Bee’s have an unusually keen sense of smell. Dutch scientists decided to take advantage of this and trained the insect to sniff out samples infected with COVID-19 – a technique they believe could cut waiting times for test results to just seconds. The testing method is a collaborative endeavor by researchers from Wageningen University & Research (WUR) and Dutch startup InsectSense.
The press statement explained:
Bees can detect volatiles with a sensitivity of parts per trillion. For example, they find a flower a few kilometers away.
The team trained the bees to stick out their tongues when they smell a person infected with COVID-19. The disease triggers metabolic changes in an infected person’s body similar to other diseases, causing a very subtle change in the way they smell. This method of detection is akin to how researchers have been training dogs to detect cancer. Bee’s can learn to identify odors and volatiles much like dogs, but they can be taught in just a few minutes.
InsectSense hopes to provide relevant solutions in disease diagnostics by unleashing the potential of using insect behavior and its underlying molecular biology. The company calls the new method “BeeSense.” It claims it can train bees in just a few minutes to recognize the scent of samples contaminated with SARS-CoV-2, the virus that spreads COVID-19.
The scientists in the bio-veterinary research at WUR trained the bees by providing them sugary water as a prize after showing them samples infected with COVID-19. The bees would get no compensation after being offered a model that is non-infected. They quickly associate the odor with the reward, spontaneously extending their tongues to receive it when presented with a contaminated test sample. They were able to detect an infected sample within seconds.
Wim van der Poel, a virology professor who took part in the research, explained:
We collect normal honeybees from a beekeeper, and we put the bees in harnesses. Right after presenting a positive sample, we also present them with sugar water. And what the bees do is extend their proboscis to take the sugar water.
The study involved over 150 bees and COVID-19 samples from SARS-CoV-2 infected masks and humans. The experiment took place at a WUR Biosafety laboratory. The results showed a low number of false negatives and false positives.
It usually takes hours to get a result from a COVID-19 test, but the bee’s response is immediate. The technique is also cheap, possibly making it useful for countries where tests are scarce. The bee technique is another new option to the growing list of potentially more affordable and more accessible COVID-19 tests.
Now, the team is developing a machine that can automate the training of the bees for the testing method. They’ve already completed prototypes for the device.
However, not everyone is convinced. Dirk de Graaf, a professor at Ghent University in Belgium who studies bees, insects, and animal immunology, said he doesn’t see the technique replacing more conventional forms of COVID-19 testing in the foreseeable future.
He said:
It is a good idea, but I would prefer to carry out tests using the classic diagnostic tools rather than using honeybees for this. I am a huge bee lover, but I would use the bees for other purposes than detecting COVID-19.
He said that too little is known about BeeSense’s effectiveness. But he also said he’s open to the idea of using it to indicate infection when PCR tests are unavailable.
