Issue link: https://hi.iaq.net/i/692160
24 DEVELOPING A LEGIONELLA WATER MANAGEMENT PROGRAM IDENTIFYING & INVESTIGATING LEGIONNAIRES' DISEASE CASES Healthcare facilities are often uniquely positioned to identify and respond to cases of Legionnaires' disease. A healthcare facility's water management program to limit Legionella growth and spread should include the actions to take when a patient is diagnosed with Legionnaires' disease or environmental triggers occur. If you decide to conduct a full investigation of the source of an infection, key elements should be included, as noted below. A full investigation following a diagnosis of Legionnaires' disease can help determine whether the infection was acquired in the facility or the community. Clinicians should test patients with healthcare-associated pneumonia for Legionnaires' disease. This is especially important among patients at increased risk for developing Legionnaires' disease (see Appendix A), among patients with severe pneumonia (in particular those requiring intensive care), or if any of the following are identified in your facility: 6 6 6 Patients with Legionnaires' disease, no matter where they acquired the infection Positive environmental tests for Legionella Changes in water quality that may lead to Legionella growth (such as low chlorine levels) The preferred diagnostic tests for Legionnaires' disease are culture of lower respiratory secretions on selective media and the Legionella urinary antigen test. Perform a full investigation for the source of Legionella when: 6 6 ≥1 case of definite healthcare-associated Legionnaires' disease (a case in a patient who spent the entire 10 days prior to onset of illness in the facility) is identified ≥2 cases of possible healthcare-associated Legionnaires' disease (cases in patients who spent part of the 10 days before symptoms began at the same facility) are identified within 6 months of each other Key elements of a full investigation include: 6 6 6 6 6 6 6 6 6 6 Working with local and/or state health department staff Reviewing medical and microbiology records Actively identifying all new and recent patients with healthcare-associated pneumonia and testing them for Legionella using both culture of lower respiratory secretions and the Legionella urinary antigen test Developing a line list of cases Evaluating potential environmental exposures Performing an environmental assessment Performing environmental sampling Subtyping and comparing clinical and environmental isolates Decontaminating environmental source(s) Reviewing and possibly revising the water management program Reference: ASHRAE 188: Legionellosis: Risk Management for Building Water Systems June 26, 2015. ASHRAE: Atlanta. www.ashrae.org Note: ASHRAE 188 Normative Annex A applies to accredited healthcare facilities that have a Certification Board of Infection Control and Epidemiology (CBIC) certified infection preventionist or a master's-level epidemiologist.