The announcements came shortly after Texas health officials and the Centers for Disease Control and Prevention (CDC) announced the first human case, which involves a person from Texas who had contact with dairy cattle, highlighting the risk to farm workers. The CDC detailed what investigators found during testing of the patient's nasopharyngeal and eye swabs. According to earlier reports, the patient's only symptom was conjunctivitis (also known as pink eye), a mild symptom seen in some earlier avian flu infections.

According to the CDC statement: “This infection does not change the H5N1 bird flu human health risk assessment for the U.S. general public, which CDC considers to be low. However, people with close or prolonged, unprotected exposures to infected birds or other animals (including livestock), or to environments contaminated by infected birds or other animals, are at greater risk of infection. CDC has interim recommendations for prevention, monitoring, and public health investigations of HPAI A(H5N1) viruses.”

In another development, Texas officials said that domestic cats showing illness signs in the dairy farm settings were also positive for the virus. Cats are among the mammals previously known to contract H5N1, with infections reported in the United States, Poland, and South Korea.

Wild birds on affected farms had earlier tested positive for H5N1. Investigations are still underway to sort out how the virus is spreading on farms, which includes identifying the extent of virus circulation in other animals or wildlife.

Federal human health officials have said the avian flu outbreaks in dairy herds and the new infection in Texas don’t change its threat assessment, which is low for the public. They have also emphasized the safety of the nation's milk supply due to safety nets including pasteurization, while warning against drinking raw milk that can harbor pathogens.