Pest No More

Imagine my surprise when I read this article in the New York Times one morning. Rats have been smart about keeping their secrets talents to themselves


Detecting Tuberculosis: No Microscopes, Just Rats    - NY Times-Jan 3, 2011

Researchers have found a new way of testing for tuberculosis that is fast, cheap and widely available: large rats that can smell the bacteria in a sputum sample. There are expensive and complicated laboratory tests for tuberculosis, and the World Health Organization recently endorsed a new machine that can give accurate results in under two hours. But the device costs $17,000, and each test requires a $17 cartridge.

Whatever else can be said about them, rats are cheaper.

Today, the most commonly used detection method in developing countries is smear microscopy. But unless there is a high concentration of them, the bacilli are easy to miss, and that results in as many as 60 to 80 percent of positive cases going undiagnosed.

Studies suggest that the Gambian pouched rat can do better. The animal, an omnivorous rodent with puffy cheeks and that chillingly familiar rat body and tail, weighs 10 to 15 pounds and thrives in colonies of up to 20 all over sub-Saharan Africa. The Gambian pouched rat apparently can smell the difference between tuberculosis bacilli and the myriad other germs that inhabit human phlegm.

 Writing in the December issue of The American Journal of Tropical Medicine and Hygiene, Dr. Poling and his colleagues report a test of the rats using samples that were confirmed by laboratory culture as either positive or negative.

The animals’ sensitivity — that is, their ability to detect the presence of tuberculosis — ranged as high as 86.6 percent, and their specificity, or ability to detect the absence of the germ, was over 93 percent. In another test that compared the rats’ success to microscopy, the rats picked up 44 percent more positive cases.

The rats, raised in captivity, are all descended from animals captured in the Uluguru Mountains in Tanzania, or on the outskirts of Morogoro, a city of about 200,000 people in the nearby Tanzanian highlands. This is the same animal, Cricetomys gambianus, that has been trained to sniff out land mines.(It is light enough not to set them off.)

End of Article

This opens up so many possibilities for the many pests which have been bothering us. Now we have to explore unique abilities of flies , mosquitoes, cockroach and the list doesn't end here. I am sure when Indian rats are put to task; they will prove there worth.

Prabhakar Devavaram