Quantifying disruptions to tuberculosis case detection in Brazilian states during the COVID-19 pandemic

Globally, tuberculosis (TB) surveillance and care were severely impacted by the COVID-19 pandemic. In Brazil, TB notification rates decreased in the first 2 years of the pandemic. There is a need for rigorous model-based methods to quantify the impact of health system disruptions on TB control. In this study, we aimed to assess how the COVID-19 pandemic affected both incidence and case detection in Brazilian states.

We used a Bayesian evidence synthesis model to estimate TB incidence and case detection rates over the period 2016-21 by using routinely collected case notification and mortality data. We then used a meta-regression framework to estimate factors associated with state-level rates of undiagnosed symptomatic TB.

We found that the probability that an individual with symptomatic TB was diagnosed decreased in the majority of states in April 2020 (median = -10.4%age points, interquartile range = -6.6, -16.2). Incident TB decreased slightly in April 2020 and rebounded beginning in 2021. Together, this led to an increase in missed TB cases in nearly every state during the pandemic. Nationally, we estimate that there were 20 671 (95% credible interval: 19 249, 22 501) missed TB cases between April 2020 and December 2021.

Disruptions to the Brazilian healthcare system during the COVID-19 pandemic prevented tens of thousands of individuals with symptomatic disease from receiving a TB diagnosis. While some Brazilian states recovered rapidly to pre-pandemic levels of TB case detection, many did not and the rates of missed TB cases remained high through 2021.