Sexual behavior among injection drug users in 3 indonesian cities carries a high potential for HIV spread to noninjectors.

Objective: To establish the prevalence of injecting practices that carry a risk of HIV infection among injection drug users (IDUs) in Indonesia and to examine the risk of sexual transmission of HIV from IDUs to noninjecting populations.

Design: A first round of behavioral surveillance among community-recruited male IDUs in 3 cities.

Methods: In late 2002, IDU gathering places were mapped in 3 cities, and 650 IDUs were recruited using multiple wave sampling originating from sites systematically selected for diversity.