The mandatory testing drive has led to widespread fears throughout the city that, as more positive cases are identified, more families could be separated -- with children placed in isolation.

On the video, Laura breaks down as Ava sobs. "I can't bear it," she says, as her husband makes a desperate appeal to a nurse, who appears to be holding the phone.

"Nurse, just give her some comfort please," Nick begs, as a nurse wearing a full hazmat suit appears on the screen, her face covered with a shield.

Under Hong Kong policy, Ava can only be discharged if she tests negative seven days after her admission. Laura and Nick are planning to take a Covid test; they say they hope it will be positive, so they have a chance of being reunited with their daughter in a government-run quarantine camp.

"We're just helpless. We are really helpless," Laura told CNN. "This is not in the best interest of her that she's without us. She needs us and we need her."

Hong Kong's toughest restrictions

But those measures no longer appear sufficient in the face of the latest wave, which officials have described as a "tsunami."

Still, Hong Kong continues to adhere to China's strict zero-Covid policy, and in an effort to combat the surging fifth wave -- predicted to peak in the next three weeks -- the city's leader, Carrie Lam, on Tuesday announced its toughest restrictions yet.

All Hong Kong residents -- about 7.4 million people -- will have to undergo three rounds of compulsory Covid-19 testing in March, Lam said during a news conference. In between those tests, residents will have to take daily rapid antigen tests, Lam added.

Public and international schools -- which are already conducting online classes -- will break early for the summer to free their premises for use as temporary isolation, testing and vaccination facilities. An existing ban on in-person dining past 6 p.m., the closure of gyms and entertainment venues, and flight bans from nine countries, will be extended until at least April 20.

In a bid to keep Hong Kong strictly in line with its zero-Covid strategy, China announced last week that it will send health experts and medical supplies to Hong Kong and help build new quarantine and isolation facilities.

"With central government's support and the Hong Kong people's unity, we will certainly triumph over this pandemic. After the storm we will see a rainbow again," Lam said Tuesday.

But even Beijing's help might not be enough.

Dr. Edwin Tsui, the controller of the Centre for Health Protection, said mass testing is likely to confirm a large number of positive cases the city would then have to manage.

He said the city's health system may need to "handle thousands or tens of thousands of cases...in a very short period of time."

Families fear separation

Ava's worried parents took her to hospital on Monday after she came down with a fever and had difficulty breathing. When Ava's Covid test came back positive, her parents were told to leave, Laura said.

The family's story was posted on a popular Facebook group and has since spread, prompting panicked discussions between Hong Kong parents about what could happen if their children test positive and they test negative, like Laura and Nick.

"We have been applying this exceptional treatment...instead of sending the very young kids on their own to a quarantine center...we will exceptionally accept the admission of the children into the hospital as well," Lam said.

But as cases soar and Hong Kong insists on sending most positive cases to hospital or government-run quarantine facilities, officials' stance on family separation seems less clear.

The chief manager of Hong Kong's Hospital Authority, Dr. Lau Ka-hin, said Tuesday officials would "try our best" to treat parents and children who have tested positive in the same hospital.

Ava's father, Nick, said they were living "a real-life nightmare."

"If she's in stable condition, why can't we just take her home?" he said.

Laura added; "We're not asking for a spare bed at the hospital. I would stand next to her bed. I will sit on a chair next to her for the remaining five days. I just I need to be with her."

A Hospital Authority spokesperson told CNN that as they had not tested positive it was "not advisable" for Ava's parents to stay in the hospital's isolation facilities.

If in due course they are confirmed as having Covid-19, "the hospital will try to facilitate and arrange them to stay in the same ward if situation allows," the spokesperson said.

The spokesperson added that when Ava was in respiratory distress, her parents were not allowed to visit as she was receiving one-on-one care in the intensive care unit.

"The hospital understands the stress of the parents for not being able to accompany their child, therefore (a) video call would be arranged up to three times a day," the spokesperson said.

According to Odile Thiang, a clinical adviser for mental health NGO Mind HK, family separation "is incredibly taxing for both the parents and the child."

"In both cases, there's experiences of anxiety, depression, and of course, PTSD (post traumatic stress disorder)," Thiang said. "And these impacts are felt long after the actual traumatic event."

For Laura, this is more than just her own family's ordeal.

"The worry is that you have to make an agonizing choice whether to take your child to get the medical care that they need or to keep them at home so you're not separated," she said.

"And that is the situation that so many parents are going to find themselves in Hong Kong. That is going to have a devastating impact. And no parents should have to make that choice."