DETAILS of Ouyen's unexpected COVID infection case were not yet clear on Friday, but the town's only supermarket, which closed for deep cleaning, is at the centre of concerns.

Whether the infected person is a staff member or was a customer at the supermarket has not been revealed, and management at Jason's IGA was unavailable for comment.

The supermarket had not been listed as as a tier 1 exposure site late on Friday.

The Ouyen case is understood to have been one of the factors that influenced the extension of the Mildura LGA's lockdown, as it demonstrated that the virus had not been contained to the northern part of the municipal area.

Ouyen shoppers, unable to travel to Mildura while under lockdown on Friday, were looking elsewhere for goods, buying milk and bread from local service stations, although some people who travelled from more remote areas for a larger shop were the most inconvenienced.

One Manangatang woman, who asked not to be identified, said she would "have to make do with what I've got for the week".

Outside the store, Greg Symes, another would-be shopper, said the identification of a case in the town of about 1000 people "worries me".

"We've been pretty good so far, but I was talking to a few friends of mine and we thought it would be just a matter of time before it got from Mildura down to here," he said.

Mr Symes said he thought the town had coped "pretty good" with lockdown restrictions, despite the closure of community facilities.

"We're a pretty close community here and people ring each other up just to make sure everybody's all right.

He was hopeful the supermarket would not be closed long as "we would be lost without it".

Another Ouyen man, Anthony Nihill, said the supermarket's closure had "caught me off guard", but he was more concerned for the health of the infected person than any shopping inconvenience.

"I just hope they get better," he said.

Mr Nihill said he hoped Ouyen people would protect themselves by continuing to "do the right thing" in wearing masks.