COVID-19 and Chronic Diabetes: The Perfect Storm for Reactivation Tuberculosis?

A Case Series

Genesis P. Aguillón-Durán; Ericka Prieto-Martínez; Doris Ayala; Juan García Jr.; John M. Thomas III; Juan Ignacio García; Brandon Michael Henry; Jordi B. Torrelles; Joanne Turner; Eder Ledezma-Campos; Blanca I. Restrepo


J Med Case Reports. 2021;15(621) 

In This Article


Given that active TB disease takes weeks or months to develop, and that we are at an initial stage of the COVID-19 pandemic, it is still early to evaluate the actual impact of COVID-19 on M. tuberculosis reactivation. Our findings alert us to be prepared in several ways.

First, diabetes and the SARS-CoV-2 infection are likely to retro feed each other to magnify the risk of M. tuberculosis reactivation to active TB. Diabetes is a major comorbidity for COVID-19 patients, resulting in poorer outcomes (RR 2.38, p < 0.001), death (RR 2.12), and more severe disease (RR 2.45).[16] Diabetes is also a well-established risk factor for TB,[17,18] and for adverse TB disease outcomes.[19,20] SARS-CoV-2 infection is associated with immunosuppression that persists past the COVID-19 episode, and likely synergizes with TB to favor primary or reactivation TB.[21,22] Thus, we predict that the threefold higher risk of active TB development in diabetes patients is further amplified by SARS-CoV-2 infection.

Second, in our post-COVID-19 TB cases, the continuum of cough throughout both episodes masked the suspicion of an emerging TB and likely contributed to the significant delay in its diagnosis (60–90 days with productive cough) and high M. tuberculosis burden in their sputum (> 10 bacilli/field). TB diagnostic delays and high bacillary burden are associated with expanded community TB transmission and poorer TB prognosis,[23] which is an added concern for post-COVID-19 TB cases.

We recommend clinicians and public health workers to regard COVID-19 patients with diabetes and latent M. tuberculosis infection as having a heightened risk for TB. In high incidence settings for latent M. tuberculosis infection, patients with COVID-19 and diabetes should be alerted and educated to "think TB" in their post-COVID-19 recovery period, to reduce patient and healthcare provider diagnostic delays. In low- to medium-risk settings for TB, screening for latent M. tuberculosis infection and treatment should be considered in diabetes patients recovering from COVID-19. Of note, current guidelines by the World Health Organization do not currently prioritize latent M. tuberculosis infection testing in diabetes patients;[24] however, this pre-COVID-19 recommendation should now be a consideration for those recovering from this viral infection. Finally, in developed countries where prophylactic TB treatment is administered, COVID-19 patients with diabetes comorbidity should be added to their targeted latent M. tuberculosis infection testing and treatment program.