Bird flu in cows ‘remarkably unremarkable’ as experts call for calmness

Alex Hamberg, bureau director of the Pennsylvania Department of Agriculture, told dairy industry stakeholders that the virus infecting US dairy cattle is ‘remarkably unremarkable’ and there’s no evidence that it has mutated.

In a conference call organized by the Center for Dairy Excellence, Hamberg relayed a conversation he had with Mia Kim Torchetti, director of the National Veterinary Services Laboratories: “I was speaking with doctor Torchetti earlier today [Wednesday, April 3] about this virus that’s affecting cattle, and in her words, it is remarkably unremarkable.

“So there’s no evidence at this point that this has changed in a manner that it’s now become mammalian-adapted; it’s still a bird virus.”

Last month, USDA confirmed that a strain of highly pathogenic avian influenza (HPAI) virus was detected in dairy cows in Texas and Kansas. The detections were believed to be the first to affect ruminants and affect older mid-lactation cows, causing them to suddenly dry off or produce thick, colostrum-like milk. The condition isn’t associated with deaths as cows mostly recover with supportive measures in around 12 days, though some do not return to lactation.

Since the first detections in March, further cases have emerged in the past week, including additional cases in Texas and New Mexico, and more recently, in Michigan, Idaho and Ohio. Cows were initially considered ‘dead-end hosts’ – i.e., unlikely to further transmit the virus – but detections on a Michigan farm that had taken in cattle from Texas suggested cow-to-cow transmission could not be ruled out. In addition, a dairy worker believed to have been in close contact with a sick cow tested positive for the virus; the person had eye redness as the only symptoms and is isolating while recovering.