Western Australia’s COVID-19 wastewater surveillance program has responded to the recently reported community cases of COVID-19 in Perth with additional sampling in locations in metropolitan Perth.
The extra sites will be under surveillance for a two-week period.
Targeted surveillance locations have been identified based on the movements of the cases during their infectious periods.
Initial results from seven wastewater sub-catchment area sites have come back negative.
The catchment areas include sampling from suburbs including Canning Vale, Booragoon, Mount Pleasant, Applecross, Kardinya, Balcatta, Westminster, Joondanna, Madeley, Nollamara, Alexander Heights, Mirrabooka, Joondalup, Landsdale, Wangara, Banksia Grove, and Wanneroo.
The virus is not ‘alive’ in wastewater and presents no public health risk.
People can continue to shed the virus for several weeks after they recover from COVID-19, even when they are no longer infectious.
Wastewater testing may provide an early warning of undiagnosed COVID-19 in the community.
Specifically, samples may detect COVID-19 in the community from people that have not yet been tested or from people who are asymptomatic.
The wastewater testing program is a collaboration between the Department of Health, PathWest, the Water Corporation and WA Country Health Service.
Weekly testing has been ongoing since November 2020 at six of Perth’s wastewater treatment plants – Subiaco, Woodman Point, Alkimos, Beenyup, Gordon Road and Point Peron.
Testing is also carried out at 10 locations in regional WA in Albany, Broome, Bunbury, Busselton, Esperance, Geraldton, Kalgoorlie, Karratha, Northam and South Hedland.
In some cases, detection of viral fragments in wastewater may lead to more wastewater testing, or to increasing public health messaging such as asking community members to get tested for COVID-19 if they have even mild symptoms.
To date, wastewater testing in Western Australia has detected SARS-CoV-2 at the Subiaco Wastewater Treatment Plant that services the State-run quarantine hotels in the Perth central business district, which is an expected result.
The Department of Health has developed an online dashboard which shows the most recent wastewater testing results for the metropolitan and regional areas.
The dashboard can be accessed at https://ww2.health.wa.gov.au/Articles/A_E/Coronavirus/COVID19-wastewater-testing
As stated by Health Minister Roger Cook:
“Targeted wastewater surveillance in high-risk areas can provide additional information about COVID-19 in these locations and forms an important part of the State Government’s pandemic response.
“The addition of these locations visited by known confirmed cases means we are taking yet another step to stay ahead of the virus and it will give further insight into whether COVID-19 is present in the community.
“The early results from the new locations are encouraging but waste water testing is not a substitute for COVID-19 testing or for getting vaccinated when you are eligible.
“The new online dashboard is yet another way we are keeping the public informed.”