Published on May 23, 2021
Ahmedabad: How do the authorities such as the state and central government decide on the spread of Covid-19 in a specific region? There are several markers – for starter, the test positivity rate (TPR) indicating how many persons are testing positive out of every 100 persons tested on rapid antigen test (RAT) or RT-PCR. It could also be the footfalls at the general practitioners or hospitals for telltale Covid symptoms.
But what about employing a method which goes beyond these statistics? Prof Manish Kumar, a member of the faculty of earth sciences at IIT Gandhinagar (IIT-Gn) along with other collaborators including Gujarat Biotechnology Research Centre (GBRC), is attempting to break the code through wastewater monitoring. Several papers on the topic later, Prof Kumar says that it could be an effective way to forecast a possible surge.
How does the Covid-19 virus end up in wastewater in the first place? The experts explain that ACE2 receptors, associated with binding of Covid-19 virus in human body, are also found in the intestines. Thus, fecal matter from Covid-19 patients can carry the virus.
Can the virus spread through fecal matter? It’s a question overwhich several studies are being conducted.
“But our current focus is on the presence of the virus in wastewater. The regular analysis at multiple sites is giving us unmistakable data on the concentration and even gene types (ORF, N, S, etc.). The data from the analysis matches with that on the ground – for example, the high concentration shows higher number of cases,” said Prof Kumar. “At the times when even RT-PCR tests are not able to detect the presence of the virus directly, and there is large number of asymptomatic patients, such method can be useful.”
The team’s latest publication highlighted that the treatment of wastewater doesn’t completely remove the virus’ presence. “Our method breaks down the RNA to find the presence of the virus. But the study pointed out that disinfection seems less effective than the adsorption and coagulation processes for SARS-CoV-2 removal. We would need more effective method to treat the water,” he said.