[Related factors and interaction on HIV/HCV co-infection of patients access to methadone maintenance treatment].

Objective: To estimate the prevalence of HIV/HCV co-infection and explore the influence factors and their interaction on HIV/HCV co-infection of patient's access to methadone maintenance treatment (MMT). Methods: A face to face interviews were conducted among 750 patients at two MMT clinics in Guangxi Zhuang Autonomous Region. The questionnaires information included demographic characteristics, HIV and HCV infection status, history of drug abuse, urine test for morphine, high risk sex behaviors, needle sharing, dropped out etc . Methods of χ (2) test one-way, multivariate logistic regression and interactions were used to analyze the related factors of HIV/HCV co-infection. Results: The study subjects included 750 participants, 18.31 % (127/691) of patients were co-infected with HIV and HCV. The HIV/HCV co-infection rate in patients who shared needles with others or dropped out of treatment was 35.84 % (81/226) and 19.88 % (64/322) respectively, which were higher than those who have never shared needles or dropped out (9.89 % , 46/465 and 17.07 % , 63/369). Logistic regression analysis results showed that after adjusted for confounding factors, patients who shared needles ( OR =4.50, 95 %CI : 2.72-7.43) and dropped out of treatment ( OR =1.71, 95 %CI : 1.04-2.80) were more likely to be infected with HIV/HCV. Interaction analysis showed that sharing needles and dropping out of treatment exist additive effect on co-infection of HIV and HCV ( RERI =4.21, AP =0.44, SI =1.95). Conclusions: Needle sharing and dropping out of treatment are associated with HIV/HCV co-infection. Health education, psychological counseling and other measures should be taken to reduce needle sharing and dropping out of MMT.