Disadvantaged populations who have poor access to health care are particularly vulnerable to the effects of HIV and sexually transmitted diseases. They are less likely to be routinely tested for HIV and sexually transmitted diseases. If they test positive they are often unable to afford the required treatments. Efforts have been made to curtail the spread of HIV and sexually transmitted diseases in many populations. Interventions have evolved from traditional classroom-type presentations that focus on the individual to those that involve couples and aim to improve their communications. Other interventions have used street theatre and novellas broadcast on television or radio. Most of these interventions have had only modest effects on behavioural change.

A study in this week's BMJ by Kelly and colleagues reports the effects of a social network intervention designed to reduce risky behaviour that can lead to HIV and sexually transmitted diseases in a high risk population of Roma (Gypsy) men in Bulgaria.1 In the intervention arm of the study, leaders of Roma men's social networks counselled their own …