An overweight African rat! This is not a phrase that normally evokes feelings of gratitude, but just waits a minute. African Scientists have reported that rats can save lives by sniffing out tuberculosis with accuracy greater than that of a microscope.
The rat in question is the Gambian pouched rats, which are found in most places in Africa. Researchers are training the rats to be able to smell Mycobacterium tuberculosis, the bacteria that cause TB.
The New York times reports a study conducted in which rats were able to smell the difference between TB bacteria and the other germs found in human sputum sample or phlegm. The rats’ ability to detect TB was as high as 86.6 percent, and their ability to rule it out was over 93 percent!
Most TB tests involve staining a sample of phlegm with a special compound and examining it under a microscope. This 100-year-old method is notoriously unreliable, however — as many as 60 to 80 percent of positive TB cases are undiagnosed, partly because the bacteria are hard to spot unless there are a lot of them in the sample. But the rats were able to sniff them out, detecting 44 percent more positive cases in a head-to-head competition.
Last month, the World Health Organization endorsed a new machine that can provide accurate results within two hours, but it costs $17,000, and each test requires a $17 cartridge. Rats, needless to, come cheap and what a treasure.
Worldwide, TB killed an estimated 1.7 million people in 2009, and 9.4 million people developed active.
The data is still preliminary but encouraging. Eventually, the rats could be used as a first line of detection for the disease
[youtube]ueYRhIV4zGw&feature=player_embedded [/youtube]
