Trends in Untreated Tuberculosis in Large Brazilian Cities

Introduction: As in many countries, tuberculosis (TB) programs in Brazil are managed at the state and local level, where the success of disease control may differ substantially from national-level averages. Methods: We used municipality-level data on case notifications, TB-related mortality, GDP per capita, and primary healthcare coverage for Brazil’s top 100 municipalities by population as well as all state capitals for 2008-2017. We constructed a mathematical model describing the relationship between these data and unobserved TB incidence and case detection probabilities. We used Bayesian methods to synthesize data and estimate TB incidence, fraction of cases treated, and the untreated TB rate ( product of incidence and one minus the fraction of cases treated ) for each year and municipality. Results: In 2017, these municipalities had an average incidence of 58.6 per 100,000 (range: 11.6, 169), with an average 5.3 untreated cases per 100,000 (range: 0.7, 23.0), a nd an average fraction treated of 0.91 (range: 0.78, 0.97). Over 2008-2017, the incidence rate and the untreated TB rates decreased at an average annual rate of 0.95% (range: -5.41% – 4.73%) and 2.88% (range: -17.4% – 7.98%) respectively; the fraction of cases initiating treatment increased at an average annual rate of 0.3% (range: -0.97% – 3.54%). The incidence rate increased in 33 municipalities and the fraction of treated cases decreased in 36 municipalities over the study period. Interpretation: The results describe substantial variation in disease burden and the strength of case detection in Brazilian municipalities. These methods can provide municipalities with information to guide local public health decision-making. Funding Statement: Dr. Menzies reports grants from Lemann Brazil Research Fund and NIH (1R01AI146555-01A1) during the conduct of the study; Ms. Chitwood reports grants from Michael von Clemm Traveling Fellowship Fund during the conduct of the study. Declaration of Interests: All authors have nothing to disclose. Ethics Approval Statement: The Office of Human Research Administration at Harvard T.H. Chan School of Public Health reviewed the Initial Study Submission (Protocol #: IRB18-0759) and determined that it met the criteria for exemption from the ethics board (IRB) review.