Oral Swabs for TB Diagnosis: Stability, Transport, and Quality Control

Gerard Cangelosi of the University of Washington in the U.S. will develop reagents to visually validate oral swabs and stabilize them for storage and transport to diagnostic laboratories in low-resource settings without the need for a cold chain. Oral swabbing to extract saliva is a non-invasive and effective method for diagnosing tuberculosis, and is faster and safer than traditional sputum collection. However, it is more difficult to review the quality of a swab sample as they are hard to see, and processing currently requires refrigeration. To address these limitations, they will develop a low-cost, quality control test with chemical reagents for detecting human mitochondrial DNA using human oral swabs from U.S. volunteers spiked with an avirulent strain of Mycobacterium tuberculosis. This will be coupled to a visual fluorescent readout that can be used to distinguish adequate from inadequate samples. They will also test different buffers for their ability to stabilize the swab samples at different temperatures for up to six months.