Super-fast breathalyzer for corona should get society back on track

That could save tens of thousands of cotton swab tests per day in one fell swoop and greatly ease the pressure on the test streets. The breathalyzer also offers a solution for schools, companies and healthcare workers: anyone who certainly does not have corona will hear it immediately and can go back to work; the remainder must still undergo a follow-up test for exclusion. The Ministry of Health, Welfare and Sport has ordered hundreds of the devices from the Leiden company Breathomix.

In recent weeks, the breath test ran on trial in a test street in Amsterdam. ‘And the results are super positive,’ says Rianne de Vries of Breathomix when asked. “The device does exactly what we hoped, which is to say with a high degree of accuracy to most people: at least you don’t have it.”

Stadium

Breathalyzer tests may also help to replenish events and stadiums in the long term, is the belief of professor of innovative surgical techniques Nicole Bouvy (Maastricht UMC), who is researching some other ‘electronic noses’. ‘I really believe that this will be the outcome to get society back on track. It is a super fast test: immediate results. And it costs nothing. ‘

She finds it difficult to estimate whether the Leiden test is the future in this regard. For example, the Finnish company Deep Sensing Algorithms is currently already producing about one hundred thousand copies of a comparable breath test, Bouvy knows. ‘Much will depend on how quickly they can scale up in Leiden.’ The further development of another promising breathalyzer, from the University of Twente, has come to a halt, partly for this reason. Bouvy saw comparable results in Maastricht with that electronic nose.

De Vries, who is still working on her dissertation, started Breathomix two years ago with a few other young scientists to further develop the ‘Spironose’. At the time, the device was still intended as a breathalyzer to detect conditions such as asthma, COPD and cancer.

But it also works for covid-19, according to the results of the trial that Breathomix carried out in the test street together with the Leiden University Medical Center and Franciscus Gasthuis en Vlietland in Rotterdam. More than 1,800 people passed in review, of whom about 1,350 would have been able to go home immediately after the breath test, says internist-infectiologist Geert Groeneveld (LUMC), who led the study.

Iron nose

‘You can tighten that boundary or make it less strict, depending on the situation,’ he says. For example, he could have adjusted the iron nose more smoothly, so that about 1,600 people could go home immediately. This included a few people who now tested positive.

‘Such choices are not ours. And in practice it will differ per situation what you find acceptable ‘, thinks De Vries. RIVM virologist Chantal Reusken, who coordinates the assessment of rapid tests, recently suggested in this newspaper that there may be situations in which a rough, but rapid test, due to its speed, can help to quickly remove at least the most contagious people from a crowd.

The electronic nose does not measure just one substance, but measures changes in the complex mix of volatile organic molecules that we exhale in addition to CO2 and water vapor. ‘After all, a whole cascade of biological processes changes during illness,’ says De Vries.

Mouthpiece

By training the machine with the breath of hundreds of people with and without corona, the nose learned to recognize who is in any case corona-free. But in the long run it may also be possible to teach the device to recognize who is positive, says Bouvy.

All together, the test takes three quarters of a minute: breathe into the device for about half a minute and wait a few seconds for the result. The blower can then be reused after disinfection and replacement of the mouthpiece and filter. A test costs a few euros, says De Vries.

One question is whether the test also recognizes ‘asymptomatic’ infected people, people who produce the virus but have no symptoms of disease. Because such apparently healthy people do not often come to the test street, follow-up research on the subgroup is needed, says Groeneveld. “We just don’t know yet.”

Alcohol

With broader deployment, Bouvy also foresees a logistical bump: “If you use it at the stadium, and you find someone who may be positive, you have to follow up immediately.” After all, Covid is a disease that must be reported by law. ‘So there must always be a line to the GGD or the doctor,’ says Bouvy.

The electronic nose also has a smaller, technical disadvantage: if it detects alcohol, it immediately gives an error message. Disinfection is therefore not possible with alcohol. ‘And you shouldn’t drink 6 to 8 hours in advance,’ says Groeneveld. “He can’t stand that very well.”