Michigan authorities on May 1 issued an emergency order to try to stem the spread of the highly pathogenic avian influenza A after the influenza was detected in multiple dairy herds and poultry flocks in the state.
The order also bars the exhibition of poultry until at least 30 days pass without new cases of the bird flu in domestic poultry.
It also imposes other requirements on Michigan dairy and poultry farms, including mandating the designation of a person to act as biosecurity manager, the establishment of cleaning and disinfection practices, and the keeping of records of all vehicles and people who enter farms.
Those records must be made available to the Michigan Department of Agriculture and Rural Development, which issued the order, upon request, the department said.
“These steps are specifically aimed at limiting the spread of the virus from farm to farm within Michigan,” Tim Boring, director of the department, told reporters in a briefing.
“These measures will help us better protect our state against the spread of this virus and keep our animals healthy throughout the state,” Nora Wineland, Michigan’s state veterinarian, added.
The order will go into effect on May 8.
“Michigan is leading on this response across the country,” Mr. Boring said.
Officials aren’t sure how long the emergency order will remain in effect and whether they'll impose any additional requirements, he said.
Bird flu has been confirmed in six dairy herds in Michigan, according to the USDA. Thirty-six herds across nine states have tested positive for the influenza, as well as one person in Texas.
The herds that tested positive in Michigan are located in Ionia, Isabella, Montcalm, and Ottawa counties, state authorities said.
Bird flu has also been detected since 2022 in flocks in some two dozen counties.
Samples of milk from various states have tested positive for the influenza, but testing of 201 of the samples found that no live virus was present in the milk.
Federal officials say all signs indicate milk and milk products are safe but have cautioned people against consuming raw milk because it doesn’t undergo pasteurization. Further testing is planned.
The USDA also said on May 1 that 30 samples of ground beef from retailers in states with herds that tested positive came back negative. “These results reaffirm that the meat supply is safe,” the agency stated.
The agency is still working on analyzing muscle samples collected at slaughter facilities and a beef cooking study.
New Studies
Scientists with the USDA and other institutions said in a paper published on May 1 that genomic testing of samples from cattle, as well as analysis of epidemiologically linked data from birds, indicated that the bird flu moved from birds to cattle in late 2023.“These data support a single introduction event from wild bird origin virus into cattle, likely followed by limited local circulation for approximately 4 months prior to confirmation by USDA,” the researchers said.
Bird flu has also spread globally to other species, including walruses, bears, and seals, in recent months.
The authors did not list any limitations or conflicts of interest. They disclosed funding from the federal government.
In another preprint, professors from the University of Maryland School of Public Health outlined the results of a systematic review of literature to look at the history of avian influenza in cats and the possible danger cats pose as a potential pathway for humans to contract the flu.
The review showed that since 2004, there have been hundreds of avian influenza infections in cats. Avian influenza started circulating decades ago in wild birds.
“Thus, we argue that surveillance among domestic cats is urgently needed,” the authors said.
They encouraged people who own cats to be aware of possible heightened risk.
The work was funded by the University of Maryland–Baltimore. No limitations or conflicts of interest were listed.
