Idaho’s avian flu outbreak in dairies is largely self-monitored

Idaho dairy producers are navigating one of the worst outbreaks of an avian flu strain in the U.S., and from an animal health and public health standpoint, the situation is largely self-monitored.

Threat to human health at this point is low, according to the Centers for Disease Control and Prevention. But that could change at any moment with each new mutation of the virus.

“I don’t know if this will turn out to be a pandemic, but we’re watching all the ingredients, and we’re watching that sequence,” said Dr. David Pate, retired president and CEO of St. Luke’s Health System. “Certainly, if you were planning out how we think a pandemic would occur, this is what you would be planning out.”

In response to the COVID-19 pandemic, Pate and another Idaho doctor, Dr. Ted Epperly, wrote the book “Preparing for the Next Global Outbreak” and Pate has been watching the avian flu outbreak closely. He argues that more should be done to prepare in case the situation becomes more dangerous for human health.

Idaho officials and dairy producers are monitoring animal health, regulating quarantine of infected animals, providing workers with personal protective equipment and offering testing of farm workers who have been exposed.

“Dairy operators, dairy workers always operate in a world where they have to take care of themselves for infectious conditions,” said Dr. Christine Hahn, state epidemiologist and state Division of Health medical director. “Cows have other germs they can spread … so they already have protocols in place.”

She said the state health department is providing information and support for those regarding protecting workers. But the decisions on how and what to implement are up to the operators.

AVIAN FLU OUTBREAK IN IDAHO

As of July 3, which was the most recent data available, there have been 27 cattle herds in Idaho affected by the virus, according to data from the USDA. Nationwide, there have been nearly 140 herds infected since the illness was first detected in U.S. dairy cattle in March, marking the first time the strain H5N1, known as highly pathogenic avian influenza, had been found in cows.

This is a big hit to Idaho, which has more than 400 dairy operations and ranks third in U.S. for milk production, according to the Idaho Dairymen’s Association.

So far no human cases have been detected in Idaho, and a total of four reports of confirmed human cases due to contact with dairy cattle have come out of Texas, Michigan and Colorado. All but one of the cases has presented through mild eye symptoms, according to information from the CDC, and one was a mild respiratory illness.

Studies by the U.S. Department of Agriculture and the Food and Drug Administration have found that the pasteurization process of heating milk effectively deactivates the virus, meaning consuming commercial milk is safe as long as it’s pasteurized, officials said.

The outbreak was first reported in Texas, and soon after appeared in an Idaho dairy that had just received cattle from Texas, said Idaho Department of Agriculture state veterinarian Dr. Scott Leibsle.

As of July 12, there are 18 facilities in nine Idaho counties under quarantine, including two in Canyon County. The last reported detection in Idaho was on June 20, and producers feel that the state may have reached its peak and is showing signs of decline in the spread of the virus, said Idaho Dairymen’s Association CEO Rick Naerebout.

However, this may change when migratory birds start returning to the state for the winter, he said.

There’s been testing of wild birds near impacted dairies and positive cases of the virus found in those birds, Leibsle said. It’s unclear which species is infecting the other one, he said.

NOT A PANDEMIC NOW, BUT WHAT’S THE THREAT?

The H5N1 virus in its current form is not very effective at infecting humans, Pate said. And when a human does contract the virus, it has occurred from prolonged contact with infected animals and it doesn’t seem to spread human to human.

The concern is that the virus could be deadly when it is contracted.

The virus has rarely impacted the U.S., but around 890 people have reported being infected worldwide since 2003, according to the World Health Organization. Of those, more than 50% died. Most of the cases were in Egypt, Indonesia, and Vietnam.

For comparison, COVID-19 had about a 1.7% case fatality rate, Pate said.

“This is about 52%, so you can see we’re talking about a whole different level of severity,” he said.

The other difference was many of the reported cases and deaths were younger, healthier people, Pate said.

Without mass testing however, it’s difficult to determine if the high reported fatality rate is because only severe cases were tested for.

Pate highlighted an effort by the state of Michigan, which has had two human cases, to test for antibodies in farm workers to determine if they had a prior infection but did not show symptoms.

Over the years, the virus has been found in sea lions and sea elephants in South America, foxes in Canada and France and other mammals around the world. In the last couple of years, the virus has popped up in new animals, Pate said.

“It was disturbing because the more animal species that get infected, the more the virus can mutate,” Pate said.

The situation is not worth panicking over, he said, but it may present an opportunity to prepare.

“We almost never see any of the steps that lead up to a pandemic,” Pate said. “We know the kinds of viruses are likely to cause pandemics or are higher up on our list … but we rarely see any of the steps until it starts in humans.”

He said he can’t know if the virus will develop into a pandemic, but the “risks are increasing all the time.”

Pate contends that not enough is being done to monitor the situation. He said that more antibody testing, such as what’s being done in Michigan, should take place and family members and household pets of exposed farm workers should be tested to determine if and how it’s being spread.

He is also calling for better transparency with the data. Because different agencies are handling different aspects of the situation, he said, it can be difficult to collect all the relevant data. And some of the information isn’t available. The USDA counts herds that have been infected, but doesn’t provide information on how many cows in the herd or the percentage of positive cases within those herds.

From a testing perspective, he thinks the government should be encouraging labs and medical centers to develop tests that are more readily available to the public to test for H5N1. There are tests available for influenza, but not this particular strain. When flu season arrives in the fall and winter, it may make monitoring the situation more difficult, he said.

Pate is also an advocate for putting resources toward vaccines. In late May, U.S. health officials announced they were taking steps to acquire or manufacture H5N1 vaccines for farm workers, veterinarians, and government officials who may be most at risk, Reuters reported.

As the virus continues to spread to different animals, it changes through a process known as “reassortment.”

“But it’s kind of like, if you have enough quarters and enough time, you sit at the slot machine, you’re eventually going to hit the jackpot,” Pate said.

It may be the case that the virus never develops in a way that presents a major risk to humans, but Pate argues there should still be a significant response.

“We should be taking advantage of this, because this is our opportunity to learn and develop our preparedness,” he said.

HOW ARE IDAHO DAIRIES RESPONDING?

Out of necessity, producers are always closely monitoring their herd, Naerebout said.

“We operate on very thin margins, there’s not a lot of room for error or a lot of room for disruptions in production in your dairy operation,” he said. “So they’re always monitoring milk production, quality of milk, all of these different pieces of data that they can observe to try and make sure that cows are performing at their peak.”

When a cow is infected with avian flu, her milk production can see a dramatic decrease. A cow can go from producing 80 pounds of milk a day to just 5 pounds the next day. Other symptoms include a fever, lethargy, loss of appetite, constipation and thickened or yellowed milk.

If there’s a suspected case, the state Department of Agriculture recommends producers contact their veterinarian immediately. The veterinarian then contacts the department to set up potential testing. In cattle, the virus shows up most prominently in the milk, which is sent to a state lab for testing.

Sick animals are sent to a separate pen, away from the rest of the herd. Milk from animals in the sick pen is not sent out for sale, and operators have been pasteurizing it before discarding it to avoid contamination of water or food supplies for other animals, Leibsle said.

When outbreaks have occurred, around 10%-15% of the herd has been infected, Leibsle said, although Naerebout observed this has been highly variable among operators in the state.

Samples from animals in the sick pen are sent to the state for testing, typically on a weekly basis, Leibsle said. It’s in their best interest to test regularly in order to be able to send their animals back into production once they’re healthy.

“To clear a quarantine, you have to show me evidence that there’s no virus left,” he said. “Just waiting an arbitrary period of time is not sufficient.”

Milking machines are flushed and sanitized between cattle to avoid spreading the virus that way.

Use of aprons, gloves and boots are already common practice among dairy workers, officials said. The health department used CDC resources to provide personal protective equipment to those who requested it. The public health division recommended eye protection as well, as many of the human cases have shown as conjunctivitis in the eye.

However, dairy workers often chose not to use a mask or goggles because of the discomfort or safety concerns due to limited vision, Hahn and Naerebout said.

“We are leaving a lot of those decisions up to the dairy operators and their workers, because they need to be safe overall and we’re just offering the best protection that we’re aware of from this particular virus,” Hahn said.

The term “highly pathogenic” means that in birds, where the virus first presented, the illness was very fatal. In cattle, the animals seem to be recovering within two to four weeks, Leibsle said.

The reduced production can still be a strain on the operators, Naerebout said.

Dairy producers are coming off an 18-month downturn in the industry, he said, in which production costs have been outpacing income. The added hit of a 20% reduction in production for a month can add to that stress.

“It’s not going to be a business-killer-type event, where this by itself is going to put a dairy producer out of business, but it definitely adds to an already stressful situation, given what they’ve battled through over the last 18 months,” Naerebout said.

HOW IS THE GOVERNMENT RESPONDING?

In Idaho, the leaders from the state Department of Agriculture and Idaho Department of Health and Welfare have been meeting regularly to coordinate efforts to protect animal and human health.

On a federal level, the USDA and CDC are monitoring and providing resources.

To address the financial impact, the USDA announced toward the end of May that it would make available funding to compensate producers for lost milk production, as well as funding for measures to improve “biosecurity.”

However, no Idaho producers have participated in this program currently, according a USDA spokesperson.

The federal agency had been slow to clarify which producers were eligible, Naerebout said. As of July 1 the agency announced it would begin accepting applications for financial assistance.

Only dairies that initially reported their positive cases to the USDA are eligible, he said.

“We’re honestly a bit frustrated with the USDA on that front,” Naerebout said. “It has been very difficult for dairy producers to track and get comfortable with what USDA’s expectations would be and how the programs would work.”

A USDA spokesperson said there are 24 producers in six states participating in its support programs.

Idaho’s Division of Public Health provides free testing to those who request it and provides CDC fact sheets with information about the virus, in both English and Spanish, Hahn said. The state works with the Idaho Dairymen’s Association and local health districts to distribute information and PPE.

The CDC provided funding for increased surveillance of the flu.

To ensure potential community spread of the virus is being monitored as well, the state has requested that all positive influenza tests in humans be sent to the state lab to test for H5N1. Hahn said that the division is also in communication with medical providers to track if there’s an increase in influenza cases.

Public health districts have antiviral medication available for those who may contract it and it is available for free for anyone infected.

MIGRANT WORKFORCE

An added challenge to testing and monitoring by government entities is that 90% of the dairy workforce are foreign-born. Many of those workers are in the state on a migrant visa and many are undocumented.

“The reality is in agriculture, we have a decently high number of undocumented individuals in our workforce,” Naerebout said, “and so there is going to be that concern that they don’t want their legal status discovered. So, they’re quite often not going to go and want to have interactions with health and welfare or other agencies just out of fear of their legal status being discovered.”

Pate said that historically, this is the case for other illnesses as well, and it’s an obstacle to those workers receiving the treatment that they need.

Hahn said the health agency is aware that this is a challenge and tries to work with the dairies to ensure that workers know that they can safely speak up if they aren’t feeling well, but it’s still a concern.

Naerebout said he doesn’t see an issue with workers telling their supervisors that they’re sick, and managers are also keeping an eye on their employees to ensure that sicknesses don’t spread throughout.

“You try and manage it just like you would any other situation where you don’t want that worker exposing coworkers to anything,” he said.

Guido covers Idaho politics for the Lewiston Tribune, Moscow-Pullman Daily News and Idaho Press of Nampa. She may be contacted at lguido@idahopress.com and can be found on Twitter @EyeOnBoiseGuido.