The significant decrease in the numbers of new cases among IDUs is evidence that HRPs have succeeded in curbing the epidemic. However, the role of non-formal education should not be ignored. The HIV epidemic began in 2004, but the pilot HRP was launched in November 2005 with limited access to drug substitution treatment, and then became nationwide after a 6-months trial. Needles and syringes are very easy to purchase in Taiwan, even without needle syringe programmes. Hence, non-formal education was also a key factor in this success. The rapid increase in the HIV epidemic caused greater media attention and increased reporting. Also, over 60% of the new reports of infections were among the incarcerated population and resulted from mandatory HIV testing. Segregating the HIV-infected prisoners prevented them from spreading the virus. Furthermore, NGOs began voluntary HIV prevention health education programmes in correctional institutions in 2004. Ko et al. (2009) found that, for drug-dependent inmates, a brief HIV education programme based on a transtheoretical model was effective.