Xiao explains that team members usually have their meal before starting work and try not to eat during the course of their shift.

"We wanted to finish the work as soon as possible to curb the epidemic, so as to allow Hong Kong residents to live a mask-free life," Xiao says.

Unfortunately, many of the support team members have developed insomnia and other sleeping problems after being on night shifts for several days. Cai Yonglin, another team member, says that many of them did not have time to rest after arriving in Hong Kong and went straight to work in the laboratory after attending the training session.

Since Cai learned that the support team's efforts and effectiveness has been highly appreciated by Hong Kong residents, he is determined to work harder to help uncover asymptomatic carriers of the virus.

"The sooner we find them, the lower the chances are that they will spread the disease," he says.

"There were four days when we tested more than 200,000 samples, which was satisfactory and had exceeded our expectations," Yu says.

As of Sunday morning, more than 1.67 million samples had been collected under the mass testing program, which concluded on Monday.