Australia’s first case of COVID-19 human-to-human transmission has been confirmed.

NSW Health Minister Brad Hazzard and NSW chief health officer Dr Kerry Chant confirmed at a media conference on Monday afternoon that a patient transferred the coronavirus to a health worker, believed to be a doctor.

• Read the Tuesday morning update here: Handshake warning as WHO says we’re entering ‘unchartered territory’

Mr Hazzard said he was informed just after 3pm of test results that indicated an increase of another three people being diagnosed with novel coronavirus in the state to nine.

More worrying, two of those cases had not travelled overseas recently, which Mr Hazzard said indicated a high likelihood of person-to-person transmission on New South Wales soil.

One was a 41-year-old woman quarantined at Westmead hospital.

She has been identified as the sister of a 43-year-old man, who started to show symptoms 24 hours after returning from Iran on Saturday.

The woman had not travelled overseas.

The second was a 53-year-old health worker, who had previously returned two negative tests but tested positive on Monday afternoon.

He is in a stable condition in intensive care.

Mr Hazzard suggested it would be prudent not to shake hands when greeting friends and family, and instead pat them on the back.

A similar cautious approach should be taken with kissing, as he said we need to be cautious but not alarmed.

“If you have been anywhere in a public space, you should be washing your hands before doing anything, especially touching your face,” Mr Hazzard said.

“I won’t be changing anything that I do.”

The news comes as health and aged-care workers returning to Australia from Italy and South Korea have been told to stay home from work amid growing fears they might infect vulnerable populations with coronavirus.

“As a healthcare worker, or as a residential aged-care worker, you should not attend your regular work for 14 days,” Health Minister Greg Hunt said on Monday.

“That is an additional level of protection, which has been advised by the chief health and medical officers and accepted by the Australian government.”

It comes as Tasmania recorded its first case of confirmed coronavirus on Monday. State authorities confirmed a 40-year-old man had tested positive after travelling from Iran to Launceston via Malaysia and Melbourne.

Also on Monday, the NSW government ordered schools to cancel any overseas trips planned for the first term, as preparations for a potential coronavirus pandemic are ramped up.

The COVID-19 outbreak has surged in South Korea and Italy in recent days, prompting the federal government to upgrade its travel advice for Italy.

Australians intending to travel there have been told to exercise a high degree of caution across the entire country, and to reconsider the need to travel to 10 virus-affected towns in Italy’s north.

Late on Monday afternoon, Reuters reported that Indonesia had its first confirmed cases of COVID-19. Indonesian President Joko Widodo said two patients were in an unnamed hospital – the first confirmed cases in the world’s fourth most populous country.

• Related: Smart Traveller update

On Monday, passengers on two flights into Sydney and Melbourne were urged to go to doctors or hospital emergency departments to be tested for the virus after travellers on both planes were confirmed with infection.

The affected flights are Qatar Airways QR908 into Sydney on February 23 and Malindo Air flight OD177 into Melbourne on February 28.

Victorian authorities are particularly worried about the Malindo Air flight, because they do not have the manifest of passengers on board. A woman in her 30s who was returning from Iran and boarded the flight in Kuala Lumpur, Malaysia, is in quarantine after testing positive to COVID-19.

Victoria’s chief health officer Brett Sutton said authorities wanted all passengers who had sat in the same row or rows either side of her to self-quarantine – but they did not have the flight manifest to contact them.

He said the Commonwealth was trying to provide the manifest “as urgently as they possibly can”.

NSW Health also fears for passengers on QR908 who were sitting near a woman confirmed as the state’s sixth coronavirus case. The woman, who is in her 50s, flew from Iran to Sydney via Qatar.

Her symptoms began within 24 hours of landing, but she did not visit hospital until six days later.

NSW chief health officer Dr Kerry Chant said affected passengers were being contacted and told to self-isolate for 14 days.

Another man in his 40s who returned from Iran on a separate flight into Sydney is also in isolation after testing positive.

The latest emergency comes as Queensland health authorities contacted up to 40 customers of a 63-year-old Gold Coast beautician who returned from Iran and tested positive to the virus.

Australia has banned arrivals from Iran, but not two other major hotspots, Italy and South Korea. Chief medical officer Brendan Murphy said the Iran outbreak was considered high risk, and the travel ban was considered an effective strategy to slow the spread of the disease.

“It is no longer possible to absolutely prevent new cases coming in, given the increasing changes in epidemiology around the country,” he said.

“Even though we have a relatively low travel volume from Iran we have had these four cases … that is why Iran has been a particularly special case.”

• Related: WA travel agent first Australian to die

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Australia has so far recorded 29 infections.

Among them was Perth man James Kwan, 78, who died on the weekend after contracting the virus on the Diamond Princess cruise ship in Japan.

Tragically, in his final hours his wife, who also has the virus, and his relatives were unable to be by his bedside.

WA Premier Mark McGowan said Mr Kwan spent his final moments alone because he was quarantined, according to news.com.au.

“It would have been awful, they couldn’t go in and touch him or hold his hand – it would have been so tragically sad,” Mr McGown said.

“You don’t want to leave this world without someone holding your hand.”

Globally, 89,000 people have tested positive to the virus and as of Monday afternoon, the death toll was 3039.

Virus spread encourages panic buying

The Australian Medical Association has urged people not to panic-buy after pictures of bare supermarket shelves began circulating online.

“There is an enormous amount of misinformation and almost fear,” the AMA vice president Tony Bartone has told the ABC.

“There’s no reason to go out and panic buy almost bunker-level materials.”

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Travel bans and new cases

Home Affairs Minister Peter Dutton warned on Monday further bans could be futile in the face of the escalating emergency.

“You get to a position where you just can’t contain that by closing borders, or closing routes from particular countries. That’s the stage we’re at at the moment,” Mr Dutton told Sky News.

“We can’t just close down every flight, every movement across our borders. We need to be realistic about the fact we’re a trading nation.”

Mr Dutton insisted he had confidence in advice from the World Health Organisation, which is yet to declare a pandemic.

-with agencies