By Nisha Sambamurty
Yes, you read that right: rats. To most people, the sight of a giant rat is disgusting. But for many scientists, these rats are extremely helpful.
One in four people are currently living with latent tuberculosis, according to the WHO. That’s almost 2 billion people worldwide. Tuberculosis is a leading cause of death by infectious disease, and existing systems that work to detect it lack accuracy, time efficiency, and cost efficiency. Because of this, people in regions like East Africa often don’t undergo screening to detect the disease—due to lack of awareness or money—and many cases go undetected. In places like jails, where TB is estimated to be up to 100 times more prevalent, this issue is much worse.
Enter the super-rat!
How, you ask?
Here’s where it gets really interesting. When these rats reach four weeks of age, they begin a rigorous training process. They are introduced to different stimuli and are trained to interact with humans. They are taught to recognize the presence of TB in human mucus. (And you thought the rats were gross!)
The rats are presented with ten samples of this mucus, or sputum, and when they detect the ones with TB, they hover over them for three seconds to let the scientist know what they have smelled and are then rewarded when they succeed. How AMAZING is that?!
Perhaps even more incredible is their success rate and the speed at which they can detect TB. These rats can detect tuberculosis with almost 100 percent accuracy. The rats have proved to be incredibly cost-effective. According to the Belgian charity, it takes four days for a lab technician to screen 100 samples. Yet once the rats are trained, they can screen around 100 samples in just 20 minutes.
This new method of screening for TB has HUGE implications for developing countries that are heavily burdened by tuberculosis. With funding from USAID (United States Aid in International Development), APOPO plans to provide full coverage in Tanzania’s TB hotspots.
Thank you, giant rats! We’ll try to think nicer thoughts if we see you around.