Effectiveness of centralized hospitalization treatment on transmission in household contacts of pulmonary tuberculosis patients: a contact-traced study.

BACKGROUND

Pulmonary tuberculosis (PTB) is a respiratory infectious disease that seriously endangers people's health and incurs high treatment costs, which quickly leads to catastrophic expenditure for patients and their families. A centralized hospitalization treatment (CHT) strategy can be implemented to mitigate the transmission of PTB. This study evaluates the effectiveness of a CHT approach in reducing the magnitude of Mycobacterium tuberculosis (MTB) transmission in household contacts (HHCs) of confirmed PTB cases and explores potential risk factors for PTB.

METHODS

This retrospective cohort study used PTB cases from Guizhou, China, between January 2022 and October 2023. The HHCs of PTB cases diagnosed etiologically and treated with non-CHT were designated as the exposed group, and the HHCs of those treated with CHT were the non-exposed group. The ratio of the HHCs to index cases was 1:1-3. Face-to-face interviews were conducted for the participants by medical staff at home. R software was used for data analysis. Continuous variables were cut to create new categorical variables and were analyzed using the Chi-square test or Fisher test according to the nature of the data. The risk factors of PTB/LTBI and covariates were analyzed using a multivariate logistic regression model evaluated by the Akaike information criterion (AIC) and elucidated by a Directed Acyclic Graph (DAG). The alpha (α) test level of all statistical tests was 0.05.

RESULTS

1007 participants were investigated, including 559 HHCs of PTB index cases from CHT settings and 448 HHCs of PTB index cases from non-CHT sites (treated at home). Of the two groups, 46 HHCs tested positive for PTB/LTBI (latent TB infections), with a 3.4% positive detection rate (19 cases) in the HHCs of PTB index cases treated with CHT and 6.0% (27 cases) in the HHCs of those treated with non-CHT, with positive detection of LTBI [17(3.0%) vs. 26(5.8%)] and [3(0.5%) vs. 5(1.1%)] of PTB in the former than that in the latter. A statistically significant difference was found between the two LTBI groups. In the univariate analysis, family caregivers, age, marital status, CHT, eating the same food with the patient, sleeping in the same room with the patient, and caring for the patient for more than or equal to 2 months were risk factors for PTB/LTBI among HHCs. The treatment of PTB families with non-CHT was an independent factor of PTB/LTBI in the HHCs through multivariate analysis and AIC evaluation.

CONCLUSIONS

The transmission of PTB/LTBI to HHCs is lower in the HHCs of CHT patients than in the HHCs of those treated with non-CHT after controlling for the other factors including older age, abnormal marriage, and staying with PTB patients equal to or more than two months.