Experts developing protocol to test sewage for COVID-19 traces: Catalyst Group

A multi-disciplinary group of experts is developing protocol to test sewage for COVID-19 traces in selected densely populated urban residential areas of Bengaluru and Kolkata, as they feel it could be a simple and non-invasive method of community surveillance for coronavirus, Catalyst Group said on Monday.

The expert group COVIDActionCollab (CAC), ideated by social enterprise platform Catalyst Group, aims to explore a more feasible and efficient way to test for presence of COVID-19 in the communities.

"COVID-19 isn't going away anytime soon. Before we move into another lockdown, it is imperative that we have continued community monitoring especially in densely populated areas to serve as an early warning system," Catalyst Group Health Strategy Partner Angela Chaudhuri said in a statement.

COVID-19 patients shed the virus through their stools and urine. Sensitive laboratory tests can detect traces of coronavirus in sewage even with high levels of dilution, Catalyst Group said.

The experts are developing a method of collecting and testing samples in a way that helps identify localities where traces are found, that can help authorities to identify these areas, it said.

By mapping collection areas, it will be possible to narrow down where people infected with the virus live and follow it up with identification through clinical tests, quarantine and treatment measures, Chaudhuri added.

According to the group, CAC is developing a cutting-edge sewage testing method for COVID-19 in selected densely-populated urban residential areas of Kolkata and Bangalore. It will also extend testing to factory clusters in these neighborhoods, it said in a statement said.

Urban local bodies in these cities like Municipal Corporations, Directorate General Of Health Services and line departments would find this immensely useful, it said, adding "concerned officials have been approached for an early pilot".

This protocol will adapt methods developed in Europe, the US and Australia for Indian conditions. This is of significance in densely populated urban areas and factory clusters where testing individuals is extremely challenging.

"If COVID-19 traces are found, they must follow it up with clinical testing to identify and treat those infected," said Sandeepan Choudhury, a Kolkata based Water Sector Consultant from STUP Consultants.

The sewage testing-based approach is used routinely in the US to monitor community-wide use of illicit drugs, tobacco and alcohol in the densely populated boroughs of New York City, said Paramita Basu, an antimicrobial resistance researcher and Associate Professor of Biomedical Sciences in the Clinical Doctor of Pharmacy program at Touro College of Pharmacy in New York City.

"...but we are working to adapt this technology for assessing community-wide health, specifically in terms of COVID-19 prevalence," Basu said.

The group said that mass testing has not been possible due to a lack of adequate kits and infrastructure. Moreover, mass testing is even more challenging in densely-populated urban areas.

As the government mulls reopening factories, it is essential to put in place a surveillance method that can quickly and reliably detect the presence of the virus in a locality, it added.