Sewage surveillance to support COVID-19 response

An Australia-wide initiative aims to integrate sewage testing results for SARS-CoV-2 with national COVID-19 health data to inform where the disease is present in the population.

Led by Water Research Australia (WaterRA) with the support of the Water Services Association of Australia (WSAA) the ColoSSoS Project — Collaboration on Sewage Surveillance of SARS-CoV-2 — will track and monitor the presence of the virus that causes COVID-19 and its persistence in the Australian sewerage network.

The collaborative effort will involve experts in health, microbiology, laboratory testing, wastewater-based epidemiology and policy communication across water utilities, health departments and researchers.

“Results from similar efforts in the Netherlands (and more recently in Australia) have shown that sewage analysis can potentially detect community spread of COVID-19, even before cases are found through the testing of individuals, which makes us confident of our project’s success,” Project Manager Dr Dan Deere said.

According to WaterRA CEO Karen Rouse, “The next step is for our project team and partners to develop and apply sensitive and robust methods that deliver results governments and the community can have confidence in.

“We have already started collecting and analysing sewage samples nationally and will be integrating these results with health data to help guide and optimise direct management of this COVID-19 pandemic, and ensure we are well prepared for future outbreaks.”

Dr Dan Deere said, “ColoSSoS aims to provide a powerful tool for decision-makers. The data it generates will potentially reveal cases in areas previously thought to be free from COVID-19; identify the extent of asymptomatic infections within communities; better characterise trends, peak infections and the persistence or re-emergence of disease; and verify whether COVID-19 has been eradicated in local populations.”

The immediate practical application of project findings could inform policy regarding tightening or loosening of disease control measures such as limits on gatherings and travel, and could enable effective targeting of investment and pandemic control efforts.

WaterRA is working with state and health authorities through the Environmental Health Standing Committee (enHealth) to ensure that project results can readily inform national COVID-19 control efforts.

Tracing SARS-CoV-2 in sewage

In a separate initiative, University of Queensland (UQ) and CSIRO researchers have achieved the first step in developing an early warning surveillance system to track COVID-19 prevalence in the community through tracing the presence of the novel coronavirus gene in raw sewage.

The researchers found RNA fragments of SARS-CoV-2 in Australian untreated wastewater samples from two wastewater treatment plants in South East Queensland, representing populations living in the Brisbane region. The RNA fragments would have been shed in the wastewater stream by people infected with COVID-19.

A paper outlining the proof of concept has been accepted for publication in Science of the Total Environment.

Director of UQ’s Queensland Alliance for Environmental Health Sciences, Professor Kevin Thomas said the validated method built on work by research groups in the Netherlands and the United States of America.

“This is a major development that enables surveillance of the spread of the virus through Australian communities,” Professor Thomas said.

CSIRO Chief Executive Dr Larry Marshall said the testing would help Australia manage COVID-19.

“The hope is eventually we will be able to not just detect the geographic regions where COVID-19 is present, but the approximate number of people infected — without testing every individual in a location.

“This will give the public a better sense of how well we are containing this pandemic,” Dr Marshall said.

CSIRO Land and Water Science Director Dr Paul Bertsch said the project showed Australia had the capability to deliver timely COVID-19 wastewater surveillance data to inform decisions, response actions and public communications.

“These data will be particularly useful for catchments with vulnerable populations where testing using other methods may not be feasible,” Dr Bertsch said.

“An early warning detection system like this would also be incredibly useful for monitoring and response in the recovery phase.”

Professor Thomas said the research used systematic sampling and analysis of wastewater for SARS-CoV-2 using a standardised, coordinated approach based on refined analytical methods.

“The wastewater samples were analysed for specific nucleic acid fragments of the virus using RT-PCR analysis, which is used to identify a gene fragment from SARS-CoV-2,” he said.

“The presence of SARS-CoV2 in specific wastewater samples was then confirmed using sequencing techniques.”

Image caption: Dr Warish Ahmed, CSIRO Land and Water.