Differences in sexual behaviour and condom use among cocaine and opioid injectors in Santos, Toronto and London

Abstract

This paper makes comparisons in the sexual risk behaviour of cocaine and opioid injecting drug users (IDUs) in the cities of Santos, Toronto and London. Using a standardised WHO Multi-City Study interview schedule, 6 months risk behaviour data were collected among 1204 community-recruited drug injectors in Santos (n=220), Toronto (n=479) and London (n=505). Statistically significant differences in patterns of drug injecting and sexual behaviour were found between the cities. Results show cocaine injection to be most likely in Santos and heroin injection to be most likely in London. Anonymous saliva samples show HlV-1 prevalence among IDUs to be significantly higher in Santos (60%) than in London (7.0%) or Toronto (4.5%). Santos IDUs also were statistically more likely than Toronto or London IDUs to report higher frequencies of penetrative sex with both primary and casual partners, sex in exchange for drugs or money, sex with same sex partners, anal sex with opposite sex partners, and lower levels of condom use. Santos IDUs also reported a higher average number of sexual partners (6.1) than IDUs in Toronto (3.7) or London (1.8). These findings show that sexual behaviour change among IDUs is needed most urgently in Santos, where rates of HlV-1 prevalence and casual partner change were highest and condom use lowest. Possible explanations for the observed behavioural differences include the impact of particular injected drugs on sexual activity/safety, and the impact of social and economic factors on risk behaviour. There is an absence of ‘social epidemiology’ in contemporary cross-national HIV research and this hinders the development of culturally appropriate interventions. Interventions, whether in developed or developing countries, not only need to promote changes in individual behaviour but also in the social and political environment.