People living in units 13 and 14 of the top six floors of Heng Tai House in Fu Heng Estate, Tai Po need to be quarantined as a precaution.

Hong Kong University Chair of Infectious Disease Prof Yuen Kwok-yung made the statement at a media briefing today after an expert team conducted initial epidemiological investigations in the building to find the cause of a new COVID-19 infection.

The new case announced this afternoon involves a 59-year-old man who lives on the 34th floor of the building.

Prof Yuen said: “There is a possibility that when the patients on the 32nd floor are defecating - we know now that the fecal material actually contains the virus - while they’re defecating the fecal material goes into the sewer system.

“There is a vent of air that comes through the venting pipe, which goes to the top floor and maybe aerosolised in the air and then the droplets try to settle but, while at the same time, when there’s a light wind blowing, in which the air current going over the rooftop carries the particles back into the top floors.

“And of course, the 34th floor is the top floor. That is the most dangerous, followed by the 33rd and 32nd floors.”

Prof Yuen added he is uncertain if the venting pipe will continue to produce more infected aerosolised particles.

“So it is just a precautionary measure that we must remove the residents from the top six floors in units 13 and 14 for a period of time.”

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