- The latest samples from the wastewater show "positive signals of the presence of the SARS-CoV-2 genome", announces Eau de Paris.
- “We have observed that samples that were negative turned positive again in some places. But seeing the virus circulating again is not something surprising, ”explains Laurent Moulin, doctor in microbiology and head of the R & D biology laboratory at Eau de Paris.
- The Eau de Paris laboratory analyzes around 100 samples per week.
Is he back? While the virus was no longer detectable since mid-May in several wastewater treatment plants in Ile-de-France, the latest samples from the wastewater show "positive signals, although very weak, of the presence of the genome of SARS-CoV-2 in certain localized monitoring points ”, officially announced this Wednesday Eau de Paris and the teams of the Obépine network (Observatory Epidemiology in Wastewater), confirming the information published by Le Monde on July 8.
“We have observed that samples that were negative turned positive again in some places. But seeing the virus circulating is not something surprising, ”explains Laurent Moulin, doctor in microbiology and head of the R & D biology laboratory of Eau de Paris, this Wednesday, in the corridors of their laboratory in Ivry- sur-Seine (Val-de-Marne). Can or should these readings raise fears of a second wave?
"We expected to see traces of the virus again"
"This very slight increase does not allow at this stage to draw conclusions on the number of people infected", warn the researchers also noting that their data does not allow to draw "strict conclusions". “It is not because a sample will become positive again that this must necessarily worry us. What interests us is to work on whether this increase will continue or stop at certain points. But the disease has not gone away. We expected to see traces of the virus again, ”says Laurent Moulin. And to specify: "these traces remain only one indicator among others concerning a possible progression of the virus". And to study the question, the face of this lab has changed in recent times.
Around 100 samples of wastewater are analyzed every week in the floors of the Eau de Paris laboratory. Initially, researchers are monitoring the quality of drinking water in Paris and the Paris region - with around 350,000 analyzes each year - but since March 5, 2020, monitoring of SARS-CoV2 in wastewater has also been put in place. and particularly at Eau de Paris, which has acquired a certain expertise in recent years on viruses that “come from human stool”. "We have an analysis role with a technique to detect the presence of SARS-CoV2 in different waters without a role of health interpretation", indicates Benjamin Gestin, CEO of Eau de Paris. "We are following the dynamics of the epidemic via wastewater treatment plants, including a dozen in Ile-de-France", abounds Laurent Moulin.
"We remove the water to keep only the viruses at the bottom of the tube"
When it arrives in Ivry, after its collection, this wastewater sample is in fact concentrated, via an ultracentrifuge, purified, conditioned and analyzed by the researchers. “First, we remove the water to keep only the viruses at the bottom of the sample tube. And then we will measure the quantity of virus, ”explains Laurent Moulin. “Then we analyze the dynamics. We look at whether we have an increase in concentration, a stabilized or decreasing level as we had at one time, ”he concludes. And the current trend for a few weeks is therefore at a "low level of presence", "without very clear dynamics" but still closely followed by researchers.
As researchers begin to provide first evidence of the risk of infection from coronavirus in the air, what about water? Alban Robin, director of research and development and water quality at Eau de Paris, is confident. “There are a number of studies being published on the subject right now and it's leaning more and more on the fact that it wouldn't be infectious. But this still needs to be confirmed ”.
Paris
Coronavirus in Paris: "No risk for drinking water" reassures the City after the discovery of "tiny traces" of the virus in the water network
Paris
Coronavirus: Traces of the virus in the water in Paris? We disentangle the true from the false
- epidemic
- Deconfinement
- Covid 19
- Confinement
- Water
- Paris