Factors associated with HIV seropositivity in European injecting drug users. The European Community Study Group on HIV in Injecting Drug Users.

OBJECTIVE

To study factors associated with HIV seropositivity among European injecting drug users (IDU).

METHODS

Data on behavioural and other factors potentially associated with HIV status were collected retrospectively by personal interview with IDU (n = 2330) in a multicentre cross-sectional survey conducted in 12 European countries from 1989 to 1990. HIV status tested at the time of the survey was examined in relation to demographic data, history of imprisonment, travel to foreign countries, high-risk drug-using practices in the previous 6 months (re-using other IDU's injecting equipment without effective disinfection) and high-risk sexual behaviour in the last 6 months (multiple partners, unless none was IDU and condoms were always used). Analysis excluded IDU who claimed to be seropositive from previous testing.

RESULTS

Imprisonment was significantly associated with current HIV status [odds ratio (OR), 1.70; 95% confidence interval (CI), 1.2-2.87]. High-risk drug-use practices were significantly associated with current HIV status in respondents not previously tested (OR, 2.86; 95% CI, 1.09-7.35) but not in respondents claiming to be seronegative. No significant association was found for high-risk sexual behaviour.

CONCLUSIONS

Our experience supports the validity of retrospective investigation of behaviour in a population that is notoriously difficult to study. However, any interpretation of the apparently different associations of HIV status with high-risk sexual behaviour and high-risk drug-use practices must consider that factors tending to attenuate the correlations may operate differently in these two areas.