Ashcroft's IGA owner Ben Ashcroft reported on Friday of 70 per cent of his staff being off work, mostly "school kids caught up as close contacts" amid the concerning situation.

The outbreak reached 234 cases at Dubbo to 8pm Sunday, with about 45 per cent of cases aged under 20, health authorities said on Monday.

The IGA store in Tamworth Street has been identified as a venue of concern on several occasions, one of more than 80 at Dubbo.

"We had a few exposures so have a few staff off for that reason also," Mr Ashcroft said.

The retailer took the decision from Wednesday August 18 to close the store one hour early each day until further notice, a temporary reduction in trading hours also seen at other supermarkets across the city last week.

Mr Ashcroft told the Daily Liberal the earlier closing time was so they could fill the shop's shelves again, and offered assurances to the community about safety.

"Still to this day COVID has not been transferred in a supermarket, we keep our interactions fast and sanitising well above a high standard and deep cleans regularly," he said.

The independent grocer urged customers to "wear a mask, sign in, use sanitiser and stay safe".

"Our staff are doing a sensational job and I've never been so proud of all the team here on the front line," he said.

"Ninety-nine-point-nine per cent of our customers have also been incredible and very understanding.

"It's great to see the community rally together and get through what has been something we were not used to dealing with being out here in the country and felt safer than the city but it is all very real now."

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