Hero rats: Tanzania’s unlikely lifesavers

In the rubble of a simulated earthquake in Morogoro, Tanzania, a rat scurries past debris and garbage, triggering a device that alerts human rescuers to a trapped survivor. This remarkable scenario is not fiction but part of a real training program by APOPO, a Tanzania-based NGO that has been harnessing the extraordinary abilities of African giant pouched rats for search and rescue, land mine detection, and tuberculosis (TB) identification.

“Their sense of smell is incredible,” Fabrizio Dell’Anna, an animal behaviorist at APOPO told ABC. “These rats are able to detect explosives, tuberculosis — even tiny amounts of the bacteria — and in this project, they are able to correctly identify and indicate humans.”

In addition to search and rescue, APOPO’s rats walk on leashes over land mines to detect explosives. Since 2014, the organisation has helped clear over 50,000 land mines in countries including Angola and Cambodia.

The rats are trained from birth for specific missions, with a lifespan of nearly a decade allowing for years of active service. Training costs approximately €6,000 ($6,990) per rat and relies on classical conditioning and positive reinforcement.

While rats in the field gain attention for detecting land mines or survivors, those working in laboratories may have the greatest social impact. APOPO began training rats for TB detection in 2007, deploying them in Tanzania, Ethiopia, and Mozambique. In partnership with 80 hospitals in Tanzania, the rats analyze sputum samples, identifying TB cases missed by conventional testing.

“Every day as many people die from TB as from land mines in a whole year,” said Christophe Cox, CEO of APOPO. “It’s more spectacular to be on the minefield … but for TB … in terms of social impact, it’s tremendous.”

TB remains a leading infectious disease, with the World Health Organization reporting 1.25 million deaths and 8.2 million infections globally in 2023.

In sub-Saharan Africa, only about half of TB patients receive a diagnosis, increasing the risk of disease spread. APOPO’s rats can scan 100 samples in 20 minutes, detecting more than 30,000 cases that had previously been misdiagnosed as negative.

“The benefits of using rats are significant,” said Felista Stanesloaus, a doctor at a TB clinic in Morogoro. “They help us detect cases that might otherwise be missed, which prevents people from unknowingly spreading infections.”

Despite these successes, APOPO faces regulatory and operational challenges. Rats are considered a second-line diagnostic tool, requiring human microscopy confirmation before treatment. The organization struggles with recognition from the WHO, limiting mainstream funding.

“It’s a big challenge,” said Cox. “Not being recognized by the WHO means that the mainstream funding for TB … never reaches us.”

APOPO’s method prioritizes identifying every positive case, even at the risk of false positives, focusing on maximizing social impact rather than meeting rigid specificity standards.

“Our choice was to go for that last patient out there — to go for the social impact,” Cox said.

By Sabina Mammadli