Browsing by Author "Escobar, Nadia"

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    Short- and long-term increased risk of all-cause mortality in a tuberculosis cohort attributed to SARS-CoV-2 infection: a time-dependent survival analysis in Chile
    (2025) Vargas García, Salvador; Undurraga, Eduardo A.; Escobar, Nadia; García, Christian; Vergara, Natalia; Balcells Marty, María Elvira
    Background: Concurrent tuberculosis (TB) and COVID-19 increases the risk of mortality; however, most studies have focused primarily on short-term outcomes. We assessed the short and long-term impact of TB and SARS-CoV-2 coinfection on all-cause mortality. Methods: We conducted a retrospective nationwide cohort study in Chile, including adults diagnosed with active TB from January 1st, 2020, to December 31st, 2021, with follow-up until November 30th, 2022. SARS-CoV-2 coinfection was defined as occurring from 30 days before to six months after TB diagnosis. Short-term mortality was defined as death within 90 days of TB or TB/SARS-CoV-2 diagnosis, and long-term mortality as death occurring after 90 days. We used a time-dependent Cox survival analysis, adjusting for sociodemographic factors, SARS-CoV-2 vaccination, and relevant comorbidities including HIV, diabetes and Mycobacterium tuberculosis drug-resistance status. Findings: The cohort included 3721 adults (median age: 47 years, interquartile range [IQR]: 32–61); of whom 63·4% were male, and 79·4% had pulmonary TB. The median follow-up was 586 days (IQR: 401–820), with 680 deaths (18·3%) recorded. A SARS-CoV-2 coinfection was identified in 393 individuals (10·5%); the mortality in this group was higher in short-term (≤90 days: 14·5% vs. 11·4%) and long-term (>90 days: 11·5% vs. 5·9%) compared to TB alone. Coinfection increased the risk of all-cause mortality during the entire follow-up (aHR [adjusted Hazard Ratio]: 2·8, 95% CI: 2·26–3·47), over three-fold in the short-term (aHR 3·4, 95% CI: 2·57–4·51) and nearly two-fold in the long-term (aHR: 1·72, 95% CI: 1·18–2·52). Excess mortality persisted beyond the first year (aHR: 2·04, 95% CI: 1·09–3·82). SARS-CoV-2 vaccination reduced mortality risk in the TB cohort by 35% (95% CI: 19–46%). Interpretation: Tuberculosis and SARS-CoV-2 coinfection was associated with significantly increased all-cause mortality in both the short and long-term, with elevated risk persisting beyond TB treatment completion. These findings highlight the need for continued post-treatment follow-up and prioritization of SARS-CoV-2 vaccination among individuals with TB.
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    Window Prophylaxis for Mycobacterium tuberculosis Infection Prevention in Child and Adolescent Household Contacts: Study Protocol for a Cluster-Randomized Controlled Trial (the TB-WIN trial)
    (2025) Le Corre Pérez, Monique Nicole; Allel, Kasim; Hernández, Mariluz; Escobar, Nadia; Ruiz-tagle Seguel, Cinthya Grace; Valenzuela, Pablo; Bernales Silva, Margarita María; García Cañete, Patricia Del Carmen; Paredes Peñaloza, Fabio Ariel; Nathavitharana, Ruvandhi; Bronzic, Yasna; Bustamante, María Cecilia; Barra, Sofia De la; Kreft, Javiera; Madrid, Ricardo; Madrid, Rossana; Méndez, Mireya; Mery, Álvaro; Meyer, Matías; Oviedo, Valeria; Pérez, María Eugenia; Pérez de Arce, Juan; Ramírez, Ana María; Rivas, Mabel; Rojas, Gladys; Balcells Marty, María Elvira
    Abstract Trials guidance: The Abstract should not exceed 350 words. Please minimize the use of abbreviations and do not cite references in the abstract. The abstract must include the following separate sections: Background : Mycobacterium tuberculosis acquisition after exposure is common but difficult to diagnose and frequently requires serial testing given that immunological evidence of infection can take several weeks to develop. Even though tuberculosis infection (TBI) is asymptomatic, its long-term effects remain unclear due to poorly understood host-pathogen interactions and delayed disease development, and research has shown that active mycobacterial replication and inflammation occur during TBI. Although the main purpose of antituberculosis prophylaxis has been to prevent people with established TBI from progressing to active tuberculosis disease, a few studies have suggested that this prophylaxis, when administered during the window period after exposure, can prevent the acquisition of TBI in very young children. Considering that newer preventive regimens are shorter and safer, this study aims to assess whether tuberculosis prophylaxis —when given in the window period after exposure— can prevent new infections in older children and adolescents who have been recently exposed. Methods : A multicentre cluster-randomized controlled clinical trial will be performed in Chile. A total of 360 households (clusters) with children aged ≥5 to <18 years, who have been recently exposed to a new case of pulmonary tuberculosis will be randomized to intervention or control arm. In the intervention arm, contacts will receive immediate tuberculosis prophylaxis, regardless of the interferon-gamma release assay (IGRA) result. In the control arm, participants will receive tuberculosis prophylaxis only if the IGRA test results positive, as per standard of care. In both arms, the prophylaxis scheme will be the usual weekly isoniazid plus rifapentine for 12 weeks regimen. The primary outcome will be assessed at the individual level by IGRA conversions from negative at baseline to positive at the 12-week follow-up. Discussion : This trial will establish the effectiveness of a window prophylaxis strategy in reducing the risk of TBI acquisition after exposure in a community setting, a strategy that can potentially contribute to global tuberculosis elimination by reducing M. tuberculosis reservoirs. Trial registration : ClinicalTrials.gov, NCT07086820. Registered 17 July 2025, https://clinicaltrials.gov/study/NCT07086820.