LANSING — A team of epidemiologists from the U.S. Department of Agriculture have traced the H5N1 viral spread in Michigan to a single herd of dairy cattle that had been unknowingly introduced in the spring to infected cows imported from a Texas dairy operation. From there, poultry farmers in the state took the viral hit.
It is unknown how the Texan dairy cow contracted the virus, though some have surmised that it was transmitted by some dead waterfowl on the property.
In Michigan, the virus escaped the barnyard and hit localized poultry operations, according to a report released by the USDA on June 9. As a result, H5N1 detections in poultry have been encountered in Newaygo County. Counties that share both poultry and cattle detections include Ottawa, Ionia, and Gratiot counties. Seven other countries in central and western Michigan have seen outbreaks of H5N1 in cattle only, according to data released by the Michigan Department of Agriculture and Rural Development, last updated on May 24.
The total number of dairy herds infected reached 25 as of June 12, according to Tim Boring, director of the MDARD. In addition, there have been seven poultry operations and one backyard flock infected.
“This is a crisis situation,” said Michigan Sen. Sam Singh, a member of the state's Senate Natural Resources and Agriculture Committee.
On Wednesday, the Michigan Department of Agriculture and Rural Development took the unprecedented step of offering $28,000 per HPAI-impacted dairy farm for participation in further epidemiological investigations with the USDA.
“We understand our dairy farmers are facing unprecedented challenges, and this action is an important step toward supporting them during this emergency,” Mr. Boring said. “The research opportunities through this package will help us advance science in real-time to best develop our continued rapid response.”
Michigan dairy operators were not totally prepared for the first-ever jump of the H5N1 avian flu virus to dairy cattle. And poultry operators were surprised by this never-before-seen vector for transmission.
“This is a disease in dairies that we have not had in the past,” Mr. Boring said.
The USDA report points to spread of the virus in Michigan as likely linked to the sharing of workers between dairy and poultry operations, milk collectors, with close contact to infected cows moving their services from one farm operation to another, and even veterinarians. While many wild birds are carrying the virus currently, there was no indication that this outbreak in Michigan started with them.
“We know the cows are not visiting the poultry farms,” Mr. Boring said.
Since cows had never before carried the H5N1 virus, biocontainment regulations have not been at the forefront of any dairy operations.
“There is a lot of concern and trepidation on the part of farmers,” Mr. Boring said. “Farms want to be protecting themselves.”
Epidemiological work indicates the virus spreads from cow to cow, cows to poultry, and cows to workers — two people detected to contracted the virus in Michigan have since recovered. But it has likely been humans who have been moving the H5N1 virus via their equipment and vehicles between farms, according to the USDA report.
For instance, 93 percent of the affected dairies are part of the same milk co-op, with milk haulers visiting those dairies 34 times, on average, within a 30-day period. The USDA also reported that 62 percent of the dairies used shared vehicles to transport cattle, with only 12 percent of the facilities cleaning the vehicles before each use. Finally, 53 percent of the dairies used the same deadstock removal company and 40 percent had animals removed from the premises by that company within 30 days prior to clinical onset of the virus.
It is also notable that 7 percent of the affected dairies' employees also work on poultry premises. That represents about 22 employees of three poultry flocks who worked weekend shifts at two dairy premises.
“We learn a bit more every day,” Mr. Boring said. “We have really worked on heightening biosecurity.”
On May 1, Mr. Boring issued an emergency order on enhanced biosecurity measures. It has been more than six weeks since any spread of the virus has been detected among poultry farms, he said.
On the national level, H5N1 in dairy cows has spread to 12 states with 101 herds confirmed to have the virus. In Michigan, the latest confirmation of the spread of the virus was detected June 7 in Clinton County.
“It is an important step to keep the virus out of states that don't already have it,” said Mr. Boring, noting that, in North Carolina, a herd has tested positive for H5N1 but had no clinical symptoms, adding a twist to epidemiological investigations.
Michigan's response does stand out nationally, and its confirmed infections reflect vigorous testing, according to Mr. Boring.
“We have had a really robust response,” said Mr. Boring, noting that 200 MDARD employees have been working 12 hours per day, seven days a week in response to the outbreak. “There are a lot of boots on the ground.”
In Michigan, the dairy sector contributes $15.7 billion annually to the economy. Poultry stands at $8.5 billion in its economic impact.
“This is a virus that has shown a propensity to mutate,” Mr. Boring said. “This disease is not going away anytime soon in dairy or poultry operations. Many cows never come back to full milk production.”
The rise of the H5N1 spread to multiple species — including seals, sea lions, cats and dogs, minks, skunks, foxes, and even a polar bear — illustrates the adaptability of the virus.
The Michigan Senate's Committee on Natural Resources and Agriculture held a joint meeting with the House Agriculture Committee on June 12 to review the H5N1 spread. Under consideration is providing more funds to farmers of all kinds to enhance biosecurity. There were some quiet musings on large animal operations.
“Decentralization builds resiliency,” Mr. Boring said.
Agricultural touchstone
The spread of H5N1 also carries a confluence of political, environmental, animal husbandry, and economic interests to the forefront of the national conversation.
“There are two firsts here. We have influenza A appear in a cow, and then we have a cow-to-human transmission. That is alarming to me,” said Dr. Cheryl Ruble, an infectious disease specialist who spends much of her time challenging industrial agriculture practices in Michigan.
For many, the spread of the H5N1 virus adds fuel to their arguments against concentrated animal feeding operations, known as CAFOs. Many have already accused these agricultural entities of inhumane treatment of animals, contributing to the growth of algae in Lake Erie, and the release of methane gases into the atmosphere. CAFOs deliver at least 90 percent of the meat and eggs to consumers in the U.S. market.
“Until now, cows were never a part of the picture,” Dr. Ruble said. “That just enhances the chances of the next human pandemic arriving from a factory farm.”
A CAFO is a dairy with more than 700 cows, according to the Michigan State University Extension. For chickens, that number is at least 125,000.
“When we have these large operations and a virus diminishes them, it really can affect our food security,” said Dr. Ruble, addressing what she refers to as "the cow in the room."
The USDA report, which was undertaken at the behest of the MDARD, identified the infected dairy cattle operations as six medium-sized farms, ranging from 100 to 499 head, and nine large farms, with more than 500. In addition, three commercial egg-laying poultry operations with more than 75,000 birds and four turkey operations with more than 30,000 birds were among those carrying the virus. One backyard poultry operation also was infected.
While Dr. Ruble is sharing her concerns with Michigan state legislators, some distress has spilled across the border into Ohio, where one dairy operation, which had also acquired animals from Texas on March 8, was detected to have H5N1 in Wood County earlier this year. It appears the virus was successfully contained to that single farm.
“The spread of HPAI in dairy cattle is not related to any operation being regulated as a CAFO,” said Brian Baldridge, director of the Ohio Department of Agriculture. “The Ohio Department of Agriculture is following guidance of the USDA and educating dairy producers on biosecurity and best practices to prevent the spread of disease.”
Meanwhile the national advocacy group, Physicians Committee for Responsible Medicine, claiming 381 doctor members in Ohio and 17,000 members nationwide, is calling for Gov. Mike DeWine to respond to the spread of bird flu by providing funding to farmers who wish to switch from livestock to crops. Three advertisements placed in locations around the governor's office in Columbus are to remain in place through July 7. In addition, a public health complaint was filed with Bruce Vanderhoff, Ohio's director of health. A similar complaint was filed with Natasha Bagdasarian, the chief medical executive in Michigan.
“I believe it is essential that state agencies, such as ODA, continue to work to hold CAFOS accountable during this time,” said Michele Grim (D., Toledo), an Ohio state representative.
Others in Ohio share such concerns.
“It must be mentioned that animals raised in stressful, crowded environments are more prone to disease,” said Lauren Maziarz, an associate professor of public health at Bowling Green State University. “Increasing animal welfare standards and improving the health and well-being of animals raised for food are viable ways to prevent disease outbreaks from occurring in the first place.”
Some advocate a complete cultural shift by moving away from meat-based diets to an increased dependence on plant-based menus.
“We like milk because it goes well with cereal. Dairy is not a necessity for human health. Calcium can come from vegetables like kale,” said Dr. Sagar Doshi, a lifestyle-management physician in Columbus. “There is nothing in chickens that we can't find in another healthier source.”
First Published June 23, 2024, 1:00 p.m.
