Series 2: Invisible Threats: A Global Scoping Review of Risk Factors for Tuberculosis Infection

Area of Science:

• Public Health
• Infectious Diseases
• Epidemiology

Background:

• Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tuberculosis) is a major global health issue.
• Approximately one-fourth of the global population is infected with M. tuberculosis, posing a risk for disease reactivation and transmission.
• Risk factors for M. tuberculosis infection include bacterial load, contact patterns, environment, and host susceptibility, especially in congregate settings.

Purpose of the Study:

• To systematically review and synthesize evidence on risk factors influencing the progression from M. tuberculosis exposure to TB infection (TBI).
• To identify key determinants of TBI risk for optimizing prevention and control strategies.

Main Methods:

• A preliminary PubMed search was conducted using keywords: "latent tuberculosis infection," "risk factors," and "systematic review."
• Targeted reviews examined factors influencing M. tuberculosis exposure to TBI progression.
• Included systematic reviews published between January 2000 and November 2024.

Main Results:

• Eight systematic reviews were analyzed, identifying three main themes: proximity/behavioral factors, environmental factors, and host immune vulnerabilities.
• Close contact in crowded settings (dormitories, healthcare, prisons) and environmental exposures (second-hand smoke, poor ventilation) elevate TBI risk.
• Host factors like advanced age, low BMI, lack of BCG vaccination, and diabetes increase susceptibility to TBI.

Conclusions:

• Effective TB infection control requires a multifaceted approach including infection control, comorbidity management, and behavioral risk mitigation.
• Tailored strategies are essential for high-risk settings like healthcare facilities and prisons.
• Multisectoral collaboration is crucial to address risk factors and protect vulnerable populations.