A Texas man has contracted a “highly pathogenic” bird flu that has spread through U.S. dairy cows in five states, according to the Centers for Disease Control and Prevention (CDC).
Authorities, however, are playing down the wider risk to public health from the strain, according to a statement from the CDC Monday.
“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,” it said.
The afflicted Texan, who has not been identified, had minor symptoms, state health officials said. Authorities did not say how the person came into contact with the infected livestock.
“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,” the CDC said.
Bird flu infections were on the rise among animals and people worldwide from 2013 to 2022, a CDC study found.
Recent bird flu infections of dairy cows in Texas, Kansas, Idaho, New Mexico and Michigan mark the first time the virus has been detected in cattle in the U.S., according to the CDC.
Viral transmission among livestock would be a notable change in the capability of bird flu viruses, which usually transmit through direct contact with infected birds and have rarely spread successfully between mammals, according to the CDC.
The initial infection of cattle could have originated from dead, wild birds found on the property, federal officials reported. Most cattle have recovered, and few cattle have died, the U.S. Department of Agriculture said.
The infection of the Texas resident marks the second human infection in the U.S. since 2022. In the first ever case of the Type A H5N1 virus in humans, a prisoner on a work program at a poultry farm in Colorado contracted the virus after killing infected birds. The man did not become seriously ill and recovered.
Experts are wary of a bird flu that mutates to spread through more avenues, and especially the worst case: human-to-human transmission.
The Texas Department of State Health Services issued an alert for health care providers “to be vigilant for people with signs and symptoms of avian influenza,” especially people who work with livestock.