A man who visited Victoria from NSW after visiting a country with the Omicron COVID-19 variant does not have the new virus strain.
"The case does not have the Omicron variant. The Department of Health will provide new advice to relevant identified contacts of this case," the department confirmed in a statement on Monday night.
The state recorded another 1007 new COVID-19 infections and three deaths on Monday.
In the chief health officer's daily release, the department confirmed they interviewed a person from NSW who had been to one of nine countries of concern and then visited Victoria.
That person has since returned to NSW and tested positive for COVID-19.
The case was "infectious and asymptomatic", as well as fully vaccinated, when they travelled to Victoria.
The health department is sending text messages or Service Victoria app alerts to anyone who may have come into contact with the case.
People of lower risk have been instructed to get a test and isolate until they receive a negative result.
"The Department of Health is taking a conservative approach to the designation of this individual's close contacts," the CHO statement said.
"Further contact tracing work is ongoing and is likely to produce more contacts."
It comes after changes to quarantine were brought in over the weekend, requiring all international arrivals to Victoria to isolate at home for 72 hours.
New arrivals who have recently been in Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa, the Seychelles or Zimbabwe must now quarantine in a hotel for 14 days.
Key questions about Omicron's transmissibility, whether it results in milder or more serious illness and the effectiveness of vaccines are yet to be answered.
Meanwhile, the health department said 19 COVID infections have been linked to recent protests in Melbourne.
Of these cases, one person is currently in hospital, 16 are unvaccinated, two are partially vaccinated, and one is fully vaccinated.
One case attended a social gathering, which led to another outbreak with 10 confirmed COVID-19 cases so far.
Victoria is now managing 11,501 active COVID-19 infections.
There are 300 COVID patients in the state's hospitals, 45 of them are actively infected with the virus in intensive care and 17 requiring ventilation.
Virus testers processed 48,397 results on Sunday, while 1813 people were vaccinated against COVID-19 in state-run hubs.
More than 90 per cent of Victorians aged over 12 are fully vaccinated.
Australian Associated Press
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