Newswise — AMES, Iowa – As highly pathogenic avian influenza has spread in dairy herds across the U.S., the virus is being detected in raw milk.
A new study by a broad team of researchers at Iowa State University’s College of Veterinary Medicine helps explain why. Sialic acid, a sugar molecule found on the surface of some animal cells, acts as a receptor for influenza. Without sialic acid providing an entry point to attach, invade and infect, a flu virus is unlikely to find a potential host hospitable.
Before the recent HPAI outbreak in dairy herds, there was scant research into sialic acid levels in the mammary glands of cattle. Scientists had no reason to suspect the milk-producing organs would be a good target for influenza. “In livestock, we hadn’t usually looked in milk for viruses.
Bacteria, sure. But not so much viruses,” said Eric Burrough, professor of veterinary diagnostic and production animal medicine. A team of Iowa State researchers who examined mammary gland samples from two infected cows found a rich supply of sialic acid, which could shed light on how the virus attaches to hosts and help develop measures to slow the illness’ spread.
“We need to stop transmission, and one way to potentially do that is through milking machines. We’re not sure that’s involved with how this is spreading, but it’s one hypothesis,” said Todd Bell, professor of veterinary pathology. All milk sold commercially in stores is pasteurized, and research consistentl.