USDA confirms cow-to-cow transmission is a factor in bird flu spread From Reuters

Tom Polansek

CHICAGO, April 19 (Reuters) – The U.S. Department of Agriculture (USDA) said this week cow-to-cow transmission is a factor in the spread of avian influenza in dairy herds, but does not yet know exactly how it spreads. virus.

Farmers and veterinarians are waiting for confirmation of how the virus is transmitted so they can better control its spread. Last month, dairy herds in eight states tested positive, as did a dairy plant worker in Texas.

“Those of us who worked with influenza for a long time soon realized that it spread from one cow to another,” Jim Lowe, associate dean of the University of Illinois College of Veterinary Medicine, said Friday. “There is no other way to explain the epidemiology.”

The primary source of the virus is believed to be wild migratory birds. However, the USDA said the investigation into bovine infections “includes some cases where spread was associated with the movement of livestock.”

There is also evidence that the virus has spread from dairy production facilities “to nearby poultry production facilities by unknown means,” he added.

The USDA noted that cows shed the virus into their milk in high concentrations, so anything that comes into contact with unpasteurized milk can spread the disease. He added that respiratory transmission is not believed to be the main route of spread of the virus among livestock.

Despite the uncertainty about transmission, the USDA has not imposed a quarantine to restrict the movement of livestock around infected dairy plants, as it does for chickens and turkeys around poultry farms. Infected livestock appear to recover, whereas avian influenza is often fatal to poultry.

Last month, officials reported that avian flu had primarily affected older cows, although more evidence now suggests younger cattle were also affected, according to the USDA.

(Reporting by Tom Polancek. Editing in Spanish by Javier Leira)