Update on cases of Legionnaires' disease
From August 21 to 27, nine community-acquired LD cases were reported:
- A male patient, aged 52 with underlying illnesses, who lives in Hang Lai House, Cheung Hang Estate, Tsing Yi;
- A male patient, aged 78 with underlying illnesses, who lives in Yan Lok House, Tin Yan Estate, Tin Shui Wai;
- A female patient, aged 75 with underlying illnesses, who lives in Yan Lok House, Tin Yan Estate, Tin Shui Wai;
- A female patient, aged 60 with underlying illnesses, who lives in Hei Wah House, Lok Wah South Estate, Ngau Tau Kok;
- A male patient, aged 80 with underlying illnesses, who lives in Wah Yat House, Tin Wah Estate, Tin Shui Wai;
- A male patient, aged 58 with underlying illnesses, who lives in Ching Tai House, Tsz Ching Estate, Wong Tai Sin;
- A male patient, aged 82 with underlying illnesses, who lives in Flourish Mansion, 9 Cheung Wong Road, Mong Kok;
- A male patient, aged 84 with underlying illnesses, who lives in Yan Chi House, Tin Yan Estate, Tin Shui Wai; and
- A male patient, aged 86 with underlying illnesses, who lives in Block O, Amoy Gardens, Ngau Tau Kok.
"Epidemiological investigations are ongoing to identify potential sources of infection, high-risk exposure and clusters, if any," a spokesman for the CHP said.
As of August 27, 52 LD cases had been reported this year. In 2021 and 2020, there were 69 and 104 cases respectively.
"Men, people aged over 50, smokers, alcoholics and persons with weakened immunity are more susceptible to LD. Some situations may also increase the risk of infection, including poor maintenance of water systems leading to stagnant water; living in areas with old water systems, cooling towers or fountains; using electric water heaters, whirlpools and spas or hot water spring spas; and recent stays in hotels or vessels," the spokesman said.
Legionellae 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 become infected when they breathe in contaminated droplets (aerosols) and mist generated by artificial water systems, or when handling garden soil, compost and potting mixes.
Immunocompromised persons should:
- Use sterile or boiled water for drinking, tooth brushing and mouth rinsing;
- Avoid using humidifiers, or other mist- or aerosol-generating devices. A shower may also generate small aerosols; and
- If using humidifiers, or other mist- or aerosol-generating devices, fill the water tank with only sterile or cooled freshly boiled water, and not water directly from the tap. Also, clean and maintain humidifiers/devices regularly according to manufacturers' instructions. Never leave stagnant water in a humidifier/device. Empty the water tank, wipe all surfaces dry, and change the water daily.
The public should observe the health advice below:
- Observe personal hygiene;
- Do not smoke and avoid alcohol consumption;
- Strainers in water taps and shower heads should be inspected, cleaned, descaled and disinfected regularly or at a frequency recommended by the manufacturer;
- If a fresh-water plumbing system is properly maintained, it is not necessary to install domestic water filters. Use of water filters is not encouraged as clogging occurs easily, which can promote growth of micro-organisms. In case water filters are used, the pore size should be 0.2 micrometres (µm) and the filter needs to be changed periodically according to the manufacturer's recommendations;
- Drain and clean water tanks of buildings at least quarterly;
- Drain or purge for at least one minute infrequently used water outlets (e.g. water taps, shower heads and hot water outlets) and stagnant points of the pipework weekly or before use;
- Seek and follow doctors' professional advice regarding the use and maintenance of home respiratory devices and use only sterile water (not distilled or tap water) to clean and fill the reservoir. Clean and maintain the device regularly according to the manufacturer's instructions. After cleaning/disinfection, rinse the device with sterile water, cooled freshly boiled water or water filtered with 0.2 µm filters. Never leave stagnant water in the device. Empty the water tank, keep all surfaces dry, and change the water daily; and
- When handling garden soil, compost and potting mixes:
- Wear gloves and a face mask;
- Water gardens and compost gently using low pressure;
- Open composted potting mixes slowly and make sure the opening is directed away from the face;
- Wet the soil to reduce dust when potting plants; and
- Avoid working in poorly ventilated places such as enclosed greenhouses.
The public may visit the CHP's LD page, the Code of Practice for Prevention of LD and the Housekeeping Guidelines for Cold and Hot Water Systems for Building Management of the Prevention of LD Committee, and the CHP's risk-based strategy for prevention and control of LD.
Ends/Monday, August 29, 2022
Issued at HKT 19:05
Issued at HKT 19:05