It comes as the western area health chief confirmed for the first time, the origin of the region's COVID outbreak was from a couple who travelled from Western Sydney.

"We believe we've tracked that down to a location in Western Sydney that has the same strain of COVID-19 and biological markers, so we do believe that we've picked up the originating case that was in a couple that were in Western Sydney, and came back into our region," Western NSW LHD Chief Executive Scott McLachlan told media in Thursday's COVID update.

He declined to give further information on specifics, saying the spread of the virus beyond the Blue Mountains was inevitable.

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"I can't give you details on exactly who it was, I don't think that's fair to the person.

"We know that there's been people moving in and out of our region, honestly I think it was just a matter of time."

Up to 8pm Wednesday, the total number of cases in Dubbo was 506, with 655 across the entire Western NSW Local Health District.

Deputy Premier John Barilaro referred to Dubbo as the "heart and centre" of the virus in regional and remote NSW, while the Member for Dubbo Dugald Saunders said it's a simple reality of the virus outbreak.

"There's no doubt that getting over 500 feels like a milestone figure for all the wrong reasons," he said. "It doesn't necessarily change the response...this is really the heartbeat of where the cases in our Western Region emanated from, and this will continue to be the main problem at the moment."

Mr Saunders said the message remains the same - get tested and get vaccinated.

Testing numbers on Wednesday improved but are still nowhere near what authorities would like to see. The total number of tests in Dubbo on was 2,400 and 4,800 across the western region. The health authority would like to see around 10,000 for the region per day.

"The reality is, we keep asking for the same scenario and that is for people to get tested and for more people to get vaccinated," he said.

"Numbers will continue to emulate what they have been at for the past few days, every day, we're somewhere between 20 and 50 in Dubbo, that's probably likely to continue.

"At some point what we need to see is a bit of a plateau and then a reversal of that along with vaccination rates rising."

The community has been responding to vaccination calls.

Fifteen thousand (15,000) people have so far been vaccinated through the ADF pop-up hubs across the western region.

Eighty per cent of the region's 8,000 healthcare workers have received at least one dose of a vaccine. The NSW Government has mandated they won't be able to work unless they have had one dose by September 30 and are fully vaccinated by the end of November.

Residents are urged to keep track of the growing list of venues of concern. The Dubbo Regional Livestock Markets was closed on Thursday for a deep clean after a person working there tested positive on Thursday, August 26.

A Dubbo Regional Council spokesperson said the site was now a venue of concern for anyone who attended the cattle sale on that date.

"Any person that attended the cattle sale...and intends to attend the Prime Cattle Sale on Saturday 4 September will be required to show proof of a negative test result at the entry gate," the spokesperson said. "If you are unable to provide proof you will not be permitted entry."

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