Coronavirus again detected in Paris sewers

French researchers warn about a possible return of the coronavirus epidemic in Paris. The testing of sewers in Paris has revealed a pattern of viral coronavirus concentrations for the first time since the self-isolation regime was lifted, Report says, citing Le Monde.
From March 5 to April 23, employees of the Inserm Research Institute conducted measurements and correlated their results with the authorities' data on the number of patients. In mid-may, following the lifting of the self-isolation regime, they found no coronavirus traces in any of the wastewater samples. However, from 22 to June 25,  six of the twelve samplings showed a weak presence. A week later, their results were confirmed.
French capital's water supply system confirmed that such a method could "partly reflect the health of the population," and at an earlier stage. The fact is that the virus appears in human waste a few days after infection, even before symptoms appear. The regional health Agency is currently working with Eau de Paris to develop a methodology for analyzing the results and options for improving data collection.