The bird flu has spread to dairy cows. Do you need to worry about another pandemic? – UCHealth Today

The bird flu has spread to dairy cows. Is is safe to drink milk? What if you have chickens in your backyard? Whats the latest news about bird flu? Photo: Getty Images.

The bird flu is here and has spread to dairy cows. Does that mean were headed for the next pandemic? Not yet.

Unless youre someone who is actively involved in raising birds or chickens, or you have close contact with infected cows, its unlikely youll be exposed, said Dr. Michelle Barron, veteran pandemic fighter and senior medical director of infection prevention and control for UCHealth

Animal handlers are usually the most at risk, said Barron, who is also a professor at the University of Colorado School of Medicine on the Anschutz Medical Campus.

We dont get too worried about spillover unless we see prolonged human-to-human transmission, she said. Weve seen some cases of bird flu that have spread within the same household but doesnt necessarily spread beyond that.

While its important to monitor the virus, its not yet a threat to humans and shouldnt take up much brain space.

Barron broke down the basics and answered our burning questions about H5N1.

No. Unlike COVID-19, this strain of bird flu (H5N1) has been around for about 30 years. So far, only two human cases have been reported since an outbreak of the virus among domestic birds began in 2022, including a Colorado poultry farm worker and a Texas dairy farm worker. Both cases were mild and resulted from direct contact with sick animals.

While the virus has been around for a while, an outbreak that began in 2022 among birds has killed about 90 million domestic birds in the United States. If you paid north of $7 for a carton of eggs in 2023, this outbreak impacted your wallet. Egg prices in Colorado skyrocketed in early 2023 after an outbreak, dubbed the worst-ever resulted in the deaths of more than 6 million chickens between infections and culling efforts to reduce spread. This is the longest and deadliest outbreak of H5N1 in history, according to Barrons colleagues at the University of Colorado School of Medicine.

The virus is making headlines again because it spread to mammals, including dairy cows, cats, dogs, bears, sea lions and more. As of May 2, H5N1 had been found in 36 herds of dairy cows in nine states among them, a dairy farm in northeastern Colorado.

The jump to mammals has experts watching closely, as the change gives the virus an opportunity to figure out how to replicate more efficiently in mammalian species.

Its bird flu, which is different from human flus or pig flus, Barron said. Animals can get the flu just like we do. The thing we know about this bird flu is that it mostly affects chickens, causing respiratory symptoms.

Highly pathogenic speaks to the mortality piece and the ability to cause severe disease. A highly pathogenic avian flu virus has a high rate of transmission and a high mortality rate in birds, Barron said.

Any animal has the potential to get infected, its just unclear how effective the virus will be, Barron said.

Yes, it can.

There have been a couple documented cases of transmission between birds and humans and cows and humans, but no human-to-human transmission, Barron said.

Barron said the risk of spillover to humans is very low right now.

But animal handlers should be careful.

Good protection measures include using gloves, masks and eye protection if you do have close contact with animals, but I imagine it can be a messy job, so that might not always be possible, Barron said. Weve seen some cases of bird flu that have spread within the same household in the past but doesnt necessarily spread beyond that. We dont get too concerned unless it spreads more widely.

Symptoms have been mild. Weve seen pink eye and some cold-like symptoms, Barron said.

Theres the potential for that to change, which makes everybody so nervous. Flu viruses can mix together and exchange genetics so pieces of a bird flu can get into a human flu, making the virus more transmissible to humans. Thats how pandemics often happen pieces of an animal flu get into human flus, and we dont have immunity to that new virus, she said.

Thats exactly right, Barron said. Pigs have receptors for bird flus, pig flus and human flus. The viruses dont necessarily make them sick, but they can hang out in the pigs respiratory systems and intermix. Thats where some of the genetic exchange can happen. Thats what happened in 2009 with the H1N1 swine flu pandemic.

Yes, pasteurized milk is safe to drink. The heating effects of the pasteurization process will kill the virus, and the virus fragments are not dangerous, Barron said.

Some believe raw milk has health benefits. Im in favor of pasteurization because of what I do, Barron said. I see what happens when people eat raw cheeses and drink raw milk. Im more worried about listeria, but bird flu is on that list now as well. The average person at the grocery store wont be encountering raw milk because it isnt sold there, although they may find some unpasteurized cheese.

Flu pandemics do occur every 20 years or so, the last one being swine flu in 2009, Barron said. When we get flu shots every year, were protecting against what we call antigenic drift. I like to tell people thats like if you have to write something over and over again on a chalkboard, by the time youre writing it the 20th time, there may be a spelling error.

That spelling error gets copied, and the original word eventually doesnt look the same. A pandemic is more likely to happen when there is an antigenic shift.

Thats when we have the human flu viruses mixed with the animal flu viruses that produce something our immune system doesnt have protection against. There have been other bird flu pandemics, including the 1997 H5N1 strain, the 1970s H1N1 flu strain, the 1968 H3N2 flu strain, and of course the 1918 H1N1 flu strain.

Right. It doesnt always have to be extremely deadly. I think thats something people assume. If you get this, youre going to die. And thats not necessarily true, Barron said. The term pandemic doesnt necessarily reflect the severity of the illness. It just means you have a susceptible group of people, and the virus can spread.

Unless you are working directly with animals, theres really nothing to do, Barron said Follow standard safe cooking practices, and consume pasteurized products. If you are working directly with animals, wash your hands frequently and consider wearing a mask or face shield to prevent splashing.

In some ways, no, Barron said. You cant stop wild birds, such as ducks and geese, from flying in and out and interacting with chickens. That proximity is always a risk. But on the flipside, backyard chicken operations are smaller, so the conditions and space constraints are different. The higher the volume, the higher the risk.

We have some antivirals that work against human flus, Barron said. I dont know if they would have the same effect against this bird flu strain. My suspicion is they would. But so far, the cases have been mild and really just call for observation and treating the symptoms as opposed to treating the disease.

At this point, its a completely different situation, Barron said. I think the main lesson is to be vigilant in our surveillance and paying attention to these smaller outbreaks.

I think the communication piece has also changed. Were making sure to get that information out there early so there arent all these conspiracy theories or information that is just wrong. Even if we dont know everything, were communicating better about what we do know, she said.

So, this is my personal bias and a professional hazard. I think you should always have hand sanitizer around because hands transmit so many infections, Barron said. But beyond that, no, I dont think so. Its good to be prepared for emergencies, but theres no need to stockpile.

Go here to see the original:

The bird flu has spread to dairy cows. Do you need to worry about another pandemic? - UCHealth Today