Prevalence and Predictors of Human Immunodeficiency Virus and Selected Sexually Transmitted Infections Among People Who Inject Drugs in Dar es Salaam, Tanzania: A New Focus to Get to Zero.

BACKGROUND: Previous studies in Tanzania indicated that human immunodeficiency virus (HIV) prevalence among people who inject drugs (PWIDs) could be as high as 40%. We aim to provide data on the prevalence of HIV and sexually transmitted infection among PWIDs to inform national plans to get to zero.

MATERIALS AND METHODS: Respondent-driven sampling was used to collect drug use, and sexual practices data among PWIDs aged 15 years and older. Blood samples were examined for HIV, herpes simplex virus type 2, syphilis, and hepatitis B.

RESULTS: A total of 620 PWIDs with a median age of 32 (interquartile range, 17-52) participated in the study. Their use of drugs had typically started during adolescence. The prevalence of HIV was found to be 15.5%, whereas that of herpes simplex type 2 was 43.3%. Associated with an increased likelihood of HIV infection was being a female (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.0-3.6), sharing of syringes (aOR, 2.4; 95% CI, 1.1-6.1), used syringes hidden in public places (aOR, 5.1; 95% CI, 1.3-10.2), and having had a genital ulcer during the last 12 months before this survey. On the other hand, being educated, use of noninjectable drugs, access (aOR, 0.5; 95% CI, 0.2-0.8), and use of clean syringes (aOR, 0.3; 95% CI, 0.1-0.6) were associated with decreased likelihood of HIV infection.

CONCLUSIONS: The prevalence of HIV infection among PWIDs in Dar es Salaam is 3 times higher than that in the general population. Behavioral and biological risk factors contribute to HIV transmission and needs to be addressed to be able to get to zero.