Hong Kong's Centre for Health Protection, part of the Department of Health, reported on October 12, 2026 that it recorded four Legionnaires' disease cases between October 4 and October 10, 2026, involving four males aged between 69 and 77, all with underlying illness. Three were locally acquired: two 76-year-old men living in Sha Tin and Kwun Tong districts, and a 77-year-old man in Kwai Tsing District. The fourth, a 69-year-old man in Kowloon City District, travelled to the Chinese Mainland during the incubation period, and further investigation is needed to determine whether the case was imported or community-acquired.

The CHP said initial investigation found the cases to be sporadic, with no epidemiological linkages established to other previously confirmed cases in Hong Kong. As of October 10, 2026, 157 Legionnaires' disease cases had been recorded that year, against 167 in 2025 and 135 in 2024.

The department noted that men, people over 50, smokers, heavy drinkers and those with weakened immunity are more susceptible. It advised regular cleaning of taps and shower heads, quarterly draining and cleaning of building water tanks, and precautions for immunocompromised people using humidifiers or respiratory devices. It also urged the public to quit smoking and avoid alcohol, citing cessation services.