New Tuberculosis Guidelines Issued

Newer diagnostic tests should be used to evaluate patients at risk for active or latent tuberculosis (TB) infection, according to updated guidelines released by the American Thoracic Society, Infectious Diseases Society of America, and Centers for Disease Control and Prevention. The new guidelines were the first issued in 17 years and were spurred by the development of new tests such as interferon-gamma release assays (IGRAs) and molecular diagnostics.

“These guidelines develop a structured approach to testing, recommending that doctors test for latent TB in patients who are at risk for infection and who would benefit from treatment, and for TB disease in patients who have signs and symptoms of the disease,” David M. Lewinsohn, MD, PhD, lead author of the guidelines, said in a statement.

The guidelines include 23 evidence-based recommendations to guide diagnostic testing for latent TB infection, pulmonary TB, and extrapulmonary TB. Individuals living with a person who has TB disease or living in settings such as prison are at high risk for latent TB, as are immigrants from countries where TB is common.

For patients suspected of latent TB, the guidelines recommend testing with IGRAs instead of a tuberculin skin test (TST) because the sensitivity and specificity of an IGRA is the same or greater than the TST in patients who have received a TB vaccination. However, a TST is acceptable to use if an IGRA is not available or if the IGRA is too costly or burdensome.

Although IGRA and TST can determine whether a patient is infected, they are unable to differentiate between active TB and latent TB. As a result, “the diagnosis of active TB must be excluded prior to embarking on treatment for LTBI," the authors wrote.

Patients with signs of active TB disease should undergo smear, cultures, and molecular diagnostic testing, according to the guidelines.

“Even though tuberculosis disease is not common in this country, it’s important that doctors remember it’s still around, and that they should test patients when appropriate,” Dr. Lewinsohn said.

—Lauren LeBano

Reference

Lewinsohn DM, Leonoard MD, LoBue PA, et al. Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children. Clin Infect Dis. 8 Dec 2016. doi: 10.1093/cid/ciw694