Victoria's Department of Health and Human Services (DHHS) has asked screening centres across the state to begin testing every fifth person who presents at the clinic, to get a clearer picture of how coronavirus is spreading through the regions.

Key points: One in every five patients presenting to health clinics across Victoria will be tested for coronavirus with positive cases spreading in regional areas

One in every five patients presenting to health clinics across Victoria will be tested for coronavirus with positive cases spreading in regional areas Until now, the focus has been on testing returned travellers and close contacts of returned travellers

Until now, the focus has been on testing returned travellers and close contacts of returned travellers The testing will identify people who are not yet symptomatic to show how the virus is spreading in local areas

Coronavirus is spreading rapidly through regional Victoria with 85 positive cases confirmed on Friday afternoon and potential hotspots building around Greater Geelong, Ballarat, and South Gippsland.

But because the current testing criteria only allows a small number of people to be tested, with a particular focus on returned travellers, a true picture of how the disease is spreading is not clear.

DHHS said in a statement that it had requested screening clinics across Victoria begin testing one in five people who presented at their clinics on top of testing those who met the criteria.

"This will give us a better picture of whether COVID-19 is circulating more broadly in the community," the statement said.

"To date it has been identified in returned travellers or close contacts of returned travellers."

Bendigo Health's COVID-19 screening clinic at Bendigo Hospital. ( Supplied: Bendigo Health )

Bendigo hospital first to test

Bendigo hospital in Central Victoria was one of the first regional clinics to implement the expanded testing regime.

So far only two people have tested positive at the hospital's clinic, and CEO Peter Faulkner hoped the expanded testing would give them a clearer picture of how the disease was spreading locally.

"We've commenced a program of testing every fifth presentation to our screening clinic in an effort to identify COVID-19 that may not yet be symptomatic, and to try and identify what the prevalence is across our community generally," he said.

Professor Bill Bowtell from the Kirby Institute for Infection and Immunity said gathering more detailed localised data was a big step forward.

"It's interesting to have the national figures and even the state figures, but it's town by town and city by city that gives us the best chance to see this thing off with the least disruption and the least illness or death," he said.

"Where [towns] say, 'Well we've got this many people, let's move swiftly so the cluster doesn't get into our community', those places really record tremendous results."

Mr Bowtell said randomised testing worked similarly to opinion polling.

"If you look at a sample size of, say, 500 or so, that will give you a pretty good indication of what's happening in the broader community around Bendigo," he said.

"And as you would expect if you get facts and figures, that really really helps."

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Ballarat to start Monday

A number of other regional hospitals, including in Wangaratta, Albury Wodonga and Swan Hill, have also begun testing every fifth person who presents at their clinics.

Ballarat Hospital will begin the expanded testing regime at a new clinic from Monday.

But despite the request from DHHS, other hospitals have not expanding testing — including Warrnambool and Shepparton.

Mr Bowtell said regional communities that did not gather more detailed local data would not be able to effectively ward off the virus.

"It's the strength of the local community and the decisions they make that really do dictate whether the outcome is good or bad," he said.

"It also doesn't became a matter of opinion between all different sorts of people; it becomes a fact and a figure and evidence.

"And that's what we need more than anything, at a local level, if we're to get on top of this virus."

Bendigo Health CEO Peter Faulkner warned people that even if they did not get tested, if they had symptoms they should still self-isolate.

"You should in fact be assuming you may have the disease, and you should be taking all of those social isolation processes and procedures."