Outbreak of A2/Hong Kong/68 influenza at an international medical conference.

Abstract During an international medical conference there was an outbreak of influenza due to the A2/Hong Kong/68 virus. Approximately a third of the participants developed typical clinical symptoms. The infection may have been brought by participants from countries where the disease was then epidemic. Local respiratory symptoms were commoner in those of 55 years and over, but in general the disease was mild in all age-groups. About a third of the participants who had fever and other symptoms at the time of, or shortly after, their return home reported respiratory disease among their contacts, but there seems to have been no wide spread of infection from these foci.