Abstract

Background The duration of infectiousness following pulmonary tuberculosis treatment initiation remains uncertain. We aimed to assess whether a bundled intervention designed to decrease respiratory exposure was feasible and would reduce new tuberculosis infections in household contacts (HHCs).Methods We conducted a pilot cluster-randomized controlled trial with a hybrid type 1 effectiveness-implementation design in Santiago, Chile. Random allocation was performed, and 2 healthcare districts were assigned to the intervention (n = 180 HHCs) and 1 to standard of care (n = 149 HHCs). Eligible participants were people newly diagnosed with pulmonary tuberculosis and their HHCs. The intervention included education, mask use, household ventilation, and nightly separation of tuberculosis patients, for 2 weeks. Intervention adherence was evaluated weekly. Effectiveness was assessed at the individual level with QuantiFERON (R)-TB Gold Plus (QFT) test conversions in HHCs at 12-week follow-up.Results Between October 2021 and December 2023, 384 HHCs and 157 people with tuberculosis were enrolled. Overall, 56.3% of contacts were women, with a mean age of 34.6 years and a baseline QFT positivity of 32.3%. A total of 216 contacts had negative QFT result at baseline, with 179 (82.9%) completing follow-up. QuantiFERON (R)-TB Gold Plus conversions occurred in 11 (12.8%) and 10 (10.8%) HHCs from the intervention and control arms, respectively (incidence risk ratio 1.10, 95% CI .71-1.71, P = .849). Good adherence to the respiratory bundle was reported by 53% of participants on day 7 and 54% on day 14.Conclusions Isolation and restrictive measures after tuberculosis treatment initiation proved challenging and did not reduce tuberculosis infections in HHCs, suggesting limited benefit for transmission control. This pilot randomized trial evaluated a respiratory bundle to reduce household tuberculosis transmission. While specific index patient factors, like bacillary load, low treatment adherence, and drug use, increased transmission risk, the intervention was not associated with lower contact infection risk.