COVID-19 testing in the coming days will determine if the Swan Hill local government area is plunged into lockdown.

Health authorities believe the Mildura outbreak seeped into the neighbouring LGA this week, with 13 active cases reported in the past three days.

There were long queues at the Swan Hill drive-through COVID-19 testing clinic on Wednesday after eight positive cases were detected.

Swan Hill Primary School underwent a deep clean after a COVID positive case visited the facility, with close contacts notified, while a hairdressing salon in Swan Hill was exposed earlier this month.

Clikk Hair Design by Stacey, at 137 Campbell Street, was listed as Tier 1 exposure site, for between 10am and 4.30pm on October 4.

Anyone who has visited the location during the exposure times must get tested immediately and quarantine for 14 days from the time of exposure.

Victoria recorded a new record high of 2297 cases yesterday, with 11 deaths.

Swan Hill District Health (SHDH) chief executive officer Peter Abraham revealed of the nine cases reported on Tuesday and Wednesday, just one case had at least one vaccine dose.

"Vaccinations work - they're safe and available," he said.

"It doesn't mean you won't get the virus, but means we won't need to see you in hospital.

"Why wouldn't you get it when you see what's happening in the community right now?"

Mr Abraham said the community should be on alert because "we know what COVID can do and we know how the Delta variant can spread".

"Everyone should be wearing a mask above the nose and always following the restrictions," he said.

"What we are seeing right now ... case numbers are not growing significantly, but we did 350 tests on Wednesday, so what we expect - but hope is not the case - is COVID is out there in the community, potentially in schools.

"We will get a good indication tomorrow, so the community should be concerned."

Mr Abraham urged anyone who was yet to be vaccinated to do so as soon as possible at one of the six vaccination providers in the rural city.

He said the outbreak was between less than five households who were all isolating at home, with the support of SHDH's at-home care and other government agencies.

"One of the cases was transferred out of home because they were feeling unwell, which just shows how rapidly COVID can catch your breath," Mr Abraham said.

"We also had a COVID positive unknown to us, which is why the community should be on alert.

"In the past 24 hours we had episodes where one COVID positive person came into the health service for unrelated care.

"It was only through our good management and staff being in full PPE gear in the ED that we were able to manage that case appropriately because of the planning done."

Mr Abraham said another scare occurred when a person walked into a health service who was a close contact of a positive case.

"That plays out in the general community, of people walking around who are well with COVID," he said.

"Water testing tells us that because it's pinging stronger and stronger with traces of COVID."

Mr Abraham said this week's scare was a test for SHDH.

"I'm really proud of how we managed it - we have battle scars from it, but overall the community should be confident this health service can manage critical situations," he said.

Mr Abraham said the coming days were "important to us", as to whether the situation gets under control or the community becomes at risk.

"What I would say is, yes, the community should be concerned, should be aware of what's happening in Mildura, what's happening in Melbourne and Shepparton," he said.

Swan Hill Council Mayor Bill Moar said council was providing assistance.

"With a number of residents likely to be isolating at home in coming days, council and a number of local and state agencies will be providing assistance to those isolating, as a result of confirmed exposure," he said.

"To contain the spread of cases, it is important to be tested if you have been notified as a result of a potential exposure, or have any symptoms." *breakout*

- Why does it take so long for exposure sites to be listed?

COVID-19 Commander Jeroen Weimar: "We identify exposure sites based on the contact tracing interviews we do with positive cases.

"It's quite common to list exposure sites a week or longer after exposure if we've only just identified the case ... a lot of it depends on when the positive case came forward for testing.

"The longer they delay, the longer everything else gets delayed."- Why aren't there more exposure sites?

COVID-19 Commander Jeroen Weimar: "The public health team are being far more forensic and targeted with exposure sites and are no longer announcing Tier 2 sites.

"They carefully assess each site a COVID-positive person has been to when deciding whether or not to make it an exposure site.

"Factors can include whether people are checking in, wearing masks and socially distancing.

"Just because the sites aren't being published doesn't mean the teams aren't looking at them. We certainly are."