Federal and state health officials today reported that a person connected to a dairy farm in Texas has tested positive for H5N1 avian flu, the first known case linked to sick dairy cows and the nation’s second since the virus began circulating in wild bird and poultry in 2022.

Today’s case announcement underscores new interim guidance that the Centers for Disease Control and Prevention (CDC) released over the weekend on preventing, detecting, and responding to avian flu infections in humans, which are very rare and mainly pose a threat to people who are exposed to sick animals or contaminated environments.