Giant Rats Sniff Tuberculosis In Mozambique

Researchers in Mozambique have found a way to improve diagnosis of tuberculosis and save lives of hundreds of thousands by employing kitten-sized animals. Nine giant rats at Eduardo Mondlane University in the capital of Maputo have been trained for six months to sniff out tuberculosis-causing bacteria from samples of sputum, media reports said Tuesday.

Placed before a row of sputum samples, the rats can use their powerful sense of smell to detect the bacteria, and then stop or rub their legs to indicate the sample that contains the bacteria.

“Within 30 minutes, the rat can test close to a hundred samples, which normally takes a laboratory technician four days,” Emilio Valverde, tuberculosis program director at APOPO, the organization leading the research, told Agence France-Presse (AFP).

According to the researchers, the project, which began in 2013, could help improve the country’s health system, which sometimes returns false negatives for tuberculosis using laboratory testing methods.

In 2014, 60,000 people were believed to be infected by the disease, a 10 percent increase from the previous year. APOPO claims that the rat-testing method is far more cost-effective than other conventional methods. While a laboratory diagnostic testing device can cost upto $17,000, the cost of training a rat falls between $6,700 and $8,000, the researchers said.

Samples found by the rats are sent to the laboratory for more sensitive testing. The Mozambican government said the research was promising, but further testing was needed. “This technique has to be compared to others that are available and already WHO approved, such as GeneXpert or LED microscope,” Ivan Manhica, national tuberculosis head at the country’s health ministry, told AFP.

The rats have also previously been used to detect undetonated landmines as the animals are light enough to walk over the mines without triggering explosion.