Hong Kong's Centre for Health Protection, part of the Department of Health, reported three community-acquired Legionnaires' disease cases for the period from August 30 to September 5, 2026, in a statement issued on September 7. The cases involved two men and one woman aged between 61 and 68, all with underlying illnesses. The patients were a 61-year-old man and a 67-year-old man living in Kwai Tsing District, and a 68-year-old woman living in Tuen Mun District.

The centre said initial investigation indicated the three cases were sporadic, with no epidemiological links established to other confirmed cases previously recorded in Hong Kong. It said epidemiological investigations were under way to identify potential sources of infection and high-risk exposure. The centre noted that Legionnaires' disease incidence is related to ambient temperature, with more cases recorded in summer months when warmer conditions favour proliferation of the bacteria. As of September 5, 139 cases had been recorded in 2026; there were 167 cases in 2025 and 135 in 2024.

The department reminded the public to use and maintain properly designed man-made water systems and listed precautions, including regular cleaning of taps and shower heads and draining and cleaning building water tanks at least quarterly. It said men, people over 50, smokers, people who drink heavily and those with weakened immunity are more susceptible, and it urged the public to quit smoking and avoid alcohol.