Tuberculosis After One Year of Combination Antiretroviral Therapy in Nigeria: A Retrospective Cohort Study

Abstract

Our objective was to determine tuberculosis (TB) incidence and evaluate TB risk in adults after one or more years of use of combination antiretroviral therapy (cART) through a retrospective cohort study in Jos, Nigeria. We studied a cohort of HIV-infected adults treated with ART for at least 1 year. Based on immunologic and virologic responses to ART, patients were categorized into four groups: CD4 T cell count ‡ 350 cells/mm3 and HIV-1 RNA level £ 400 copies/ml (group 1), CD4 T cell count ‡ 350 cells/mm3 and HIV-1 RNA level > 400 copies/ml (group 2), CD4 T cell count < 350 cells/mm3 and HIV-1 RNA level £ 400 copies/ml (group 3), and CD4 T cell count < 350 cells/mm3 and HIV-1 RNA level > 400 copies/ml (group 4). Time to incident TB for the four groups was analyzed using the Kaplan–Meier method. Cox regression models were used to evaluate predictors of incident TB. In this cohort of 5,093 HIV-infected adults, of which 68.4% were female, with a mean age 35.1 years (standard deviation 9.1 years), we observed 98 cases of incident TB during 4 years and 3 months of follow-up. The overall TB incidence rate was 8.7 cases/1,000 patient-years of follow-up. Adjusted hazards for incident TB were 2.11 (95% CI 0.97–4.61), 2.05 (95% CI 1.10–3.79), and 3.65 (95% CI 1.15–5.06) in group 2, 3, and 4 patients, respectively, compared to group 1. Tuberculosis incidence in patients on ART is driven by poor immunologic and/or virologic response. Optimization of HIV treatment should be prioritized to reduce the burden of TB in this high-risk population.