In the past few weeks, a lot has happened in Austria when it comes to testing for SARS-CoV-2. Just a few months ago, hardly anyone would have thought it possible that hundreds of thousands of tests – from the PCR test to the “nose pick” antigen rapid test – are carried out every day in this country. Zuber, who works at the Research Institute for Molecular Pathology (IMP) and is active in the “Vienna COVID-19 Detection Initiative” (VCDI), believes that much more will soon be possible with sophisticated logistics and innovative test procedures that have already been tested in various pilot projects is. Specifically, it is about almost real-time monitoring of the entire population using the reliable PCR method for virus detection.
The basis for the project, which is currently being developed, is a study carried out by a team led by simulation researcher Niki Popper at the Technical University (TU) and the TU spin-off dwh together with Julius Brennecke from the Academy’s Institute for Molecular Biotechnology (IMBA) der Wissenschaft (ÖAW) and Zuber at the beginning of January. Here, the scientists showed that targeted, repeated testing of large population groups has a major braking effect on the infection process. Households were viewed as units. The samples of the household members could either be submitted individually or as a collective sample (pool). If the result is positive, everyone goes into quarantine.
The joint testing and isolation of households would have the decisive advantage that transmission chains would be interrupted early after infection in the household. In order for this to prevent the uncontrolled spread of the pandemic even without lockdown measures, around 150,000 households in Vienna would have to be tested per day, said Zuber. The key to this is an intelligent combination of many individual samples in pools, which are only examined individually when the overall PCR test works.
This is possible because even the smallest virus concentrations can be reliably detected with it. In fact, around 200 viruses per milliliter of sample material are sufficient. In contrast, rapid antigen tests require a concentration of more than a million viruses per milliliter, which means that it is more likely to find highly infectious people. Used on a broad basis, this is of course helpful, but with sensitive PCR tests it goes even better, Zuber was convinced.
The idea is for people to gargle samples twice a week at a location close to them. The meanwhile large laboratory capacities would then make it possible to provide information very quickly. An efficient monitoring system should ideally recognize all potentially infectious persons with certainty. “Unfortunately, antigen tests cannot do that, but PCR tests easily”. The key to success lies above all in logistics. Zuber: “We no longer need measuring devices, but cleverly organized ‘pooling centers’ that prepare the samples for the laboratories.”
The necessary high participation can be achieved, among other things, if the understandably lockdown-tired population realizes that broad participation offers a realistic chance to prevent the next restrictions. “All we have to do is gargle twice a week and drop off our sample somewhere,” emphasized the scientist.
If we succeed in realizing this “dream”, one could also be proud in this country, “because essential elements of this test strategy were developed and used for the first time in Austria. We now have the chance to close the bag and end up in a system where we can really control the pandemic, “said Zuber with conviction. A pilot test program for companies based on this principle is now running in Vienna under the title “Alles gurgelt”. Zuber and Brennecke are involved in this in the scientific amount.
Once established, such a system can be restarted within a few weeks if, for example, a SARS-CoV-2 variant emerges that actually escapes the established immune protection, or a pandemic with another pathogen is looming. Adapting PCR tests to new targets in the genome of pathogens is relatively easy to do. That way you would be well positioned in the event of the next pandemic.
(SERVICE – the study online: http://go.apa.at/T45YvPz0; information on “Alles gurgelt”: https://coronavirus.wien.gv.at/alles-gurgelt-testprogramm-fuer-betriebe/)
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Coronavirus measures Vienna completely tested