COVID-19 as a Potential Trigger for Tuberculosis: Insights From a Large-Scale Japanese Insurance Database Analysis

The long-term impact of COVID-19 on tuberculosis (TB) is concerning. This study assessed whether COVID-19 was associated with an increased risk of active TB treatment risk in Japan using a nationwide propensity score-matched cohort design.

A retrospective cohort study used Japan's National Insurance Database from January 2020 to December 2022. COVID-19 patients were matched 1:1 with controls using propensity scores based on age, sex, immunosuppressants use, Charlson comorbidity index, related medical conditions, healthcare utilization and prior TB history. The primary outcome was initiation of isoniazid-based therapy plus rifampin with a TB-related ICD-10 diagnosis code. Cox proportional hazards models estimated hazard ratios (HRs) for COVID-19's effect on TB treatment initiation.

After matching, 3,097,422 individuals were included per group. During 8-month median follow-up, 886 participants initiated TB treatment. The HR among COVID-19 infected individuals was 4.14 (95% CI: 3.51-4.89) versus matched controls. Subgroup analyses showed interaction between prior TB history and COVID-19, with HR of 14.7 (5.35-40.2) in those with prior TB history, versus those without (HR 3.84, 95% CI 3.24-4.54). Risk remained elevated in participants without hospitalization (HR 3.96, 95% CI 3.35-4.68).

This study provides robust population-based evidence demonstrating a moderate association between prior COVID-19 and subsequent initiation of active tuberculosis treatment, particularly in those with prior TB history.