Almost 1.8 million farmed and captive birds have been culled in the past three months because of the spread of avian flu across the UK, the BBC has learned. There have been 33 outbreaks of the virus on farms so far,

Three veterinarians had antibodies to bird flu virus, which suggests recent infection, the report said. None of them knew they were working with dairy cattle with known or suspect

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

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

A new CDC report found evidence of previous bird flu infection in veterinary practitioners who work with cattle and who did not know they had been exposed.

Signs of recent bird flu infection were found in three US veterinarians, two of whom had no known prior exposure, researchers said, suggesting potentially wider spread of the dangerous virus than has been suspected.