With COVID cases and hospitalisation on a slight uptick, TAC recommends standardisation of sewage surveillance methods 

Sewage surveillance is known to help in early identification of any impending wave of COVID-19 and notifying the emergence of new variants of SARS-CoV 2, if any, to initiate local public health actions

With a slight uptick in COVID cases and hospitalisations in Bengaluru, the State’s COVID-19 Technical Advisory Committee (TAC) has recommended a standardisation of sewage surveillance methods adopted by the multiple agencies involved in the surveillance.  It has also recommended bringing all agencies involved in sewage surveillance under one umbrella.

Sewage surveillance is known to help in early identification of any impending wave of COVID-19 and notifying the emergence of new variants of SARS-CoV 2, if any, to initiate local public health actions. Multiple agencies - Precision Health, National Institute of Virology (NIV), Benagluru, IDRF, TIGS, - have been involved in sewage surveillance in Karnataka for the last one year.  

Up to 40% of the cases are known to be pre-symptomatic and asymptomatic who secrete and excrete the virus that goes into the sewage and is expected to be picked up by the surveillance. However, the results of the surveillance done by different agencies are varying in Bengaluru. 

While there has been no presence of SARS-CoV-2 in the sewage samples that were tested by Infectious Disease Research Foundation (the agency working with the health department) in Bengaluru city and Bengaluru International airport in the last four weeks, surveillance done by another agency - Tata Institute of Genetics and Society (TIGS) has shown a consistently high positivity rate for SARS-CoV-2 in the wastewater for weeks including in the last one week (March 6 to March 11).

In this context the TAC that met on Sunday has recommended bringing all agencies involved in sewage surveillance under one umbrella. “The test positivity rate is on the rise while there is a fluctuation in daily testing numbers. Sewage surveillance assumes importance in this context. As the various agencies doing sewage surveillance are using different methods, TAC recommends that this needs to be standardised,” stated the TAC’s report.

“The agencies should adopt uniform testing procedures and the State Health Department should demarcate areas for testing by various agencies in Bengaluru in coordination with the BBMP. This is to avoid any overlap or duplication. Besides, it is recommended that all the agencies should report the surveillance data to a single nodal authority in the State and BBMP,” the report said.

The TAC that also reviewed Influenza data from ICMR approved laboratories pointed out that Influenza H3N2 is the predominant sub-type among the samples testing positive for Influenza in India (according to data shared by the Union Health Ministry) since the beginning of this year.