Surveillance of SARS-CoV-2 in wastewater allows for early action before the disease spreads, and the detection of the virus in wastewater should be seen as a warning sign for the (re)emergence of the pandemic or resurgence of new outbreaks, reducing its impact on the community.
On March 17th 2021, the EU published the Commission Recommendation (EU)2021/472 on the common strategy to be adopted for systematic surveillance of the SARS-CoV-2 virus presence in the population through its monitoring in wastewater.
A person infected with COVID-19 eliminates SARS-CoV-2 virus in the stool from the 2nd day after infection. Symptoms manifest on average from the 5th day, which then leads to the individual RT-PCR test. Only on the 7th day after the infection a test result is obtained, with a consequent focus alert.
Clinical testing does not allow the prediction of outbreaks or detection of asymptomatic individuals in useful time. Detection of SARS-CoV-2 in wastewater anticipates by 2 to 7 days an outbreak detection.
Systematic surveillance of SARS-CoV-2 in wastewater and analysis of outcome trends is thus helpful in evaluating the effectiveness of measures taken in mitigate virus transmission.
The locations and sampling frequency should be defined in accordance to the local epidemiological situation and risk (ex: main systems for capturing hospitals, schools, university campus, airports, transport platforms, nursing homes, prisons, tourist accommodation establishments, among others).
Advantages of detecting SARS-CoV-2 in wastewater
- Regularly monitor the community.
- Detect the presence of asymptomatic individuals.
- Anticipate outbreaks of COVID-19 within 2 to 7 days.
- In defined locations, isolate individuals from the sector that resulted in a positive wastewater.
- Test only individuals in isolation and reduce testing costs.
- Quickly activate contingency plans and save lives.