Management of Latent Tuberculosis Infection

Diagnosis and Initial Evaluation

The American Thoracic Society recommends obtaining a chest radiograph to identify any evidence of active pulmonary tuberculosis, including cavitary lesions, infiltrates, or other abnormalities consistent with active disease, in individuals with a positive tuberculin skin test (TST) 1, 2, 3
A thorough clinical evaluation assessing for TB symptoms, including productive cough, fever, night sweats, weight loss, hemoptysis, and duration of symptoms, should be performed in individuals with a positive TST 1, 2
The Centers for Disease Control and Prevention (CDC) recommends collecting sputum specimens for acid-fast bacilli (AFB) smear microscopy, mycobacterial culture, and drug susceptibility testing in individuals with pulmonary symptoms and a positive TST 1, 4
HIV testing is recommended as HIV co-infection fundamentally changes treatment approach and duration in individuals with a positive TST 4

The CDC recommends 9 months of daily isoniazid as the preferred treatment for latent TB infection (LTBI), which reduces TB risk by up to 90% when completed 3
Alternative regimens include rifampin with or without isoniazid for 4 months, and isoniazid plus rifapentine weekly for 3 months under direct observation 1, 3
The CDC advises against using rifampin plus pyrazinamide for 2 months due to unacceptably high rates of severe hepatotoxicity and death 3

The American Academy of Pediatrics recommends aggressive LTBI treatment for high-risk individuals, including HIV-infected persons, recent contacts of infectious TB cases, and children younger than 5 years 3, 5, 6, 7
The CDC recommends prioritizing directly observed therapy (DOT) for the highest-risk LTBI patients, including children younger than 5 years, HIV-infected contacts, and other contacts with risk factors for progression to TB disease 5

Baseline liver function tests are indicated for HIV-infected persons, pregnant women, persons with history of liver disease, regular alcohol users, and those at risk for chronic liver disease before starting LTBI treatment 4
Monthly clinical monitoring assessing for symptoms of hepatitis is recommended during LTBI treatment 4
The CDC advises discontinuing isoniazid immediately if aminotransferases exceed 5 times the upper limit of normal in asymptomatic patients or 3 times the upper limit of normal with symptoms 4, 8