As evident in the 2003 SARS outbreak, the dry up of the U-traps had rendered the air barrier function futile in some of buildings, causing the virus to spread in bathroom through droplets which then became one of the agents for the outbreak.
The Centre for Health Protection reminds the public to ensure the U-traps contain water for air barrier in the bathroom and don’t let it dry up. It is recommended to pour half a litre of water into each drain outlet every week, and check the washbasins, bathtubs, toilets, and drainpipes regularly. If drainpipe leaks or is blocked, or foul odour comes out from drain outlets, arrange immediate repair by qualified plumber to curb virus spread.