Over the past month, there has been a sharp uptick in reported outbreaks of highly pathogenic avian influenza (HPAI) in farmed poultry in both these Asian nations.
In South Korea, the number of confirmed outbreaks of HPAI since mid-October has risen to 46.
The latest HPAI infections confirmed by the agriculture ministry were in 317,800 laying hens in Gyeonggi, and 36,000 meat ducks in South Jeolla. These provinces are located in the north-west and southwest of the country, respectively.
So far this season, presence of the HPAI virus has been reported in 19 flocks of ducks, 13 of laying hens, nine in broilers, three of breeding poultry, and one each of quails and ornamental birds. Only serotype of the virus detected so far in the country has been the H5N1 variant.
As the number of outbreaks has risen over recent weeks, the ministry has announced ever tighter measures to control the spread of the virus.
From now on, egg farms within 3km of a confirmed outbreak will be subject to special measures. These apply immediately to 119 premises, where local authorities will manage routes for the transportation of eggs, and inspect both internal and external disinfection procedures. Furthermore, disinfection around farms with laying hens is to be stepped up, and official inspections will be more frequent to ensure enhanced quarantine and biosecurity standards are being met.
For duck farms in high-risk areas, birds will be shipped earlier than usual — at 38-39 days instead of the usual 45 days. Hobby and backyard poultry will be procured and culled.
According to the ministry, these intensive controls are justified because of the higher prevalence of HPAI cases in wild birds than in previous years, and the apparent increase in pathogenicity of the virus, particularly with respect to mortality in ducks.
In recent weeks, the ministry has announced an expansion in preventative culling in some areas of South Jeolla, which is an HPAI “hot-spot.” Because of the high local risk, all poultry will be culled within 500 meters of an outbreak, and all ducks within a 2-km radius of a confirmed infection. These measures will remain in effect until December 24.
Japan’s outbreak total reaches 35
In Japan, first HPAI cases in poultry of the 2022-2023 season were officially reported by Japan on October 26.
Based of notifications to the World Organisation for Animal Health (WOAH), the total had reached 22 outbreaks by the end of November. Directly impacted were just over 3.5 million of the nation’s poultry. The majority of the infections were in commercial flocks of laying hens.
Since the end of last month, the agriculture ministry has confirmed a further 13 outbreaks, bringing the nation’s total to 35 so far this winter. Including three other flocks epidemiologically linked to the December outbreaks, this brings the total number of poultry affected to more than 6 million (as of December 15). At all affected premises, presence of the H5N1 HPAI virus serotype has been detected.
Together with rising feed costs, soaring price of eggs in Japan has been partly attributed to the number of HPAI outbreaks on egg farms, reports Japan Times. Earlier this month, the wholesale price of a kilo of eggs was 275 yen (JPY; US$2.01). This equates to an increase of 31% year-on-year. Also contributing to rising cost is a recovery in the hospitality sector following the COVID-19 pandemic, while higher feed led to a reduction in egg production.
As of last week, this source put the loss of hens due to HPAI at more than 3.8 million, or around 2.7% of the nation’s total layer population. The agriculture ministry reports retailers have already raised their egg prices this month.
Japan’s poultry industry warned that egg prices are likely to remain high if there are further HPAI outbreaks in the country.
HPAI returns to Israel
One month ago, the H5N1 HPAI virus was detected again in a commercial poultry flock, according to the nation’s veterinary authority. The WOAH notification notes that the country had been free of the disease since January of this year.
Over the past four weeks, Israel’s veterinary authority has officially registered three outbreaks on commercial farms with WOAH — all in meat turkeys.
While the source of infection is uncertain, all of the affected premises were located near to fish ponds, which may have attracted wild birds carrying the virus.
At the first outbreak in the Northern District, elevated mortality was observed in birds from one out of the premises’ four pens at the time of loading for the slaughterhouse. As the birds were slaughtered before the diagnosis of HPAI was made, the meat was heat-processed before sale.
The two subsequent outbreaks were detected on adjacent farms in the west of the Central District. They bring the total number of birds directly impacted by the current HPAI wave to 38,000.
Two more outbreaks in Taiwan
For some years, HPAI virus of the H5N2 serotype has been afflicting poultry flocks in Taiwan.
Latest reports to WOAH put the number of outbreaks since November of 2021 in the territory at 42, involving almost 517,000 poultry.
According to the recent notification, two flocks of meat ducks tested positive for the virus in different counties around mid-November.
Further cases in south India
In the southern state of Kerala, around 8,000 poultry have been culled following outbreaks of HPAI, reports Chinese news agency Xinhua. Affected were birds in two areas of the district of Kottayam, where they had tested positive for the H5N1 virus serotype.
In October, the authorities notified WOAH that the H5N1 HPAI virus had been detected in two duck flocks in Alappuzha, a district in the same state.
HPAI cases in wild birds in three Asian nations
Since mid-November, HPAI cases in wild birds have been reported to WOAH by the veterinary authorities of Hong Kong, Japan, and Russia. In each case, the virus serotype involved was H5N1.
At a nature reserve in Hong Kong, this virus variant was detected in samples of droppings from wild birds. Also as a result of surveillance, one migratory wild bird was found dead.
Earlier this month, the territory’s authorities declared the outbreak series “resolved.”
Since September of this year, Japan has reported to WOAH a total of 428 cases of HPAI linked to the same virus serotype. The latest cases include 358 cranes found dead at various locations.
In the Khabarovsk region in Russia’s Far Eastern federal district, five corvids have tested positive for the H5N1 virus serotype at two locations since mid-November.
Human case of avian flu in China
In the Western Pacific region, one new infection with the avian influenza A(H5N1) virus serotype has been registered with the World Health Organization (WHO).
This latest patient was a 38-year-old female farmer from Qinzhou in China’s Guangxi province. Previously, she had contact with backyard poultry. Her symptoms began on September 22, and she passed one month later.
The case brings to 240 the number of lab-confirmed cases of human infection with this virus serotype in the region since 2003, according to WHO. Of these, 54 cases including 52 deaths were in China. This was the first case in China since 2015.
View our continuing coverage of the global avian influenza situation.
