First case of bird flu detected in Arizona cattle

Earlier this week, the Arizona Department of Agriculture (AZDA) confirmed Arizona’s first identified H5N1 avian influenza detection in milk produced by a dairy herd in Maricopa County. As a protective measure, the facility is currently under quarantine to contain the bird flu.

Unlike other detections involving B3.13 H5N1, cattle have not yet displayed signs of illness with this particular D1.1. However, if clinical symptoms become evident, cattle will be isolated from the main herd.

Dr. Michael Worobey, a researcher at University of Arizona, joined “Arizona Horizon” to discuss this newfound bird flu in Arizona.

In Arizona, dairy is tested every day. AZDA has been working closely with the Arizona Department of Health Services and the Maricopa County Department of Public Health. Working closely with these health departments ensures the safety of workers and consumers. There is monitored staff at the affected site, and they also help prevent the spread among all the different livestock.

Over the last couple of years, a variant of the influenza virus that in previous decades has been associated with high mortality rates has been spreading through the bird population.

“About a year ago, we realized it has crossed into dairy cattle, a species that hasn’t been infected before. So we knew this was something spreading in dairy cattle around the country. But Arizona just announced that they have discovered a second jump from birds into at least one herd of dairy cattle in Maricopa County,” said Dr. Worobey.

How does that affect the milk that comes from this herd?

“Well, it’s interesting. The virus, when it gets into dairy cattle, unlike when it gets into us and infects our airways, can replicate at very high levels in the milk glands of the animals. So milk can have a very, very high amount of virus in it. But the good news is that if milk is pasteurized, it just completely eliminates the risk of infection from the milk,” said Dr. Worobey.

Dr. Worobey explained, “If you just imagine wild birds flying across airways or flyways, as we call them. State to state and locally, these animals interact with our animals.” So they will sometimes land on dairy farms, and they’ll sometimes land near poultry operations. Dr. Worobey added even someone’s backyard flock can become infected by the mixing between the wild birds and the domesticated species. So there’s no way to really prevent this from happening with 100% precision.

“What we have to do is try to find it early when it does happen.” said Dr. Worobey.