Prevalence of latent tuberculosis infection and HIV among people who inject drugs in Iran

Introduction Iran has an human immunodeficiency viruses (HIV) epidemic that is concentrated among people who inject drugs (PWID), who have higher risks of progression from latent tuberculosis infection (LTBI) to active disease. The aim of this study is to measure prevalence of LTBI, HIV infection and any risk behaviors among PWID in Iran. Methods The cross-sectional study was conducted from August to December 2013 in six cities across Iran. A total of 420 PWID were recruited from drop-in centres using convenience sampling. Trained interviewers collected data on socio-demographic characteristics, drug use history and drug-related risk behaviors across the study sites. A tuberculin skin test (TST) was performed, and HIV infection was assessed by a rapid test. Multivariable modified Poisson regression and logistic regression were used for data analysis. Results Prevalence of positive TST and HIV positivity was 35.7% and 8.6%, respectively. The prevalence of LTBI and HIV was significantly different across the cities of this study. Positive TST was independently associated with older age (APR 1.03, 95% CI 1.01, 1.05) and being HIV positive (APR 1.89, 95% CI 1.45, 2.47). HIV infection was associated with lifetime history of sharing syringes (AOR 3.28, 95% CI 1.44, 10.71) and lifetime number of imprisonment (AOR 1.09, 95% CI 1.03-1.14). Discussion and Conclusions Prevalence of LTBI infections among PWID is high and independently associated with HIV infection. Given that there are currently no TB services available within drop-in centres, programs which integrate TB case finding, TB preventive therapy, referral and care services for PWID are urgently needed.