Two highly pathogenic avian influenza (HPAI) virus variants are circulating in Hungary, and one of these is a new reassortment. New outbreaks of the disease have been confirmed in poultry in Germany and Poland, as well as Taiwan and Vietnam.
It has emerged that two different HPAI viruses are currently present in Hungary. One is an H5N8 subtype that is very similar to one detected in the country in 2018-19. However, the presence of a second variant — H5N2 — has been revealed by the Italian health authority and research organization for animal health and food safety . This is a new reassortment comprising some genes from the H5N8 virus, and others from a low-pathogenic avian influenza virus type that is present in Eurasian domestic and wild birds.
Both virus variants have been detected in Hungary’s early HPAI outbreaks, which first started in mid-February, according to IZSVe. The first cases in mulard ducks were the result of a co-infection in which both virus types have subsequently been identified. In more recent outbreaks, the H5N2 variant has been detected in laying hens, and other ducks flocks have tested positive for the H5N8 virus.
IZSVe is the European Reference Laboratory for Avian Influenza and Newcastle disease.
Over the past week, Hungary’s agriculture ministry has officially reported a total of 39 new HPAI outbreaks in poultry.
Two of the outbreaks were the first to be confirmed on duck farms in Csongrad, according to the official report to the World Organisation for Animal Health (OIE). With a total of more than 195,600 birds, the affected premises are located in different districts in this southern county. Despite confirmation of the presence of the H5N8 virus variant, none of the birds showed symptoms of the disease, and there were no mortalities. All the birds have been culled, and their carcasses destroyed.
Also caused by the H5N8 virus, Hungary’s other 37 newly reported outbreaks started in the period March 22-30. They occurred in eight districts in the central-southern county of Baks-Kiskun, which borders Csongrad. The official report omits some detail about the number of birds in affected flocks, but at least 282,742 poultry were involved. More than 4,200 of the birds died, and the rest have been destroyed.
These latest outbreaks bring the total confirmed in Baks-Kiskun county to 38, and direct losses of poultry through mortality and culling to almost 300,000 birds.
First HPAI case in western Poland
HPAI has been detected for the first time in the western Poland, according to the latest report from the country’s agriculture ministry to the OIE.
Starting on March 23, the outbreak was at a farm with more than 94,200 poultry in the province of Lubusz. Around 600 of the birds died, and the rest of the flock has been destroyed.
Based on the official reports to the OIE, this was the 31st HPAI outbreak in Poland since December 31, and more than 518,000 poultry have died or been destroyed at infected farms.
Germany reports HPAI in third region
At the end of March, there was a new outbreak of HPAI linked to the H5N8 virus subtype in the central region of Saxony-Anhalt. The infection was confirmed after 130 fattening turkeys died out of a flock of around 20,000 birds, according to the official report from the federal agriculture ministry to the OIE. Restriction zones have been established, an epidemiological investigation is on-going, and culling has started.
The source of the infection is unknown, but this region borders others where the disease has been confirmed in recent months, including, Saxony, Lower Saxony, and Brandenburg.
In Saxony, the same virus variant has been detected in a single duck that died at a zoo in Zwickau. According to the latest OIE report, none of the other 285 birds at the zoo showed signs of disease.
There have been two previous outbreaks in this region during March. Both were in Leipzig, where the virus was detected in a dead buzzard, and in a backyard poultry flock.
HPAI 'resolved' in the Czech Republic
Within the past week, the national veterinary authority in the Czech Republic has declared the HPAI situation “resolved” to the OIE.
This declaration follows two HPAI outbreaks linked to the H5N8 virus. This variant was detected in a small mixed flock in the central region of Vysocina in mid-January, and one month later in a commercial turkey flock in neighboring Pardubice.
Seven new HPAI outbreaks in Taiwan
Taiwan’s Council of Agriculture has confirmed a further two outbreaks of HPAI linked to the H5N2 virus subtype, which has been circulating in its poultry flocks since 2015.
The latest outbreaks — both on farms in Yunlin county — affected a flock of more than 8,000 native chickens in Dongshi, and around 1,450 turkeys in Tuku. They bring the county’s total outbreaks this year to 14.
So far this year, Taiwan has confirmed the presence of this virus in 26 farms, and direct losses of poultry to more than 256,000.
The H5N5 HPAI virus was first detected in Taiwan in September of 2019. With the latest five outbreaks to be confirmed, the total number has now reached 23.
Almost 56,000 poultry were affected in the most recent outbreaks, which involved flocks of laying hens, turkeys, and meat ducks. The virus was detected at farms in the counties of Yunlin, Pingtung, and Changhua, and in the city of Tainan. One of the layer flocks also tested positive for the H5N2 virus.
Vietnam confirms five new HPAI outbreaks
In its latest series of HPAI cases linked to the H5N6 virus subtype in its northern provinces, Vietnam’s agriculture ministry has reported five new outbreaks to the OIE.
During February, this virus was detected among village poultry flocks in Hanoi city and Thanh Hoa province. Around 460 of the birds died, and 4,300 are reported to have been destroyed.
These outbreaks bring the losses in the region since mid-January to almost 70,000 poultry from 34 villages in eight northern cities/provinces.
In the south of Vietnam, there have been five confirmed outbreaks of HPAI linked to the H5N1 virus February of this year. With the most recent cases confirmed on February 19, the agriculture ministry has declared to the OIE that the disease situation in the region has been “resolved.”
View our continuing coverage of the global avian influenza situation.
