Authors: Gertjan Medema and colleagues at KWR in The Netherlands
In a non peer reviewed preprint (preprint pdf) report on their use of rt-PCR to detect RNA from SARS-COV-2 at multiple locations. Their sampling started in February, before COVID19 cases were detected in The Netherlands, and extended when cases were detected at all sites.
The February samples were negative at all sewage sites examined (incoming wastewater at treatment plants). In early March, 5 of 7 sites were positive (while only 4 of 7 of the corresponding cities had reported positive COVID cases). By their March 15/16 samples, 6 of 7 sites were positive for RNA from SARS-COV-2.
While no inference about the presence of viable virus can be made from the data, the authors conclude “The detection of the virus in sewage, even when the COVID- 19 prevalence is low, indicates that sewage surveillance could be used to monitor the circulation of the virus in the population and as early warning tool for increased circulation in the coming winter or unaffected populations.”