Wastewater data: In Prague, five times more can be infected than is known
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According to data from long-term wastewater monitoring, up to ten thousand people can currently be infected with coronavirus in Prague. It was published by the Institute of Water Technology and the Environment of the University of Chemical Technology, which is cooperating on the project with Prague Waterworks and Sewerage.
Scientists led by Jan Bartáček measures twice a week, the RNA content of SARS-CoV-2 virus particles in the wastewater at the main tributary of the Prague treatment plant. “The current number of virus particles corresponds to the number of particles that we measured at the turn of March and April, and at that time around ten thousand were infected in Prague,” Bartáček describes the result.
It is only a rough estimate, however, according to the author of the project, certain trends can be observed thanks to the chosen methodology. “We cannot design a viral load in a population affected by vaccination or the currently circulating delta variant. However, we know that in the place where wastewater flows from half of the population of Prague, the number of say the detection of the virus has increased, “says the scientist.
Estimate infected from stool
The number of infected – an estimated ten thousand currently positive individuals in Prague – is estimated by scientists due to correlation. “Since we have been monitoring the viral load in wastewater in various parts of Prague for a whole year, our results have always correlated us with the currently actually detected positive cases by testing. The difference today is that our results show us an order of magnitude five times more positive in Prague, ”says a specialist in technology and wastewater recycling.
The number of patients in Prague is currently around two thousand active cases, with tests revealing 546 positive people on Thursday.
Researchers from the Institute of Chemical Technology are working with a method that takes samples of wastewater that contains the stool of people. A positive individual sheds SARS-CoV-2 virus samples. After taking a sample, they then segment the virus genome and – simply put – the more the genome of the virus they find in the samples, the more positive it should be in Prague.
“We do not work with epidemiological or sociological data, because we are not experts in those fields. What we can say is that there is currently a larger viral load in the wastewater. Whether other viral loads are affected by the delta or vaccination, say other scientists, “explains Jan Bartáček.
Pilot project in a retirement home
The scientist also supported that according to his data it is not currently possible to set any specific measures. “But what institutions can do is expand testing. We are currently testing a pilot project together with hygiene in a retirement home, where we are also monitoring the viral load in wastewater. If we catch something, we tell the hygienists, they can test the home and catch the problem before it actually breaks out, “says Bartáček, adding that institutions throughout the country could solve this.
In addition to the inflow of the wastewater treatment plant in Prague, scientists from the Institute of Water Technology and the Environment also monitor other smaller discharges, for example in shopping centers or at the airport. “The increase is mainly in the central tributary. At the other measuring points, the values are stably higher and according to them nothing concrete can be said, “says the scientist.