This article is more than 6 months old

This article is more than 6 months old

The first cohort of Australian evacuees are set to leave quarantine on Christmas Island on Monday, with no reported cases of the new coronavirus among the 277 Australian citizens and permanent residents held on the island.

A government-chartered evacuation flight brought 241 Australians from Wuhan on 3 February, with another 36 arriving two days later, via a New Zealand government charter through Auckland, that left China on 5 February.

All of those evacuated from Wuhan, where the Covid-19 disease first emerged, have been required to stay in quarantine, in the almost empty Christmas Island detention centre, for 14 days from the date of leaving mainland China.

Inside the centre, evacuees have been kept isolated in small family or social groups, to limit the spread of any potential outbreak.

Three possible cases of coronavirus have been tested among the cohort inside the detention centre. All have come back negative for the disease.

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Possible cases were isolated from all other evacuees inside the centre while tests were undertaken, but have since rejoined other evacuees.

On Monday, three chartered flights were set to leave the remote island, returning all those from the first group home.

Contrary to the federal government’s earlier statements, Australians will not have to make their own way home from Perth – but will be flown to Sydney, Melbourne, Canberra, Brisbane and other capital cities. Earlier this month, the government also backtracked on plans that evacuees would have to pay $1,000.

The first flight from Christmas Island is scheduled to leave at 8am local time, with others following in two-hour increments, but all are subject to weather and delays.

The first flight will take passengers to Port Hedland, then to Sydney and Canberra, arriving in Sydney and Canberra in the evening. The second flight will go to Adelaide and Melbourne, touching down in Victoria just before midnight, local time. The third will fly to Perth and then Brisbane.

Australians who arrived in the second cohort to Christmas Island are also on track to leave on Wednesday morning.

Prof Yan Zhang, an academic at Western Sydney University who was on the first evacuation flight from Wuhan, said he was “very excited” to return home and see his wife and daughters.

“I’m very grateful to all staff from Ausmat [Australian Medical Assistance Teams], the Australian army and other departments for their kindness, caring and unconditional support during our 14-day quarantine period.

“I thank my wife and daughters – they talked to me every day to make sure I was OK here. I also thank my university colleagues and friends for their caring and support.”

Australian company AusDiagnostics, which is providing the testing equipment and kits for the medical teams inside the Christmas Island detention centre, said that the testing process has been “relatively straightforward”.

After a phone call on the Friday before evacuees arrived, AusDiagnostics rapidly had equipment and testing kits shipped to Darwin, where it was flown to the island on a Hercules C-130 military aircraft.

“As well, one of our staff members volunteered to travel with the equipment, and to go into quarantine, to help train the medical staff and assist with testing,” managing director Prof Keith Stanley said. “That was a great act of service to the community.”

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AusDiagnostics, based in Sydney but with offices around the world, developed a test for Covid-19 as soon as the virus was sequenced.

The advantage of having testing equipment and kits on the island means that the results of a test for a suspected case can be returned within “three or four hours”, Stanley told Guardian Australia, rather than samples having to be sent to a mainland hospital, where the turnaround might be two days. Faster results mean that isolation of suspected cases – within the quarantine facility – can be managed much more effectively.

He said the test for the Covid-19 is “relatively straightforward” and “much the same as a doctor would do for influenza in the winter”.

A swab is taken from a patient’s nose or throat and then the nucleic acid from that sample is tested for the coronavirus, as well as other illnesses.

“Our process looks for specific sequences which are characteristic of a particular virus. We developed a test for this specific coronavirus, but our process also tests for the standard winter coronavirus, Mers, the Middle East coronavirus, and Sars.”

Stanley said the two key assessments of any new viral outbreak were infectivity and mortality. Covid-19 appeared to be “quite infectious”, Stanley said, meaning early triaging and quarantining of suspected patients was vital, but that the mortality rate was still not clear, though it has been posited at being about 2%, “nothing like as bad as Sars and Mers”.

“Yes we need to have precautions such as quarantining, but most people who have this infection would only experience symptoms something like a common cold.”