Mainz (dpa / lrs) – With wastewater analyzes on Corona and a scientific accompanying study, scientists in Rhineland-Palatinate are investigating the transition from the pandemic to an endemic. “We are the only federal state in Germany that conducts wastewater tests with a survey (observation),” said state vaccination coordinator Daniel Stich (SPD) of the German Press Agency in Mainz. “In this way, Rhineland-Palatinate is also preparing for possible future pandemics.”
In 15 sewage treatment plants in the country, samples are taken twice a week and examined for the corona virus and its current variants. In addition, there are almost 7,500 people in the five regional centers in the state who do a quick corona test twice a week, as Professor Karl-Heinz Küfer from the Fraunhofer Institute for Industrial Mathematics (ITWM) in Kaiserslautern said.
This is already “a pretty good number for estimates” for the entire population in Rhineland-Palatinate. “But there should be more in the final expansion phase,” said Küfer. Around 12,000 to 14,000 people are necessary to have a “slightly fluctuating representative group”.
The study is entitled Monitoring and early warning system for SARS-CoV-2 infections, or “SentiSurv” for short. They give you a very meaningful incidence, said Stich.
Other federal states have already expressed an interest, reported Küfer. The scientist is leading the investigation on behalf of the Ministry of Health together with the University Medical Center in Mainz. The physicians working with Professor Philipp Wild can access data from the Gutenberg Health Study.
“Wastewater tests are forward-looking and can also measure other pathogens,” said Küfer. He cited influenza and the respiratory virus RSV as examples. Polio (child paralysis) and smallpox viruses have also been found in wastewater in New York and London. However, influenza, for example, is much more difficult to detect than the corona virus.
Fluctuations in the sewage treatment plants also complicated the results. “Every sewage treatment plant has different strengths and weaknesses,” said Küfer. In Ludwigshafen, for example, the results are distorted by chemicals. But there are also a number of other factors that lead to fluctuations in the measurement results. For example rainwater, measurement inaccuracies, the transport of waste water and tourists.
“But we can see a week earlier in the wastewater what will be in the hospitals in the next week or two,” said Küfer. “It’s an early warning system, but nothing more,” emphasized the scientist. The results of the wastewater tests could not be extrapolated to the number of people. It would certainly not be possible to derive individual isolation measures from this, for example in relation to retirement homes.
The state government is spending around 2.5 million euros on the wastewater analysis and the study. The wastewater analyzes started in October 2022 and the project is scheduled to last until the end of this year. “It’s a smart, easily scalable model,” said vaccination coordinator Stich. It is also a good alternative to mass tests without cause, such as with Corona. These were never representative in a statistical sense and mostly underestimated the incidence, said Küfer. In addition, there were misconceptions such as test results from schools and kindergartens. “The children didn’t infect their parents as often as we thought.”
