Sewage testing is a cost-effective way to keep track of transmission dynamics in a community. Sewage testing provides a sensitive signal of whether SARS-CoV-2 is present in the population and whether transmission is increasing or decreasing.

For an effective testing and traceability strategy, wastewater testing is an additional tool in the fight against the spread of the virus.

During periods of low infection, local, undetected COVID-19 clusters can become the source of renewed spread. SARS-CoV-2 infections with few or no symptoms then call for increased attention to prevent resurgence.

Effluent monitoring on Corona is a solution to this. Shortly after infection, the virus is detectable in human excreta. These virus fragments are found even when there are only asymptomatic COVID-19 cases in the population. Wastewater surveillance is therefore an early warning system, and can help detect infection outbreaks earlier and predict them more accurately.

Wastewater surveillance for SARS-CoV-2

Early detection of a developing infectious event in a catchment area of a wastewater treatment plant allows:

• take timely, containment measures,
• break an incipient wave, and
• prevent the spread to neighbouring regions

For the examination, samples are taken in the wastewater treatment plant between the first (mechanical) and the second (biological) treatment stage. It is possible to examine mixed or individual samples. For composite samples, samples are usually taken and mixed continuously over 24 hours.

Samples should be stored at 4 °C and also refrigerated during the composite sample collection. Our laboratory team uses PCR technology to detect and quantify SARS-CoV-2 genetic material. In the test report, we indicate whether virus particles were found.

In case of detection, we calculate the virus concentration in 100 ml of unconcentrated wastewater.