HIV prevalence and risk behaviour among female injecting drug users in London, 1990 to 1996

To describe trends in HIV prevalence among female injecting drug users (IDU) in London between 1990 and 1996.

HIV prevalence and risk behaviour were measured yearly between 1990 and 1993, and in 1996, in point prevalence HIV surveys of IDU recruited from both drug-treatment and community-based settings within Greater London. Sample sizes were 173 in 1990, 111 in 1991, 128 in 1992, 146 in 1993 and 200 in 1996.

Each survey used structured questionnaires and common sampling and interview strategies. Oral fluid specimens were collected for testing for antibodies to HIV (anti-HIV). Multiple logistic regression was used to assess the trend in HIV prevalence.

The percentage of female IDU testing positive for antibodies to HIV showed a marked decline over the study period, from 15.0% in 1990 to 1.0% in 1996 (P < 0.001). This trend was independent of all other variables examined. Each year, higher HIV prevalences were found among IDU recruited from community settings compared with treatment agencies.

These results concur with those of IDU recruited from treatment sites, although the yearly estimates in this study are higher. London benefits from low prevalence of HIV infection among IDU, coupled with behaviour change facilitated by early intervention. Continued surveillance of injectors recruited from both community and treatment settings is necessary in order properly to assess HIV prevalence among IDU.