HONG KONG -- Half an hour before the sampling of nucleic acid tests began, people were already lining up outside the Ma On Shan Recreation Ground in Hong Kong.

Around 20 blue tents were stood at the empty recreation ground, which was used for sports and leisure activities before becoming a testing site under the COVID-19 epidemic. In the tents, sampling workers in white protective gowns have started their busy day.

They are a team of health experts and workers from the mainland, who arrived in Hong Kong on Feb 19 to work with the Hong Kong Special Administrative Region (HKSAR) government in fighting the latest COVID-19 outbreak.

Zhang Nu, vice-president of the First Affiliated Hospital of Sun Yat-sen University in Guangzhou, capital of south China's Guangdong Province, is the person-in-charge for the team's nucleic acid sampling work.

He recalled how he got notified of joining the team in assisting Hong Kong while performing a surgery, "I packed my bags that night and left for Hong Kong the next afternoon," Zhang said.

He had traveled to Hong Kong before, but he knew that this trip was not a leisure one.

After their arrival, the team quickly received training on the procedures of nucleic acid testing in Hong Kong, which are slightly different from the mainland. For example, the mainland uses throat swab and Hong Kong uses a mixture of throat swab and nasal swab to collect samples.

At 10 am, people who were lining up for nucleic acid tests began flocking into the playground. Members of the medical team communicate in fluent Cantonese and English with the people including elderlies in wheelchairs, parents holding their babies, white-collar workers and foreigners, completing the testing procedures skillfully and smoothly.

"Their support means so much to us as we do not have enough manpower under the epidemic," a Hong Kong resident, surnamed Lam, expressed his sincere gratitude to the medical staff from the mainland.

The 60-years-old man needs to undergo required nucleic acid tests as he tested positive for COVID-19 before and recently turned negative.

With the assistance from the mainland medical team, the waiting time for taking the test has been significantly reduced. "Now we only have to line up for less than 30 minutes instead of a few hours, and will receive test results the day after," Lam told Xinhua.

Starting from Feb 20, more than 100 team members were put to work at five testing sites in Yuen Long, Yau Tsim Mong District, North District, Ma On Shan and To Kwa Wan. As of March 10, they have conducted tests for over 60,000 people, effectively relieving the pressure for COVID-19 testing in Hong Kong.

The job is definitely one that tests the team members' willpower.

Apart from being in possible contact with the highly transmissible Omicron variant of COVID-19 every day, challenges also came along with the unpredictable weather in early spring -- the unprecedented cold wave that hit Hong Kong in late February brought strong wind that blew over the tents and broke their dressing mirrors; and the bright sunshine in early March caused them to sweat head to toe in their protective gowns.

The medical staff have to wear full protective gears for six hours a day, during which they can not eat, drink or go to the bathroom.

"You see deep marks on their faces every time they take their masks off," Zhang spoke of their tough working conditions. "A lot of team members left their young children behind to come to Hong Kong and can only communicate with their families online."

Zhang said he is very proud of every team member that overcame multiple difficulties and performed duties outstandingly in such hectic working conditions.

As the epidemic raged, the medical team built a life-saving island in their work stations, giving the Hong Kong people hope and confidence.

More and more people deliberately came all the way to conduct nucleic acid tests at the team's work stations as they find the mainland medical staff very gentle and patient during the process.

Zhang and his colleagues felt a sense of warmth and accomplishment when they heard words of thanks and received thank you cards from local residents. "Someone even wrote a thank you note on a piece of tissue paper when he forgot to take paper," Zhang recalled.

Situ Miaoqiong, a mainland medical team member who also works at the First Affiliated Hospital of Sun Yat-sen University, once came to Hong Kong in 2020 to support the fight against the epidemic.

She was touched when she saw pedestrians waving and cheering for the team on her way to work. To the team members, the recognition and gratitude from the Hong Kong people warmed their hearts and gave them motivation.

On March 9, the HKSAR government announced a series of new anti-epidemic measures, and the exponential rise in COVID-19 cases has been largely contained.

Situ wished to take her family to Hong Kong for a trip after the epidemic is over.

"I want to take them back here to see the flourishing flowers and children happily playing around," she said.