Tanzania uses giant rats to detect tuberculosis

Specially-trained giant rats help Tanzania detect TB.

The almost 100 per cent accuracy rates of the specially-trained rats will see Tanzania's TB clinics increase from 29 to 60, according to the Belgian non-governmental organisation APOPO which trains the rodents.

The giant rats, which measure up to almost one metre long, can detect TB in samples of human mucus and are a cost-effective and faster alternative to chemical testing. The rats take 20 minutes to screen 100 mucus samples compared to four days for a lab technician.

The system involves mucus samples being sent by courier to TB laboratories where the rats are based, including one in Dar es Salaam that has 10 resident rats. Introduced to Tanzanian clinics a decade ago, the rats undergo training from when they are one month old, involving banana rewards for good behaviour.

Tanzania is among 30 nations that the World Health Organization (WHO) views as TB hotspots due to the country's high incidence of the curable and prevantable disease. Some 287 in 100,000 Tanzanians are thought to be infected with TB.

The rats are currently fighting TB in Mozambique and Ethiopia, and APOPO has also been successful in training the rats to sniff out landmines in countries such as Mozambique, Cambodia and Colombia.

Tuberculosis is caused by airborne bacteria that usually affects the lungs and whose symptoms include a chronic cough, fever and weight loss. TB was a killer disease in the 19th- and 20th centuries but was brought under control by vaccines and long-term treatment with antibiotics. However it remains one of the top 10 causes of death worldwide, responsible for 1.7 million deaths in 2016 according to WHO.