Czech scientists from the T. G. Masaryk Water Research Institute (VÚV TGM) have had promising results in detecting a coming coronavirus epidemic before it starts to spread in the population. The researchers found that, after several months of research, the only thing they need is a sample of wastewater.

Because bacteria and viruses do not get leave the body only through respiratory droplets but also through excrement, wastewater could become a valuable source of information.

“Indeed, it seems that this approach could be used as a basis for an early warning system for detecting the onset of another epidemic,” explains Hana Mlejnková of VÚV TGM, who is in charge of the wastewater project.

Czechia is one of the pioneers of wastewater research, one of only six countries in the world that have been able to carry out such demanding research.

“If it turns out to be a reliable tool, it will become one of the possible ways to detect a coming second wave,” says Jan Kynčl, head of the Department of Infectious Diseases Epidemiology at the State Institute of Public Health.

However, researchers had little reason to be optimistic in early April because, for a long time, they could not find the virus in the wastewater.

“At the beginning, it was surprising that we did not find any traces of coronavirus in the large wastewater treatment plants, as we knew there was a high number of infected individuals in the area,” says Mlejnková.

But the situation changed when the first results from small wastewater treatment plants in the municipalities arrived. Suddenly, scientists started to detect the coronavirus in these samples, even though the number of infected people in municipalities was, on average, much lower than in cities.

This was an important signal for researchers. It turned out that traces of the virus can be found in wastewater and that the method works, even if there are only a few coronavirus patients in the area. Researchers from the VÚV TGM explain that the small dilution and short piping probably made it easier to detect the virus. Thus, the small wastewater treatment plants could be a pillar of a coronavirus early warning system in the future.

“It will probably be necessary to identify critical places, in which the number of infected individuals could grow rapidly, but at the same time, the wastewater in the area will be concentrated,” comments Mlejnková on further steps of the research.

As wastewater treatment plant operators take samples regularly, the new method would not impose any additional burden on employees at the wastewater treatment plants.

“The early warning system could be implemented right away,” Mlejnková believes, pointing out that if the method proves successful, it could detect not only COVID-19 but also warn against other epidemics.