Melbourne hospital outbreak threatens Victoria's reopening as new cases emerge

Melbourne is staring down the very real possibility of an extended lockdown, as Victorian health authorities are scrambling to contain an outbreak at a hospital in the city's east.

A patient and two staff members at Box Hill Hospital have tested positive to the virus, which is believed to be contained to just one ward.

But authorities are unsure of how the outbreak began.

All appropriate health protocols are being taken to contain the spread.

"Investigations are continuing into an outbreak at Box Hill Hospital, which includes two staff members and one patient," a Department of Health and Human Services statement read.

"The contact tracing process is underway and all appropriate public health actions are being undertaken, including cleaning, testing and quarantining."

More staff are expected to go into quarantine in the coming days, to contain the outbreak.

The hospital outbreak is threatening to put a break on Victoria's road map out of recovery, which is due to ease in 10 days.

Premier Daniel Andrews has moved to lower expectations amid the fresh outbreak.

"I think it is highly unlikely that nothing will change," he said.

"There will be some changes, the exact nature of those we will need to look at."