ZHH Special Report: Avian flu in dairy cows and a person.  What does it mean for businesses?

A business guide to the bird flu basics

April 2, 2024

What is the avian flu? 

The H5N1 bird flu, also known as a highly pathogenic avian influenza virus A (or HPAI), is a disease that’s been spreading like wildfire among wild and commercial bird flocks across the globe, including here in the U.S. Over the past two years, it’s spread to wild mammals. 

How did it spread to dairy cows?

Dairy cows in at least five states have tested positive for HPAI. While the first cows that got sick likely had direct contact with sick birds or their waste, there’s evidence now that it has spread from cow to cow. 

What does it mean that a human got sick from a cow? 

In Texas, a person who worked closely with a sick cow tested positive for HPAI after experiencing mild symptoms (primarily eye inflammation). There have been a few other human cases of HPAI, and most are very mild. But this rare incidence of cow-to-human transmission underscores the potential threat to humans and means we need to keep a very close eye on how it’s spreading. 

Will our dairy supply be affected?

We know that avian flu can affect our food supply - remember when it felt impossible to find eggs a few years ago? - but currently, the dairy supply is stable. Commercial milk is also pasteurized, which kills flu virus. Only the milk of sick individual cows is affected, and any milk from them is thrown out. That said, there is evidence that cows are spreading HPAI to each other, not just getting it directly from contact with sick birds. If this started to spread faster among dairy cows and enough got sick, the milk supply might ultimately be affected. But that’s not happening today; it’s only affecting a few farms right now. The milk you buy from distributors or at your local grocery store is safe, and the risk to the general public is low. 

Could it spread from person to person? 

The short answer is that we don’t know yet. Public health experts will certainly track this Texas dairy worker’s close contacts to see if any of them develop symptoms. If it does spread from human to human, that’s a higher level of concern. For now, the risk of widespread person-to-person transmission is low. 

Has the virus mutated to infect humans? 

We’ve been studying HPAI for a long time, and actually know a lot about it. There are some key genetic areas that, if they mutated, would make the virus much easier to spread from human to human. Right now, the virus doesn’t seem to have mutated in any of those crucial areas. If it did, then we’d be very concerned about tracking its spread and severity. 

What are some warning signs we should look out for? 

We’re on the lookout for human-to-human transmission, of course, though with the current virus the risk to people is relatively low. Epidemiologists are also watching closely for signs of infection in pigs. Birds and cows aren’t particularly similar to humans in terms of their bodies and immune systems, but pigs are another story. They’re known as “mixing vessels” for viruses because they’re susceptible to both human and avian viruses, which can combine and rearrange inside of them. That’s one of the ways the major mutations that make this virus scary for humans could theoretically occur. 

What can we do to be prepared for what may be ahead? 

In the short term, consider your dairy needs and keep an eye on the supply chain. Start to think about what you might do if milk prices went up or if availability was reduced if this were to become a cow-to-cow epidemic. In the longer term, if you haven’t gathered a team to review your lessons learned from the pandemic and put together a playbook for the next one, now is a great time to do it. If an HPAI human epidemic were to happen, we’d likely have a vaccine pretty quickly, so you can create a communications plan for a generic vaccination education campaign. To prepare, you can imagine what would happen if there was another major mutation in COVID like the original Omicron surge, and use that as a benchmark for what resources you wished you had at the time. We hope that HPAI won’t be nearly as dangerous and disruptive as COVID, but we definitely recommend being prepared.

Sources: YLE, CDC, NIH, Vox