Amidst a growing outbreak of bird flu, U.S. agriculture officials have issued an order requiring all lactating dairy cows to undergo mandatory testing and post negative results before moving to a new state. This federal directive, announced on Wednesday, serves as a measure to track and control the spread of the Type A H5N1 virus, which has been detected in dairy cows since March. Nearly three dozen herds in eight states have been affected to date, representing an escalation of the highly pathogenic avian influenza outbreak primarily transmitted by wild birds. Since the outbreak’s onset, over 90 million birds in commercial flocks have succumbed to the virus or been culled.
Health officials have conducted tests on 23 individuals and are currently monitoring 44 more who have come into contact with infected animals. Two farmworkers have been confirmed infected with bird flu since the outbreak’s emergence. While the virus has not yet exhibited signs of enhanced transmissibility to humans, samples from a cow in Kansas suggest potential adaptation to more animal species. The detection of the H5N1 virus in the lung tissue of a culled dairy cow has raised concerns. However, officials from the Centers for Disease Control and Prevention have not observed any changes indicating increased transmissibility to humans.
The new testing requirement will aid the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service in understanding how the virus spreads. Administrator Michael Watson expressed confidence in conducting tens of thousands of tests daily. Previously, testing was voluntary and limited to cows exhibiting symptoms. The ongoing outbreak has had a significant impact, with more than 90 million birds in commercial flocks perishing or culled to prevent further spread. Implementing this mandatory testing measure aims to mitigate the risk of interstate transmission and gain a better grasp of the virus’s trajectory.
