Two cases of the B.1.1.529 coronavirus variant have been reported in Hong Kong, with the new strain spreading from a traveller from South Africa who was undergoing quarantine to a person occupying the room across from him in a hotel where they were both in isolation.
Hong Kong’s Department of Health said genome sequencing revealed that the first patient had come from South Africa while another hotel guest, from Canada, had tested positive for the B.1.1.529 strain five days later. Both travellers were fully vaccinated and undergoing quarantine, which is required for all international arrivals into Hong Kong which is still following a “zero COVID” strategy and has not seen any local outbreaks for many months.
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Travellers from South Africa, India, the U.S., the U.K and other countries deemed high risk have to undergo 21 days of isolation in a “designated quarantine hotel” in Hong Kong.
The new strain, which some experts say may be more transmissible because of mutations, spread within one of the quarantine hotels.
The traveller from South Africa, who is 36 years old, landed on November 11 and tested positive on November 15. All travellers undergo tests on arrival and a further six tests during their 21 days of quarantine. The second case was confirmed in the same hotel on November 20.
Epidemiological investigations by Hong Kong health authorities revealed that the virus likely spread from one hotel room across the corridor because the first traveller was using an improper mask, fitted with a valve, the South China Morning Post reported.
Valved masks to blame
Valved masks, health officials said, protect the wearer but allowed infected air to leave and spread across the hotel corridor. The spread likely occurred when the traveller opened his hotel room door to receive a package, which is allowed in quarantine hotels, although residents cannot step out of their rooms.
As a precautionary measure, all other residents of the same floor have been transferred to a centralised quarantine facility for a further 14 days of isolation. Health authorities said travellers and those undergoing quarantine will no longer be allowed to wear masks fitted with valves.