Scientists criticize government response to avian influenza outbreak at dairy farm

One month after federal authorities intervened announced the trend Regarding the outbreak of avian influenza on dairy farms, the government has repeatedly reassured the public that the surge in infections has not affected the country's food or milk supplies and poses little risk to the public.

However, the outbreak among cattle may be more serious than initially thought.in vague online updates The Department of Agriculture announced this week that there is evidence the virus is spreading among cattle and from cattle to poultry.

North Carolina officials have detected avian influenza infection in an asymptomatic herd, The New York Times reported. This information is not publicly shared by the USDA. This finding suggests that the infection may be more widespread than thought.

The USDA does not require farms to test cattle for infection, so it remains unclear whether there are asymptomatic animals elsewhere. The government reimburses farmers for testing costs, but only 20 obviously sick cows per farm. The department announced this week that it would begin reimbursing farms that test asymptomatic cattle.

Federal officials are sharing limited genetic information about the virus with scientists and officials in other countries, which is important for understanding how the virus evolves as it spreads.

They are not actively monitoring pigs for infection. Pigs are notoriously effective hosts for evolving influenza viruses and are often kept in close proximity to cattle. And the officials Said Despite the lack of hard data, they have “no concerns” about the safety of their milk.

In a joint statement in March, the Department of Agriculture, Food and Drug Administration, and Centers for Disease Control and Prevention assured the public that pasteurized milk is safe. However, the FDA is still conducting tests to see if the process removes the virus. The agency did not say when the results of these tests would be available.

Some experts said authorities should not have claimed milk was safe before they had the data, even if there was a small chance of it posing a risk to people.

“I understand that the milk market is very concerned about losing even a few percent of milk consumption,” said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota.

But, he added, “the idea that you can avoid this kind of discussion by just offering absolutes is not going to help them.”

He and other experts say the federal government's response so far reflects failures early in the pandemic. “They seem to have learned very little from the communication lessons that COVID-19 has taught us,” Dr. Osterholm said.

Dr. Rosemary Sifford, the USDA's chief veterinarian, said in an interview this week that more than a dozen federal epidemiologists, roughly twice as many laboratory and field staff, academic researchers and state collaborators were all involved in the investigation. He said he was involved.

“Remember, we’ve been working on this for less than a month,” she said. “We are working hard to produce more information.”

USDA officials are only analyzing virus genetic sequences taken from sick cattle, but they plan to release the information to outside experts “in the very near future,” Dr. Sifford said.

“We definitely recognize that we need to learn more about the big picture,” she added.

Dr. Tom Inglesby, director of the Johns Hopkins Center for Health Security at the Bloomberg School of Public Health, said scientists outside the government could have already helped contain the virus if the department had been more proactive.

“Long gone are the days when it was considered a good plan or even acceptable for government agencies to manage all their own data,” he said.

Some experts say part of the problem is that the USDA has long been responsible for regulating and promoting agricultural operations.

“We all want farms to succeed and we all want American consumers to have a stable food supply,” said Don Teske, president of the Kansas Farmers Union. “But when you also have supervisory duties, it becomes a bit of a problem.”

Current avian influenza viruses have been circulating in domestic poultry, wild birds, and recently in a wide range of mammals since 2020.

As of Friday afternoon, the dairy cow outbreak had spread to the following areas: 32 herds in eight states: Texas, New Mexico, Michigan, Kansas, Idaho, Ohio, North Carolina, and South Dakota.

It is unclear how the outbreak started on the dairy farm. Dr. Sifford said early data suggests there have been at least two outbreaks of virus spillover from birds to cattle in the Texas Panhandle and New Mexico.

So far in cattle, the virus, called H5N1, appears to only affect lactating cows, and only temporarily. There have been no diagnoses and no deaths in calves, pregnant heifers, or beef cattle. But in at least one case in Texas, the virus appears to have crossed over from cattle to poultry.

The infected flock and the poultry flock were on different farms. However, the Texas Animal Health Commission says the virus could have been carried between people and animals who came into contact with objects contaminated with milk containing the virus.

Infected cows are thought to contain large amounts of the virus in their milk. (However, the USDA is testing a relatively small number of animals using nasal swabs and not feces, which is a common reservoir for the virus.)

Milking equipment on dairy farms is typically thoroughly cleaned at least once a day, but not sterilized. People milking cows are encouraged to wear safety glasses, masks, and face shields, but this recommendation is often ignored.

In cows infected with H5N1, milk production decreases rapidly and the milk becomes viscous and yellowish. “We've never seen anything like this before,” said Dr. Keith Paulsen, director of the Wisconsin Veterinary Diagnostic Laboratory.

(Milk collected from infected but asymptomatic cows does not appear to have changed, according to a spokesperson for the North Carolina Department of Agriculture.)

In interviews, some experts criticized the USDA's testing recommendations, which until this week promised reimbursement only for pools of obviously sick animals. Farmers may not have discovered many infectious diseases because they simply weren't looking for them.

Caitlin Rivers, an epidemiologist at the Johns Hopkins Center for Health Security, said widespread testing of animals, both symptomatic and non-symptomatic, early in the outbreak is critical to understanding the scale of virus transmission and possible mechanisms. He said that.

Many experts noted that pigs are the cornerstone of influenza surveillance because they are susceptible to both avian influenza and human influenza. They may act as a “mixing bowl” and allow H5N1 to gain the ability to spread efficiently among people.

Dr. Sifford said the USDA does not test pigs or require farmers to do so.

Testing for H5N1 infection in cattle requires approval from state authorities. Milk samples collected by a certified veterinarian are typically packed into tubes, packaged in an insulated cooler, and shipped along with a unique identifier to a USDA-approved laboratory. A positive test result was later confirmed at the USDA National Laboratory in Iowa.

Dr. Inglesby said each step delays the rapid response needed to contain the outbreak. Testing must be simple, free and accessible, he said.

Dr Sifford said the USDA had already received a “small number” of samples from asymptomatic cows. “We strongly recommend testing before traveling between states, including asymptomatic herds,” the ministry said in a statement.

Already, some state health departments and farmers are growing frustrated with the federal government's approach. Several farms in Minnesota (not included in the eight states with confirmed cases) are sending cow blood samples to private laboratories to test for antibodies to the virus, indicating current or past infection. veterinarian Dr. Joe Armstrong said. University of Minnesota addition.

Dr. Amy Swinford, director of the Texas A&M Veterinary Diagnostic Laboratory, said other dairy farmers are reluctant to test because they fear concerns about avian influenza could hurt their operations.

“I think this is happening in many more dairy farms than the ones we got our samples from,” she says.

Rick Neerbout, chief executive of the Idaho Dairy Association, said dairy farmers are struggling with low milk prices and high feed costs.

“We are already in a very tough economic situation, but the possibility of losing 20% ​​of our income over a period of two to four weeks adds even more anxiety to the situation,” he said.

Idaho banned cattle imports from the state following news of an outbreak of bird flu in the Texas Panhandle, but a week too late. Despite these precautions, the cluster of cases in Idaho “was kind of a test of our courage,” Neerbout said.

Matt Herrick, a spokesman for the International Dairy Association, said federal authorities should provide more resources and equipment for farmers to protect themselves and should disseminate updated information more widely, including through social media.

There is no mention of an avian influenza outbreak on the USDA's website. The last outbreak-related announcement from the Animal and Plant Health Inspection Service, a division of the agency, was dated April 2.

The USDA vaccine research Measures are being taken to protect cattle from H5N1, but it is unclear how long it takes for symptoms to develop. Dr. Armstrong, of the University of Minnesota Extension, said many farmers and veterinarians hope the virus will “burn out on its own.”

Rather, it may become a long-term problem. “The goal is to be ready for it,” he said. “It's not a matter of wishful thinking that it's just going to disappear.”