Fifteen years of HIV surveillance among people who inject drugs: the Australian Needle and Syringe Program Survey 1995-2009.

OBJECTIVES: Following bipartisan political support in Australia for the timely introduction of needle and syringe programs (NSPs), HIV prevalence among people who inject drugs (PWID) remains low. This study aimed to determine the correlates of HIV infection among PWID; and to examine these correlates over time.
DESIGN: Annual cross-sectional seroprevalence studies among attendees of sentinel NSP sites.
METHOD: Multiple logistic regressions conducted on aggregated, de-duplicated data from 1995 to 2009 to determine variables independently associated with HIV infection.
RESULTS: Data were available for 22 478 individual NSP attendees, equating to a mean annual response rate of 44% (range 38-60%). Two-thirds of participants were men, with a median age of 30 years, and a median of 10 years since first injection. Eighty-five percent identified as heterosexual, 10% as bisexual and 5% as homosexual. Serology was available for 21 248 participants, of whom 230 (1.1%) tested HIV antibody positive. Variables independently associated with antibody seropositivity were homosexual or bisexual identity; male sex; older age; older age at first injection; and survey participation between 1995 and 1997 rather than later periods.
CONCLUSIONS: Unlike settings in which evidence-based public health approaches to illicit drug policy are yet to be implemented, the epidemiology of HIV among NSP attendees mirrors that of Australia's general population, with the majority of exposures attributed to male-to-male sexual contact. This pattern has remained unchanged over 15 years despite significant variation in drug markets and patterns of drug use. NSPs also play a crucial role in this country's comprehensive HIV surveillance mechanisms.