Border Force offices at Melbourne Airport were also undergoing a deep clean after a cleaner tested positive on Saturday.
Many of Monday’s 75 cases were picked up in the door-to-door testing blitz targeting Melbourne’s 10 “hotspot suburbs”, with a lot of outbreaks occurring at work and gatherings affecting multiple households.
Professor Sutton said: “I think it’ll get worse before it gets better. It is a concerning number, but it’s very hard to make predictions in this space.”
The hotspot suburbs are Maidstone, Albanvale, Sunshine West, Hallam, Brunswick West, Fawkner, Reservoir, Pakenham, Keilor Downs and Broadmeadows.
Professor Sutton said further conversations about lockdowns would be held over the next couple of days.
“We don’t want to drive people out of suburban areas, into new, unaffected areas, so there’s a balancing act in terms of making the call on a lockdown,” he said.
“It would be a significant logistical exercise to manage stay-at-home that’s just about particular postcodes, particular suburbs or local government areas. But it is absolutely an option and we flagged the possibility of using it and we will use it if it is required.”
Professor Sutton said the most recent cases had been transmitted five or six days ago and more time was needed to see if people had responded to the communication blitz about the need to be tested and stay home if sick.
“That has to be the focus,” he said.
“We absolutely want people to get the message that if they have symptoms, they shouldn’t be going and visiting other people, they shouldn’t be going out to any other setting, including work, because that is where we are seeing transmission at the moment.”
Professor Sutton said he was still considering whether masks should be recommended in hotspot suburbs, particularly in enclosed spaces where it was difficult to keep a distance from other people.
But he said he didn’t think wearing masks would have made much difference in recent cases, as most occurred when people visited extended family in different households.
“People don’t wear masks to see extended family members, they wear masks when they’re going out in public places but if it’s got a role that can add some value in terms of reducing transmission in crowded places, I’m all for it.”
However, national Deputy Chief Medical Officer Nick Coatsworth said medical officials were considering whether to recommend people in Melbourne wear masks in public.
The nation’s expert health committee considers its position on masks every week. “But certainly, if there is a place where we are looking to see whether masks should be recommended, it’s down in Victoria.”
Professor Mary-Louise McLaws, epidemiologist and disease control expert at the UNSW and a member of the World Health Organisation COVID-19 experts advisory panel, said it was time authorities accepted masks were a necessity for people living in hotspots.
Professor McLaws characterised Victoria’s COVID situation as “a resurgence of epic proportion”.
Of Monday’s 75 cases, only one was linked to hotel quarantine, 14 were linked to known outbreaks, 37 had been detected through routine testing and 23 were under investigation.
Professor Sutton said there was still an opportunity for COVID-19 cases to “turn around”.
“If it isn’t, absolutely … changing the law is something we have to consider because we have to do whatever is required to turn this around.”
Monash University Associate Professor Philip Russo, an internationally regarded expert in healthcare associated infection prevention, said logistically it would be difficult to police a lockdown of individual areas.
“I think Dr Sutton is right in that there is a danger it might actually drive people underground and introduce infections into areas where there are low levels of cases at the moment,” Associate Professor Russo said.
He said there had been an increased emphasis from authorities in recent days on the need for the public to stay home, isolate and get tested.
“The hope is numbers will start to turn around in the next few days and drop off, which would mean those interventions put in place five to six days ago had started to take effect,” Associate Professor Russo said.
“However if there is a continued significant increase in cases for the next week that is when lockdown discussions would come back on the agenda.”
Two businesses in a COVID-19 hotspot contacted by The Age said they were confused about what a suburb lockdown would mean for them.
Melba’s Food Hall, a grocery store and cafe in Brunswick West, one of the COVID-19 hotspots, has been allowed to stay open through the pandemic because the supermarket component is an essential service.
However, owner Vince Garuccio said that if Brunswick West went into lockdown, he may be instructed to close because people could shop in other suburbs.
“That would kill me because I have got a lot of perishable products and there would be a lot of wastage,” he said. “Absolutely, it is a stressful period, because you don’t know what to do about staff.”
Rodney Mom, from Brunswick West cafe Mister and Missus M, lives in COVID-19 hotspot Keilor Downs.
“I’m not sure I would be able to travel from Keilor Downs to West Brunswick if the suburbs went into lockdown – your guess is as good as mine,” he said.
Professor Sutton said the risk of transmission was well managed in restaurants that had applied COVID-19 safety regulations.
“So it may not look the same in terms of shutting down a lot of those settings because that’s not where transmissions are occurring,” he said.
Meanwhile, Victoria is rolling out a saliva test with 87 per cent accuracy for vulnerable people such as the elderly and children, who might not otherwise take the more intrusive throat and nasal swab test.
Jewel Topsfield is Melbourne Editor of The Age.