NO S--T: How testing our sewage helped expand border bubble
TESTING for coronavirus in five sewerage plants in northern NSW may have influenced the Queensland Government's decision to expand the border bubble.
Queensland's Chief Health Officer Jeannette Young said she had kept a close eye on the number of COVID-19 cases in northern NSW.
At 1am on Thursday, five local government areas were added to the NSW-Queensland border zone including Byron Shire, Ballina Shire, City of Lismore, Richmond Valley Council, Glen Innes and the postcodes: 2880, 2840, 2839, 2838, 2834, 2833, 2406, 2405, 2409, 2410, 2361, 2372, 2476, 2474, 2484, 2489, 2488, 2484 and 2486.
One of the ways Queensland's Chief Health Officer judged whether to open up the border bubble further revolved around what was being flushed down our toilets.
Ms Young revealed yesterday that testing in sewerage systems had been one way to track the virus.
"We know that one person in 10,000 in the community can be picked up through sewerage testing, so it is very sensitive," she told the ABC.
"Tests along the border have not found any trace since a Byron Bay outbreak [more than a month ago] so there is no virus in sewage there.
"So there are a whole lot of reasons we can now safely open up to northern NSW."
In a statement Queensland Health said results of sewage tests in communities on the Queensland side of the border zone had been "helpful" in informing decisions about border restrictions.
They had also monitored the results of wastewater tests by NSW Health.
Other factors considered when making such decisions included: the number of cases, source of infection, the general movement of people, connection to Queensland through work, recreation or regular access to services such as health and education, and location of key services for border towns on both sides of the border.
According to the Director of the North Coast Public Health Unit, Paul Corben, five sewerage plants in the Northern NSW Local Health District (NNSWLHD) had been participating in a sewage surveillance research program co-ordinated by NSW Health since late July.
The research program tests untreated sewage for fragments of the COVID-19
virus to provide data to support NSW Health's pandemic response.
The latest available results for the week commencing September 26 showed there was no detections of the COVID-19 virus at sites in the NNSWLHD.
There have been no confirmed COVID-19 cases in residents of northern NSW since July 25.
There has been no detection of the virus in sewage samples since the testing week commencing July 27.
"Detection of virus fragments in sewage can be due to shedding of the virus by
someone who may have previously had the illness, with the virus 'shedding' through
their system for up to four weeks after their recovery," Mr Corben said.
"A positive sewage result can also provide early warning of potential virus introduction
into areas where transmission is not expected or not thought to occur.
"As well as being present in stools, viral fragments can enter the sewer when washed
off hands and bodies through sinks and showers."
Usual sewage treatment processes inactivate, or kill, the COVID-19 virus, and
sewage discharge to the environment is regulated by the NSW EPA.