Hong Kong reports six new Legionnaires' disease cases in one week
Hong Kong's Department of Health reported six community-acquired Legionnaires' disease cases from 25 to 31 October, involving men aged 48 to 78 in various districts. The centre said the cases are sporadic with no epidemiological link to previous cases, bringing the 2026 total to 169.
Hong Kong's Department of Health reported six new community-acquired cases of Legionnaires' disease in the week from 25 to 31 October, involving six men aged between 48 and 78. The patients resided in Wan Chai, Yau Tsim Mong, Southern, Sha Tin and Tai Po districts, the department said in a statement on 2 November.
The Centre for Health Protection has launched epidemiological investigations to identify possible sources of infection and high-risk exposure factors. Preliminary findings indicated the cases are sporadic, with no evidence linking them to other confirmed cases previously recorded in Hong Kong, the centre said.
As of 31 October, a total of 169 Legionnaires' disease cases have been recorded in Hong Kong this year, compared with 167 in 2025 and 135 in 2024, according to the department.
The department noted that men, people aged over 50, smokers, heavy drinkers and those with weakened immune systems are more susceptible to Legionnaires' disease. Other risk factors include poorly maintained water supply systems, use of old water systems in homes, proximity to cooling towers or fountains, use of electric water heaters, spas or hot springs, and recent stays in hotels or on ships.
Legionella bacteria can thrive in various environments, particularly in warm water between 20 and 45 degrees Celsius. Sources include water tanks, hot and cold water systems, cooling towers, spas, fountains, humidifiers and home respiratory medical equipment. Infection can occur through inhaling contaminated water droplets or mist from human-made water systems, and also when handling garden soil, compost or potting mix.
The department advised immunocompromised individuals to use sterile or boiled water for drinking, brushing teeth and rinsing; avoid using humidifiers or other mist-producing devices; and, if using such devices, to use sterile water or freshly boiled cooled tap water rather than direct tap water. It also urged regular cleaning and maintenance according to manufacturers' instructions.
The department also called on the public not to smoke and to avoid alcohol, and provided contact details for its smoking cessation hotline and an alcohol screening and brief intervention tool for primary healthcare providers.
