24 August 2015
The Centre for Health Protection (CHP) of the Department of Health is today (August 24) investigating two sporadic cases of Legionnaires' disease (LD) affecting two men aged 50 and 78 respectively.
The first case involves a 50-year-old man with good past health. He lives in a private building on Laguna Verde Avenue, Hung Hom, Kowloon. He has presented with fever, headache and diarrhoea since August 17, was admitted to a private hospital on August 20 for management, and was discharged today. The clinical diagnosis was pneumonia and he has been in stable condition.
His urine specimen tested positive for Legionella pneumophila serogroup 1 antigen upon testing by the CHP's Public Health Laboratory Services Branch.
Initial enquiries revealed that the patient had travelled to Hanoi, Vietnam, from August 13 to 15 during the incubation period. His travel collateral has remained asymptomatic.
The second case involves a 78-year-old man with underlying illnesses. He lives in a private building on Man Ying Street, Yau Ma Tei, Kowloon. He has presented with fever and cough with sputum since August 17 and was admitted to Queen Elizabeth Hospital (QEH) on August 20 for management. The clinical diagnosis was pneumonia and he has been in stable condition.
His urine specimen tested positive for Legionella pneumophila serogroup 1 antigen upon testing by QEH.
Initial enquiries revealed that the patient had no travel history during the incubation period. His home contact has remained asymptomatic.
"We are conducting epidemiological investigations into the possible source of infection of both cases. Relevant water samples and environmental swabs will be collected from potential sources for laboratory testing. We have provided health advice against LD to both patients," a spokesman for the CHP said.
"As Legionella are found in various environmental settings and aqueous environments, investigations are ongoing," the spokesman added.
These are the 38th and 39th LD cases reported to the CHP this year. In 2014 and 2013, 41 and 28 were recorded respectively.
Legionella are found in various environmental settings and grow well in warm water (20 to 45 degrees Celsius). They can be found in aqueous environments such as water tanks, hot and cold water systems, cooling towers, whirlpools and spas, water fountains and home apparatus that support breathing. People may get infected when they breathe in contaminated droplets (aerosols) and mist generated by artificial water systems. They may also get the infection when handling garden soil, compost and potting mixes.
It is most important to operate and maintain properly designed man-made water systems to prevent LD. The public may visit the pages below for more information: