Avian Flu Virus Confirmed in Michigan Dairy Herd

By Stephanie Soucheray

Highly pathogenic avian influenza (HPAI) virus has been confirmed in a dairy herd in Van Buren County, Michigan—the nation's first detection for almost 2 weeks. The last detection in Michigan was on July 26, also in Van Buren County. 

The detection brings the number of affected dairy herds in Michigan to 28, and samples have been sent to the US Department of Agriculture's (USDA) National Veterinary Services Laboratories for additional confirmatory testing, according to the Michigan Department of Agriculture & Rural Development.

According to state rules, the detection will now prohibit the exhibition of all lactating dairy cattle, and those in the last 2 months of pregnancy, until there are no new cases of HPAI in Michigan dairy cattle for at least 60 consecutive days.

In the past 30 days, 5 states have reported 20 cases of HPAI in dairy cattle, according to the USDA. The most recent previous detections were in Colorado and Idaho. 

Study suggests antibodies to flu common in raptors 

In other avian flu news, a preprint study of raptors from the University of Minnesota's Raptor Center and the Hawk Ridge Bird Observatory in Duluth during the 2022-23 H5N1 avian flu outbreak finds that 69.1% of bald eagles were seropositive for influenza virus, and 52 of 67 (77.6%) of them tested positive for antibodies to both H5 and N1.

The study, which has not yet been peer-reviewed, offers new insight on the seroprevalence of influenza viruses in wild birds. According to the authors, the prevalence of influenza antibodies observed in this study was higher than reported from raptors sampled in this same region in 2012