#18,413
After a summer lull - where fewer than 100,000 birds were reported infected on U.S. farms over August and September - we saw a sharp rise in outbreaks during the month of October, resulting in the loss of 4.37 million birds, primarily in California, Utah, and Washington state.
The first week of November saw only 50,000 birds affected (see screenshot below), but today the USDA has announced 5 outbreaks (all dated 11/12/24 ) totaling more than 2.5 million birds, mostly from California.
The listing of the 5 latest farms affected follows:
The largest of these new outbreaks is in Kern County, which was one of the first California counties to report a human case linked to dairy cattle exposure. At this time, we don't know which genotype (e.g. B3.13, D1.1, D1.2, etc.) is responsible for this poultry outbreak.
Meanwhile, Canada's CFIA is reporting 5 more outbreaks since my last update on Monday, all in British Columbia (list below).
While the assumption is that most, if not all, of these outbreaks are due to H5N1, yesterday we did learn via a WOAH report that at least one outbreak in B.C. was due to HPAI H5N2. While Canada has been quick to say that the Bovine B3.13 genotype has not been detected, we've no information on the genotype involved in any of these recent poultry outbreaks.
What is clear is that HPAI H5 is once again spreading rapidly along the migratory bird flyways, and that current biosecurity measures aren't keeping the virus completely of out of commercial flocks.
Since `bird flu season' typically starts in October or November, and runs through the spring, poultry interests are looking at a long and challenging winter ahead.
