The Centre for Health Protection today said it is investigating nine additional COVID-19 cases, of which six are imported, two are epidemiologically linked with imported cases and one is local.

All of the cases involve mutant strains.

One of the linked cases entails a 21-year-old woman who worked at a clinic at Gold Coast Piazza in Tuen Mun on January 3 where two previous cases' patients had sought medical attention.

The other one involves a woman, aged 46, who is a household contact of an earlier case.

For the local case, the 29-year-old male patient lives at Yat Wan House, Tin Yat Estate in Tin Shui Wai. He works at construction sites in Kai Tak and Tai Po, and also works as a takeaway food courier in Yuen Long.

The patient was admitted to a hospital on January 12 due to a traffic accident. He preliminarily tested positive during an admission screening, with a cycle threshold (Ct) value larger than 30.

An initial investigation revealed that the man has no recent travel history and has not visited places where any positive cases have stayed. No close contacts between the man and other recent positive cases have been found so far.

The centre is tracing the places where the patient visited in the past 21 days in order to ascertain the infection source and terminate the silent transmission chains in the community.

Separately, the centre reported that the preliminarily positive test result of a sample from a 22-year-old nurse was not caused by infection.

The nurse works at three clinics in Tuen Mun, same as the abovementioned 21-year-old patient. Her sample tested preliminary positive by a private laboratory earlier, with a Ct value larger than 30.

According to the test result released by the Department of Health's Public Health Laboratory Services Branch, the sample does not carry the N501Y mutant strain, but it does carry the D614D strain which is compatible with the SARS-CoV-2 vaccine strain.

The nurse's test result for the virus after admission to the hospital was negative and she did not have any conditions that could be caused by a real infection.

The centre today visited the clinic where the sample was taken. After examining relevant findings, it considered that the case is compatible with vaccine strain contamination and hence will not be classified as a case of COVID-19 infection.

The quarantine order of the nurse's close contacts will also be lifted.

Meanwhile, the Government made a restriction-testing declaration for Tower 4, Bauhinia Garden in Tseung Kwan O tonight due to the detection of a preliminarily positive case. People within the restricted area need to undergo compulsory testing by 1am tomorrow.

The case involves a 51-year-old woman who is a security guard working at the Penny's Bay Quarantine Centre. Her colleague, who is also a security guard, was infected with COVID-19 earlier and the woman was classified as a close contact.

The woman began undergoing quarantine on January 11. She developed symptoms yesterday and tested preliminary positive today.

In view of one import-related case and one case who tested preliminarily positive, five specified premises are included in a compulsory testing notice.

The Government also announced that four specified premises included in the compulsory testing notice announced on January 8 are deleted.

Furthermore, the address of a specified premises included in the compulsory testing notice announced on January 10 should be Community Testing Centre at Henry G Leong Yaumatei Community Centre, 60 Public Square Street in Yau Ma Tei.

The Government will reopen five mobile specimen collection stations in Kowloon Tong, Tuen Mun, Tung Chung and Discovery Bay tomorrow to provide free services for people subject to compulsory testing. 

A total of 385 positive cases were reported in Hong Kong in the past 14 days, of which 59 are epidemiologically linked with imported cases or possibly import-related, one is local, and the rest are imported.

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