One of the biggest unknowns about the spread of the coronavirus (SARS-CoV-2) is how many people have not tested positive and yet are infected with the virus and have mild symptoms or even remain asymptomatic.
Some scientific initiatives are trying to devise methods for the active search and detection of cases – which, on the other hand, was one of the successful prevention measures of countries that have COVID-19 controlled, such as Vietnam or Taiwan. A group of researchers from Cranfield University has developed an innovative approach: testing the wastewater from certain communities to see if they are infected by the virus.
The detection method is as simple as finding biomarkers in feces and urine that end up in the sewage system, and thus determining if there are possible carriers of COVID-19 in local areas.
The project has been coordinated by Dr. Zhugen Yang, professor of sensor technology at the Cranfield Institute of Water Sciences: “In the case of asymptomatic infections in the community or when people are not sure whether they are infected or not, detecting community wastewater in real time through paper analytical devices could determine if there are COVID-19 carriers in an area to enable rapid detection, quarantine and prevention. “
Therefore, by monitoring local areas such as building blocks, an effective intervention can be carried out as soon as possible to restrict the movements of that local population, working to minimize the spread of pathogens and the threat to public health.
How to detect coronavirus in stool or urine?
Recent studies have shown that SARS-CoV-2 can be isolated from the feces and urine of infected people, and the virus can generally survive for up to several days in an appropriate environment after leaving the human body.
The paper device in question folds and unfolds as the nucleic acids of the pathogens in the sewage samples pass; then a biochemical reaction detects whether the nucleic acid of the genetic material (RNA) from the SARS-CoV-2 infection is present. Although it is a molecular process, the results are visible to the naked eye: a green circle indicating positive and a blue circle indicating negative.
Paper analytical devices: big perspectives
This interesting method of detecting the genetic material of the virus could have many possibilities, not only for the use proposed by this laboratory, in fecal waters. Also, it is cheap (it costs less than a dollar, according to scientists) but still needs a number of improvements to be easily used by non-experts. Among the advantages of paper analytical devices, he also highlights that they are easy to store and transport because they are thin and light , and they can also be incinerated after use, which reduces the risk of spread.
“We anticipate that the device will be able to provide a complete and immediate picture of the health of the population once this sensor can be deployed in the near future,” the authors said in a Cranfield University news release.
A form similar to this device is already used to track illicit drugs and obtain information on health, diseases and pathogens. Dr Yang had previously developed a similar device on paper to successfully perform rapid veterinary diagnostic tests in India and blood malaria tests among rural Ugandan populations.
Referencia:
Kang Mao, Hua Zhang, Zhugen Yang. ‘Can a Paper-Based Device Trace COVID-19 Sources with Wastewater-Based Epidemiology?’ Environmental Science & Technology journal. (Marzo, 2020)
