Abstract
Despite its characteristically low sensitivity, sputum smear microscopy remains the standard for diagnosing tuberculosis (TB) in resource-poor countries. In an attempt to develop an alternative or adjunct to microscopy, researchers have recently examined the ability of pouched rats to detect TB-positive human sputum samples and the microbiological variables that affect their detection. Ten published studies, reviewed herein, suggest that the rats are able to detect the specific odor of Mycobacterium tuberculosis, which causes TB, and can substantially increase new-case detections when used for second-line TB screening following microscopy. Further research is needed to ascertain the rats’ ability to detect TB in children and in HIV-positive patients, to detect TB when used for first-line screening, and to be useful in broad-scale applications where cost-effectiveness is a major consideration.
Highlights
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis
Sputum smears are stained with the Ziehl-Neelsen method, which causes M. tuberculosis bacteria to appear as bright red rods when viewed under a light microscope
Weetjens et al arranged for DOTS-center technicians to evaluate each sample via microscopy and freeze the remaining material, which was transported to Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO)'s lab for analysis by the rats
Summary
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. About one-third of Earth's population has latent TB, which means that they have been exposed to M. tuberculosis but not become ill. TB is a treatable and curable disease, it causes immense suffering and many deaths in Africa, due in part to the absence of a cheap and reliable technique for detecting it. Sputum smear microscopy is the standard technique for diagnosing TB in resource-poor countries, due to its relatively low cost [2]. In this technique, sputum smears are stained with the Ziehl-Neelsen method, which causes M. tuberculosis bacteria to appear as bright red rods when viewed under a light microscope. Sputum smears are stained with the Ziehl-Neelsen method, which causes M. tuberculosis bacteria to appear as bright red rods when viewed under a light microscope This technique misses many cases of TB. In addition to suffering the consequences of untreated disease, each patient missed by microscopy (or any other diagnostic), and not treated, is likely to spread the disease to between 10 and 15 other people each year [1]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
