Scientists in the Netherlands recently detected COVID-19, the disease caused by the coronavirus, in a city’s sewage system before any cases were officially reported by human testing, indicating that wastewater tests could be used as an early warning sign of rising coronavirus cases.
Researchers found COVID-19 in the wastewater in the city of Amersfoort on March 5, before any cases were reported in that city through testing, but after the Netherlands reported its first case in the country. This study has not been peer reviewed, but has been published by the KWR Water Research Institute, a research group based in the Netherlands.
“It is important to collect information about the occurrence and fate of this new virus in sewage to understand if there is no risk to sewage workers, but also to determine if sewage surveillance could be used to monitor the circulation of SARS-CoV-2 in our communities, that could complement current clinical surveillance, which is limited to the COVID-19 patients with the most severe symptoms,” the study said.
The authors say the early results show “sewage surveillance could also serve as early warning of (re-)emergence of COVID-19 in cities,” especially when testing is limited. Though the virus is unlikely to be transmitted by sewer water, the authors write, traces of the coronavirus will show up in sewage systems because the disease’s RNA can be detected in stool.
Authors of the study have cautioned that their methods need further substantiation and validation, but say the findings could mean that “the water sector will have a tool that provides valuable additional information about the spread of the virus in the population.”