What is the recommended treatment or observation for someone exposed to active Tuberculosis (TB)?

From the Guidelines

For individuals exposed to active Tuberculosis (TB), the recommended approach is to undergo TB testing, and if the test is positive, initiate preventive treatment, with a preferred short-course rifamycin-based treatment regimen of 3-4 months, as outlined in the 2020 guidelines from the National Tuberculosis Controllers Association and CDC 1. When considering the management of someone exposed to active TB, it's crucial to prioritize the prevention of latent tuberculosis infection (LTBI) progression to active disease, given that approximately 5-10% of people with LTBI will develop active TB if left untreated. The initial step involves TB testing, typically using a tuberculin skin test (TST) or an interferon-gamma release assay (IGRA) blood test.

• If the test results are positive, indicating TB infection, a chest X-ray is necessary to rule out active TB disease.
• For those with positive test results but no evidence of active TB, preventive therapy is generally recommended to prevent the progression to active disease.
• The choice of preventive treatment regimen is critical, with short-course (3–4 months) rifamycin-based treatment regimens being preferred over the longer-course (6–9 months) isoniazid monotherapy for the treatment of LTBI, according to the 2020 guidelines 1. Key considerations during treatment include regular monitoring for side effects, particularly liver function, regardless of the regimen chosen.
• Alternative regimens, such as rifampin 600mg daily for 4 months or a combination of isoniazid and rifapentine once weekly for 12 weeks (3HP), may be considered based on patient-specific factors and drug tolerability.
• Even if initial testing is negative, it is essential to consider follow-up testing for close contacts of active TB cases 8-10 weeks after exposure, as the infection can have a delayed onset. Given the potential for significant morbidity and mortality associated with active TB disease, a proactive approach to identifying and treating LTBI is paramount, guided by the most recent and highest quality evidence available, such as the 2020 guidelines from the National Tuberculosis Controllers Association and CDC 1.

From the FDA Drug Label

Isoniazid is recommended as preventive therapy for the following groups, regardless of age. 2. Close contacts of persons with newly diagnosed infectious tuberculosis (≥ 5 mm) In addition, tuberculin-negative (< 5mm) children and adolescents who have been close contacts of infectious persons within the past 3 months are candidates for preventive therapy until a repeat tuberculin skin test is done 12 weeks after contact with the infectious source. If the repeat skin test is positive (> 5 mm), therapy should be continued.

The recommended treatment or observation for someone exposed to active Tuberculosis (TB) is preventive therapy with isoniazid, especially for:

• Close contacts of persons with newly diagnosed infectious tuberculosis
• Tuberculin-negative children and adolescents who have been close contacts of infectious persons within the past 3 months, until a repeat tuberculin skin test is done 12 weeks after contact with the infectious source 2 Key points to consider:
• Preventive therapy should be considered for individuals who have been exposed to active TB
• Isoniazid is the recommended medication for preventive therapy
• The duration of therapy may vary depending on the individual's risk factors and medical conditions 2

From the Research

Treatment Options for Latent Tuberculosis Infection

The treatment of latent tuberculosis (TB) infection is crucial for preventing the development of active TB. Several treatment options are available, including:

• 9-month regimen of isoniazid monotherapy, which has been shown to be effective in preventing active TB 3, 4, 5, 6, 7
• 4-month regimen of rifampin monotherapy, which has been found to be noninferior to the 9-month isoniazid regimen and is associated with higher treatment completion rates and better safety 4, 5, 6
• 3-4 month regimen of isoniazid and rifampin, which has been shown to be effective in preventing active TB, but may have similar completion and toxicity rates as the 9-month isoniazid regimen 3, 5
• 3-month regimen of once-weekly directly observed isoniazid-rifapentine, which has been shown to be noninferior to the 9-month isoniazid regimen 7

Factors to Consider in Treatment Selection

When selecting a treatment regimen for latent TB infection, several factors should be considered, including:

• Patient adherence and completion rates, which can be improved with shorter regimens 4, 5, 6
• Potential adverse effects, such as hepatotoxicity, which can be reduced with rifamycin-based regimens 4, 5, 6
• Individual patient characteristics, such as age, health status, and presence of comorbidities, which can influence treatment selection 5, 6
• Availability of resources and support for treatment completion, which can impact treatment success 6, 7

Monitoring and Adherence Strategies

To ensure successful treatment of latent TB infection, monitoring for potential adverse effects and adherence strategies are crucial, including:

• Regular follow-up appointments to monitor for adverse effects and assess treatment adherence 5, 6
• Patient education and counseling to promote treatment adherence and completion 6, 7
• Use of directly observed therapy (DOT) to ensure treatment completion and reduce the risk of nonadherence 7