There is an arm of science focused on revealing insights about human behavior and public health by analyzing the contents of our sewage. Known as wastewater-based epidemiology (WBE), this technology has become a very valuable tool widely employed by authorities around the world, and now one of the scientists on its cutting edge wants to use it to help monitor outbreaks of COVID-19.

In essence, WBE is a process whereby scientists conduct chemical analyses on samples taken from sewage plants to find out what's inside. The presence of certain metabolites could indicate the prevalence of illicit substance use in communities, for example, helping governments better understand the drug usage habits of a population.

This remains the primary way WBE is used around the globe, but it could offer far more than that. Scientists hope that rather than the laborious process of analyzing samples in the lab, remote sensors could be installed at treatment plans that reveal the contents of samples for more efficiency.

Leading the charge in this area is Dr Zhugen Yang, a lecturer in sensor technology at Cranfield University’s Water Science Institute. Yang leads a team that is bringing together cutting-edge biomedical and chemistry techniques to build cheap, paper-based sensors that can detect antibiotic-resistant genes to track the rise of superbugs, bacteria that can indicate community obesity levels, and pathogens that can cause outbreaks of diseases, early on in the piece. Like many scientists around the world, he and the team are now turning their attention to COVID-19.

“In the case of asymptomatic infections in the community or when people are not sure whether they are infected or not, real-time community sewage detection through paper analytical devices could determine whether there are COVID-19 carriers in an area to enable rapid screening, quarantine and prevention,” says Yang. “If COVID-19 can be monitored in a community at an early stage through WBE, effective intervention can be taken as early as possible to restrict the movements of that local population, working to minimize the pathogen spread and threat to public health.”

The paper-based sensors Zang and his team are working on would be used at treatment plants to pick up biomarkers of COVID-19 in feces and urine that make their way into the sewerage system. As it is folded and unfolded, the sensor filters the nucleic acids of pathogens, which then react with preloaded reagents to reveal the presence of certain infections. The results can be seen with the naked eye, presenting as a green circle when positive. The team imagines it could be tweaked to detect COVID-19 without too much trouble, with other research showing that the virus can be isolated from the feces and urine of infected people and survive for days in the right environment.

“We have already developed a paper device for testing genetic material in wastewater for proof-of-concept, and this provides clear potential to test for infection with adaption,” added Dr Yang. “This device is cheap (costing less than £1 (US$1.25)) and will be easy to use for non-experts after further improvement. We foresee that the device will be able to offer a complete and immediate picture of population health once this sensor can be deployed in the near future.”

The researchers have published a paper detailing the technology in the journal Environmental Science & Technology.

Source: Cranfield University