The parents of an 18-month old Australian toddler stranded in the Hubei province of China have pleaded with the federal government to evacuate her from the centre of the new coronavirus outbreak.

So far more than 500 Australians have been airlifted out of the city of Wuhan by two Australian-operated flights that prioritised the “isolated and vulnerable”, including the young and elderly.

But Chloe Luo, an Australian citizen, remains in the neighbouring city of Suizhou – which has the world’s fourth-highest number of coronavirus cases, and has been under lockdown since 24 January.

The toddler from Canberra was being looked after by her grandmother, but last week her grandmother was hospitalised with a cold, unrelated to coronavirus, leaving Chloe with her great-aunt.

Her parents, Yufei Luo and Yi Zhao, who live in the Canberra suburb of Ngunnawal, said they were willing to fly into Suizhou, which is three hours drive from Wuhan, to be with Chloe and bring her back home. But the Australian government has said it is not planning on organising a third evacuation flight for citizens remaining in Wuhan and Hubei.

Yufei told Guardian Australia they decided in early January that Chloe should visit China because they were worried that bushfire smoke in Canberra was damaging her health.

“We thought to send her back just for a couple of weeks, just a month, until the smoke was gone,” he told Guardian Australia. “We tried to give her better conditions. Then everything happened in Wuhan.”

On 1 January, Canberra’s air quality reached 1296 micrograms of PM2.5 particles per cubic metre, compared with 41 micrograms in Beijing.

Since 24 January, people have not been allowed to move through the Hubei province without authorisation, and all public transport has been suspended.

Other Australians citizens still in Wuhan have said they felt they are being “swept under the carpet” by the Australian government, and that other elderly and vulnerable people remained stranded in the city.

Desmond Lim from Sydney said the method of determining who was prioritised was unclear, and his wife, Jing Gong, who is also an Australian citizen, had been left in the city despite multiple requests for assistance.

Yufei said the Australian government told him that they could not evacuate Chloe on any of the earlier flights.

“We talked to the government – they said they can only take permanent residents or citizens. Chloe is an Australian citizen but her grandma isn’t.

“She can’t get to the plane because only her grandma can take her – but her grandma is not an Australian citizen, or permanent resident.

“Both my wife and I can’t go and pick up Chloe because we don’t have any pass [to travel through Hubei]. We don’t have any pass to pick up Chloe and stay with her. That’s what is happening at the moment.

“I think she can’t travel by herself. I can only trust myself to go back to pick up Chloe, or my wife.”

Yufei said he was worried for Chloe’s wellbeing in the city, where China’s medical system is under strain from the impacts of coronavirus.

“She was staying with her grandma. But her grandma developed other conditions, and went to hospital last week. So at the moment, she is staying with my mother-in-law’s sister.

“She is still in hospital. Not with coronavirus – just a normal cold. But at this stage, sometimes if you go into a hospital you have to stay there for at least 10 days. My daughter is only one and half. It’s really hard to look after a little kid, with just one adult.

“All I hope is that I can get some pass or the government can help me get back to Suizhou. Then I can stay there for a few days, or get there and bring Chloe back to Australia. I asked them, they said they can’t do anything.”