A new report suggests that more Americans may be walking around with bird flu − and not even know it. Researchers from the Centers for Disease Control and Prevention randomly tested 150 veterinarians for H5N1,

Bird flu infections were detected among veterinarians tested last fall, including two people with no known exposure to animals with the virus, according to a report released by the U.S. Centers for Disease Control and Prevention on Thursday.

CDC finds H5 bird flu antibodies in 3 veterinary practitioners, highlighting need for enhanced surveillance and safety protocols.

A new study shows that bird flu has silently spread from animals to some veterinarians. The study published Thursday by the Centers for Disease Control and Prevention echoes two smaller ones that detected evidence of infection in previously undiagnosed farmworkers.

The new study is more evidence that the official U.S. tally of confirmed human bird flu infections—68 in the last year—is likely a significant undercount.

A CDC study has found H5N1 bird flu antibodies in veterinarians who had no symptoms and no knowledge they had been working with infected livestock.

The vets had no symptoms, and one worked only in states where no dairy infections had been reported. Three dairy veterinarians, including one who worked only in states with no known bird flu outbreaks in cows,