3 Idaho dairies now quarantined for bird flu. What’s happening to cows, and what it means

BOISE (Idaho Statesman) — Last spring, Cassia County dairy cows were the first to become infected with bird flu in Idaho.

The disease quickly swept through farms in the southern portion of the state and public health officials scrambled to figure out how to protect an industry that’s worth billions of dollars.

Now, several months later, Idaho has three dairies under quarantine for bird flu — two in the Treasure Valley, which includes Boise, and one in the Magic Valley in south-central Idaho. State Veterinarian Scott Leibsle said Wednesday that he expected one of the herds to come off of quarantine within a week, once the farm clears a second regulatory test of its milk supply.

Since bird flu arrived in Idaho, the state has had to quarantine 35 dairies, he said. The herds that are still affected are rebounding. The state has also reported 41 cases of bird flu in poultry since March.

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INFECTED DAIRIES NOT IDENTIFIED PUBLICLY

Idaho hasn’t disclosed which dairies have been affected by the virus. The Idaho Statesman reported in June that dairy farmers have been reluctant to report positive cases or give regulatory agencies open access to their operations.

“We were not the first state to endure this, but we were the first state to endure it as hard and as fast as we did,” Leibsle said. “What California is going through right now, we went though in May and June. We’ve got the benefit of six months of hindsight in managing this disease.”

Bird flu has been circulating among cattle in the U.S. after the disease cropped up at a Texas farm in March.

In California, where public health officials have been proactive about testing, there have been over 200 confirmed cases of bird flu on commercial dairies in the last month alone. Newsweek reported in October that so many cattle were dying from the disease in the state that rendering trucks could not keep up, and the CEO of a dairy trade association said dairies are “desperately overwhelmed.”

Utah has reported 13 new cases of bird flu in the last 30 days. Idaho, the nation’s third-largest milk-producing state, identified two. Leibsle said he suspects cattle in Idaho may have increased immunity from the initial wave of infections, when cows were more visibly sick.

“We’re now seeing cattle that are shedding the virus, but they’re not showing any signs of symptoms,” Leibsle said. “There’s so many different ways that this virus can spread that we still do not understand.”

The virus can spread via direct contact with contaminated surfaces like farm equipment, according to the U.S. Department of Agriculture. Dr. David Pate, the former CEO of St. Luke’s Health System, said researchers have shown through laboratory testing that the virus can also be transmitted via respiratory droplets.

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DAIRY IS BIG IN IDAHO, WITH 45,000 JOBS

The dairy industry supports over 45,000 jobs and generates hundreds of millions of dollars per year in economic impact in Idaho, according to the Idaho Farm Bureau Federation. Dairy is the state’s No. 1 agricultural commodity. The 376 dairies in the state brought in an estimated $4.2 billion in revenue in 2022, the federation said. The state has more dairy cows than all but two other western states, California and Washington, according to the University of Idaho.

Overall milk production dropped about 3% year-over-year for a few months in early summer, according to Rick Naerebout, CEO of the Idaho Dairymen’s Association.

“But none of that had any profound impact on markets,” Naerebout said. “It tightened up the milk locally a little bit for that period of time, but every dairyman I’ve talked to that’s had it has recovered fully and is back to normal.”

While some states, like Massachusetts, conduct regular surveillance testing, Idaho’s regulations remain looser. Pate worries the virus is more prevalent in Idaho’s herds than is reported.

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IDAHO HEALTH LEADER SUSPECTS ‘VAST UNDER-REPORTING’

“Frankly, the USDA has not been able to control the spread of this infection,” Pate said. “I suspect there’s vast under-reporting, probably both in terms of the number of cattle infected and the number of farm workers infected.”

He said some farm workers might not seek medical care because they either can’t afford it or fear losing their job. According to the Idaho Dairymen’s Association, about 90% of on-dairy jobs in the state are filled by foreign born workers, many of whom are undocumented.

Pate said cases can also go unreported if workers or animals are sick but don’t show any symptoms.

“We learned with the COVID pandemic that one of the real challenges to controlling any infectious outbreak is that if people don’t have symptoms or if animals don’t have symptoms, it’s really hard, unless you’re doing testing, to know about cases,” Pate said.

Idaho has not yet identified any cases of bird flu in humans, but seven people have so far been tested, according to Dr. Christine Hahn, an epidemiologist at the Idaho Department of Health and Welfare.

Washington state reported its first case of bird flu in humans in October, and the Washington State Department of Health has since confirmed 10 more cases, all linked to poultry. On Nov. 15, the Centers for Disease Control and Prevention confirmed the first human case in Oregon in connection with an outbreak at a commercial poultry farm near Portland. California has had 27 human cases, all linked to exposure to cattle.

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CDC SAYS PUBLIC-HEALTH RISK IS LOW

The CDC says that there is no evidence of person-to-person transmission and that the current public health risk is low. However, people who work with cattle or other animals are at a higher risk of infection.

Hahn said no states require people exposed to animals with bird flu to be tested. In Idaho, personal protective equipment is also optional, though Health and Welfare has also used federal money to provide dairies with personal protective equipment upon their request, she said.

“It’s all voluntary,” Hahn said. “Certainly, we’d like to see this disease completely disappear from the dairy operations. We aren’t where we need to be. But we do feel like things are stable, and we continue to work with Department of Agriculture on this.”

If dairy workers know they were exposed or suspect they might be sick, they can provide a sample to their local public health district and get results back from a lab in less than 24 hours, Hahn said. Infected workers can get the antiviral medication Tamiflu from the health districts at no cost, she added.

“It’s all there in place,” she said. “We just have not had a lot of demand for testing in our state, but we stand ready. We could test even asymptomatic people, if desired.”

The CDC released updated guidelines Nov. 8 that recommend offering testing to asymptomatic workers who have been exposed to animals infected with bird flu, including workers who were not wearing personal protective equipment or who experienced a breach of such equipment, and asymptomatic close contacts of a confirmed case.

USDA TO REQUIRE TESTING AT EVERY DAIRY

Leibsle, the state veterinarian, said the USDA recently announced a forthcoming mandatory testing program that would involve testing milk from every dairy. For Idaho, where some farms have 20,000 cows, carrying out such a program is tricky and could involve multiple trips to each farm to get different samples from a bulk tank of milk that represents the entire herd, he said.

“Fortunately, we know for a fact that food safety is not an issue,” Leibsle said. “Pasteurization kills the virus.”

Naerebout said the federal testing program may begin rolling out in December or January.

“Hopefully, we’ll have a vaccine that dairymen would be able to vaccinate the herd with in the near future,” he said. “Without a (bird)flu vaccine for cattle, you really have to just treat this just like you and I would treat the flu.”