The OIE this morning has been notified of an outbreak of LPAI H5N2 in Barron County, Wisconsin - a region that was hard hit nearly two years ago by highly pathogenic H5N2 (see H5N2: 8 More H5N2 Farms In Minnesota, 3 More In Wisconsin).
Today's announcement, while a concern for local poultry producers, is far less dire.
LPAI viruses are quite common in wild birds, cause little illness, and only rarely death in poultry. Human infections, while they have been reported, are almost always mild (the exception being LPAI H7N9 in China which can cause severe human illness).
H5 & H7 strains, however, have the potential to mutate into HPAI strains. And so they are taken seriously.
According to this OIE report, analysis of this LPAI H5N2 virus shows it to be distinct from the HPAI H5N2/H5N2 viruses that caused 2015's record-setting avian epizootic.
Source of the outbreak(s) or origin of infection
Unknown or inconclusive
The USDA Animal Plant Health Inspection Service (APHIS) and the Wisconsin Department of Agriculture Trade and Consumer Protection are responding to this event.
- Testing of the commercial turkey flock occurred after the birds exhibited signs of depression.
- Samples were submitted for laboratory testing and were confirmed positive for influenza A virus H5N2 LPAI North American wild bird origin. Both the HA and NA are distinct from the EA/AM H5N2 clade 188.8.131.52 viruses from 2015.
- The infected premises was quarantined and the turkeys will be depopulated through controlled marketing.
- A comprehensive epidemiological investigation with enhanced surveillance is ongoing.