Effective Tuberculosis Contact Investigation Using Interferon-Gamma Release Assays

Area of Science:

• Pediatric infectious diseases
• Public health surveillance
• Mycobacterial infections

Background:

• Tuberculosis (TB) remains a significant global health concern, particularly in pediatric populations.
• Contact investigation is crucial for early detection and prevention of TB transmission.
• Assessing the diagnostic yield of different TB screening methods in children is essential for effective public health strategies.

Purpose of the Study:

• To evaluate the effectiveness of tuberculin skin test (TST) and interferon-gamma release assay (IGRA) in identifying children with latent or active tuberculosis infection.
• To determine the risk of developing active tuberculosis disease among children who tested positive for TB infection using TST or IGRA.
• To analyze screening data from a defined pediatric cohort undergoing TB contact investigation.

Main Methods:

• Retrospective analysis of TB screening data from 1831 children screened between 2000 and 2018.
• Utilized tuberculin skin test (TST) and interferon-gamma release assay (IGRA) for TB infection detection.
• Calculated the incidence of positive test results and the subsequent risk of active tuberculosis disease.

Main Results:

• A total of 1831 children were screened; 33% had a positive TST and 12% had a positive IGRA.
• Among children with positive TST results, 6.1% developed active tuberculosis disease.
• Among children with positive IGRA results, 13% developed active tuberculosis disease.

Conclusions:

• Both TST and IGRA are valuable tools for TB screening in children during contact investigations.
• IGRA may indicate a higher risk of progression to active TB disease compared to TST in this pediatric cohort.
• Continued vigilance and follow-up are necessary for children with positive TB tests to prevent disease progression.