Abstract
INTRODUCTION: The incidence of coinfections and superinfections following SARS-CoV-2 pneumonia has garnered increasing attention, with complications arising from various pathogens, including viruses, bacteria, and fungi. Nevertheless, the relationship between COVID-19 and tuberculosis (TB) is not fully understood. This study investigates the incidence and risk factors for post-COVID-19 pulmonary TB in a low TB prevalence area in southeastern Spain, alongside the influence of COVID-19 on indeterminate results in the Quantiferon-TB Gold Plus (QFT-Plus) test and its prognostic role. MATERIAL AND METHODS: A retrospective cohort study was conducted involving 475 hospitalized COVID-19 from March 2020 to March 2022, all of them with a QFT-Plus performed. RESULTS: The study found three cases of pulmonary TB in the post-COVID-19 period, yielding an incidence density of 3.56 cases per 1000 patient-years, all associated with chronic systemic corticosteroid therapy. Notably, the percentage of indeterminate QFT-Plus results during COVID-19 was significantly higher than when it was performed before the disease (16.82% vs. 3.37%). Patients with indeterminate results exhibited elevated inflammatory markers and a greater need for invasive mechanical ventilation, correlating with more severe disease, although without statistical significance. CONCLUSIONS: The findings suggest that prolonged systemic corticosteroid therapy is a common risk factor for pulmonary TB development and that systematic LTBI screening may not be necessary for all COVID-19 patients unless prolonged corticosteroid treatment is foreseen. This study highlights the need for further research to clarify the relationship between COVID-19 and post-COVID-19 pulmonary TB, as well as the prognostic implications of QFT-Plus results.