ABSTRACT
BACKGROUND: In 2003, a major epidemic of human immunodeficiency virus emerged among injection drug users in Taiwan. In response to the twin epidemics of HIV and intravenous drug addiction, the government implemented comprehensive harm reduction programs beginning in 2005. Collected data from relevant agencies were used to explore the impact of the harm reduction programs on HIV and illicit drug use. METHODS: This study divided 2002-2015 into three intervention phases and used the surveillance data and statistics on the HIV epidemic, drug abuse, and the intervention from relevant agencies to explore the correlations between different variables in different intervention periods and the combination effects of interventions on the HIV epidemic. RESULTS: In the pre-intervention phase, the growth of the HIV epidemic followed the rapidly increasing number of heroin users, reaching a peak in 2005. After the initiation of harm reduction programs, the HIV epidemic ceased growing, even rapidly declining with the expansion of needle and syringe exchange programs and opioid substitution therapy; however, the number of heroin users remained high. When the implementation of the needle and syringe exchange programs and the opioid substitution therapy program reached the plateau level in the consolidation phase, the number of heroin users also decreased rapidly. The combination effects of the harm reduction programs in this period also pushed levels of HIV infection below those before this outbreak. CONCLUSIONS: The HIV epidemic among injection drug users incorporates the dual problems of drug addiction and needle-sharing behaviors, so the use of a single intervention will not resolve all of the problems. Facing a severe HIV epidemic among injection drug users, quickly scaling up and promoting comprehensive harm reduction programs is a good strategy that can be used to simultaneously reverse the HIV epidemic and to resolve the illicit drug use problems. More research is needed to find out the reasons behind why there were cases that declined opioid substitution therapy, so that efforts can be undertaken to avoid the epidemic rebounding.