As the northern hemisphere enters the peak winter period, highly pathogenic avian influenza (HPAI) is spreading to affect ever more poultry flocks, particularly in Japan, South Korea, and Europe. Already, South Korea has culled more than 10 million birds to bring the infection under control, and the disease has impacted the largest Japanese poultry flock yet.
Avian influenza in Japan
As a new HPAI virus variant is detected in Europe, six states register further outbreaks in commercial birds. Another human case of avian influenza has been confirmed in China.
In Japan, there has been a significant development in the current HPAI situation. For the first time this winter, the virus has been detected in the east of the country, and in the largest poultry flock.
First cases of avian flu have occurred in Chiba, bringing the number of prefectures recording outbreaks to 13. According to Nippon.com last week, affected is a flock of laying hens in Isumi city. Around 1.16 million birds are going to be culled — the largest cull in the country’s history. Pathogenicity of the virus was still to be confirmed. Chiba is the second most important prefecture for egg production in Japan.
Japan’s agriculture ministry has officially registered a further 30 outbreaks of HPAI linked to the H5N8 virus variant in poultry. According to the reports to the World Organisation for Animal Health, these were confirmed between December 1 and 23, and directly involved 3.04 million birds. Since the first cases were confirmed in Japan in the first week of November, the number of outbreaks now stands at 45, involving more than 4.72 million poultry.
For the first time this year, the same virus has been detected in wild birds at six locations in Japan, according to OIE reports.
Across Asia and Europe, HPAI virus of the H5N8 family have been detected in wild birds and poultry flocks. However, the strains found in Japan and South Korea is different from that detected in Europe, according to the U.S. Center for Disease Research and Policy (CIDRAP) at the University of Minnesota.
New HPAI cases in South Korea
There are two new suspected outbreaks of HPAI among South Korean poultry flocks, reports Yonhap. Bringing the country’s total outbreaks to 33 so far this winter, these affected duck farms in North Jeolla and South Chungcheong. As all poultry within three kilometers of a confirmed outbreak are culled, more than 10 million birds in South Korea have been destroyed since the first cases in late November.
Earlier this week, the same source reported an outbreak in chickens at Yeoju, which is around 100 kilometers southeast of the capital, Seoul. All the birds there and at two farms within 500 meters were culled.
Over the past week, South Korea’s agriculture ministry has also registered with the OIE that wild birds at nine locations in six provinces have recently tested positive for the H5N8 HPAI virus.
Vietnam’s agriculture ministry has reported to the OIE that there have been no new cases of HPAI linked to the H5N1 virus variant. Between July and early September, three outbreaks occurred at different locations in the far south of the country.
Israel’s veterinary authority has registered a further outbreak of HPAI with the OIE. Latest to be affected was a flock of 18,500 growing turkeys in the Jerusalem region. Presence of the H5N8 virus has been confirmed, bringing the country’s total outbreaks since October to 12. More than 356,600 birds have been affected directly.
Developments in eastern Europe
The HPAI situation in Kazakhstan has been “resolved,” according to the latest official reports to the OIE. The agriculture ministry reports there have been no new cases in poultry or wild birds for some months. In the region of North Kazakhstan, more than 56,000 poultry have received vaccinations.
During September and October of this year, there were 11 confirmed outbreaks linked to the H5N8 HPAI virus in poultry in five regions across Kazakhstan. Almost 671,000 birds were directly impacted, including those on a large farm in Almaty. The same virus was detected in wild birds following mass mortality in the city of Petropavlovsk almost four months ago.
An H5 HPAI virus has been detected in a number of wild birds found dead in Rostov oblast, according to the Russian animal health authority. This virus was last known in the area in March of 2017. Rostov oblast is part of Russia’s North Caucasus federal district.
In Ukraine, an H5 HPAI virus has been detected for the first time in poultry in the central oblast of Kiev. According to the latest reports of the national veterinary agency to the OIE, this virus has been detected at two locations in the region, affecting 464 poultry.
A further outbreak linked to the same virus has been confirmed in the southern oblast of Mykolaiv (Nikolayev). As with the two earlier outbreaks during December, the disease affected a small non-commercial poultry flock.
Evolving avian flu situation in Europe
Germany has recorded its first ever cases linked to the H5N3 HPAI virus strain. Last week, some wild birds found dead in the northern state of Schleswig-Holstein tested positive for this variant. This is the fourth HPAI virus variant to be detected in Europe this winter.
In another “first,” Germany has registered its first outbreak of HPAI among poultry in the eastern state of Saxony. According to the official OIE report, the H5N8 virus variant was present at a farm in the Leipzig area. More than 70 of the 9,000 breeding geese at the farm died, and the rest will be culled.
For the first time this winter, wild birds in Germany’s southwestern state of Baden-Wurttemberg have tested positive for an H5 HPAI virus. This is the first detection of the virus in almost four years.
This season’s first outbreak of low-pathogenic avian influenza (LPAI) has been detected in a Belgian poultry flock. A flock of around 79,000 chickens on a farm in West Flanders province tested positive for an LPAI virus of the H5 group in mid-December, according to the official report to the OIE. Unusually for a mild form of the disease, around 5,000 of the birds died. The rest have been destroyed. The country’s last outbreak linked to this virus was in January of 2009.
Last week, the Swedish Board of Agriculture declared to the OIE that the avian flu situation among its poultry sector had been “resolved.” This followed a single outbreak linked the to the H5N8 HPAI virus in mid-November. No further cases have been found since that time.
Following detection of HPAI in a number of wild birds across the country, the government of the Irish Republic has ordered all poultry to be kept housed. This regulation came into effect on December 21.
More outbreaks among European poultry flocks
Over the past week, four countries in central and western Europe have registered with the OIE further HPAI H5N8 cases among their respective poultry flocks.
Germany’s agriculture ministry has confirmed seven new outbreaks in Lower Saxony, and one in Schleswig-Holstein.
Between December 14-21, the virus was detected at a further six locations in western and southwestern France. The majority of these outbreaks were among commercial ducks. One was in a backyard, and another in a commercial flock of around 5,000 guinea fowl.
In Poland, three additional outbreaks have been registered with the OIE — one in each of the provinces of Lower Silesia (Dolnoslaskie), Great Poland (Wielkopolskie), and Warmia-Masuria. A recent update from the country’s chief veterinary office puts the country’s total outbreaks in poultry so far this winter at 17.
Also confirmed to the OIE were three new outbreaks in the United Kingdom (U.K.). Affected were a small laying flock on the Orkney island of Sanday, and in England, a commercial flock of breeding ducks in Norfolk and backyard birds in Dorset.
Further HPAI cases among European wild birds
Following earlier positive cases of HPAI H5N8, more wild birds have tested positive for this variant in Germany, the Republic of Ireland, Italy, The Netherlands, Norway, Sweden, and the U.K.
Over the past week, further cases of H5N5 HPAI have been detected in the German state of Schleswig-Holstein. In the Veneto region of Italy, more wild birds have tested positive for the H5N1 HPAI virus, as has another swan in the Dutch province of North Holland.
New human case in China
A second human case of avian influenza A(H5N6) this month has been confirmed in China.
The latest patient is a 54-year-old woman in Hunan province. Her conditions is described as “critical,” according to the Centre for Health Protection in Hong Kong. This latest case brings the total cases linked to this virus worldwide since 2014 to 26. All have been recorded in mainland China.
View our continuing coverage of the global avian influenza situation.
