ABSTRACT
BACKGROUND: The incidence of tuberculosis among HIV-infected populations with high CD4 count in high burden countries has not been well studied. OBJECTIVE: To assess the TB incidence in HIV-infected adults and its associated risk factors. METHOD: A cohort study with retrospective review of medical records and prospective follow-up of HIV-infected adult participants attending CTC who were 18-55 years old, had CD4 count more than 250 cells/mm3 in the period of 2008-2010 and were not on ART at enrolment. Cox proportional hazard regression was used to explore the predictors of incident TB. RESULTS: Overall 777 (24%) of 3,279 CTC enrolled HIV-infected adults fulfilled the inclusion criteria of the study. The incidence of TB in the study population ranged from 0.8/100 per person years (PY) at risk (95% CI 0.5-1.3) in the main analysis to 1.7/100 PY at risk (95% CI 1.0-2.6) in sensitivity analyses. Only prior history of TB disease was found to have a significant association with an increased risk of TB, hazard ratio 5.7 (95% CI 2.0-16.4, p value 0.001). CONCLUSION: Tuberculosis incidence among HIV-infected adults with medium/high CD4 count in Bagamoyo is lower than in other high TB burden countries. Previously TB treated patients have a much higher risk of getting TB again than those who never had TB before.
Subject(s)
Anti-HIV Agents/therapeutic use , Antiretroviral Therapy, Highly Active , HIV Infections/complications , HIV Infections/drug therapy , Tuberculosis/epidemiology , Adolescent , Adult , CD4 Lymphocyte Count , Coinfection , HIV Infections/epidemiology , Hospitals, District , Humans , Incidence , Middle Aged , Proportional Hazards Models , Risk Factors , Rural Population , Tanzania/epidemiology , Young AdultABSTRACT
SETTING: Arusha, Mwanza, Mufindi and Kilosa in Tanzania. OBJECTIVE: To assess the test characteristics of three indirect adherence measures against a gold standard of direct measurements of drug intake for use in a resource-constrained setting. METHODS: We assessed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and the diagnostic odds ratio (dORs) of three indirect adherence measurement tools against direct measurement in urine using the IsoScreen assay. RESULTS: The single adherence question of missed doses in the last 2 days had the highest dOR (40.3) compared to the Morisky medication adherence scale (MMAS, 2.5) and pill counts (3.4). The sensitivities of these measures were respectively 97.9%, 92% and 89.6%. Specificity ranged from 46.4% (adherence question) to 17.9% (MMAS). The PPVs of adherence question, pill counts and MMAS were respectively 97.6%, 96.5% and 94.2%, while the NPVs ranged from 50% (adherence question) to 3.1% (MMAS). CONCLUSION: Among several instruments for indirect adherence measure in the routine setting of the Tanzanian National Tuberculosis and Leprosy Programme, a single adherence question was found to have the best discriminatory power. However, the single adherence question might not adequately identify patients who are non-adherent. Confirmatory studies are needed, especially in settings with low adherence rates.
