SARS-CoV-2 was detected in Barcelona sewage long before the declaration of the first COVID-19 case, indicating that the infection was present in the population before the first imported case was reported. Sentinel surveillance of SARS-CoV-2 in wastewater would enable adoption of immediate measures in the event of future COVID-19 waves.
![](https://evidencenotfear.com/wp-content/uploads/2020/06/medRxiv-Sentinel-surveillance-of-SARS-CoV-2-in-wastewater-anticipates-the-occurrence-of-COVID-19-cases.png)
https://www.medrxiv.org/content/10.1101/2020.06.13.20129627v1