What are the next steps after a positive Tuberculosis (TB) test?

From the Guidelines

If you have a positive tuberculosis (TB) test, the next steps involve further evaluation and possible treatment, with the decision to initiate treatment based on epidemiologic information, clinical findings, and the results of microscopic examination of acid-fast bacilli (AFB)-stained sputum smears and cultures for mycobacteria, as recommended by the American Thoracic Society and Centers for Disease Control and Prevention 1. The evaluation process typically includes a chest X-ray and additional tests to determine if you have latent TB infection (LTBI) or active TB disease.

• For LTBI, treatment typically involves a single medication such as isoniazid (INH) for 9 months, rifampin for 4 months, or a combination of INH and rifapentine once weekly for 12 weeks.
• For active TB disease, treatment is more intensive, usually requiring a combination of four drugs (isoniazid, rifampin, ethambutol, and pyrazinamide) for 2 months, followed by isoniazid and rifampin for an additional 4 months, as outlined in the treatment guidelines 1. It's crucial to complete the full course of treatment even if you start feeling better, as incomplete treatment can lead to drug-resistant TB.
• During treatment, your doctor will monitor you for side effects and treatment effectiveness through regular check-ups, including monthly sputum specimens for microscopic examination and culture, and clinical evaluations to identify possible adverse effects of the antituberculosis medications and to assess adherence 1. TB is caused by Mycobacterium tuberculosis bacteria that primarily affect the lungs, and proper treatment is essential to prevent spread to others and avoid serious complications.
• A person with TB expertise should be consulted for unusual or complex situations, and patients with HIV infection or other risk factors should receive special consideration, including counseling and testing for HIV infection, and monitoring for possible adverse effects of the antituberculosis medications 1.

From the FDA Drug Label

Isoniazid is recommended as preventive therapy for the following groups, regardless of age. Candidates for preventive therapy who have HIV infection should have a minimum of 12 months of therapy. Candidates for preventive therapy who have fibrotic pulmonary lesions consistent with healed tuberculosis or who have pulmonary silicosis should have 12 months of isoniazid or 4 months of isoniazid and rifampin, concomitantly

The next steps after a positive Tuberculosis (TB) test include:

• Preventive therapy with isoniazid for certain groups, such as those with HIV infection, close contacts of persons with newly diagnosed infectious tuberculosis, and recent converters
• 12 months of therapy for candidates with HIV infection, fibrotic pulmonary lesions, or pulmonary silicosis
• 4 months of concomitant therapy with isoniazid and rifampin for candidates with fibrotic pulmonary lesions or pulmonary silicosis 2
• Consideration of risk factors such as age, medical conditions, and high-incidence groups to determine the need for preventive therapy
• Weighing the risk of hepatitis against the risk of tuberculosis in positive tuberculin reactors over the age of 35 2

From the Research

Next Steps After a Positive TB Test

• A positive Tuberculosis (TB) test indicates that a person has been infected with Mycobacterium tuberculosis, but it does not necessarily mean they have active TB disease 3, 4.
• The next steps typically involve a medical evaluation to determine whether the person has active TB or latent TB infection (LTBI) 5.
• For individuals with LTBI, treatment is usually recommended to prevent the development of active TB disease 3, 4.
• The standard treatment for LTBI is typically a 6-9 month course of isoniazid, although shorter treatment regimens may be recommended in some cases 3, 4.
• For individuals with active TB, treatment typically involves a combination of antibiotics, such as isoniazid, rifampin, pyrazinamide, and ethambutol, for a period of 6-12 months 3.
• Directly-observed therapy (DOT) is often recommended to ensure that patients complete their treatment regimen and to prevent the development of drug-resistant TB 3.

Diagnostic Tests

• The tuberculin skin test (TST) and interferon-gamma release assays (IGRAs) are commonly used to diagnose LTBI 4, 5.
• Chest X-rays may be used to screen for active TB in high-risk populations, such as those living in long-term care facilities 6.
• However, chest X-rays are not always effective in detecting active TB, and other diagnostic tests, such as sputum smears and cultures, may be necessary to confirm the diagnosis 6.

Treatment Outcomes

• Treatment outcomes for LTBI and active TB can vary depending on a number of factors, including the effectiveness of the treatment regimen and the patient's adherence to the treatment plan 3, 4.
• Studies have shown that treatment completion rates can be high when patients are closely monitored and supported throughout the treatment process 4.