Officials have played down the possibility that two cases of the coronavirus in a single block in Tsing Yi could herald a major outbreak similar to the cluster of Sars cases at Amoy Gardens in Kowloon Bay in 2003.
Housing Department engineers will begin inspecting the toilets in flats in the building on Tuesday after it emerged that a 62-year old woman had developed the disease after another patient, who lives 10 storeys directly above her, was earlier diagnosed with the new virus.
People living in the equivalent flat – flat seven – on all 35 floors of Hong Mei House in the Cheung Hong Estate are being sent into quarantine centres while investigations continue.
The authorities say it's possible the virus spread through faecal matter. But officials say the building's U-shaped water pipes are in a good condition. The failure of U-shaped water seals at Amoy Gardens allowed the spread of Sars, eventually affecting more than 300 people, of whom 42 died.
University of Hong Kong microbiologist Yuen Kwok-yung told an early-morning media briefing on Tuesday this was not another Amoy Gardens. He said one possibility was that a broken exhaust pipe had allowed the virus to spread.
Wong Ka-hing, the controller of the Centre for Health Protection, said that if the toilets are in order "the residents in this particular unit can soon move back from the quarantine centre to their residence, if they do not have any symptoms suggestive of this new infection."
Officials said there was no need to evacuate everyone in the building, which is understood to be home to more than 2,000 people.
TA spokesman for the centre said: "As for household environmental hygiene, members of the public are advised to maintain drainage pipes properly and regularly pour water into drain outlets (U-traps); after using the toilet, they should put the toilet lid down before flushing to avoid spreading germs."