Diagnosis and treatment of latent tuberculosis infection among household contacts in inland Bahia, Brazil: a cross-sectional follow-up study.

BACKGROUND

The diagnosis and treatment of latent tuberculosis infection (LTBI) are crucial for tuberculosis (TB) control. Household contacts (HHC) of patients with pulmonary TB are at a high risk of LTBI due to their close proximity to source cases.

OBJECTIVE

To describe the diagnosis and treatment of LTBI among HHC.

DESIGN AND SETTING

This cross-sectional follow-up study was conducted in the municipality of Paulo Afonso, northeastern Brazil, between 2013 and 2022.

METHODS

We retrieved secondary data from the medical records of HHC who were followed up at a specialized referral center for TB. LTBI prevalence estimates were calculated and are presented with 95% confidence intervals (CIs).

RESULTS

In total, 622 HHC were screened for LTBI, with 620 evaluated using the tuberculin skin test (TST). Of these, 40 (6.5%) did not return for TST reading. The overall prevalence of LTBI was 53.1% (95% CI: 49-57.1%), with a high prevalence among females and individuals aged 25-34 years. The overall LTBI treatment initiation rate was 26.1% (95%CI: 21.5-31.3%), and 64.2% (95%CI: 53.3-73.8%) of HHC who initiated treatment completed their course.

CONCLUSION

This study revealed a high prevalence of LTBI among HHC, particularly among women and individuals aged 25-34 years, underscoring the ongoing TB transmission within the community. Only 26.1% of the diagnosed HHC initiated treatment, with approximately 64% completing their course. This highlights the challenges in managing LTBI and emphasizes the need for targeted screening and interventions for high-risk groups.