THE TRANSITION FROM INJECTING TO SMOKING HEROIN IN 3 SPANISH CITIES

Aims. To measure the current prevalence of different routes of heroin administration among users and to describe the most frequent patterns in the evolution of the main route from the time of first use to the p resent and their implications for the control of the HIV epidemic. Des ign. Cross-sectional study. Face-to-face interviews using a structured questionnaire. Setting and participants. Nine hundred and nine regula r heroin users from Madrid, Barcelona and Seville (about 300 per city) , half of them recruited in treatment centres and the other half out o f treatment. Measurements. Socio-demographic characteristics, current and historical behaviours related to route of administration. Findings . Before 1980 injection was the first main route of heroin administrat ion for most users in Barcelona and Madrid; in Seville smoking already predominated, although 40% of users began by injecting. Sniffing subs equently became predominant in Barcelona, while smoking became the pre dominant first route in Madrid and Seville (smoking has been the only first route in Seville since 1991). The prevalence of injection as the main route of administration during the last 30 days was 77.3% in Bar celona, 24.3% in Madrid and 23.9% in Seville; smoking predominated in the latter two cities. The factors most strongly associated with injec tion as the preferred route were city of recruitment and having a part ner who injected. Some 73% of those who stopped injecting in their las t change of route stated that the results of their HIV test or fear of becoming infected had been important in making this decision. Conclus ions. The change from injecting to smoking will greatly facilitate the control of HIV infection in Spain. However, the main causal factor do es not appear to be the perception of HIV risk, but rather other, ecol ogical factors (cultural or market-related). The absence of these fact ors in some areas may impede the spread of smoking.