Health Minister Brad Hazzard said it still wasn’t clear if the man had infected others after becoming contagious.
NSW Health Ministry and the local health districts are busy talking to various people he might have come into contact with.
“We are making sure we get in contact with them and make sure they don’t have symptoms,” the minister told Nine’s Today program on Tuesday.
“It’s a bit of a worry.”
NSW has now had nine confirmed cases of COVID-19, with five being diagnosed in the past week.
The latest three were confirmed on Monday. The other four have recovered.
Two of those cases include the doctor, 50, and the 41-year-old sister of an infected man who had recently returned from Iran where the virus is rampant.
Both were person-to-person transmissions outside of China, where the outbreak began.
The doctor had not recently been overseas leading experts to conclude he may have contracted the virus while working in a clinical environment or while in the community, although it was not yet clear which.
NSW Chief Health Officer Kerry Chant said the case of the health worker raised the question: “Was there a case that was missed?”
“Our key focus at the moment is to contact staff or patients that may have been close contacts of this gentleman,” she said on Monday.
The third new case in NSW is a 31-year-old man who flew into Sydney on Saturday from Iran and developed symptoms 24 hours later
Mr Hazzard on Tuesday again cautioned NSW residents to be cautious and make sure they wash their hand regularly, not shake hands and to sneeze into their elbow if a tissue wasn’t available.
“Perhaps it is time to forget handshaking at the moment because that’s a very easy way to transmit the virus,” he added.
“If you are out and about and you put your hand on a banister on a train or railway or bus, it is possible you end up with the virus on your hands.”
Asked about cases of people stockpiling non-perishable goods and toilet paper, Mr Hazzard said everyone should remain calm.
“I think we should be very cautious, washing our hands, but not rushing out and buying up,” he said.
The state government is also warning of a likely convergence of a COVID-19 pandemic with the annual winter flu season and announced a lowering of the age at which pharmacists could administer flu jabs, to 10.
Coronavirus is now spreading much more rapidly outside China than within, leading the world into uncharted territory – but the outbreak can still be contained, the World Health Organisation says.
Almost nine times as many cases had been reported in the past 24 hours beyond China than inside, WHO chief Tedros Adhanom Ghebreyesus says.
He added that the risk of coronavirus spreading was now very high at a “global level”.
He said outbreaks in South Korea, Italy, Iran and Japan were the greatest concern, but there is evidence surveillance methods are working in South Korea, the worst-affected country outside China, and the epidemic can be contained there.
“We are in uncharted territory – we have never seen before a respiratory pathogen that is capable of community transmission but at the same time which can also be contained with the right measures,” he told a news briefing in Geneva on Monday.
The fight against the coronavirus should become a bridge for peace, Tedros said, commending the US for supporting sending medical aid to Iran despite the tensions between them.
Finance ministers of the G7 group of leading industrialised democracies are expected to hold a conference call on Tuesday to discuss measures to deal with the economic impact, three sources told Reuters.
The global death toll was up to 3044, according to a Reuters tally.
South Korea had 26 deaths and reported another 599 infections on Monday, taking its tally to 4335 following the country’s biggest daily jump on Saturday.
Of the new cases in South Korea, 377 were from the city of Daegu, home to a branch of the Shincheonji Church of Jesus, to which most of South Korea’s cases have been traced.
Some members of the church visited China’s Wuhan city, where the disease emerged.
The Seoul government asked prosecutors to launch a murder investigation into leaders of the church amid allegations they did not co-operate to stop the spread of the virus.
Wuhan, at the centre of the epidemic in Hubei province, shut the first of 16 specially built hospitals after it discharged its last recovered patients, Chinese state broadcaster CCTV said.
News of the closure coincided with a steep fall in new cases in Hubei, but China remained on alert for people returning home with the virus from other countries.
The virus broke out in Wuhan late last year and has since infected more than 86,500 people, mostly in China.
Outside China, it has in recent days spread rapidly, now to 53 countries, with more than 6500 cases and more than 100 deaths.
The death toll in Italy, the hardest hit European country, has jumped to 52 from 18 and the number of cases to more than 2000 from 1694, the Civil Protection Agency said on Monday.
Another of the worst-hit nations, Iran, reported infections rising to 1501 on Monday, with 66 deaths, including a senior official.
Latvia, Saudi Arabia, Tunisia and Senegal reported their first cases.
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