USPSTF Recommendation: Preventive Treatment for Latent TB Infection Provides Benefit

Credit: The US Preventive Services Task Force (USPSTF)

Today, the US Preventive Services Task Force (USPSTF) recommended the screening of adults at an increased risk for latent tuberculosis (TB) infection (LBTI).

LBTI involves infection with Mycobacterium tuberculosis, the bacterium that causes tuberculosis, but does not show any symptoms of the disease. The condition can progress to active tuberculosis, which can cause morbidity and mortality. To address this issue, the USPSTF commissioned a systematic review to assess the benefits and harms of screening for and treatment of LTBI in adults.

The recommendation is intended for adults, barring those included in other recommendations for LTBI testing and treatment, such as individuals living with HIV, those about to receive solid-organ transplantation, tumor necrosis factor-α inhibitors, or other groups at increased risk due to immune suppression.²

According to the USPSTF, ensuring adequate follow-up of those with positive test results, like a medical and radiographic evaluation to exclude TB disease, offering TPT to all those who are eligible, along with education and counseling was recommended.¹

Investigators led by Daniel Jonas, MD, MPH, from RTI International–University of North Carolina at Chapel Hill Evidence-based Practice Center, Research Triangle Park, and the Department of Internal Medicine, Ohio State University College of Medicine, conducted the systematic review and found screening for LTBI with tuberculin skin test (TST) or interferon-gamma release assays (IGRA) tests were moderately sensitive and highly specific, and treatment of LTBI with recommended regimens reduced the risk of progression to active tuberculosis.³

However, the team observed isoniazid treatment was associated with higher rates of hepatotoxicity when compared with placebo or rifampin.

The review included 113 publications (112 studies) with a total of 69,009 participants. While there were no studies directly evaluating the benefits and harms of screening for LTBI compared with no screening, TST and IGRAs revealed moderately sensitive and highly specific detection of LTBI.

Investigators reported pooled estimates for sensitivity of the TST exhibited 0.80 at the 5-mm induration threshold, 0.81 at the 10-mm threshold, and 0.60 at the 15-mm threshold. For the sensitivity of IGRA tests, it displayed a range of 0.81-0.90. The pooled estimates for specificity of screening tests ranged from 0.95-0.99.

For treatment of LTBI, the review identified a large, good-quality randomized clinical trial showed a 24-week course of isoniazid reduced the risk of progression to active TB compared with placebo (RR, 0.35 [95% CI, 0.24-0.52]; n = 27,830).

The data related to isoniazid indicated an association with a higher risk of hepatotoxicity than placebo or rifampin (RR of 4.59). A previously published meta-analysis reported that multiple regimens were effective compared with placebo or no treatment, and a meta-analysis found a greater risk for hepatotoxicity with isoniazid than with rifampin (pooled RR of 4.22).³

Dick Menzies, MD, McGill TB Centre, Montreal Chest Institute, and the Research Institute of the McGill University Health Centre, published an editorial on the TB screening recommendation, emphasizing the necessity of ensuring care is well organized for all steps in the cascade to minimize losses, requiring substantial time and resources.¹

He noted the USPSTF could not find any randomized clinical trials that directly compared the health benefits or harms of LTBI-screened populations with unscreened populations, indicating no study has evaluated the full cascade of care from screening to TPT completion.

However, Menzies noted intervention studies have shown problems causing cascade losses can be identified and corrected, which can enhance the number of eligible persons who initiate and complete TPT. In addition, observational studies have demonstrated that in well-organized programs, more than 50% of those potentially eligible have completed TPT. ¹

References:

1. US Preventive Services Task Force. Screening for Latent Tuberculosis Infection in Adults: US Preventive Services Task Force Recommendation Statement. JAMA. 2023;329(17):1487–1494. doi:10.1001/jama.2023.4899
2. Menzies D. Screening for Latent Tuberculosis Infection. JAMA Netw Open. 2023;6(5):e2312114. doi:10.1001/jamanetworkopen.2023.12114
3. Jonas DE, Riley SR, Lee LC, et al. Screening for Latent Tuberculosis Infection in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2023;329(17):1495–1509. doi:10.1001/jama.2023.3954