Physicians should screen people at high risk for tuberculosis for the latent form of the disease, according to the U.S. Preventive Services Task Force.
The recommendation covers people who were born in or who have lived in places with a high burden of TB, according to , of the University of California San Francisco, and colleagues.
It also includes people born in the U.S., but who live in or have lived in, what the task force panel called "high-risk congregate settings," such as jails or homeless shelters, Bibbins-Domingo and colleagues .
The recommendation is based on a conducted by , of RTI International in Research Triangle Park, N.C., and colleagues, and also published in JAMA.
Kahwati and colleagues found that some key questions, such as a direct comparison of the benefits and harms of screening versus no screening, have not been studied. But there was enough evidence to make a judgment on the sensitivity and specificity of tests for latent TB and on the benefits and harms of treatment versus no treatment, they reported.
The recommendation has a B grade, meaning the task force thinks there is "high certainty that the net benefit is moderate, or there is moderate certainty that the net benefit is moderate to substantial."
Physicians should offer the service, the task force said.
On the other hand, that might be easier said than done, commented of Emory University in Atlanta and , of New York University School of Medicine in New York City.
In an , they noted that tools are lacking that will help physicians decide who actually fits the category and is likely to progress to full-blown TB.
The recommendations "provide a service by focusing discussions on how to expand" targeted testing and treatment of latent TB in primary care settings, they wrote.
But "there will be challenges with implementation of these recommendations because of the current inability to precisely define individuals at high risk for progression to active TB," they cautioned.
The task force said it did not consider those at highest risk for TB -- people with HIV, contacts of those with active TB, or people receiving tumor necrosis factor alpha inhibitors -- because TB screening for them should be considered part of standard care.
The review process, including 72 studies with 15,711 participants, found that, in regions with a low TB burden:
- The tuberculin skin test was moderately sensitive at 0.79, while the sensitivity of interferon-gamma release assays ranged from 0.77 to 0.90.
- The skin test and the interferon-gamma release assays had specificities ranging from 0.95 to 0.99.
The review also found that 24 weeks of isoniazid therapy for people with pulmonary fibrotic lesions and latent TB cut the relative risk of active disease within 5 years by 65%, compared with placebo. The benefit came at the cost of a 4.59-fold increase in the risk of hepatoxicity.
But for both benefit and harm, the absolute risks were small, the review found.