The Centre for Health Protection (CHP) of the Department of Health today (March 10) reported the latest number of cases of Legionnaires' disease (LD), and continued to urge those who participated in the package tours organised by the Sino Step Travel Services to Qingyuan and Foshan between February 20 and 28 to contact the CHP as soon as possible for a health assessment and medical surveillance.

     From March 2 to 8, the CHP recorded eight imported and two community-acquired LD cases.
 
     All eight imported cases participated in package tours organised by the Sino Step Travel Services to Qingyuan and Foshan last month. Six of the cases had been announced on March 5 and March 7 respectively. The two most recent cases involve a 78-year-old male and a 66-year-old male who travelled on the package tours from February 20 to 22 and February 21 to 23 respectively.
 
     The CHP has been investigating and following up on the cases since receiving notification of the first case. The CHP has proactively contacted the participants of the same tour group that included the first infected person, as well as two other groups with the same itinerary and hotel accommodation, to provide assessments and medical surveillance, and has discovered the two new cases. Investigations revealed that the eight cases had no common local exposure history. Six of them participated in the package tour to Qingyuan and Foshan that departed on February 20, and two participated in the same tour that departed on February 21. Similar to the five imported cases recorded in November last year involving two package tours to Foshan, they stayed at the Mehood Hotel in Foshan during the trip (address: 16 Hongling 1 Road, Shishan Town, Nanhai, Foshan).
 
     The CHP has notified the health authorities of Guangdong about the above cases for environmental investigations. The CHP's epidemiological investigations are still in progress.
 
     The CHP has also notified the Travel Industry Authority to alert the travel industry about the situation. The CHP once again urges those who joined the following three package tours to call the hotline (Tel: 2125 2670) as soon as possible:
 
     Travel agent: Sino Step Travel Services
     Travel dates: February 20 to 22;
                    February 21 to 23; and
                    February 26 to 28
     Tour code: LB3280
     Destinations: Qingyuan and Foshan
 
     The hotline, which was launched on March 6, will be in operation until Friday (March 14) from 9am to 5pm from Monday to Friday. People who have joined the aforesaid package tours should seek medical advice immediately if they have a fever or feel unwell.
 
     Regarding the two community-acquired LD cases, details are as follow:
 

1. A male patient, aged 61 with underlying illnesses, who lives in Southern District; and
2. A male patient, aged 94 with underlying illnesses, who lives in Wan Chai District.

 
     The CHP is conducting epidemiological investigations on the above two community-acquired cases to identify potential sources of infection, high-risk exposure and clusters, if any.

     As of March 8, 31 LD cases had been recorded this year. In 2024 and 2023, there were 135 and 121 LD 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; 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.

     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; 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: 

1. Wear gloves and a face mask;
2. Water gardens and compost gently using low pressure;
3. Open composted potting mixes slowly and make sure the opening is directed away from the face;
4. Wet the soil to reduce dust when potting plants; and
5. 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, March 10, 2025
Issued at HKT 18:00

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