Using wastewater to detect SARS-CoV-2

New details about SARS-CoV-2, the virus that causes COVID-19, seem to emerge daily.

Expanded Testing Requirements

A concerning but important finding is that viable virus can be recovered from pre-symptomatic individuals several days before symptoms appear – as well as from asymptomatic individuals.

This highlights the need for effective surveillance and contact tracing programs, which include identifying and testing asymptomatic and pre-symptomatic individuals, to prevent further spread.

While contact tracing will always require clinical testing for those who’ve had contact with infected individuals, different strategies are available for a more holistic approach to monitoring.

Clinical Testing

One method is to conduct routine clinical testing of a portion of the population. This could include daily testing of all staff at a workplace or even larger groups, like what was done in Wuhan, China in May. Unfortunately, there are several challenges with implementing such massive efforts and, even at a relatively small scale, it can be impractical to maintain the practice over an extended period of time.

Environmental Monitoring

Another option is to conduct group testing at a wider level (e.g. organizational or community), which can then be used to trigger more specific individual testing, as required.

An example that has been highlighted here before is environmental sampling, where high-touch areas can be tested for the presence of the virus within a given facility. If it’s detected, follow-up testing can then be completed to identify the source and prevent further spread.

Wastewater Monitoring

At a community level, influent wastewater monitoring has been shown as a potentially powerful tool for identifying spread. Researchers in the Netherlands, US, Spain, and Australia have detected the virus in untreated wastewater samples. Some cities, like Tempe, AZ, have dashboards showing the concentration of SARS-CoV-2 in district wastewater.

Here in Canada, LuminUltra has partnered with researchers at Dalhousie University who are investigating how wastewater monitoring could be used for early detection of community spread. There is growing evidence that supports its use as an early indicator of the disease.

In the study that was completed in the Netherlands, researchers were able to detect the virus even when the number of cases was thought to be low in the community. Moreover, researchers in Italy were able to detect the virus in old wastewater samples, confirming that the virus first emerged there in December 2019, well before the outbreak was first detected.

Scientists and medical experts are recognizing the potential for wastewater monitoring as a tool for combating COVID-19. On July 7,  France’s Académie Nationale de Médecine recommended that wastewater monitoring should be used in France to monitor for SARS-CoV-2. Given the need for as many tools as are available, it’s likely that this area will continue to be explored for community monitoring.

Learn more

LuminUltra has launched an environmental testing solution that allows you to confirm whether a surface is in a safe state in as little as 90 minutes from the time of sampling. With minor adaptations, this kit could be used to test for the SARS-CoV-2 virus in wastewater samples. Learn more at luminultra.com/environmental.