African researchers have trained rats to detect tuberculosis in children. As a result, they had a better success rate than the standard smear test.
The super sense of smell of rats has been known for a long time. Already trained to detect the vapors of explosives, they have now been trained to sniff out the characteristic smell of tuberculosis in children. This is the research work conducted by scientists from the Sokoine Agricultural University in Tanzania (East Africa). The results of their work have been published in Pediatric research.
In countries of sub-Saharan Africa and South-East Asia, tuberculosis is widespread. The problem is that the diagnosis is most often made using an inexpensive smear test whose accuracy varies with the quality of the sputum sample used. Young children are often unable to provide a significant volume of respiratory mucus, and the test may be negative, not detecting the bacterium Mycobacterium tuberculosis that causes tuberculosis when it is in fact present.
In order to find a more efficient method, rats have been trained to recognize the characteristic odor of the molecules released by the bacteria into the sputum. 982 sputum samples of children under 5 were recovered. All had already been analyzed by the standard smear test, which revealed 34 cases of tuberculosis. The rats detected 57 additional cases, all subsequently confirmed by a more advanced test. They were able to identify 68% more TB infections than the standard test.
These results were transmitted to the clinics concerned and the children were able to be cared for. This new method therefore seems very promising for diagnosing the disease in the youngest and in low-income countries. However, other studies concerning the accuracy of rats, and involving other types of samples, are still needed.