of 46,461 birds including native chickens, native ducks and laying hens were affected. All are stored in Changhua County.

The chairman of the Taiwan Provincial Committee on Agriculture blamed the recent egg shortage on a global outbreak of highly pathogenic avian influenza. Focus Taiwan reported that the official said there have been 74 cases of H5N1 HPAI in the area and that 1.03 million poultry have been culled. As the government works with the poultry industry to restore the laying hen flock, the pseudo-vice president expects the egg shortage to ease in early March.

Further outbreaks of highly pathogenic avian influenza near Nepal's capital

In the past month, Nepalese veterinary authorities have registered a total of 7 outbreaks of highly pathogenic avian influenza at poultry farms in WOAH. At commercial premises within about 10 kilometers of the capital, Kathmandu, nearly 29,000 birds are directly affected by the H5N1 virus serotype.

The last six outbreaks have affected flocks of 700 to 1,110 birds. These include mixed flocks of chickens and turkeys from the Nepal Institute of Animal Science.

So far, more than 18,700 poultry have been culled to control the spread of the virus. In addition, a local official said that more than 11,000 eggs, a ton of feed and 1,000 egg crates from the infected site had been destroyed, while the farm was disinfected, according to the Kathmandu Post.

Avian influenza situation in India

The increase in mortality at a government-run poultry farm in the eastern state of Jharkhand is attributed to highly pathogenic avian influenza, according to the Press Trust of India. At the farm in Lohanchal in Bokaro district, chickens of the local breed Kadaknath have been affected by the disease. Within 1 km of the outbreak is the epidemic area, and the surrounding 10 km radius is the monitoring area.

According to the Times of India, the loss of more than 900 birds in five days broke out.

Over the past week, India's animal health agency announced to WOAH that three earlier waves of highly pathogenic avian influenza outbreaks had been "resolved".

One of them involved the H5N8 virus variant, which affected four farms in the northern state of Haryana in early 2021. Two other disease series are associated with the H5N1 serotype and occur in Maharashtra. In this western state, a total of 55 poultry outbreaks were confirmed by WOAH from January 2021 to February last year.

While there are several other HPAI outbreak series underway in India in different states with WOAH, the most recent previous case was reported in ducks in the southern state of Kerala last December.

HPAI news from elsewhere in Asia

The H5N1 HPAI virus was detected for the first time in the Republic of Turkey (Turkey) late last month since May 2015.

The latest update of WOAH has increased the number of poultry involved in the outbreak to nearly 2.97 million, all from exponential farms in the west of the country. Officials chose to cull all poultry within a 10-kilometer radius of the affected sites and destroy all poultry products. They reported to WOAH that the decision was based on a risk assessment of screening activities.

Last week, the Philippine News Agency (PNA) reported the first outbreak of highly pathogenic avian influenza this year on an egg farm in the country. Depopulation was carried out on farms in the province of Bracan in central Luzon. Close surveillance within 1 kilometre indicates that the outbreak is under control. However, the surveillance area has been extended to within a 7-kilometer radius of the outbreak.

Between February and April 2022, there was a surge in highly pathogenic avian influenza outbreaks in the Philippines. To prevent a recurrence this year, the Authority reported that a senior official of the Ministry of Agriculture warned poultry breeders to be especially alert for signs of the disease, report abnormal mortality rates to the authorities and follow biosecurity protocols.