Prevalence and incidence rate of tuberculosis among HIV-infected patients enrolled in HIV care, treatment, and support program in mainland Tanzania

BACKGROUND: Despite improvements in access to antiretroviral therapy (ART), mortality in people living with human immunodeficiency virus (PLHIV) is still high and primarily attributed to tuberculosis (TB) infection. In Sub-Saharan Africa, approximately 80% of HIV-related mortality cases are associated with TB. Relatively little is known about the incidence of TB among PLHIV in Tanzania and the determinant factors. We report the prevalence and incidence rate of confirmed TB and determine association with selected demographic and program-related factors based on data in the national HIV care and treatment program from 2011 to 2014. METHODS: We used the Tanzania National AIDS Control Programme database to obtain information on all HIV clients enrolled in the HIV care and treatment program between January 2011 and December 2014. We analyzed retrospective cohort data to assess the prevalence and TB incidence rate per 1000 person-years. A multivariable Cox proportional hazards regression model was used to estimate hazard ratios and 95% confidence intervals for putatively associated factors. RESULTS: Over 4 years, there were 22,071 confirmed cases of pulmonary TB in 1,323,600 person-years. The overall TB incidence was around 16.7 (95% CI 16.4–16.9) cases per 1000 person-years. The annual incidence rate decreased by 12.4 % from 17.0 (95% CI 16.5–17.4) in 2011 to 14.9 (95% CI 14.5–15.4) in 2014. The TB incidence rate was higher in persons not using ART and in males than in females. The incidence of TB was higher in patients with advanced HIV disease and decreased with increasing age. The overall prevalence of TB was 2.2%, with a peak prevalence of 2.5% in 2013 and was higher among children < 15 years (3.2%) in the same year. CONCLUSION: The study found an overall decrease in the incidence of TB in PLHIV. Our results emphasize the need for early initiation of ART and the provision of TB preventive therapy for those PLHIV without active TB after intensified TB case-finding.