A public health approach to increase treatment of latent tuberculosis infection: a study of effectiveness, sustainability, feasibility and cost-effectiveness

This thesis, presented in two articles, evaluates the effectiveness, sustainability, feasibility, cost-effectiveness and budgetary impact of a program that investigates and treats latent tuberculosis infection (LTBI) among household contacts (HHC) of patients with active tuberculosis in Brazil. In the first article, we presented the results of two consecutive control trials, where we evaluated the effectiveness, sustainability and feasibility a public health intervention that aimed to increase the proportion of initiation of treatment for ILTB among HHC of patients with active tuberculosis. In the first trial, twelve clinics underwent a standardized evaluation, including questionnaires administered to tuberculosis-patients, contacts and healthcare workers and clinical data on the cascade-of-care for contacts. Six clinics were then randomized to receive LTBI strengthening activities, including monthly in-service training work process organization, and implementation of specific local solutions. In the second trial, a similar but streamlined evaluation was conducted in two clinics, who then received initial and subsequent intensive in-service training provided by a physician. In the second article, we evaluated the cost-effectiveness and budget impact of scaling-up an enhanced tuberculosis HHC program in Brazil. Two enhanced HHC management strategies were compared to the current HHC management situation in Brazil (status quo). HHC cascades-of-care were conceptualized for the status quo and for two enhanced HHC strategies: 1) active tuberculosis detection only and 2) active tuberculosis detection and LTBI investigation and treatment. In both studies, at the evaluation phase, knowledge gaps among all interviewee groups were observed, and although many contacts were identified, few started LTBI treatment. Following the implementation of solutions, the number of contacts initiating treatment per 100 TB patients increased by 10 [95% confidence interval (CI): -11, 30] in the first study, compared to 44 (95%CI: 26, 61), in the second study. In our economic evaluation, we found that for an enhanced HHC management cascade-of-care, the costs to have one additional HHC to complete LTBI treatment would be half of those to find one additional active TB patient (united states dollars,158.6 vs USD 299.7). Considering the current epidemiologic TB situation in Brazil, the enhanced HHC management that would include LTBI investigation beyond active TB case finding would result in 4,001 averted cases utilizing 12% of the Brazilian TB budget. A public health approach with standardized evaluation, local decisions for improvements, followed by intensive initial and in-service training appears promising to scale up LTBI management.