Two more counties in Wisconsin have fallen prey to the Highly Pathogenic Avian Influenza H5N2 strain which continues its exponential race across the Mississippi flyway, along which this infection has been gaining momentum. According to the report in Madison, this new outbreak, affecting the Barron and Juneau counties, have put almost 126,000 heads of poultry at risk.
Although this disease seems to be highly infectious and has a very high case fatality rate, it has not yet made the species jump at similar proportions and is believed to be of little infectivity and virulence to man.
A chicken farm in Wisconsin has been added to the tally of Highly Pathogenic Avian Influenza H5N2 hit areas, while more turkey farms have been added to the ongoing spread of HPAI H5N2 in South Dakota and Minnesota. A detailed report has been hosted by the Center for Infectious Diseases Research and Policy (CIDRAP).
For some time it has been believed that the H5N2 virus was less lethal to wild birds which hosted the virus and was eventually spread to the poultry through their fecal matter. However, given how rapidly this outbreak is expanding, and, more importantly, popping up in geographically distant areas, this hypothesis needs to be revisited. This virus was also being considered less virulent for chicken, but the involvement of a chicken farm is starting to raise doubts about this too.
Moreover, the South Dakota farms that have been affected share a common processing hub, indicating that there is reason to believe that this could be a point source epidemic.
More information shall come to light when the epidemiological investigations are completed. Till then one can follow this outbreak with some interest to figure out what is going on!