Study Suggests HK Has 700 'silent Carriers' Of Virus

An expert who advises the government on Covid-19 warned on Saturday that hundreds of 'silent carriers' who recently returned to Hong Kong from overseas may be spreading coronavirus in the community, amid a sharp spike in cases in the territory.

Professor David Hui, a respiratory disease expert from Chinese University, said analysis of saliva samples from incoming travellers show around one percent are asymptomatic carriers – meaning they tested positive for the coronavirus without displaying any symptoms.

Multiple studies have shown such carriers can spread the virus and infect others, despite suffering no visible ill effects themselves.

Hui said this is concerning because a large number of people had flooded back to Hong Kong before the imposition of mandatory 14-day quarantines on almost all incoming travellers earlier this month.

“If you look at the number of people who returned to Hong Kong before March 19, there were about 70,000, so [based] on this one percent positive result, there would be around 700 people moving around in the community. So potentially some of them may still carry the virus, and can introduce the virus into the community”, he said.

Hui urged the government to consider using another new public housing block as a temporary quarantine centre, to house people who are not suitable to be isolated at home because of cramped conditions.

He said the risk of transmission is relatively high in Hong Kong, given the lack of space and the population density.

Another expert, Dr Leung Chi-chiu, who chairs the Medical Association’s Advisory Committee on Communicable Diseases, also questioned the effectiveness of home quarantine for people who live in small flats.

He told the same radio programme that few people under quarantine have independent bedrooms or bathrooms, meaning that other people living in the same flat would potentially be exposed to the virus.

He called on the government to seek out more hotels to use as quarantine centres, to house such people until they’re cleared of the virus.

A record 65 new coronavirus cases were reported in Hong Kong on Friday, bringing the total tally to 518.