Scientists in Tanzania Dar Er Salaam successfully trained rats to detect tuberculosis (TB) in human saliva by smell, using techniques first developed to teach the animals to find landmines.
The project was carried out at the Sokoine University of Agriculture in Morogoro. Researchers found that while a laboratory technician, using a microscope, can analyse only 20 samples of saliva a day, a trained rat can analyse about 120 to 150 samples in just 30 minutes.
When a rat detects TB, it indicates its presence by keeping its nose in there for three seconds. Their correct indications on known positive samples are rewarded with a food treat.
Millions of people worldwide suffer from TB, says the project director, Bart Weetjens. To them and their relatives, this [discovery] is very good news, and we have started to receive calls from all over the world.
According to the World Health Organization, worldwide deaths from tuberculosis are expected to increase from 2 million this year to 8 million by 2015. The situation has been exacerbated by the close association between TB and HIV/AIDS.
Weetjens points out that since about 40 per cent of the 60,000 Tanzanians suffering from TB are HIV-positive, detecting TB at an earlier stage raises the chance of securing effective treatment for both diseases.