Hong Kong reports six new Legionnaires' disease cases in a week
Hong Kong's Centre for Health Protection recorded six community cases of Legionnaires' disease from 1 to 7 November. All patients are aged 60 to 80 with underlying illnesses. The department urged at-risk groups to follow prevention guidelines.
Hong Kong's Centre for Health Protection (CHP) has reported six new community-acquired cases of Legionnaires' disease in the week from 1 to 7 November, according to a government press release on 9 November. The patients, five men and one woman aged between 60 and 80, all have chronic underlying medical conditions. They reside in Sha Tin (two), Tai Po, Sai Kung, Kwun Tong and the North District.
The CHP has launched epidemiological investigations to identify possible sources of infection and high-risk exposure factors. Preliminary findings indicate the cases are sporadic, with no evidence linking them to other confirmed cases previously recorded in Hong Kong.
As of 7 November, 175 cases of Legionnaires' disease have been recorded this year. Hong Kong reported 167 cases in 2025 and 135 cases in 2024.
Men, people aged over 50, smokers, heavy drinkers and those with weakened immune systems are at higher risk of contracting the disease, the CHP said. Other risk factors include poorly maintained water systems, living in buildings with old plumbing or nearby cooling towers or fountains, and use of electric water heaters, jacuzzis, hot springs or recent stays in hotels or on ships.
Legionella bacteria thrive in warm water between 20 and 45 degrees Celsius and can be found in water tanks, hot and cold water systems, cooling towers, jacuzzis, fountains, humidifiers and home respiratory equipment. Infection typically occurs when contaminated water droplets or mist from artificial water systems are inhaled. Handling garden soil, compost or potting mix can also pose a risk.
The CHP advised immunocompromised individuals to use sterile or boiled water for drinking, brushing teeth and rinsing, and to avoid using humidifiers or mist-generating devices unless filled with sterile or cooled boiled water. All such equipment should be cleaned and maintained regularly, with water reservoirs emptied and dried daily.
General advice includes maintaining personal hygiene, not smoking and avoiding alcohol. Residents should regularly clean and disinfect tap and shower head filters, and drain unused water outlets for at least one minute weekly. Building water tanks should be drained and cleaned at least quarterly. The government also urged smokers to call the Department of Health's smoking cessation hotline at 1833 183 for professional counselling.
