Latent Tuberculosis Infection

Overview

Latent tuberculosis infection (LTBI) is common in refugees from high-prevalence countries. Screening and treatment can prevent progression to active TB.

Screening

Who to Screen

• All refugees from high-prevalence countries
• Not recommended for children <2 years old

Testing Options

• Tuberculin skin test (TST)
• Interferon-gamma release assay (IGRA) - Preferred in BCG-vaccinated individuals

Ruling Out Active TB

Before treating LTBI, rule out active TB with:

• Symptom screen (cough, fever, weight loss, night sweats)
• Chest X-ray
• Sputum testing if indicated

Treatment

Multiple regimens are available:

• Isoniazid (INH) 9 months
• Rifampin 4 months
• INH + Rifapentine (3HP) 12 weekly doses

Monitor liver function tests, especially in patients >35 years old or with risk factors for hepatotoxicity.