Bird flu may be passed on by humans: International scientific team

Medical sleuths puzzling over three related bird flu cases in Thailand last autumn now strongly believe that two women who cared for a sick child both caught the virus from the girl.

This is not the first evidence of human-to-human transmission of the virus, which has killed more than three dozen people in Thailand and Vietnam since the outbreak last year. In 1997, scientists believe bird flu also spread between people in rare cases in Hong Kong.