HPAI circulating in US dairy cattle since 2023?

While it may be a truism to say that a virus must be present to be detected, simply reporting virus’ detection tells you little more than that. The March 25 statement from the U.S. Department of Agriculture (USDA) that H5N1 highly pathogenic avian influenza had been detected in dairy cattle for the first time was no more than that, an announcement that it had been detected. It would seem that the virus could have been present in the U.S. dairy herd since late last year. Read more