January 10, 2011
The most commonly used TB detection method in developing countries is sputum smear microscopy. But while the 100-year-old technique can be employed in places with minimal facilities, it is not very sensitive: Without a high concentration of TB bacilli, some 60 percent to 80 percent of positive cases go undiagnosed. Preliminary new research suggests Gambian pouched rats can do better.
Dr. Alan Poling, a professor of psychology at Western Michigan University, and colleagues tested the rats' TB detection sensitivity using samples that were laboratory-confirmed as either positive or negative. The rats' sensitivity ranged as high as 86.6 percent and their specificity, or ability to detect the absence of TB, was more than 93 percent. When the team compared the rats' results to microscopy, the animals detected 44 percent more positive cases.
Cricetomys gambianus are omnivorous rodents that weigh 10-15 pounds and live in colonies of up to 20 all over sub-Saharan Africa. The same animals have been trained to sniff out landmines.
New York Times
01.04.2011; Nicholas Bakalar
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