The drop-in centers of the five cities project provided a variety of services, which are proving to be sensitive and responsive to their local contexts. There has been a noted reduction in the amount of injecting drug use (and therefore, events placing people at risk of HIV infection) in these locations.

The reduction in injecting drug use can be perceived in a number of ways:

1. Substitution of drugs injected by sublingual buprenorphine. For some people, this has led to a complete cessation of injecting drug use.

2. For others, substitution has led to a dramatic reduction in the daily frequency of injecting drug use (e.g. from 6 times per day to once a day). Such a change has been supported by the needle and syringe exchange programme, which provides access to clean injecting equipment, possibly for every injecting episode. Together, oral substitution and needle and syringe exchange have worked to complete the reduction in risk of HIV infection associated with injecting drug use.

3. Many people entered the programme looking for drug treatment, not HIV prevention services. The referral networks offered to people gave them easier access to treatment services, so many people have joined the substitution programme as a way of gaining access to drug treatment. Many of them have now stopped using drugs altogether.