Four Australians are reportedly among a further 39 passengers on the beleaguered Diamond Princess cruise ship to test positive for the lethal coronavirus on Wednesday.

The grandfather of a 21-year-old Melbourne woman confirmed her infection to radio 3AW on Wednesday, while the ABC reported late in the afternoon that three other Australians were among the dozens of new cases from the ship.

However, Australian authorities are yet to confirm the diagnoses.

A Japanese quarantine officer who had been treating passengers locked on the ship is also among the confirmed patients. The official had worn a mask and gloves while collecting and processing questionnaires from passengers.

Japanese Health Minister Katsunobu Kato announced the surge in confirmed tests of the coronavirus (which has been renamed COVID-19 by the World Health Organisation) on the Diamond Princess on Wednesday.

Japanese broadcaster NHK said 174 people on board the liner – which is moored at Yokohama – were now confirmed to have the deadly disease.

China reported yesterday that the death toll from the virus had topped 1100, even as the country remains largely closed down to prevent the spread of the disease.

The total number of cases in mainland China is 44,653, although many experts say a large number of others infected have gone uncounted.

News of the surge in confirmed cases came as the federal government confirmed on Wednesday it had no plans for another flight to rescue Australians stranded in Wuhan. At least 13 Australian children and their families remain trapped in the Chinese city at the epicentre of COVID-19.

The grandfather of the Melbourne woman aboard the Diamond Princess, who gave his name only as Peter, told 3AW she was taken off the ship with her parents and younger brother and taken to a hospital about two hours from the port.

“My granddaughter Bianca, who is 21 years old, tested positive and now she’s in isolation in the hospital and my three other family members are all in isolation wards over there,” Peter said.

• Related: Coronavirus declared ‘public enemy No1’

More than 3700 passengers, including about 200 Australians, have been stranded on the ship for a week after dozens of people tested positive for COVID-19.

Yardley Wong, who is among those quarantined on board the Diamond Princess, said the latest rise in confirmed cases was making him anxious.

“Anxiety rising. [I] don’t know when it will possibly be my turn — or my family,” Mr Wong told the ABC.

Some of the Australians on board have described the new cases as “scary”, but others said they were remaining positive.

Peter said the Australians had not heard from the federal government since they were quarantined.

“These people are in limbo and no one cares about them,” he said.

“That’s how it seems because we’ve had no contact from the government in any way.”

Peter said the family had been struggling mentally and physically, as a result of being trapped in their cabins prior to the diagnosis.

“They were locked up in these two little rooms, 3×3 (three metres by three metres) perhaps, without any access to clean air or anything,” he said.

• Related: Quarantined passengers turn to humour

Never leave home without them. You never know when you may find yourself under a two-week quarantine aboard a cruise ship. (Full credit to my wife for the foresight in packing and shopping.) pic.twitter.com/NVtjovV7ki

— Matthew Smith (@mjswhitebread) February 9, 2020

Princess Cruises has not confirmed the growing tally of patients among its passengers.

“We are following guidance from the Japan Ministry of Health on plans for disembarkation protocols to provide medical care for these new cases,” it said.

“Since it is early in the quarantine period of 14 days, it was not unexpected that additional cases would be reported involving individuals who were exposed prior to the start of the quarantine.”

The quarantine end date remains February 19, unless there are any unforeseen developments.

Princess Cruises has confirmed all guests aboard the cruise will be refunded their fare, including air travel, hotel, ground transportation and other expenses.

-with AAP