AS of yesterday at 3pm there were 27 confirmed cases of COVID-19 in Victoria, none of them in northern Victoria according to a statement made by Victoria's chief health officer, Professor Brett Sutton.

Kerang District Health director of clinical services Kelly Byron-Gray said on Thursday Victoria had so far done very well in managing the spread of the virus.

"We don't have any transmission in our areas that we know of at this time," she said.

"We're very fortunate that we live in the country with wide open spaces and fresh air and are not an overpopulated area, like in the city."

However, Ms Byron-Gray said the situation was a fast-changing one that health services are adapting to.

Although it is likely that more cases of the disease will be identified in coming weeks, health services are emphasising the need for calm.

Ms Byron-Gray said a suspected COVID-19 case at Swan Hill, which saw a patient air-lifted to the Alfred Hospital in Melbourne on Monday, had not been confirmed as COVID-19.

Swan Hill District Health (SHDH) chief executive officer Peter Abraham told Swan Hill newspaper The Guardian this week, the patient was not the only one in Swan Hill to present with symptoms.

"That case did have some signs and symptoms of infection, and ... it is better to be cautious than not," Mr Abraham said.

"That one was heightened because you see ambulances and you see a lot of people around in hazmat (hazardous material) suits, but we have a number of patients who have presented and are self-isolating."

Ms Byron-Gray said results from swab tests for the virus can take some time to be returned in country areas and warned against confusing medical precautions with confirmation of the virus.

"If people get tested it might be because they have travelled and might have some symptoms, but they might end up negative," she said.

"What we're preparing for is if we do end up with a positive case.

"In the meantime the most important thing is that the community is well informed ... so there's no hysteria out there about how this is being handled because I think we're handling it very well."

The authoritative source of information about COVID-19 is the Department of Health and Human Services website at dhhs.vic.gov.au/coronavirus.

There is also a Victorian Coronavirus Hotline - 1800 675 398 - which people are asked to call only if they suspect they have the virus.

Information is also available from the Nurse-On-Call Hotline - 1300 60 60 24.

On Wednesday, Kerang District Health sent out letters to the families of aged care residents and put up signage advising against visiting when ill.

"They were just to reassure families that residents are being well cared for, that we have plans in place and no-one should visit if unwell," Ms Byron-Gray said.

"Ideally no-one should visit an aged care facility or hospital if they're unwell, whether it's with coronavirus, another respiratory disorder, gastro or anything else."

"We consider an ageing population a vulnerable population because they can have a lot of underlying chronic conditions and may be on medications that suppress their immune system so it puts them at greater risk of developing infections.

"However, a lot of people who contract the virus currently are not unwell with it and are able to manage the condition at home while self-isolating."

Australia's chief medical officer Brian Murphy told the media this week, "For most people who get this virus, it's a very mild illness."

The criteria for COVID-19 testing includes fever or acute respiratory infection (for example, shortness of breath or cough) with or without fever, international travel in the 14 days before the onset of illness or close or casual contact with a confirmed case of COVID-19 in the 14 days before illness onset.

Anyone who believes they may have the virus is asked to phone ahead before attending a health service.

Ms Byron-Gray said district health services were communicating well and working together to prepare for worst-case scenarios.

She said it was important for residents to stay calm but alert, self-isolate when directed to do so and follow travel and health advice from the Department of Health and Human Services and the Smartraveller websites.