Detection Rats Technology is a cost-effective methodology consisting of equipment, training methods and operational procedures in which trained rats detect Tuberculosis in saliva.
Every TB evaluation unit consists of a semi-automated cage, featuring ten holes and an automated food pellet dispenser. Beneath each of the ten holes, saliva samples are presented for odor discrimination by rats. The lids are uncovered one-by-one and the animals sniff hole-per-hole for positive targets. Every hole is equipped with a laser beam, broken by the nose of the rat. A rat only needs a few hundredths of a second to discriminate the target odor. In case of a negative sample the rat immediately moves on to the next sample. Positive samples are indicated by keeping their nose fixed in the sniffer hole for at least three seconds, which is registered in a database.
Known positives are inserted to allow reinforcement of indication behavior. At three seconds indication of known positive samples, the animals hear a click sound and they receive a food reward. Rat-detected suspect samples are re-tested for the presence of TB using concentrated smear and LED microscopy.
The rats evaluate 100 saliva samples within 20 minutes, which would take a lab technician more than two days using microscopy. So far more than 5,800 TB patients who were initially missed by means of microscopy have been positively diagnosed, thus preventing 87,000 potential infections.
APOPO has managed to increase the TB case detection rate by an average of 40%.
There are approximately 8.5 million new cases of TB per-year and 1.3 million people died from TB in 2012. Left untreated, a person with active TB can infect 10-15 new people each year. Therefore a fast and accurate diagnostic technology is needed.
In many developing countries, TB is still detected through microscopy. The method can be precise but it is also slow, and between 20-80 % of positive cases can be missed. "Detection Rats Technology" frees low-income countries of their dependence on the expensive and often unavailable TB diagnostics as it is a fast, accurate and cost-effective screening tool.
Publicly available: yes
Countries where available: Tanzania, Mozambique