Sewage surveillance finds zero positivity in Bengaluru in last five weeks

TAC has also recommended starting sewage surveillance in major cities of Hubballi-Dharwad, Kalaburagi, Mysuru, Mangaluru, and Belagavi

Samples of waste water for the sewage surveillance were collected from the Bengaluru airport, two major hospitals, and apartment complexes in 15 locations of 12 wards. 

Sewage surveillance that is being conducted in Bengaluru city by the Infectious Diseases Research Foundation (IDRF) since this June has found zero positivity of SARS-CoV-2 in the last five weeks.

Based on the State’s COVID-19 technical Advisory Committee (TAC) recommendations, IDRF conducted waste water surveillance in the city and from June to December 17, 627 samples were tested, of which only 211 (33%) were positive for the virus.

TAC chairman M.K. Sudarshan told The Hindu after the committee’s meeting with Chief Minister Basvaraj Bommai on Thursday that the virus has not ben detected from waste water in any site tested in the last five weeks.

“Presently the incidence of COVID-19 is at its lowest ebb in the State and the mortality rate is also very low in recent months. The situation is under good control. In the last two days, no COVID-19 patient has been hospitalised in Bengaluru. Moreover, on Wednesday no district in Karnataka reported any positive case, except Bengaluru where 18 cases have tested positive,” Dr. Sudarshan said.

“According to IDRF’s 28th weekly report received on December 17, SARS-CoV-2 was not detected in waste water samples (0% positivity) from those collected from December 9 to December 15, 2022. More so, the virus has not been detected from waste water in any site tested in the last five weeks. Samples have been collected from the airport, two major hospitals, and apartment complexes in 15 locations of 12 wards in the city and the airport. The daily average cases reported from all the wards is <=1 case for this time period, suggesting an overall decrease in SARS-CoV-2 circulation,” Dr. Sudarshan said.

“As the SARS-CoV-2 situation can change quite fast, based on multiple epidemiological factors including new variants with higher propensity for immune escape, it is recommended to continue sewage surveillance in Bengaluru city more cautiously and intensively by IDRF. Additionally, sewage surveillance at Mangaluru airport should also begin. TAC has also recommended starting sewage surveillance in major cities of Hubballi-Dharwad, Kalaburagi, Mysuru, Mangaluru, and Belagavi,” the TAC chairman added.