If bird flu is lurking undetected on Minnesota’s dairy farms, the state is determined to find it.
Starting in February, milk from each of Minnesota’s 1,625 permitted cow farms will test once a month for H5N1, the virus commonly called bird flu that began infecting cattle last spring.
Milk haulers already collect samples for routine testing while loading tankers at dairy farms, and portions of those raw milk samples will go to the Minnesota Veterinary Diagnostic Lab for H5N1 tests.
“We want to be fair, consistent and equitable, making sure that we’re treating Minnesota dairy herds the same, so that we’re not over-sampling some herds and under-sampling others,” said Nicole Neeser, director of dairy and meat inspection for the Minnesota Department of Agriculture, during a webinar introducing the testing plans last week. “Our program is efficient, meets our needs and ... uses the systems we already have in place.”
Testing will continue for at least four months and become less regular if there is no evidence of H5N1, though efforts could ramp up if tests do detect the virus.
A positive result would not put the commercial milk supply at risk, because pasteurization inactivates the virus, according to the Food and Drug Administration. Outbreaks on dairy farms can put workers at risk of infection, however, and human exposure can help the virus mutate into a pandemic threat.
Minnesota has not reported a human case of bird flu. Nationally, one person has died from H5N1 and 67 have contracted it as of Friday. Of the positive human cases, 40 came from dairy herds.
“While most of these rare human infections have been mild, our biggest concern, because this virus is constantly changing, is that someone will be co-infected with a human seasonal influenza virus and an avian influenza virus,” said Dr. Stacy Holzbauer, an epidemiologist at the Minnesota Department of Health, on the webinar. “The genetic material of these viruses will go through a process that’s called re-assortment, creating a new influenza virus that could be easily transmitted from person to person.”