The Centre for Health Protection is investigating a case of Legionnaires' disease involving a 78-year-old Tsuen Wan man.

He came down with a fever, coughing, muscle pain and tiredness on July 2. He was admitted to Yan Chai Hospital July 7 and was discharged July 11.

He has no recent travel history.

It is the 21st case this year. There were 13 last year.