How testing sewage could help map Canberra's COVID-19 spread

Experts in public health at the Australian National University will begin testing sewage in the coming week.

ANU National Centre for Epidemiology and Population Health Fellow and lecturer Dr Aparna Lal said a recent study in the Netherlands found the virus could be detected in the sewerage system even when the number of positive cases was very low, and before they had been picked up by the health system.

"It means we can monitor the circulation of the virus in the community and use it as an early warning tool of increased circulation," Dr Lal said.

"At this stage in Canberra we appear to have no community transmission but it might be an artefact of just testing people who have returned from overseas or been in contact with a confirmed case.

"This novel method will provide us with possible community transmission and load of the virus in the population.

"It can be used as an additional tool when case numbers have really declined, to ensure us there is not a high level of undetected coronavirus."

The team from ANU will work with Icon Water to sample sewage at the intake point for the Lower Molonglo sewage treatment plant for at least the next 12 months.

Wastewater is already used to look at antibiotic use and opioid use in the community.

"The method itself is an established one, it's just novel we're going to be using it to detect and monitor the virus in the population over time. This is really exciting for Canberra," Dr Lal said.

Infectious diseases expert Peter Collignon is part of the team working on the project. He said this testing method has the potential to give an early warning sign to stop the spread of COVID-19.

"It's still research at the moment but if we want a warning in the community that things are either under control or going out of control, this is one of the better ways of looking for an early warning sign," professor Collignon said.

"It's the one thing that samples the whole population.

"Sewage is an under-tapped resource tool for public health. It tells you what is actually happening in the community if you pick the right things to measure."

ANU Dean of the College of Health and Medicine Russell Gruen said the university had been developing models and plans and giving advice to the ACT and federal governments as to what an "exit strategy" from social distancing measure might look like, and what the triggers would be to implement that.

"We've got ourselves in a strong containment mode now, we're looking at when and how do we come out of that," professor Gruen said.

"It will end, we will make an active decision at some point to lighten the restrictions. It's got to be the right time and a safe time but we know we can monitor the virus in the community."

Our COVID-19 news articles relating to public health and safety are free for anyone to access. However, we depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support. If you're looking to stay up to date on COVID-19, you can also sign up for our twice-daily digest here.