AN OUTBREAK OF HEPATITIS-A AMONG HOMOSEXUAL MEN IN MELBOURNE

Objective: To describe an outbreak of hepatitis A virus (HAV) infectio n that occurred in Melbourne in 1991. Design: (i) We reviewed Health D epartment Victoria surveillance data from 1989 to 1991 (primary survei llance) and identified all notified cases of HAV infection with an ons et of illness between 1 January and 31 December 1991 (secondary survei llance data). (ii) We studied HAV seroprevalence in Melbourne among ho mosexual men attending gay venues. Results: (i) In the two years 1989- 1990 there were only 55 notifications of HAV infection to Health Depar tment Victoria, with a male:female ratio of 1.2:1. Of the 495 notifica tions for 1991, 407 (82%) were male, of whom 210 (52%) were known to b e homosexual. Many reported sexual and social contact at Melbourne's g ay venues and with the Sydney gay community. (ii) Of men attending gay venues, 27% had serological evidence of past infection with HAV, comp ared with 45.8% in a 1981 Melbourne study. Conclusion: The outbreak of HAV infection in Victoria largely affected homosexual males in their sexually active years. Contact with the Sydney gay community was commo nly reported.