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Difficult start for COVID-19 breathalyser tests

Difficult start for COVID-19 breathalyser tests

Photographer:Fotograaf:

MUMC

MAASTRICHT. In October and November 2020, a trial with three COVID-19 breathalyser tests was to start in Amsterdam, including the Aeonose, which was researched at the UM. The latter, however, appears to have been withdrawn at the last minute. A breathalyser test from Leiden withstood the test and was used by the Area Health Authority (GGD), but its use was recently stopped. It is likely to be reintroduced soon.

The last meeting with RIVM was on Wednesday 4 November, after which the ‘Maastricht’ breathalyser test – designed by The eNose Company from Zutphen – was to be used in a testing centre in Amsterdam. But that never happened. The Zutphen company recalled the Aeonose, as the device is officially called, at the last minute. 

This while initial scientific results show that the negative predicting value was 96 per cent; just like the other noses, the device works less well with positive results, in which case a PCR test (with a cotton swab) is carried out to confirm the result. But if everyone who is healthy can be sent home immediately, that takes a lot of pressure off the test centres. 

The Aeonose, however, appeared insufficiently trained. This ‘nose’ detects abnormal patterns in an exhaled breath, and learns to recognise them better the more people breathe into the device. The company, unfortunately didn’t have sufficient test subjects because many hospitals did not want to participate, says its CEO in an online article about innovative health care. Many specialists have little trust in a device that detects COVID-19 through breath. 

In addition, says Maastricht surgeon and researcher Nicole Bouvy, who was the first to try out the device among hospital personnel. “If the device is insufficiently trained, it can be subject to failure in the test centre. In an outdoor environment, humidity and fluctuating temperatures can influence the results.”

Safety

Bouvy thinks it is unfortunate that it all takes so long, now that society is in dire need of rapid tests. “At the moment, a disadvantage of the Aeonose is that people have to blow into the device for five minutes, after which it has to be rinsed for ten minutes. That takes too long if you want to test at the gates of a football stadium, for example. The other two ‘noses’ are faster.”

The Maastricht surgeon is referring to the one from Leiden and one from Finland, which have been experimented with in the test centre in Amsterdam. The SpiroNose from Leiden, developed by a group of scientists and entrepreneurs united in the company Breathomix, works well. The nose from Finland – by the Deep Sensing Algorithms company – proved to act up at times, also because of humidity and temperature fluctuations.

Bouvy has been in contact with the makers of the Finnish device and is now researching this nose in a GGD test centre in Maastricht. Reliability figures will be available soon. The device has previously been tested in South Africa and Mexico, but the results weren’t great. “The question is how meticulously those studies were carried out.”

Even if the Finish nose appears to be effective, it cannot be used immediately, says Bouvy. “This device doesn’t have a CE marking, so it doesn’t comply with the European safety, health and environment requirements. The company applied for the marking in September 2020, but it remains to be seen when it will be approved. The factories are ready and waiting, thousands of specimens of the Finnish device can be produced each month.”

Alcohol

The Leiden nose has ended up in a real rollercoaster. At the end of January, after the OMT issued a positive recommendation, the Area Health Authority had officially introduced the SpiroNose officially at two locations in Amsterdam. Two weeks later, the GGD stopped using the breathalyser test because of unclear test results: after a negative result, some people still tested positive in the PCR test.

According to the Breathomix company, the test wasn’t carried out properly. It is important to make sure that the internet speed at the test location is up to scratch and that the disinfectant used contains no alcohol. The ministry and the Area Health Authority have informed that they will soon start using the breathalyser test again. Breathomix was unavailable for comments.

And the Aeonose? This has by now been tested by hospitals in Den Bosch, Zwolle and Twente. It can be put to use everywhere, says Bouvy. “Also in outdoor test centres, because once they have been trained, environmental influences are not a serious issue. If you want to test large groups of visitors going to an event, however, you need plenty of these devices.”

Student house

The breathalyser tests didn’t exactly get off to a flying start, she admits. “We need to be more patient. At any rate, about two million people have antibodies in their blood by now, either through vaccination or because they were infected.”

She didn’t manage to steer clear of it herself. She lost her sense of smell and taste and appeared to have become infected because of a small outbreak in MUMC, just before Christmas. “I most likely passed on the virus to my student daughters and they in turn spread it further in their student house. These house mates then took it home to their parents. I felt so ashamed, but then again, what can you do about it...”

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