A slimmed-down MMWR resumed publication last week but included none of the bird flu reports. Public health experts have criticized the unprecedented break in publication and the h

Blood testing of large-animal veterinarians suggests that H5N1 bird flu has spread more widely than US surveillance of the virus is capturing, according to a new study by federal and state disease detectives.

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

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.

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.