Morogoro, Tanzania - In the midst of earthquake debris, a man lies motionless as a rather unusual savior approaches: a rat with a backpack. This rat, part of a life-saving operation, maneuvers through rubbish, overturned furniture, and strewn clothing to locate him, pulls a trigger on its pack, and signals rescuers above with a click that a survivor has been found. Emerging from the dilapidated building, the rat is rewarded with a banana, marking the completion of a successful mission as part of its training in search and rescue operations.
APOPO, a non-profit organization in Tanzania, trains these African giant pouched rats for crucial tasks such as detecting explosives and tuberculosis, and more recently, locating earthquake survivors. "Their sense of smell is incredible," says Fabrizio Dell'Anna, an animal behaviorist at APOPO. These rats, distinguished by their acute olfactory abilities, are moving into new territories, including Angola and Cambodia, having helped APOPO clear over 50,000 land mines since 2014. In a nearby field, more rats navigate a grid filled with land mines, indicating potential dangers by their actions.
APOPO's "hero rats,” trained since shortly after birth using classical conditioning and positive reinforcement, boast one of the animal kingdom's keenest noses. Each rat, with a training cost of around 6,000 euros (USD 6,990), spends nearly a decade specializing in lifesaving missions, and a first group has already been deployed in Turkey for earthquake rescues. But it is inside the labs where these rats truly shine, proving instrumental in the global battle against tuberculosis (TB).
Each day, TB claims as many lives as land mines do in a year, laments Christophe Cox, CEO of APOPO. Despite the disease's ancient origins and century-spanning research efforts, TB persists as a leading infectious disease killer, with 1.25 million deaths and 8.2 million infections recorded in 2023, according to the World Health Organization (WHO). The situation is exacerbated in sub-Saharan Africa, where only about half of TB cases are diagnosed, leaving many unwittingly spreading the disease further.
APOPO ventured into TB detection in 2007, deploying rats in Tanzania, Ethiopia, and Mozambique. In partnership with 80 Tanzanian hospitals, sputum samples are gathered daily for the trained rats to analyze, searching for TB-positive cases initially marked negative. Research indicates these rodents detect six unique volatile organic compounds in TB samples, according to Cox.
False negatives hinder TB control efforts, as each undiagnosed individual is a potential vector for widespread infection. Dr. Felista Stanesloaus, at a TB clinic in Morogoro, underscores the impact of these rats. "They help us detect cases that might otherwise be missed, preventing the unknowing spread of infections,” she affirms.
Even as technological advances like AI and devices like GeneXpert have transformed TB detection, they remain inaccessible to many rural or impoverished areas burdened by TB. Clinics often resort to error-prone and labor-intensive microscopy. However, APOPO’s rats can evaluate 100 samples in just 20 minutes, identifying over 30,000 previously overlooked TB patients.
While promising, scaling this method poses challenges. Sample transportation and rat operations require coordination, particularly effective in urban hubs like Dar es Salaam, explains Cox. Additionally, regulatory hurdles and skepticism toward this unconventional approach persist, with APOPO’s rats serving as a secondary diagnostic line rather than a primary tool approved by the WHO.
“It's a big challenge,” Cox states, discussing the funding obstacles faced due to a lack of WHO recognition. However, despite pressure from donors who encourage pursuing this recognition, Cox maintains focus on detecting every potential case in pursuit of maximizing social impact, even if it may mean more false positives. "Our choice was to go for that last patient out there — to go for the social impact,” Cox asserts.
(Only the headline of this report may have been reworked by Editorji; the rest of the content is auto-generated from a syndicated feed.)
