What is the recommended treatment and follow-up for latent tuberculosis (TB) infection?

From the Guidelines

The preferred treatment for latent tuberculosis infection is once-weekly isoniazid plus rifapentine for 3 months (3HP), consisting of isoniazid 15 mg/kg (maximum 900 mg) plus rifapentine 600-900 mg (weight-based) once weekly for 12 weeks, as it has excellent tolerability and efficacy, shorter treatment duration, and higher completion rates compared to longer regimens. This regimen is recommended by the National Tuberculosis Controllers Association and CDC in 2020 1.

Treatment Regimens

The following regimens are recommended for the treatment of latent tuberculosis infection:

• 3 months isoniazid plus rifapentine given once weekly (preferred)
• 4 months rifampin given daily (preferred)
• 3 months isoniazid plus rifampin given daily (preferred for some populations)
• 6 months isoniazid given daily (alternative)
• 9 months isoniazid given daily (alternative)

Patient Evaluation and Monitoring

Before starting treatment, patients should undergo baseline liver function tests and visual acuity testing if receiving ethambutol. During treatment, monthly clinical monitoring for adverse effects is essential, with more frequent liver function tests for those with risk factors for hepatotoxicity. Pyridoxine (vitamin B6, 25-50 mg daily) should be given with isoniazid to prevent peripheral neuropathy, especially in pregnant women, breastfeeding mothers, malnourished individuals, and those with HIV, diabetes, or alcohol use disorder.

Follow-up

After completing treatment, no routine follow-up testing is required unless symptoms of active TB develop. These regimens effectively reduce the risk of progression to active TB by 60-90% by eliminating dormant TB bacteria before they can reactivate and cause disease. The World Health Organization also recommends systematic testing and treatment of LTBI in high-risk individuals, including those living with HIV, contacts of pulmonary TB cases, and patients with certain medical conditions 1. In addition, guidelines from the U.S. Public Health Service and the Infectious Diseases Society of America recommend treating LTBI in HIV-infected persons, regardless of age, who have a positive TST result but have no evidence of active TB and no history of treatment for active or latent TB 1.

From the FDA Drug Label

PRIFTIN is indicated in adults and children 2 years and older for the treatment of latent tuberculosis infection caused by Mycobacterium tuberculosis in patients at high risk of progression to tuberculosis disease PRIFTIN must always be used in combination with isoniazid as a 12-week once-weekly regimen for the treatment of latent tuberculosis infection The recommended dose of PRIFTIN should be determined based on weight of the patient up to a maximum of 900 mg once weekly The recommended dose of isoniazid is 15 mg/kg (rounded to the nearest 50 mg or 100 mg) up to a maximum of 900 mg once weekly for 12 weeks for adults and children 12 years and older, and 25 mg/kg (rounded to the nearest 50 mg or 100 mg) up to a maximum of 900 mg once weekly for 12 weeks for children 2 to 11 years.

The recommended treatment for latent tuberculosis (TB) infection is a 12-week once-weekly regimen of PRIFTIN in combination with isoniazid. The dose of PRIFTIN is determined by the patient's weight, up to a maximum of 900 mg once weekly. The dose of isoniazid is 15 mg/kg (up to 900 mg) for adults and children 12 years and older, and 25 mg/kg (up to 900 mg) for children 2 to 11 years. Follow-up is necessary to monitor for symptoms of liver injury and to ensure completion of the 12-week treatment regimen 2.

From the Research

Diagnosis of Latent TB Infection

To access latent TB after treatment, it is essential to understand the recommended treatment and follow-up for latent tuberculosis (TB) infection. The diagnosis of latent TB infection is crucial for TB prevention globally.

• Current tests for latent TB infection include the tuberculin skin test (TST) and interferon-gamma release assays (IGRAs) 3.
• IGRAs are preferred in bacille Calmette-Guérin-vaccinated populations, while TST is still used when cost or logistical advantages exist 3.
• Both TST and IGRAs have low positive predictive values, and tests that differentiate the TB spectrum and better predict future TB risk are needed 3.

Treatment and Follow-up

The treatment of latent TB infection is essential to prevent progression to active TB disease.

• Isoniazid preventive therapy has been shown to reduce the risk of progression to active TB in individuals with latent TB infection, particularly in those with a positive TST result 4.
• Interferon-gamma release assays have a better predictive ability than TST for progression to active TB, and individuals who are positive by IGRA might benefit from preventive treatment 5.
• Dual testing with both IGRA and TST might improve detection, but further confirmation is needed 5.

Factors Associated with Latent TB Infection

Several factors are associated with latent TB infection, including:

• Direct contact with family or friends with TB, which was unexpectedly found to be negatively associated with positivity by either IGRA or TST in one study 6.
• Immunocompromised populations, in which both IGRA and TST have low sensitivity 7.
• Bacille Calmette-Guérin vaccination status, which can affect the performance of TST and IGRA 4, 3.