The government on Monday said it had completed a mass Covid-19 testing exercise involving 18,900 residents of care homes and nursing homes for the elderly, with no new cases found.

Officials said the exercise was launched early last month, reflecting the fact that elderly people, especially those living in care homes, are at the highest risk in the pandemic.

The testing covered close to 800 homes and involved all residents who hadn't tested positive for Covid in the preceding three months. Staff members were also expected to undergo daily rapid tests or regular nucleic acid tests.

"The testing aimed to identify silent transmission in [residential care]/nursing homes and helped to achieve the goal of 'early identification, early isolation and early treatment', and to prevent transmission of the Covid-19 virus," a government spokesman said.

The only positive cases involved about 90 people whose tests had high CT values, which indicates a low viral load, described as re-positive cases.

The government said it was also encouraging residents and staff of care homes to get vaccinated and had carried out three phases of outreach vaccination. It said 66 percent of residents and 99 percent of staff had received at least two doses. Some 15 percent of residents and 47 percent of staff had received at least three.

Officials said they would continue to conduct regular tests on residents, and to require all care home staff to take daily rapid tests or regular nucleic acid tests.

"These measures can strengthen the anti-epidemic barriers of homes and identify any silent transmission as early as possible so as to empower the homes in tackling the possible sixth wave or the rebound of the fifth wave of the epidemic more effectively," the spokesman added.