Researchers from Dutch startup InsectSense and Wageningen University & Research (WUR) devised an unusual method for detecting COVID-19. The team of scientists trained bees to extend their tongues when they sense a person infected with COVID-19, a Wageningen University press statement explains.
Much like other diseases, COVID-19 triggers metabolic changes in an infected person's body, causing a subtle change in the way they smell.
The team behind the new method, called "BeeSense" said they can train bees in a matter of minutes to recognize the scent of samples infected with SARS-CoV-2, the virus that spreads COVID-19.
"Bees can detect volatiles with a sensitivity of parts per trillion. For example, they find a flower a few kilometers away," the press statement reads.
Much like dogs, bees can learn to detect volatiles and odors. Unlike dogs, however, they can be trained in just a few minutes.
On its website, InsectSense says its main goal is to explore the possibilities of using "insect behavior and its underlying molecular biology, to provide relevant solutions in the fields of disease diagnostics."
Using sugar water as a reward, the "BeeSense" bees were trained to detect infected samples of SARS-CoV-2. Every time the bees were exposed to the scent from one of these infected samples, they received a dose of sugar water as a reward. The bees would extend their tongues to collect their reward.
By repeating the reward action several times over the course of a few minutes, the bees would associate the scent with the reward and would start to instinctively extend their tongues every time they sensed SARS-CoV-2. The researchers said a trained bee can detect an infected sample within seconds.
The methodology is based on the classical method of Pavlovian conditioning, also known as "Pavlov's dog."
The research was conducted with over 150 bees at the Biosafety laboratory of Wageningen Bioveterinary Research. Samples from SARS-CoV-2 infected minks as well as human samples were used. The results showed a very low number of false positives and false negatives.
Next, the WUR researchers and InsectSense are working on developing a machine that can automate the training of the bees for the testing method. The startup has already developed prototypes for the machine.
The WUR bee method is a new addition to a growing list of potentially more accessible, cheaper options for COVID-19 tests — the most commonly required test for travel, PCR, can cost upwards of $400.
In another recent example, Vittorio Saggiomo and a group of researchers, also from WUR, devised a method for a COVID-19 home testing kit using Nespresso capsules. They called that "CoroNaspresso."
The researchers behind the much more sensibly named "BeeSense" say their new method could be used in low-income countries where traditional testing methods are less accessible to the population.