TB Risk Factors: Who is Most Vulnerable?

High-Risk Groups for Tuberculosis

1. Close Contacts

Household or prolonged close contact with active pulmonary TB case (highest transmission risk).

2. Immunocompromised Individuals

• HIV/AIDS (20–30x increased risk)
• Diabetes mellitus (2–3x risk)
• TNF-α inhibitors, corticosteroids, post-transplant immunosuppression
• Malignancy, especially hematologic
• End-stage renal disease

3. Socioenvironmental Factors

• Overcrowded housing, homelessness, incarceration
• Malnutrition, food insecurity
• Indoor air pollution (biomass fuel)
• Migration from high-burden countries

4. Substance Use

• Alcohol use disorder
• Injection drug use
• Tobacco smoking (doubles risk)

5. Age Extremes

• Young children (<5 yrs): rapid progression to severe disease
• Elderly: reactivation of latent TB, comorbidities

6. Healthcare Workers

Occupational exposure in high-burden settings without adequate infection control.

Public Health Implications

Targeted screening (IGRA/TST) and preventive therapy (isoniazid, rifapentine) for high-risk groups are cornerstones of TB elimination strategies.