Further tests on water samples taken from a Discovery Bay spa pool have confirmed the growth of Legionella, a type of bacteria causing Legionnaires' disease.

The Centre for Health Protection closed the spa after a 38-year-old man fell ill with the disease on December 27. He is stable in a private hospital. During the incubation period he stayed in a relative's home and used the spa, and had also travelled to the Mainland.

The centre's hotline 2125 1122 has so far received 66 enquiries about the disease, with 40 from people who visited the facilities. None have symptoms.

The centre urges operators of jacuzzis and owners of man-made water systems to keep the facilities disinfected and clean to prevent infection. Symptoms include fever, dry cough, shortness of breath, tiredness, headache, muscle pain, abdominal pain and diarrhoea. The incubation period is two to 10 days.

Discovery Bay residents who have visited the facilities should monitor their health and see a doctor if symptoms start.