Gladys Berejiklian under pressure to make masks mandatory as NSW records 13 new cases

Gladys Berejiklian is facing mounting pressure to make it mandatory to wear a face mask in certain parts of New South Wales as her government hopes to avoid a Covid-19 trajectory similar to Victoria.

The calls came after a family of four including an infant from the NSW regional town of Wagga Wagga tested positive for Covid-19 after returning from Victoria, as Berejiklian flagged the possibility of even tougher border restrictions.

NSW reported 13 new cases of Covid-19 on Monday, adding a Bondi yoga studio and a gym in Rockdale to the ever-growing list of venues attended by positive cases.

Announcing the state’s daily numbers, Berejiklian reaffirmed her “significant advice” that residents in her state carry a mask and wear it in situations when social distancing is compromised.

Related: Gladys Berejiklian urges more use of face masks as NSW faces 'high-alert state' of Covid-19 pandemic

NSW opposition leader Jodi McKay later on Monday called for masks to become mandatory because Berejiklian’s position “doesn’t convey the severity of the situation”.

Virus experts in the state are also calling for the premier to take a more serious position on the issue and make masks mandatory, arguing it’s an “inexpensive” measure “with lots of positive effects” that could prevent Victorian-style lockdowns in NSW and ultimately “save lives”.

At the press conference on Monday, Berejiklian said she had begun wearing a mask when shopping and now carries one in her pocket constantly in case she felt she couldn’t socially distance herself, after her state began urging residents to wear masks on Sunday.

“I recommend everyone have one in their pocket or their bag, and if they feel they are in a situation where they need to wear one, they should,” Berejiklian said.

“I trust the vast majority of people in our state to do the right thing. They know when they might be exposed to social distancing, and they also appreciate where there might be active cases in the community which would make them more likely to be having to wear a mask.

“We are holding the line, but the next few weeks are precarious. We are about halfway through what we always knew would be a very difficult period ... I say to everybody in NSW, let’s do the hard yards now so we have a better chance moving forward and not have to go into the situation Victorians find themselves in,” she said.

However McKay on Monday called for masks to be compulsory on public transport, in supermarkets, shopping centres and places of worship in NSW.

“NSW is on a knife edge. We can’t afford to sleepwalk into a second lockdown. Gladys Berejiklian must take decisive action against the spread of Covid-19 in NSW and make masks compulsory.”

“We know it won’t be popular and there’ll be some push back. But she won’t get any criticism from us if she makes masks compulsory in these settings. I will back her 100%,” McKay said.

Opposition health spokesman Ryan Park also said Australia “cannot afford” for “its two economic engines, NSW and Victoria to stall from Covid-19”, and said “wearing a mask saves lives and saves jobs”.

Marylouise McLaws, a professor of epidemiology at the University of New South Wales, said masks should be compulsory, at least for Greater Sydney and the Hunter region, given infection numbers over the past two weeks.

McLaws said mask use made sense in NSW because there have been “no particular residential hotspots”, but mostly “social hotspots” around clusters linked to restaurants, bars, and shopping areas.

She said this suggested spread was occurring among younger people who were “hyperconnected socially, and underemployed”.

“Masks are so inexpensive. I know that many people think the public are incapable of wearing them safely and by touching their face will risk contracting the virus. But the public are clever, they can learn. They’ll still need to practice hand hygiene and social distancing.”

McLaws also said widespread mask use will serve as a constant visual sign of the seriousness of the pandemic, and help avoid a relaxed attitude to social distancing.

“Masks are a good reminder to everyone that we’re not out of danger yet,” she said

However Peter Collignon, a professor of infectious diseases at the Australian National University, said he did not think Covid-19 cases in NSW required forced mask use yet.

“It’s on a knife edge, but it’s just still under control,” he said, noting mask use wasn’t as effective as social distancing and hand hygiene, and that mask use could create a false sense of security,” he said.

Raina MacIntyre, an epidemiologist at the University of New South Wales, told the Guardian she thinks “it’s time” for mandatory mask use in NSW.

“The earlier that it’s brought in, the more chance it has of reducing the size of an outbreak, and it may help us avoid a lockdown situation like in Victoria.

“You have to act early, we know it can help avoid more cases and more deaths,” she said.

Among the new cases reported on Monday, NSW Health said only one was not linked to a known outbreak.

In addition to the 13 cases, NSW Health confirmed that a Wagga Wagga family of four, including a baby, were isolating after being diagnosed with Covid-19 after returning from Melbourne.

Berejiklian also welcomed the introduction of stage four restrictions in Victoria, which have seen residents in the state subject to a curfew and even tougher limits on movement, saying they were a “positive outcome” for NSW.

“No border is impenetrable,” she said. “If you ask the border communities, they would say I am being too tough but I don’t think I am.

“But if we need to do more, we will. We will know in the next few days what that flow is like as a consequence of the shutdown in Melbourne. Which obviously will have a positive impact on the way we can manage the virus in NSW.”

She said the state’s “geographic proximity” to Victoria made it “the first line” of having to deal with the outbreak.

“It only takes one case to get out of hand to cause enormous ripples throughout the community,” she said.

Related: Stage 4 lockdown in Melbourne a hammer blow to Covid-weakened Australian economy

Of the 13 new cases reported on Monday three were returned travellers in hotel quarantine and one person had recently returned from Victoria.

Other cases were linked to known outbreaks at the Apollo restaurant at Potts Point, Mounties at Mount Pritchard and the Advanced Early Learning childcare centre at Merrylands in Sydney’s south-west.

Five of the new cases were close contacts of known cases and the source of one is not known. NSW Health also revealed that in the past week there have been seven cases in NSW not linked to a known outbreak.