London, March 31
Researchers are working on a new paper-based device that can be used to detect SARS-CoV-2 (coronavirus) within the wastewater of communities infected with the virus.

According to the study, published in the journal Environmental Science & Technology, rapid testing kits using paper-based devices could be used on-site at wastewater treatment plants to trace sources and determine whether there are potential COVID-19 carriers in local areas.

The wastewater-based epidemiology (WBE) approach could provide an effective and rapid way to predict the potential spread of COVID-19 by picking up on biomarkers in feces and urine from disease carriers that enter the sewer system.

"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," explained researcher Dr Zhugen Yang, Professor at Cranfield University in the UK.

WBE is already recognised as an effective way to trace illicit drugs and obtain information on health, disease and pathogens.

Dr Yang has developed a similar paper-based device to successfully conduct tests for rapid veterinary diagnosis in India and for malaria in blood among rural populations in Uganda.

Recent studies have shown that live SARS-CoV-2 can be isolated from the faeces and urine of infected people and the virus can typically survive for up to several days in an appropriate environment after exiting the human body.

According to the researchers, the paper device is folded and unfolded in steps to filter the nucleic acids of pathogens from wastewater samples, then a biochemical reaction with preloaded reagents detects whether the nucleic acid of SARS-CoV-2 infection is present.

Results are visible to the naked eye: a green circle indicating positive and a blue circle negative.

"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," said Dr Yang.

"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," Yang added.

Paper analytical devices are easy to stack, store and transport because they are thin and lightweight, and can also be incinerated after use, reducing the risk of further contamination, the study noted.

Paper-based device to soon detect COVID-19 in sewage