Additional cases of avian influenza have been detected in wild and domesticated birds in Canada and the US, as a severe outbreak of the virus continues to spread in Europe.
The first case of H5N1 in North America this season was detected in Newfoundland and Labrador in late December. Since then, the virus has spread to other locations in Canada and the US.
Last week, the Canadian Food Inspection Agency (CFIA) confirmed the presence of Highly Pathogenic Avian Influenza (HPAI), subtype H5N1, in two flocks in Nova Scotia. One outbreak was in a backyard flock, while the other outbreak was in a commercial flock. According to CBC, 12,000 turkeys were euthanized at the commercial barn during the second outbreak.
Meanwhile, in the US, the first cases of the virus were detected in South Carolina in mid-January before the virus spread to North Carolina and Virginia in recent weeks, with Florida reporting its first cases last week.
Two cases of Eurasian H5 avian influenza were detected in American green-winged teals in Palm Beach County, Florida, on February 1, according to the US Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS). Altogether, at least 90 cases of Eurasian H5 HPAI have been reported to the USDA since January, with nine of the cases confirmed as the H5N1 subtype.
The USDA has said that it expects to find further cases among wild birds and advised people to avoid coming into direct contact with wild birds. The service urged farmers and hunters to practice good biosecurity to prevent the spread of the virus.
The USDA added that the US Centers for Disease Control and Prevention (CDC) still considers the risk to the general public from the variant to be low. No human infections from the variant have occurred in the US. A recent update by the World Health Organization stated that the overall pandemic risk associated with the H5 lineage is considered "not significantly changed" in comparison with previous years.
A large number of bird flu outbreaks have been reported throughout Europe, Africa and Asia in recent weeks, mostly due to the H5N1 subtype, which comes from the H5 lineage, according to the World Organization for Animal Health. The organization warned that a further increase in outbreaks is expected in the coming months.
Over a million birds were found to be infected with the variant in Israel in recent months, although Israel's Agriculture Ministry declared in recent weeks that the outbreak is now under control.
The OIE has urged countries to increase surveillance for HPAI outbreaks, as the virus has been reported in over 40 countries since July.
The H5N1, H5N3, H5N4, H5N5, H5N6 and H5N8 subtypes of HPAI are circulating in bird and poultry populations across the globe, sparking concern at OIE, which called this an “unprecedented genetic variability of subtypes ... creating an epidemiologically challenging landscape.”
Last month, OIE Director General Monique Eloit told Reuters that "this time the situation is more difficult and more risky because we see more variants emerge, which make them harder to follow."
"Eventually the risk is that [the virus] mutates or that it mixes with a human flu virus that can be transmitted between humans then suddenly it takes on a new dimension," she added.
Germany’s Federal Research Institute for Animal Health, the Friedrich Loeffler Institute, told the German Deutsche Presse-Agentur (DPA) that Europe is experiencing its “strongest avian flu epidemic ever.”
The institute added that “there is no end in sight” as the virus spreads throughout the continent and around the world, with new cases reported on a daily basis.