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.

After going quiet on bird flu, CDC scientists have published a report on its spread among veterinarians. The findings suggest a need for better surveillance.

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