Risk Factors of Latent Tuberculosis Infection among Incarcerated Populations: A Case-Control Study in Shenzhen, China

Latent tuberculosis infection (LTBI) constitutes a significant reservoir for future tuberculosis (TB) cases, particularly among incarcerated populations, which experience a disproportionately elevated burden. Recognizing modifiable risk factors in correctional facilities is crucial for formulating effective public health strategies to mitigate TB spread.

This case-control research examined 1,252 incarcerated inmates in Shenzhen, China. Subjects (n = 215) were interferon-gamma release assay (IGRA)-positive, whereas controls (n = 1,037) were IGRA-negative. Data were obtained from computerized medical records. Multivariable logistic regression discerned independent risk variables. A bootstrap mediation study (5,000 iterations) was conducted to investigate potential routes.

Four independent factors of LTBI were identified: present smoking (adjusted odds ratio = 1.57), absence of a bacillus Calmette-Guerin (BCG) scar (aOR = 6.08), initial incarceration (aOR = 2.16), and absence of medical insurance (aOR = 0.05). Mediation analysis indicated that smoking behavior largely mediated the connections between insurance status and first incarceration with LTBI risk, underscoring the interrelated behavioral and structural pathways.

The results indicate that LTBI in correctional facilities is influenced by a confluence of biological, behavioral, and socioeconomic factors. An integrated preventative plan is essential, encompassing mandatory entry screening, verification of BCG vaccination, institutional smoking cessation programs, and measures to guarantee healthcare access. Future longitudinal studies ought to validate these mediation mechanisms and evaluate their influence on the progression to active illness.