By Shakoor Rather :
The study, led by scientists in IIT-Gandhinagar, found that increased ‘gene copies’ of the virus in Ahmedabad’s wastewater matched the incidence of the disease in the city With this India joins the ranks of a handful of countries doing water-based epidemiology on COVID-19
SCIENTISTS in India have for the first time detected genetic material of the SARS-CoV-2 virus in waste water, a breakthrough that paves the way for using waste water-based epidemiology (WBE) for real-time surveillance of COVID-19 in the country. The study, led by scientists in IIT-Gandhinagar, found that increased “gene copies” of the virus in Ahmedabad’s wastewater matched the incidence of the disease in the city. With this, India “joins the ranks of a handful of countries doing WBE on COVID-19”, Andrew Singer, an environmental microbiologist at the UK Centre for Ecology & Hydrology, said on Twitter.
WBE is a promising approach to understand the status of disease outbreak in a certain catchment by monitoring viral load in wastewater. Recent studies had reported that the novel coronavirus (SARS-CoV-2) is present in the faeces of infected individuals. Genetic material (RNA) from the virus has been found in sewage entering treatment plants. Because treatment plants collect wastewater across large regions, measuring the level of RNA in untreated wastewater may provide a valuable insight into the percentage of people infected within a region, the researchers said. In the latest study released on June 18, scientists from the Indian Institute of Technology (IIT) in Gandhinagar collaborated with the Gujarat Biotechnology Research Centre (GBRC) and the Gujarat Pollution Control Board (GPCB).
They studied samples of wastewater collected on May 8 and May 27 from the Old Pirana Waste Water Treatment Plant (WWTP) in Ahmedabad. The plant receives up to 106 million litres per day (MLD) of influent from the Ahmedabad Civil Hospital which is treating COVID-19 patients, explained Manish Kumar of the Discipline of Earth Sciences, IITGN, who led the research effort. All the three SARS-CoV-2 genes -- ORF1ab, N and S -- were found in the wastewater coming into the treatment plant, said the researchers, who have submitted their study for publication in the international journal ‘Science of the Total Environment’. They noted that no gene was spotted in the effluent leaving the plant after treatment. The scientists said the gene copy loading - the quantity of the genetic material of the virus - detected on May 27 was almost 10 times more than that detected on May 8. This corresponded broadly with the trajectory of the incidence of the disease.
The number of active COVID-19 patients in the Ahmedabad city was two times higher on May 27 than on May 8, they said. According to the scientists, WBE was an effective tool during outbreaks of other viruses such as poliovirus and hepatitis A. The Ahmedabad study aims at assisting concerned authorities and policymakers to formulate or upgrade COVID-19 surveillance to have an explicit picture of the phase of the pandemic, the researchers added. Kumar cited reports to say a WBE study has indicated the presence of the coronavirus in Italy in December 2019, way before the first confirmed case in the country. “Developing an advanced surveillance system for environmental samples using biotechnological approaches is the need of the hour.
This can help us track real time situations not only for the current pandemic but also for seasonal epidemics,” Madhvi Joshi, joint director of GBRC and one of the authors of the paper, told PTI. According to the researchers, the number of gene copies was found comparable to that reported in the untreated wastewaters of Australia, China and Turkey, and lower than that of the US, France and Spain.