Rats are commonly thought to carry disease, but what if they diagnosed disease instead? In fact, they do. Contrary to popular belief, rats are highly intelligent creatures that can be trained to sniff out specific odors with incredible accuracy. They have already been used in warzones to sniff out landmines; now, a research center in Tanzania has rats detecting tuberculosis in patients’ saliva.
The giant rats being trained are especially successful at distinguishing an affected person’s saliva because they can smell “in stereo,” meaning that with one sniff they can differentiate two different odors. One out of every 100 rat genes is dedicated to their olfactory abilities – in humans, only one of every 1000 genes has to do with our capacity to smell. Rats’ superior noses allow them to diagnose a TB patient in only seven minutes. Diagnosis by human physicians can take all day.
Working to make TB diagnosis easier and more accurate is especially important for low- and middle-income countries, where 95 percent of all TB-related deaths occur. If caught early, TB can be treated with a course of antibiotics. Because TB is a bacterial disease, its symptoms may not present for long periods of time; the bacteria, which are spread through the air when affected individuals cough or sneeze, can lie dormant in the body before they begin to cause more severe symptoms. Because rats use the smell of the bacteria rather than a patient’s symptoms to diagnose TB, they can diagnose patients much earlier than doctors can.
Though the equipment and expertise necessary to train these rats can be somewhat expensive, this method has the potential to save over a million lives and prevent illness in nearly nine million more every year. Foreign aid could be useful in providing trained rats to health centers in developing countries or assisting in the training of rats abroad.
Seeing rats as agents of health rather than disease is the first step to eliminating TB altogether. By bringing these intelligent animals into our health centers and our hearts, we can prevent the transmission of one of the world’s deadliest diseases.
– Elise L. Riley