Scientists in India have for the first time detected genetic material of the SARS-CoV-2 virus in wastewater, a breakthrough that paves the way for using wastewater-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.
What
  1. WBE is a promising approach to understand the status of disease outbreak in a certain catchment by monitoring viral load in wastewater.
  2. 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.
  3. 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.
  4. 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). 
  5. They studied samples of wastewater collected on May 8 and May 27 from the Old Pirana Waste Water Treatment Plant (WWTP) in Ahmedabad.
  6. All the three SARS-CoV-2 genesORF1ab, 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.
  7. 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.
  8. According to the scientists, WBE was an effective tool during outbreaks of other viruses such such as poliovirus and hepatitis A.
  9. 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.
  10. WBE study has indicated the presence of the coronavirus in Italy in December 2019, way before the first confirmed case in the country.
  11. Developing an advanced surveillance system for environmental samples using biotechnological approaches is the need of the hour. 
  12. 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.
  13. Estimates based on European and North American data suggest that each person infected with SARS-CoV-2 will excrete millions if not billions of viral genomes into wastewater per day.
  14. While infectivity of SARS-CoV-2 through wastewater has not yet been reported, the virus potentially enters the wastewater stream from patient excretions and thus can be a great tool for pandemic monitoring.
  15. Using reverse transcription PCR (RT-qPCR)–a laboratory technique of molecular biology–researchers should be able to detect the novel coronavirus with high sensitivity.
  16. This report will surely facilitate a nationwide initiative for detecting the early warning signals of COVID-19 outbreaks in various communities.