Waste

COVID-19: Wastewater surveillance can help discover spread, says scientist

Surveillance through wastewater-based epidemiology can help the country in its fight against the novel coronavirus disease (COVID-19) pandemic, according to the scientist

 
By Sushmita Sengupta
Last Updated: Wednesday 10 June 2020
It was not about the detection live SARS-CoV-2 samples in wastewater, but about detecting genetic material (ribonucleic acid) Photo: Down To Earth

The surveillance of wastewater through wastewater-based epidemiology (WBE) can help reveal the spread of the novel coronavirus (SARS-CoV-2) that causes the COVID-19 disease in India, said Manish Kumar, a scientist at the Faculty of Earth Sciences, Indian Institute of Technology in Gujarat’s Gandhinagar.

WBE surveillance can help the country in its fight against the COVID-19 pandemic, Kumar told Down To Earth on June 9, 2020.

Kumar conducted a study in association with the Gujarat Biotechnology Research Centre (GBRC) and the Gujarat Pollution Control Board (GPCB). Wastewater samples collected from Ahmedabad’s civil hospital on May 8 and May 27 formed the basis of Kumar’s research.

The study found a marked difference in the SARS-CoV-2 gene loading between the days the samples were collected. “Monitoring sewage treatment plants is optimal. We can tell in advance whether the situation will worsen or become better much before test results are out,” he said.

Testing huge populations for the virus is next to impossible, said Kumar, adding WBE can give early warning in this case.

Current testing methods were not enough to determine the exact situation concerning the SARS-CoV-2 infection in India as symptoms take three to 15 days to appear, according to Kumar.

This is where WBE — based on the detection of coronavirus genetic material in the sewage — can help.

It was not about the detection live SARS-CoV-2 samples in wastewater, according to Kumar.

It was, instead, about detecting genetic material (ribonucleic acid) through Real-Time Quantitative Polymerisation Chain Reaction (RTqPCR) followed by gene sequencing and matching with a library of coronavirused.

“We can extrapolate the results of this genetic material estimation to assign it with a probable number of people infected in a given locality or community,” Kumar added.

This is the first time an Indian scientist has made a claim like this. Earlier reports of this had emerged from different parts of the world, at the beginning of the pandemic.

Reported molecular detection from SARS-COV-2 from different countries

Country

State / City Water Type Detection Result ( positive results in samples in percentage)
Australia Brisbane, Queensland Untreated wastewater 22
The Netherlands Amsterdam, The Hague, Utrecht, Apeldoorn, Amersfoort, Schiphol, Tilburg Untreated wastewater 58
USA Massachusets Untreated wastewater 71
France Paris

Untreated wastewater

Treated wastewater

100

 

75

USA Bozeman, Montana Untreated wastewater 100

Source: Kumar, M. 2020. Propensity of SARS-CoV-2 Migration to Aquatic Environment and Wastewater Based Surveillance. National Technology Day lecture

In April 2020, the city water authority of France capital Paris, claimed miniscule traces of the SARS-COV-2 virus that causes COVID-19, were found in non-potable water supply.

During the same time, Biobot Analytics, a biotech startup, along with a team from the Massachusetts Institute of Technology (MIT) and Brigham and Women’s Hospital estimated at least 440 people were likely infected with COVID-19 in the area around the treatment facility, much higher than the reported cases.

SARS-CoV-2 may be present in the water cycle, with the poor and marginalised being more prone to health risks, leaving rural and impoverished communities vulnerable, said an editorial published on April 2, 2020 in journal Environmental Science: Water Research and Technology.

Kumar said reports of the presence of molecular SARS-CoV-2 had emerged from countries struggling to curb the pandemic.

Questions arise over whether the pandemic can spread through wastewater. Till date, there is no concrete evidence to prove this.

A paper published in Nature Medicine in February pointed out the potential shedding of the virus from the gastrointestinal tract well after nasopharyngeal swabs turned negative.

The study was carried out on paediatric patients. The research concluded on the possibility of faecal-oral transmission.

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