BACKGROUND: The Florida Department of Health’s (DOH) Food and Waterborne Disease Program (FWDP) investigated two legionellosis outbreaks in the same retirement community facility in 2014 and 2015. The facility is regulated by multiple state agencies, including DOH, the Agency for Health Care Administration (AHCA), the Department of Business and Professional Regulation, and the Department of Environmental Protection.
METHODS: FWDP conducted an investigation of legionellosis cases associated with the facility in 2014 and made transmission prevention recommendations. Increased surveillance detected another outbreak among facility residents in 2015. In both outbreaks, the FWDP reviewed risk factors, exposure information and performed facility environmental assessments. Water samples collected were analyzed by the DOH Bureau of Public Health Laboratories (BPHL). The facility hired an independent consultant to collect water samples, which were tested at a private laboratory and BPHL.
RESULTS: Four cases were associated with the 2014 outbreak; all required hospitalization and two were independent living (IL) residents. BPHL identified Legionella pneumophila (Lp) in 65.5% (5/8) of water samples collected. Remediation involved multiple thermal disinfection treatments and installation of a continuous secondary disinfection system. An informal Legionella monitoring program was attempted. One month prior to the 2015 outbreak, the disinfection system was offline due to equipment failure. Water samples indicated Legionella had recolonized the water system and the private company made recommendations to hyperchlorinate the system. The owner declined. In 2015, seven cases were hospitalized and two died; three were IL residents. Water samples analyzed by BPHL were negative for Legionella. However, the private laboratory detected Legionella in 26.7% (20/75) of water samples. Remediation included a 24-hour hyper-chlorination treatment. Both outbreaks were complicated by the lack of medical records for IL residents. The AHCA license does not require hybrid facility nursing staff to maintain medical records on IL residents or track community-acquired pneumonia cases.
CONCLUSIONS: Despite remediation efforts after the 2014 outbreak, inadequate management of facility maintenance may have contributed to recolonization of the plumbing system. Hybrid facilities caring for both IL and nursing home residents result in disease monitoring that goes beyond regulation requirements. Facilities should enforce their prevention plan, have increased awareness, and continued public health surveillance of illness clusters potentially associated with the facility. These outbreaks highlight the importance of owner-approved Legionella prevention planning, to include maintenance and water safety management protocols, as well as conducting enhanced surveillance of hybrid care facilities for multiple types of vulnerable populations.