Two Hong Kong Paralympic Village residents infected with norovirus have been discharged from hospitals, and food samples taken from the village tested negative for the virus, Director of Health Dr PY Lam says.

The two women came down with gastroenteritis symptoms on August 31 and September 1. The 19-year-old was admitted to Prince of Wales Hospital on September 1 while the other to Princess Margaret Hospital on September 4.

Dr Lam said so far no direct linkage is shown between the two cases, and the source of infection is still under investigation.

He noted the village's hygiene is of the highest standard, adding it has been accredited for implementation of Hazard Analysis & Critical Control Point, so its food is safe.

The village has no other outstanding cases of norovirus infection or acute gastroenteritis. It has carried out thorough disinfection following the Centre of Health Protection's health advice.

Transmission of norovirus can occur through contact with infected people, direct contact with infected secretions and contaminated objects. Observation of good personal hygiene and thorough disinfection will help cut its transmission.