Due to a high number of variants, the current wave of bird flu seen in Asia and Europe has a greater risk of spreading to humans, cautions the World Organisation for Animal Health (OIE).
The spread of highly pathogenic avian influenza has raised concern as outbreaks lead to the death and culling of tens of millions of birds, trade restrictions, and a disruption to the market.
OIE Director General, Monique Eloit, told Reuters in a recent interview: “This time the situation is more difficult and riskier because we see more variants emerge, which make them harder to follow.”
She added that the risk is that it mutates or mixes with a human flu virus that can be transmitted between humans and then “suddenly it takes on a new dimension”.
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“Various subtypes of high pathogenicity avian influenza have been reported by more than 40 countries over the last 6 months,” reported the OIE in November, and earlier this month noting that 15 countries had reported outbreaks of bird flu in poultry between October and the end of December, mostly the H5N1 strain.
Italy, it said, was the worst hit in Europe with 285 outbreaks and nearly 4 million birds culled. Other countries that reported bird flu outbreaks over recent months include the UK, which has experienced its largest bird flu outbreak, Poland, the Netherlands, and Russia.
“Over recent years, numerous subtypes of the HPAI viruses have been circulating in diverse bird populations on a large geographical scale. In particular, in 2021, an unprecedented genetic variability of subtypes has been reported in birds, thus creating an epidemiologically challenging landscape.
H5N1, H5N3, H5N4, H5N5, H5N6 or H5N8 are the subtypes currently circulating in poultry and wild bird populations across the world,” reported the OIE.
In total, around 850 people have been reported to be infected with the H5N1 strain, of which half died, the OIE said. Eloit stressed, however, that most countries had learned to contain outbreaks and transmissions to humans would be sporadic as bird flu is usually passed through close contact.