The Centre for Health Protection today said it is investigating five additional COVID-19 cases, all involving mutant strains. Four of them are imported cases and one is an import-related case.

For the imported cases, one patient arrived in Hong Kong from a high-risk place with enhanced surveillance and the other three flew in from high-risk places. Two patients tested positive upon arrival while two tested positive during quarantine.

Regarding the import-related case, after admission to hospital, the 64-year-old male patient had a cycle threshold (Ct) value below 30. He also tested positive for antibodies, compatible with his vaccination history.

He is a cleaner at an airport Midfield Concourse toilet solely used by preliminary positive imported cases waiting for transfer to hospital. The test results of the 26 environmental samples collected during the site visit there yesterday were all negative, the centre said.

In addition, about 14 people who are the patient’s close contacts, as well as about 40 household contacts and close contacts of those 14 individuals, have been arranged to undergo quarantine at a quarantine centre. No relevant confirmed case is detected at the moment.

The centre will conduct a further genetic analysis and a comparison with recent imported cases linked to the N501Y and T478K mutant strains, it added.

Furthermore, as the patient may carry the Omicron variant, the Government last night made a restriction-testing declaration at On Hei House, Siu Hei Court in Tuen Mun where the patient lives. The compulsory testing frequency has also been increased for related people.

Separately, the centre announced that according to the whole genome sequencing analysis conducted by the Government’s Public Health Laboratory Services Branch, the seven imported cases announced on December 20 and 21 carry the Omicron variant. There are hence 41 cases so far involving the Omicron variant in Hong Kong.

In view of four preliminary imported cases and a non-local case involving patients who had stayed in Hong Kong during the incubation period, 37 specified premises are included in the compulsory testing notice.

Mobile specimen collection stations will be set up at the basketball court in Tai Po Community Centre, Luen Wo Hui Community Hall in Fanling and the open area outside On Hei House, Siu Hei Court in Tuen Mun to provide a free testing service for people subject to compulsory testing.

A total of 72 cases have been reported in the past 14 days. All of them were imported.

For information and health advice on COVID-19, visit the Government’s dedicated webpage.