More than 344,000 Michigan birds have been euthanized in the last 30 days following bird flu detections in six turkey farms in Ottawa County, and two backyard flocks in Jackson and Oakland counties.
Early testing indicates it’s the strain of HPAI H5N1 (Highly Pathogenic Avian Influenza H5N1) found in wild birds, which is currently tied to ongoing outbreaks in flocks across the U.S. And the timing of the outbreaks fits with what we know about migratory patterns of wild birds, says Michigan Department of Agriculture and Rural Development Director Tim Boring.
“Since November 1, there have been around 90 commercial poultry operations impacted by this across the country, impacting upwards of 17 million birds,” Boring said on Friday.
Because the virus is so lethal in birds, and has to be contained quickly, entire flocks have to be euthanized essentially overnight. It’s still not clear how the virus spread among turkey farms in Ottawa County, though Boring said the outbreak there appears to be contained.
“We're taking all the steps that we can to eradicate the virus in these animal health populations, so the virus doesn't continue to perpetuate and become a more significant human health threat here moving forward."
What can we learn from this outbreak about how the virus spreads?
There have been 66 bird flu cases in the U.S. in this outbreak so far, including one death, according to the CDC. Two of those cases were in Michigan dairy workers last spring, though neither was severely ill.
Overall, the risk to the general public from bird flu is still low, health authorities say. But the more widely H5N1 is able to circulate, the higher the risk of the virus evolving to spread from person to person, and potentially create a pandemic.
“We have to recognize that the longer that this outbreak goes on, the more opportunities to cities there are for the virus to continue to evolve and mutate, which means there's a potential for additional species to be impacted, including humans,” said Dr. Kim Dodd, dean of the Michigan State University College of Veterinary Medicine, and an expert in laboratory diagnostics and outbreak response for emerging infectious diseases in animals.
Even when people don’t get sick, bird flu is devastating for poultry farmers, including the state’s $100 million turkey industry. Some 70% of those birds are raised in Ottawa County, according to the Michigan Allied Poultry Industry.
“The mental health impacts are really significant — these farmers work every day with these birds,” said Dr. Nancy Barr, executive director of the Michigan Allied Poultry Industries. “It's a tremendous emotional toll.”
Then there’s the economic hit of suddenly losing entire flocks: the USDA will cover the replacement of the bird and help with the virus elimination process, Barr said. But it takes anywhere from 3 to 6 months for farms to get production up and running again, and there’s no reimbursement for that lost time. Plus, the processing plants that work with those farms may have to cut down on employees’ shifts until production ramps back up. “So it's a real domino effect,” she said.
Because a single sick bird can mean whole flocks are wiped out, commercial poultry farms build their operations around preventing infection, Barr said. And the state issued an emergency order in May requiring dairy farms and commercial poultry farms to use biosecurity measures to prevent the spread of the virus.
So how did six different farms in Ottawa County have detections within less than a month? Did it spread from one farm to another? And if so, how?
“We know at this point that this is most likely a wild bird HPAI [strain] and it is likely that at least the first farm was impacted directly from wild bird virus,” Barr said. “Whether or not the spread has been lateral or between the farms, or has been individual point source infections, we don't know that yet, and it will be some time. But certainly that is a concern.”
When one farm has a detection, the state will test other farms in the area to see if their birds are also infected, Boring said. That’s how the virus was detected at some of the other Ottawa County farms, he said, and as of now, “we see containment of the current outbreak within those Ottawa County facilities.”
Barr said the farmers in the area who haven’t been affected are bracing themselves, and “operating at really high levels of biosecurity in an attempt to protect their flocks as well.”
“We know that when turkeys become infected, they shed quite a bit of virus, and that's why there's an urgency to making sure that we control that quickly,” Barr said. “And so whether or not that has been done successfully, that's sort of the question.”
