Decline in the incidence of tuberculosis among HIV-infected patients enrolled in HIV care, treatment and support programme from 2011 to 2014 in Mainland Tanzania

Abstract

Background Despite improvements in access to antiretroviral therapy (ART), mortality in people living with human immunodeficiency virus (PLHIV) is still high and largely 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 incidence of TB among PLHIV in Tanzania and the determinant factors. We report 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 The Tanzania National AIDS Control Programme, Care and Treatment database was used to obtain information of all HIV clients enrolled in the HIV Care and Treatment Program between January 2011and December 2014. We analyzed retrospective cohort data to assess 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 putative associated factors. Results Over the period of four 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. TB incidence rate was significantly higher in persons not using ART and in males than 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 peak prevalence of 2.5% in 2013 and being higher among children < 15 years (3.2%) in the same year. Conclusion The study found an overall decrease of incidence of TB in PLHIV. Our results underline the current recommendations of HIV test and treat and provision of TB preventive therapy for those PLHIV without active TB after intensified TB case-finding.