They might be plague-bearers and pests. But their sniffing, twitching noses can also point the way toward a healthier, safer future. And that's no mere abstract proposition, either. From scenting out land mines to deadly disease, rats are already being used to save lives from Tanzania to Mozambique.
In Mozambique, for example, raccoon-size rats are trained to scurry about and scent out lethal explosive devices, left over from the wars that have scarred the landscape over the last century. Giant pouched rats (they look just like they sound) are the heart of the effort -- an African species popular for its "large size, sunny disposition and ultra-keen nostrils." The rats are too light to set off the explosives, but their noses have an exquisite enough sensitivity that they can be used to alert others to the presence of dangerous weapons (which can then be removed). What's more, a single rat can sweep 1,000 square feet in half an hour.
By 2008, some 250 mine-detecting rats were being trained in Tanzania at the Sokoine University of Agriculture. And -- once scorned by international aid officials -- rat squadrons have lately ingratiated themselves in the wider development community, winning accolades from the World Bank and the United Nations.
Yesterday, Kate wrote about one way to detect tuberculosis that's potentially both cheap and effective. Rats are another. Once trained (it costs about $3,000-5,000 to train a rat), the rodent can signal with paw motions after it detects the presence of Mycobacterium tuberculosis in patient saliva. Tests suggest rodents are in fact more effective at detecting tuberculosis in a patient than use of a standard microscope (about 67% vs. 60%). They're also quicker: while a lab technician will diagnose maybe 20 samples in a day, a rat can sniff-test up to 2,000 samples.
Sniffing out disease might sound bizarre, but it's actually one of the oldest diagnostic tools around. According to Megan Bedard, who writes about tuberculosis-sniffing rats in TakePart this week, doctors in ancient Greece and China used to test patients for tuberculosis by burning their spit and contemplating the odor released.
And in terms of man's best friend, for dog-lovers, don't worry -- they're not quite out of the running. A dog's nose can do all this as well. Still, though: not only are rats cheaper to train, they're simpler to house and transport and far less vulnerable to tropical disease. Rats also have the decided advantage in that they don't get emotionally involved in a single handler. They'll work with anyone, so long as they're given the right commands and rewarded with some peanuts.
Just a few peanuts and some training -- all in exchange for thousands of lives.
(h/t: the ONE blog)
Article By Te-Ping Chen