A case-control study on the causes of new HIV infection among heroin addicts attendees at the methadone maintenance treatment clinics / 中华流行病学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the routes and factors associated with HIV new infection of heroin addicts who had been attending the methadone maintenance treatment (MMT) program.</p><p><b>METHODS</b>A 1 1 nested case-control study was implemented with the cases (new HIV infections) and controls (HIV negative) selected from the treatment cohort of China MMT clients. Questionnaire was developed to collect information on demographic characters, behaviours on drug use, sexual behaviour, daily dosage of methadone intake, adherence to MMT, and psychological problems. Univariate analysis and multivariate condition logistic regression were used to identify factors associated with HIV infection.</p><p><b>RESULTS</b>108 (54 paired) clients on MMT were recruited, with 76 males and 32 females. Among them, 95 were Han Chinese and 13 were minorities, with average time of drug use as 12.1 ± 5.0 years. Among 54 new HIV infections, 33 were infected through sharing needles, 12 were through sexual contact and 9 unidentified. Results from multivariate condition logistic regression indicated that having longer duration of heroin use before on MMT (More than 10 years vs. less than 10 years,OR = 20.9, 95% CI1.62-269.34, P = 0.02), shared needles in the last 6 months (OR = 276.7, 95%CI5.65-> 999.99, P < 0.01) were risk factors while better adherence (More than 0.5 vs. less than 0.5,OR = 0.07, 95%CI0.42-0.87, P = 0.04) and living with families (OR = 0.002, 95% CI0.001-0.94, P < 0.01) were protective factors.</p><p><b>CONCLUSION</b>Sharing needles was the main route of HIV new infection among those clients that were on MMT. Factors as having received more support from both family and community, improvement of adherence to MMT, reducing the frequency of injection etc., could reduce the risk of HIV infection among those MMT clients.</p>