Tuberculosis infection rate and associated factors among household close contacts of hospitalized pulmonary tuberculosis patients: a retrospective cross-sectional study based on QFT-Plus screening
Year: 2026
Type: article
Study design: Observational Study
Abstract: Tuberculosis (TB) remains a major infectious disease threatening global public health. Household close contacts (HCCs) of patients with pulmonary tuberculosis (PTB) are at increased risk of Mycobacterium tuberculosis (MTB) infection due to prolonged and close exposure. Systematic assessment of MTB infection status and associated factors among HCCs may contribute to the optimization of TB screening and preventive strategies. QuantiFERON ® -TB Gold Plus (QFT-Plus), an interferon-γ release assay (IGRA), has been widely used for MTB infection screening; however, the risk characteristics of MTB infection among HCCs of PTB patients require further clarification. To evaluate QFT-Plus positivity among HCCs of PTB patients, identify factors associated with QFT-Plus positivity, and develop a prediction model for QFT-Plus positivity. This study comprised a retrospective analysis of clinical data from hospitalized PTB index patients combined with cross-sectional QFT-Plus screening of their HCCs. HCCs of hospitalized PTB patients admitted to our hospital between January 2023 and December 2025 were included. Demographic characteristics, lifestyle factors, exposure-related information of HCCs, and clinical characteristics of index PTB patients were collected. All HCCs underwent QFT-Plus testing. Individuals with positive QFT-Plus results underwent further evaluation based on chest computed tomography findings and microbiological examinations when necessary. Univariate analysis was performed using the chi-square test, and multivariable logistic regression analysis was conducted to identify factors associated with QFT-Plus positivity. The discriminatory ability of the prediction model was evaluated using receiver operating characteristic (ROC) curve analysis. Among 408 HCCs, 134 (32.84%) had positive QFT-Plus results, indicating evidence of MTB-specific immune responses. Multivariable logistic regression analysis showed that age ≥ 45 years, body mass index (BMI) ≥ 24 kg/m², initiation of contact within 3 months before diagnosis of the index patient, daily contact duration > 8 h, pleural effusion in the index patient, and microbiological positivity of the index patient were independently associated with QFT-Plus positivity among HCCs (all P < 0.05). The combined prediction model demonstrated an area under the curve (AUC) of 0.806 (95% confidence interval [CI]: 0.760–0.852). A relatively high proportion of HCCs of PTB patients had positive QFT-Plus results. Individual characteristics of HCCs, exposure patterns, and clinical and microbiological characteristics of index patients were associated with QFT-Plus positivity and corresponding immunological evidence of MTB exposure. QFT-Plus screening combined with multivariable risk assessment may support risk stratification among HCCs and provide information for targeted screening and further clinical evaluation. This was an observational study and did not require clinical trial registration.
Source: BMC Infectious Diseases
Authors: Yuchun Cai, Jun Tao
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,090
OpenAlex ID: W7225159135