Treatment for Positive Tuberculosis Test

Initial Evaluation After Positive TB Test

The American College of Physicians recommends that all individuals with a positive tuberculin skin test (TST) must undergo chest radiography and clinical evaluation to exclude active TB disease before initiating treatment for latent TB infection (LTBI) 1
Symptoms suggestive of TB, such as cough, fever, night sweats, and weight loss, warrant prompt evaluation regardless of TST status, as recommended by the European Respiratory Society 1
The presence of any symptom suggestive of TB plus any abnormality on chest radiography offers the highest sensitivity to identify active TB, according to the European Respiratory Journal 2

A positive TST is defined as ≥10 mm induration for residents of high-risk congregate settings and healthcare workers, as recommended by the Centers for Disease Control and Prevention (CDC) 3
A positive TST is defined as ≥15 mm induration for persons with no known risk factors, according to the CDC 3
Immigrants from high TB burden countries are considered high-risk and require a positive TST definition of ≥10 mm induration, as recommended by the European Respiratory Society 2

The European Respiratory Society recommends treatment for LTBI with one of the following regimens: 3-month weekly rifapentine plus isoniazid or 3-4 month daily isoniazid plus rifampicin 2

The American College of Obstetricians and Gynecologists recommends that liver function tests should be monitored every 2-4 weeks during treatment, especially for pregnant women and persons with history of liver disease 4
Patients should be educated about symptoms of hepatotoxicity, such as nausea, vomiting, and jaundice, and instructed to stop medication and seek medical attention if these develop, as recommended by the American Medical Association 1
Patients receiving isoniazid should also receive pyridoxine (vitamin B6) to prevent peripheral neuropathy, especially HIV-infected persons, according to the Infectious Diseases Society of America 1

Patients on immunosuppressive therapy, including biologics, should receive treatment for LTBI before continuing or initiating biologic therapy, as recommended by the American College of Rheumatology 1
For patients from areas with high TB drug resistance (>10% background resistance), more aggressive treatment may be needed, according to the World Health Organization 5
Single-drug therapy should never be used for active TB disease, as this can lead to drug resistance, as recommended by the CDC 4