A man fishes along Victoria Harbour in Hong Kong on May 8, 2022. (DALE DE LA REY / AFP)

HONG KONG – Hong Kong reported 250 new COVID 19 cases on Friday as health authorities investigated four untraceable cases of the Omicron subvariant BA.2.12.1.

Albert Au, Principal Medical and Health Officer of the Communicable Disease Branch of the Centre for Health Protection, said at a press briefing that the new cases comprised 29 imported infections and 221 local cases, bringing the tally to 1,198,957.

He added that 105 infections were confirmed through nucleic acid testing and 145 by rapid antigen tests.

READ: HK sees 251 new virus cases, Taikoo Shing cluster grows

Among the 29 imported cases, 13 were detected at the Hong Kong airport while 11 at quarantine hotels, Au said.

The untraceable cases suggested that there are silent transmission chains of the BA.2.12.1 subvariant in the community, particularly in Wan Chai area.

Albert Au, Principal Medical and Health Officer of the Communicable Disease Branch of the Centre for Health Protection

One case involved a 49-year-old cargo flight crew member who arrived in Hong Kong on May 26. He lives in Sai Kung and remained asymptomatic. The remaining four cases were detected after the travelers completed their hotel quarantine but they are believed to be re-positive cases, Au said.

Au also said that the source of infection of four cases detected in the community involving the Omicron BA.2.12.1 strain remained unknown.

The cases have no recent travel history and whole genome sequence analysis showed that they are linked to the McDonald’s cluster in Taikoo Shing.

Three of the four cases were members of the same family, with one of them – a 63-year-old woman – working at the Hong Kong Convention and Exhibition Center as a cleaner. 

The fourth case involved a 55-year-old woman who works at in a restaurant kitchen at the HKCEC. The two did not know each other but had both used the staff canteen and changing room, Au said.

“The untraceable cases suggested that there are silent transmission chains of the BA.2.12.1 subvariant in the community, particularly in Wan Chai area,” he said.

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He called on members of the public who had not been fully vaccinated to get the jab as soon as possible to lower the risk of infection.

Authorities are also investigating a possible cross-infection at quarantine hotel Courtyard Hong Kong Sha Tin

Authorities are also investigating a possible cross-infection at Courtyard Hong Kong Sha Tin.

Two new cases of the Omicron variant were reported at adjacent rooms of the quarantine hotel, involving a 39-year-old man from Singapore and a 32-year-old man from Sweden.

Au said the authorities will inspect the hotel to determine if the virus has spread in the hotel.

Larry Lee Lap-yip, chief manager (Integrated Clinical Services) of the Hospital Authority, said at the briefing that an 82-year-old man infected with COVID-19 passed away in the last 24 hours, raising the death toll during the fifth wave of COVID-19 to 9,162.