Hepatitis C antibody prevalence among Mexico City prisoners injecting legal and illegal substances.

BACKGROUND: Hepatitis C virus (HCV) infection is highly prevalent among prisoners and this prevalence estimates reach 64% among prisoners who inject illicit drugs. Prisons are important sites for HCV transmission in the absence of access to sterile injecting equipment; hence, it can be transmitted between prisoners who share contaminated needles and syringes. We aimed to estimate the prevalence of risk factors for anti-HCV prevalence, with particular interest on injecting behavior, and to assess correlates of anti-HCV positivity among Mexico City prisoners.

METHODS: Cross-sectional study based on information -collected in three male and two female prisons in Mexico City during 2010-2011- about sexually transmitted infections, socio-demographics, criminal history, substance use, vitamin injection, tattooing, among others (n=3,910). Weighted multivariable adjusted logistic regression models were estimated to assess the overall and differential odds for anti-HCV due to injecting behavior.

RESULTS: Overall prevalence of anti-HCV was 3.3%. This figure rose to 43.1% among prisoners with a history of illicit drug injection. Prisoners with history of vitamin injection showed a similar prevalence of anti-HCV (43.8%). After stratifying by substance injected, the adjusted odds ratio was 9.8 (95% CI: 4.0, 23.8) for illicit drug injection and 11.9 (95% CI: 5.8, 23.8) for illicit drug and vitamin injection.

CONCLUSION: Based on data from the most populous prisons in Mexico City, this study showed that anti-HCV is highly prevalent among prisoners with history of injecting behavior. In this sense, injecting behavior per-se, independent of the substance used, is associated with increased odds of anti-HCV positivity.