A surge in legionnaires' disease, which at seven cases this year is an eight-year high, could be due to better awareness and improved diagnostics, the Centre for Health Protection said.
'The rise in the number of legionnaires' disease this year might be related to the vigilance of medical practitioners and advances in laboratory test methods in recent years,' said a spokeswoman for the centre.
The centre ruled out any clustering or a mainland factor, even though three patients diagnosed late last month were infected while travelling in China.
But infectious disease specialist Lo Wing-lok, who is a former legislator, said he believed high temperatures and heavy rainfall on the mainland 'are environmental factors that might affect legionnaires' disease'.
Legionnaires' disease is caused by the bacteria legionella. The disease was named after an outbreak in Philadelphia, in the United States, during the American Legion convention in 1976.
It can be spread through anything that sprays water, such as cold and hot water tanks, cooling towers, whirlpools, spas and water fountains.