Minnesota ID‘s first case of avian influenza in a dairy herd

Officials say risk to humans ‘remains low at this time‘

Lauren takes a trip to the dairy farm.
More than 40 cows showed signs of avian influenza in central Minnesota.
Lauren Ober for APM Reports | 2020

A first case of highly pathogenic avian influenza in Minnesota dairy cows has been confirmed in a central Minnesota herd, state animal health officials said Thursday.

A Benton County farmer noticed signs of illness in a few cows last weekend. By the next day, more than 40 cows showed signs of fever, the Minnesota Board of Animal Health said in a statement.

The risk to the public from this virus “remains low at this time,” although “people who work with or have direct contact with infected animals could be at risk of getting sick,” the agency added. The Benton County herd will be quarantined for 30 days with the milk from sick cows disposed.

Pasteurized dairy products remain safe to consume, according to the Centers for Disease Control and Prevention.

The CDC recommends people who work with sick or potentially infected animals wear personal protective equipment. Officials have reported cases in Michigan and Texas where humans were infected.

“We knew it was only a matter of time before this detection would reach our doorstep,” State Veterinarian Dr. Brian Hoefs said in a statement. He said it’s important for farmers to monitor their herds and test sick cows.

Audio transcript

[MUSIC PLAYING] NINA MOINI: Well, more than 40 cows on a central Minnesota dairy farm have fallen ill with avian flu. This morning, the Minnesota Board of Animal Health confirmed its first case of the disease in a dairy herd in the state. Health officials have confirmed cases in 10 other states around the country, including neighboring South Dakota.

Joining me now to talk about what this means is Dr. Brian Hoefs, state veterinarian and the executive director of the Animal Health Board. Thank you for being here, doctor.

BRIAN HOEFS: Yes. Thank you for having me.

NINA MOINI: Well, this is tough news to hear about. To start, could you tell us, what is avian influenza? And why is it showing up in cows?

BRIAN HOEFS: Yeah, great question. So the highly pathogenic avian influenza is a member of the influenza A family, so the same flu virus that we succumb to usually every year in the flu season in humans. Unfortunately, in poultry, it has a different effect.

Poultry are highly susceptible, and it has a high mortality rate. So nearly 100% of poultry that are affected with the flu virus, the avian influenza virus, end up succumbing to the disease. So that's the concern in our state, number one turkey-producing state and, certainly, a state that has a lot of other poultry industry within our boundaries.

The shift over to cattle has been a curious one. So earlier in March, it was detected in some dairy cattle in Texas. It's considered a spillover event, meaning that there was some introduction from wild birds in a Texas dairy herd, then the virus was able to mutate a little bit. That allowed it to infect these dairy cattle.

The curious thing in dairy cattle, one of the curious things, is it doesn't have the same level of detrimental effects in dairy cattle. Their signs are usually transient. While they cause illness in these cows, within a couple of weeks, those cattle usually make a full recovery and return to the milking herd.

NINA MOINI: Oh, good.

BRIAN HOEFS: The concern, however, is that interaction between two industries. So Minnesota is a perfect example of that perfect storm. We have a large dairy industry in the state, and we have a large poultry industry in the state. And unfortunately, they're very close in proximity.

So our concern is the ongoing highly pathogenic avian influenza cases that we are seeing in poultry in Minnesota and why it hasn't moved on with the migratory birds as it typically does. And I think this kind of indicates where it's been. We're suspicious of dairy cattle harboring the virus, and now we have evidence of that in our first case confirmed in Minnesota.

NINA MOINI: So you'll be watching and monitoring that closely. One thing, when you might just be an everyday person and see headlines about something like avian influenza, it can sound kind of scary. So I want to make sure we talk about, are there risks to consumers through the dairy these cows produce? Or is it more just risk to farm workers and people who are interacting with these animals?

BRIAN HOEFS: Yeah. I think, first and foremost, the biggest risk is to poultry and to birds. That's the real concern we have. Second to that would be the dairy cattle. They end up with some illness, as I mentioned, and it causes decrease in production. As far as consumer safety, that's really minimal.

The CDC and USDA has done a lot of research to show that pasteurized dairy products are absolute at eliminating the infectious nature of the virus. So consuming pasteurized dairy products is completely safe. There is no risk of the disease being spread in that way.

There have been a few cases of dairy workers that have developed signs of this virus or infections from this virus-- three in total over thousands that have been have been tested across the country. Two of those have been described as mild cases of pinkeye. And a third one in Michigan recently was described as upper respiratory signs.

So all of these workers had direct contact with infected dairy herds, however, and some of them specifically stating that they worked in the hospital pen with the cows that were infected, and probably weren't using proper personal protective equipment to prevent that from happening. So we work closely with our partners at the Minnesota Department of Health to make sure that we are getting the word out to our dairy farmers, dairy workers, that PPE is available at no charge from the Department of Health.

We encourage them to use various forms of PPE. Certainly, eyewear seems to be a good idea and gloves, as well as other protective equipment that we've become familiar with during the days of the pandemic. In addition to that, our department of health partners are involved in our research and investigation of these cases.

They do their due diligence to work with farm workers to identify anyone who might be showing signs and referring them to get testing done at no charge, confidential testing, as well as provide any kind of support, medical support, that might be needed in the case that we have a positive detection.

Again, it's low risk to consumers. It's low risk to farm workers, especially if we're observing proper biosecurity, and cleaning, and disinfecting around those herds.

NINA MOINI: Yeah, and good to know about those resources available for everybody too. Dr. Hoefs, thank you so much for giving us the very latest.


NINA MOINI: That's Dr. Brian Hoefs, executive director of the Minnesota Board of Animal Health and state veterinarian.

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