# Interaction between type 2 diabetes and past COVID-19 on active tuberculosis

## TL;DR

People with type 2 diabetes and a history of COVID-19 are at significantly higher risk of developing tuberculosis, suggesting a need for targeted screening and treatment.

## Contribution

This study identifies a synergistic interaction between past COVID-19 and type 2 diabetes in increasing tuberculosis risk.

## Key findings

- The odds of new TB were significantly higher among diabetic individuals with past COVID-19 (aOR 7.9) compared to those without.
- Past COVID-19 increased TB risk only in individuals with type 2 diabetes, not in the general population.
- The study recommends latent TB screening and prophylactic treatment for the high-risk group of diabetic individuals with past COVID-19.

## Abstract

The global setback in tuberculosis (TB) prevalence and mortality in the post-COVID-19 era have been partially attributed to pandemic-related disruptions in healthcare systems. The additional biological contribution of COVID-19 to TB is less clear. The goal of this study was to determine if there is an association between COVID-19 in the past 18 months and a new TB episode, and the role played by type 2 diabetes mellitus (DM) comorbidity in this relationship.

A cross-sectional study was conducted among 112 new active TB patients and 373 non-TB controls, identified between June 2020 and November 2021 in communities along the Mexican border with Texas. Past COVID-19 was based on self-report or positive serology. Bivariable/multivariable analysis were used to evaluate the odds of new TB in hosts with past COVID-19 and/or DM status.

The odds of new TB were higher among past COVID-19 cases vs. controls, but only significant among DM patients (aOR 2.3). The odds of TB given DM was 2.7-fold among participants without past COVID-19 and increased to 7.9-fold among those with past COVID-19.

DM interacts with past COVID-19 synergistically to magnify the risk of TB. Latent TB screening and prophylactic treatment, if positive, is recommended in this COVID-19/DM/latent TB high-risk group.