COVID tracking breakthrough could end mass lockdowns

LOCKING down an entire city or state might not be needed, promising new research on tracking coronavirus in sewage shows.

Brisbane scientists have shown virus traces can be found by sampling toilets on long haul flights and on cruise ships.

The technique could also be used to identify outbreaks, by postcode, simply by testing at key points in the sewage system.

University of Queensland and CSIRO scientists who have been tracking RNA (the virus' genetic material) at Luggage Point wastewater plant also said there was now no detectable RNA in the wastewater.

"We did a proof of concept study about a month ago on cruise ships and three long haul airline flights,'' CSIRO Land and Water science director Paul Bertsch said.

"You would have to modify the toilets on planes, because they have their own treatment system, but this study shows it can work.

"We could also do this by postcode if we went further up the pipes to sample.

"The advantage of that is it would narrow a positive sample down.

"The situation in Victoria shows the importance of being able to do this in future.''

Dr Bertsch said while testing could be done by sending a human down a manhole into the sewer system, a US company called Biobot had already developed robots which could automate the collection process.

He said the Singaporean Government was finetuning its testing, conducting sampling at individual dormitories used to house foreign workers.

The dormitories had been the source of Singapore's second wave of coronavirus cases.

Testing could also be done at the level of individual aged care homes or prisons.

"It's a lot more cost effective than current testing methods. You could monitor 2.5 billion people by sampling only about 100,000 wastewater systems,'' Dr Bertsch said.

A major focus of research by about 50 scientists in Brisbane and overseas was on improving the sensitivity, or accuracy, of sampling methods.

New techniques used by UQ/CSIRO could now recover up to 67 per cent of virus fragments in samples, double what they had previously achieved.

Data from around the world was also improving estimates of how much virus infected people "shed'' in faeces, and when they shed the virus.

It appeared more virus fragments were shed into faeces in the first few days after infection, before any severe symptoms appeared, but shedding continued for days after a patient recovered.

Singaporean scientists had also discovered testing of sewage plants needed to be done only in the morning, which translated to large cost savings.

Originally published as COVID tracking breakthrough could end mass lockdowns