Europe: The largest epidemic of bird flu

Based on national reporting to the European Commission, there were a total of 2,398 outbreaks during the 2021/2 season, with 46 million birds culled in the affected establishments, 168 detections in captive birds and 2,733 highly pathogenic avian influenza events in wild birds in 36 European countries.

Between 16 March and 10 June 2022, 1,182 highly pathogenic avian influenza virus detections were reported in 28 EU/EEA countries and the UK with 750 of these in poultry, 410 in the wild and 22 in captive birds. During this most recent reporting period, 86% of the poultry outbreaks were secondary infections due to the spread of highly pathogenic avian influenza between farms.

Of the poultry outbreaks, the worst affected country has been France with 68% of all recent cases, while Hungary saw 24% of cases. No other EU country reached more than 2%. However, the greatest number of detections in wild birds were reported in Germany (158), followed by the Netherlands (98) and the UK (48).

The paper, ‘Avian Influenza Overview – March-June 2022’ said the persistence of the HPAI (H5) virus in wild birds since the 2020-1 epidemic wave indicated that it had become endemic in wild bird populations in Europe, meaning poultry farmers can expect it to be present throughout the year, with the highest risk in autumn and winter months.

One of the co-authors, Professor Ian Brown, head of the virology department at the UK’s Animal and Plant Health Agency, told the Poultry Health and Welfare Group that prospects for the immediate future control of the diseases were not great.

The paper adds that medium to long-term strategies for reducing poultry density in high-risk areas should be considered. Genetic analysis results show that the viruses circulating in Europe belong to clade 2.3.4.4b HPAI A(H5) viruses that were also detected in wild mammal species in Canada, the US and Japan, and showed genetic markers of adaptation to replication in mammals.

In the UK, environmental groups have called for the government to ban the release of gamebirds to avoid, a “catastrophic” avian flu outbreak. Shooting of reared pheasants and partridge begins on 1 October. The virus has been detected at least 9 times in wild and farmed pheasants in England, Scotland and Wales since early 2021.

Outbreaks of bird flu on poultry farms have continued this month with Devon currently being the worst affected.