Mycobacterium tuberculosis Infection in School Contacts of Tuberculosis Cases: A Systematic Review and Meta-Analysis

Area of Science:

• Public Health
• Infectious Diseases
• Epidemiology

Background:

• Substantial tuberculosis transmission occurs outside of households.
• Tuberculosis surveillance in schools is a proposed strategy for early detection.
• The prevalence of tuberculosis outcomes among school contacts is not well characterized.

Purpose of the Study:

• To assess the prevalence of Mycobacterium tuberculosis infection among close school contacts.
• To evaluate the yield of tuberculosis outcomes from school-based surveillance.
• To inform the potential for school contact investigation and general surveillance in high-burden settings.

Main Methods:

• Systematic review of studies from PubMed, Elsevier, China National Knowledge Infrastructure, and Wanfang databases.
• Included studies reporting the number of children tested and positive for M. tuberculosis infection.
• Performed subgroup analyses by study location, index case bacteriological status, and school type.

Main Results:

• Analyzed 28 studies involving 54,707 school contacts.
• Overall prevalence of M. tuberculosis infection was 33.2% (QuantiFERON Gold).
• Tuberculin skin test (TST) prevalences were 27.2% (≥5 mm), 24.3% (≥10 mm), and 12.7% (≥15 mm).
• Prevalence was lower in China (22.8%) than other regions (36.7%) using TST ≥5 mm.
• Prevalence was higher with bacteriologically positive index cases (43.6%) versus negative (23.8%).

Conclusions:

• School contact investigation and surveillance are valuable for early case detection in children.
• Findings support considering school-based screening in high-burden settings.
• The prevalence of M. tuberculosis infection in school contacts warrants further investigation and intervention strategies.