Prevalence of Latent Tuberculosis Infection among Spouses and First-Degree Relatives of Pulmonary Tuberculosis Cases in South India.

BACKGROUND: A study was conducted to examine variations in latent tuberculosis infection (LTBI) risk factors among household contacts (HHCs) of tuberculosis (TB) patients.

OBJECTIVES: The objective of this study was to assess LTBI prevalence among first-degree relatives (FDRs) and spouses of TB patients and identify associated risk factors.

MATERIALS AND METHODS: A cohort study at JIPMER under Regional Prospective Observational Research for TB India included HHCs of newly diagnosed pulmonary TB patients. Prevalence ratios with 95% confidence intervals (CIs) were calculated using generalized linear modeling.

RESULTS: Among 1318 HHCs of 548 TB patients, the mean ages were 45.2 (13.7) and 29.5 (16.1) years, respectively. LTBI prevalence was 58.1%, with 0.5% progressing to active TB. Spouses had a higher LTBI prevalence (64.2%) than FDR (55.8%), with a significantly elevated risk (PRR: 1.42, 95% CI: 1.11-1.83). Older age (40-59 and ≥60 years), bed-sharing, female gender, prolonged exposure, undernutrition, overweight/obesity, and alcohol use were linked to higher LTBI prevalence. Female spouses spent more time caring for index cases than male spouses.

CONCLUSION: Spouses had a higher LTBI prevalence than FDR. Screening programs should prioritize female spouses, undernourished individuals, overweight/obese individuals, and alcohol users to reduce TB transmission.