Avian influenza on farms in California

Three herds of dairy cattle in California tested positive for avian influenza H5N1. Federal officials said the test results showed that the strain of influenza infecting California herds was the same as that found in dairy herds in Colorado. This suggests that the infections were caused by the movement of cattle from one state to another. Emerging Disease Coordinator Bryan Richards clarified that the infection did not originate from wild birds. Authorities have stated that human transmission of avian influenza has not occurred and the infection risk is low. Products such as milk and dairy products are not at risk because contaminated milk cannot be sold and pasteurisation inactivates the virus. The U.S. Department of Agriculture has restricted the movement of cattle by requiring that dairy cattle be tested for avian influenza before being transferred.