News From the Centers for Disease Control and Prevention Section Editor: Rebecca Voelker, MSJ.
Until product shortages are alleviated, the Centers for Disease Control and Prevention (CDC) has advised clinicians that they may have to substitute a blood test for the tuberculin skin test (TST) when assessing patients for Mycobacterium tuberculosis infection.
The 2 purified-protein derivative tuberculin products approved by the US Food and Drug Administration—Tubersol and Aplisol—have been unavailable or in short supply, according to the CDC. The only other method used to detect latent M tuberculosis infection is a blood test, the interferon-γ release assay (IGRA). When results from chest radiography, nucleic amplification tests of sputum, or mycobacterial cultures can confirm or exclude a tuberculosis (TB) diagnosis, a TST or an IGRA may not be needed. However, the CDC cautions that negative TST or IGRA results don't exclude the possibility of M tuberculosis infection because some people are compromised in their ability to react to the tests. Even so, most people diagnosed with TB in the United States have had positive results from a TST or an IGRA.
Product Shortages Prompt CDC Advice on TB Testing. JAMA. 2013;309(22):2319. doi:10.1001/jama.2013.6388