City's Covid cases in 2022 were 4 times higher than reported: Study

The study has shown that genomic surveillance of wastewater can be used to predict Covid-19 outbreaks allowing them to be used as a warning system

Press Trust of India

Bengaluru: Infections from the Covid-19 virus were four times higher in Bengaluru than the number obtained via clinical tests, according to a joint study by Tata Institute for Genetics and Society (TIGS), National Centre for Biological Sciences (NCBS), and Biome Environmental Trust here.

The study titled “SARSCoV-2 infection dynamics and genomic surveillance to detect variants in wastewater – a longitudinal study in Bengaluru, India”, was published in The Lancet Regional Health – Southeast Asia.

The study has shown that genomic surveillance of wastewater can be used to predict Covid-19 outbreaks allowing them to be used as a warning system which also has the ability to identify new emerging virus variants. Scientists from the Tata Institute for Genetics and Society (TIGS), National Centre for Biological Sciences (NCBS), and Biome Environmental Trust in the study have disclosed that genomic surveillance of wastewater could effectively be used to understand Covid-19 trends.

It can also be used to make early detection of new viral emergencies, the study maintained. The study has been conducted on the basis of collecting wastewater samples once every week from 28 sewer sites spread across the city between January and June 2022.

The scientists have also made a comparative study of the SARS-CoV-2 virus obtained both from wastewater samples and through individuals affected by Covid-19, and found them to be correlated to each other. The outcomes of the sensitivity analysis taken up have suggested that the total number of infections caused by the virus is over four times higher than the number obtained through clinical tests.

“Genomic sequencing is the backbone of wastewater surveillance and needs to be done in real-time to understand the variants that cause the emerging viral load patterns in wastewater,” Dr Farah Ishtiaq, the scientist heading wastewater surveillance at TIGS and the study said in a statement.

The findings of the study have been shared with the city municipal body Bruhat Bengaluru Mahanagara Palike (BBMP) and Bangalore Water Supply and Sewerage Board (BWSSB) in order to help them make informed decisions while coming up with plans to curb the spread of the virus.