After a short absence, highly pathogenic avian influenza (HPAI) has been confirmed in commercial poultry flocks in Bulgaria and Taiwan. In Italy, two different viruses linked to the mild form of avian flu have been detected in recent months.
Bulgaria experiences poultry losses
Further cases of the H5N8 HPAI virus has been detected in Bulgaria.
In the first week of June, 68 birds died at a farm in the Asenovgrad region, according to the official report to the World Organisation for Animal Health (OIE). Bulgaria’s agriculture ministry records the outbreak in a flock of almost 79,000 poultry at the farm, which is located in the province of Plovdiv.
Previous reporting by local media identified the affected flock as one of around 28,500 poultry about one year of age.
The source of the latest infection is unknown. This virus type was last detected during the month of March in two provinces — Plovdiv and Kardzhali. These outbreaks brought the country’s total since the first cases in mid-February to eight — including seven in Plovdiv — and the direct losses of poultry to more than 178,600.
Taiwan declares H5N2 HPAI situation resolved
The Council of Agriculture has reported to the OIE that it has “resolved” the H5N2 situation.
Since the first outbreak in early 2015, this virus has caused massive losses of poultry from mortalities and culling. In 2020 alone, there were 26 confirmed outbreaks, involving more than 256,000 poultry. The most recent cases were on farms in early March. In the meantime, the Council declares no further cases have been identified as the result of intensive surveillance within 3 kilometers of infected farms.
A new outbreak has been reported of HPAI linked to the other avian influenza virus — H5N5 — circulating in Taiwan. The H5N5 virus subtype has been detected at a farm in Changhua county, reports Focus Taiwan. More than 9,500 chickens were culled at the farm after the owner observed elevated mortality in his flock. Cleaning and disinfection are ongoing.
Taiwan’s last reported H5N5 HPAI outbreak was in Yunlin county one month ago. It brought the total number of outbreaks linked to this virus subtype to 32. The virus first emerged in Taiwan in September of 2019.
Two mild avian flu strains detected in Italy
Over the past week, the Italian veterinary authority has reported to the OIE the detection of two different low-pathogenic avian influenza (LPAI) viruses in commercial birds after clinical symptoms were observed.
In April of this year, the H7N1 LPAI virus was detected among two turkey flocks in the province of Treviso in the Veneto region. The flocks — each numbering 7,150 birds — were close neighbors in the same district.
Mortality rate was not affected, but respiratory symptoms were observed in the birds, according to the Italian health authority and research organization for animal health and food safety (IZSVe). Source of the infection is uncertain, but the farms were located near wetlands used by wild ducks and other birds.
As this virus has not been detected in the area since that time, the veterinary authority has already declared the disease situation to be “resolved.”
This week, another LPAI virus was reported in northern Italy. According to the official OIE report, ostriches in the Lombardy region have tested positive for the H5N3 LPAI virus after showing clinical signs of disease.
However, the IZSVe reports the birds had shown no symptoms, and the infection was detected as a result of testing under the national surveillance program. Five of the birds produced serologically positive results following slaughterhouse testing. All 132 ostriches at the farm — 120 meat birds and 12 breeders — have been culled, and the premises are cleaned and disinfected.
Again, source of the infection has not been definitively identified. Located in the Suzzara district of Mantua province, the ostrich farm is near to the Po river where wild ducks have been observed.
View our continuing coverage of the global avian influenza situation.
