STAT recently spoke to Erica Pan, California’s state epidemiologist, about what public health officials are doing to monitor for human H5N1 infections. The conversation, which took place before California announced its human cases, has been lightly edited for clarity and length.

Both patients were dairy workers whose illnesses were mild. Investigators are continuing to evaluate the contacts of a Missouri patient who had no exposure to animals.

Health officials in California are monitoring exposed workers for symptoms on two dairy farms where two human cases of bird flu tested positive, the U.S. Centers for Disease Control and Prevention said.