California confirms bird flu outbreaks in dairy herds

California has confirmed the presence of H5N1 bird flu in three dairy herds located in the Central Valley, marking the first cases of this infection in the state. The California Department of Food and Agriculture initiated an investigation after the herds began showing clinical signs consistent with bird flu on August 25. Following preliminary testing, samples were sent to the U.S. Department of Agriculture veterinary lab, which confirmed the infection. This development makes California the 14th state to report bird flu in dairy cows. The situation highlights the importance of biosecurity measures, as workers on these farms are typically dedicated to a single herd, unlike practices in states like Colorado and Michigan, where workers may shift between dairy and poultry operations. This difference could potentially reduce the risk of cross-contamination. The USDA has launched an $824 million initiative aimed at enhancing testing and surveillance for bird flu on dairy farms, which includes a voluntary pilot program for weekly testing of bulk milk samples. Despite these efforts, participation from the dairy industry has been limited, raising concerns about the adequacy of testing. Colorado has taken a more proactive approach by mandating weekly testing of bulk milk samples from all dairy farms, which has led to the discovery of additional infected herds. Other states, including Iowa, have implemented more restricted surveillance protocols, but no other state has adopted Colorado's comprehensive testing strategy. The USDA has acknowledged the need for a coordinated national response to bird flu testing, emphasizing that decisions regarding mandatory testing ultimately rest with individual states. The lack of a unified approach is seen as a missed opportunity for enhancing public health measures for both animals and humans.