Update of investigation into a cluster of Legionnaires’ disease

     The Centre for Health Protection (CHP) of the Department of Health today (March 4) announced an update on its investigation into a cluster of Legionnaires' disease (LD) cases involving 15 patients reported in February.

     The cluster of LD cases, which was announced on February 1, 3, 6, 7, 10, 11, 13, 17, 18 and 29, involves a total to 12 male and three female patients aged 52 to 94. The patients’ respiratory specimens were positive for Legionella pneumophila serogroup 1 (Lp1) upon laboratory testing.

     "Our laboratory investigations show that respiratory specimens of eight patients of the cluster and two water samples collected from cooling towers at the Choi Hung MTR station before disinfection were of the same sequence type of Lp1. Investigations suggest that the cooling towers could be source of infection of this outbreak," A spokesman for the CHP said.

     "Upon laboratory testing, water samples collected from four cooling towers at the Choi Hung MTR station after disinfection revealed concentration of Legionella pneumophilia below the action level." A spokesman for the CHP added.

     As of February 29 this year, 27 LD cases had been reported. In 2019 and 2018, there were 105 cases each year.