Seroprevalence of hepatitis B virus infection, anti-HCV antibodies and HIV and knowledge among people who use drugs attending methadone therapy clinic in Tanzania; a cross-sectional study

Background: Methadone therapy clinics have been recently introduced in Tanzania, aiming at reducing risk behaviors and infection rates of viral hepatitis and HIV among people who use drugs. The objective of this study was to estimate the prevalence, associated factors and knowledge level of these conditions among people who use drugs attending a methadone clinic in Tanzania. Methods: We enrolled 253 People who using drugs receiving Methadone therapy. Clinical data was retrospectively collected from the medical records and face-to face interviews were conducted to determine the behavioral risk factors and respondents’ knowledge on viral hepatitis and HIV. Results: An overall seroprevalence of viral hepatitis (either hepatitis B surface antigen or anti-hepatitis C virus) was 6.3%, while that of hepatitis B virus mono infection was 3.5% and anti-hepatitis C antibodies was 3.5%. Seroprevalence of HIV was 12.6%. Viral hepatitis was strongly predicted by advanced age (> 35 years) (p = 0.02) and staying at Kirumba area (p = 0.004), and HIV infection was predicted by increased age (> 37 years) (p = 0.04) and female sex (p < 0.001). Regarding the knowledge of viral hepatitis, majority of the respondents were unaware of the transmission methods and availability of hepatitis B virus vaccines and only 17% were classified as well informed (provided ≥4 correct answers out of 7 questions). Good knowledge was highly predicted by higher education level of the individual (p = 0.001). Conclusions: Despite the efforts to curb viral hepatitis and HIV infections through Methadone clinics, infection rates among people who use drugs are still high and the general knowledge on preventive measures is inadequate.