For two years, as the pandemic raged around the world, Hong Kong largely contained the virus, and there was a growing feeling the city might keep the virus out forever.

As cases rose this year, the government reimposed its strictest rules, limiting public gatherings to two, closing restaurants and bars after 6 p.m., and roping off public playgrounds.

But it still wasn't enough. With few other levers to pull, the government plans to launch a mandatory mass testing drive in an attempt to purge the city of Covid. Schools will break for summer early and be repurposed as isolation, testing and vaccination facilities. And it's still unclear whether a citywide lockdown is on the cards.

"March is going to be a very, very difficult time," said Sridhar. "(It's) definitely an unprecedented health crisis for Hong Kong."

For a city that has already put up with two years of tough restrictions, news of citywide testing has proved too much for some residents who are frantically looking for a flight out.

And while vaccines mean Hong Kong is better off than it would have been two years ago, immunization rates are still lagging among its elderly population -- meaning many of the city's most vulnerable are still unprotected.

What went wrong in Hong Kong

At Queen Elizabeth, one of Hong Kong's largest hospitals, patients sit in a sparse, windowless observation room while they wait for a bed in an isolation ward. Two nurses, who asked not to be named because they fear repercussions for speaking out, told CNN last week the observation room smells of feces -- there are no restrooms, so patients are forced to use bedpans.

The nurses say staff shortages mean there's often a delay in checking on patients as more arrive for care, and there are too many people wanting treatment and not enough beds.

"A patient is unlikely to get into an isolation ward unless that patient is on the verge of dying," one staffer said. "No matter how hard we work, the situation doesn't change, yet we still cannot stop. The situation is hopeless."

The hospital's morgue is overflowing and some bodies are being stored for hours at room temperature, according to one of the nurses.

A medicine and geriatrics doctor at another hospital in Hong Kong, who asked not to be named as she fears repercussions, said the sheer number of patients was "astounding," with some waiting up to four days to be seen by a doctor.

"It's so packed and spread so thin for manpower, you have like one nurse seeing 20 patients," she said last week. "What we're seeing here is nothing I've ever seen before."

In a statement to CNN, the Hospital Authority said it was facing "unprecedented challenges," and apologized to patients who had experienced long wait times.

With a sharp increase in Covid-19 deaths due to the cold weather, the "storage space in hospital mortuaries has reached full capacity," the statement said.

In a briefing Tuesday, health officials said they are adding refrigerated containers and expediting the construction of a new mortuary to provide at least 800 extra units. To date, Hong Kong has recorded 1,554 deaths since the beginning of the pandemic, up from 213 at the end of December 2021.

That surge in cases is also putting pressure on hospital wards.

But some positive cases are desperate to be admitted to government-run facilities, no matter how sick they are, because for much of the pandemic they've been told that's the right thing to do, Hong Kong University professor Jin Dong-yan said. That's not only putting pressure on the system, he said, but is exposing others to infection.

"They just hang around, come to this or that hospital, just hoping to be admitted," he said last month. "They might spread the virus to others."

The situation is also being exacerbated by Hong Kong's high proportion of unvaccinated people.

On Friday, government officials said vaccinating the elderly was now a public health priority, describing care homes as "hot spots" for the virus. And as of Friday, the wait time between the first and second doses of the Chinese-made Sinovac shot would be reduced from 28 days to 21 days for the elderly.

The low vaccination rate among the elderly appears to be playing out in the city's death toll. Almost all of the city's Covid-19 deaths reported this year are elderly and unvaccinated -- and many of them lived in care homes.

Stephanie Law, an executive committee member from the Elderly Services Association of Hong Kong, said for many older residents, concerns about Covid vaccine side effects outweighed the risks of getting the disease.

"In the past, a lot of people felt that it's not a priority to have the vaccine," she said. Now, care workers feel "helpless" as the virus spreads through homes, where some residents live four or six people to a room, she said.

Karen Grepin, an associate professor at the School of Public Health at the University of Hong Kong, said the narrative in the city had evolved to the point that people had started to believe Hong Kong could keep the virus out forever.

"People really started to believe that even the miniscule risk associated with vaccination was higher than the risk of Covid," she said.

"We are paying for that complacency."

Why Hong Kong is unable to shift

Hong Kong isn't the only zero-Covid place in the world to experience an outbreak.

Experts say Hong Kong could have done more to emphasize the importance of vaccination -- especially among the elderly and vulnerable.

Unlike many places in the West, Hong Kong didn't push vaccines as a way out of the pandemic because living with the virus has so far been rejected as an option.

The Hong Kong government is ultimately answerable to China's ruling Communist Party, which maintains a stringent "zero-Covid" policy and has touted its suppression of the virus as evidence of the supposed superiority of its one-party system over Western democracies, especially the United States.

Last month, Chinese President Xi Jinping instructed Hong Kong to "take all necessary measures" to contain the outbreak.

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

Lam has maintained the latest measures are not dictated by Beijing, and instead are the result of the two sides "exchanging ideas."

Dr. Ramanan Laxminarayan, the founder and director of the Center for Disease Dynamics, Economics and Policy, says Beijing believes its Covid policy is superior to other countries.

"It's the narrative that China will always be free of Covid that will be problematic for China going forward," he said. "A theory based on this idea that you can keep Covid out of your population forever just defies any sort of logic."

Zeng Guang, chief epidemiologist at China's Center for Disease Control and Prevention, said this week that the zero-Covid policy won't remain unchanged forever -- but added there was "no need to open the door at the peak of the global epidemic."

An uncertain future

As other places around the world open up and learn to live with Covid, Hong Kong still has some of the strictest border rules in the world, including a ban on most non-Hong Kong residents entering. And for many in the city, the apparent absence of a more forward-facing plan is difficult to bear.

Within days of the announcement of mass testing, a new Facebook group for advice on relocating had attracted more than 3,900 members, with some saying they wanted to get out before citywide testing started.

"I feel like the kids are being punished the most throughout this whole thing. It's not fair on them," she said, referring to the restrictions. "(The public health policy) scares me more than the virus itself."

Many locals, too, are growing frustrated.

James Hov, 31, poured his life savings into a barbershop that has been closed for weeks under the restrictions. He worries he could lose his business and struggle to pay off the engagement ring he bought for his future spouse.

"You can't end Covid. Closing barbershops but having a cluster of people on trains for their daily commute -- it's moronic -- I'm not so sure any logic was behind it," he said.

One 25-year-old tattoo artist who asked not to use her real name as she is afraid of repercussions, said last month she is continuing her business underground despite a current ban. She is refusing to get a vaccine as she doesn't trust either the Chinese or Pfizer vaccines available in the city.

She is skeptical of Hong Kong's policies, which she said were merely there to satisfy China. "It's harming society, it's harming economics, it's harming people's well-being," she said.

For Hong Kong, there's an unprecedented health crisis ahead, and then little light at the end of the tunnel -- even if the city opens up, another wave is inevitable, said virologist Sridhar.

"We're just waiting for either the next wave or a shift in stance from the powers that be."