New TB Test May Improve Accuracy of Diagnosis

Researchers from Stanford University, Texas A&M Health Science Center, and GBDbio used a new chemical compound to create a test that identifies tuberculosis (TB)-causing bacteria accurately and trounces the speed and reliability of the Smear microscopy test—the most widely used TB test in the world.

The new test determines a patient’s TB diagnosis with 86% sensitivity and 73% specificity compared to the 50% to 60% sensitivity that the Smear microscopy can identify.
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“Our new, rapid point-of-care TB test dramatically reduces the current delays in diagnosis with incredible accuracy, accelerating appropriate treatment, and reducing the death rate of the highly infectious disease. We’re looking at a low-cost, easy-to-use test that has the potential to eradicate TB,” said Jeffrey Cirillo, PhD, the study’s lead author and professor at the Texas A&M Health Science Center College of Medicine.

The test works by targeting BlaC—an enzyme yielded by TB-causing bacteria—to indicate the presence of bacteria using a florescent substrate.  Then investigators use a battery-powered, portable tabletop device (TB REaD™) to detect fluorescence from a patient’s sputum samples combine with a reactive substance. The results can be delivered in 10 minutes.

The test should be on the market in the next 18 months, according to investigators. It is currently in the later stages of clinical trials.

Cirillo notes that while the test is ultimately used for TB diagnosis, it could be used to identify other respiratory diseases and infections as well.

The complete study is published in the July issue of Angewandte Chemie.

-Michelle Canales

References:

Cheng Y, Hexin X, Sule P, et al. Fluorogenic probes with substitutions at the 2 and 7 positions of cephalosporin are highly BlaC-specific for rapid Mycobacterium tuberculosis detection. Angew Chem Int Ed Engl. 2014 July [epub ahead of print] doi: 10.1002/anie.20140524.

Texas A&M Health Science Center. Low-cost TB test means quicker, more reliable diagnosis for patients [press release]. July 3, 2014. https://news.tamhsc.edu/?post=low-cost-tb-test-means-quicker-more-reliable-diagnosis-for-patients. Accessed July 7, 2014.