Changing epidemiology of hepatitis A in the 1990s in Sydney, Australia.

Surveillance of hepatitis A in residents of Eastern Sydney Health Area identified substantial epidemics in homosexual males in 1991-2 with a peak rate of 520 per 100,000 recorded in males aged 25-29 years, and again in 1995-6, with a peak rate of 405 per 100,000 per year in males aged 30-34 years. During 1994-5 an epidemic was detected among disadvantaged youth associated with injecting drug use; peak rates of 200 per 100,000 per year were reported in males aged 25-29 years and of 64 per 100,000 per year among females aged 20-24 years. The epidemiology of hepatitis A in these inner suburbs of Sydney is characterized by very few childhood cases and recurrent epidemics among homosexual men. Identified risk groups need to be targeted with appropriate messages regarding the importance of hygiene and vaccination in preventing hepatitis A. However, poor access to health services among disadvantaged youth and a constant influx of young homosexual males into these inner suburbs present major challenges to hepatitis A control.