13 Jun Legionnaires’ Disease Is Widespread and Deadly in US Health Care Facilities

MedicalResearch.com Interview with:
Elizabeth A. Soda, MD
Epidemic Intelligence Service
Divison of Bacterial Diseases
National Center of Immunization and Respiratory Diseases
CDC

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Legionella is a waterborne bacterium responsible for Legionnaires’ disease, an often severe pneumonia. Legionnaires’ disease primarily affects certain groups of individuals such as those ≥50 year of age, current or former smokers, and those with chronic diseases or weakened immune systems. Health care facilities often have large and complex water systems and care for vulnerable populations that are susceptible to developing Legionnaires’ disease. Thus preventing hospitalized patients from developing Legionnaires’ disease is the ultimate goal. This analysis aimed to describe health care-associated Legionnaires’ disease in 2015 from the 21 U.S. jurisdictions that completely reported their health care-associated Legionnaires’ disease cases to the CDC’s Supplemental Legionnaires’ Disease Surveillance System (SLDSS).

Over 2,800 cases of Legionnaires’ disease cases were reported to SLDSS by the 21 jurisdictions, and 553 (20%) were considered health care associated. The analysis showed 16 of the 21 (76%) jurisdictions had at least one case of Legionnaires’ disease definitely related to a stay in a hospital or long-term care facility. In total there were 85 (3%) definite health care-associated Legionnaires’ disease cases (as defined by continuous exposure to a hospital or long-term facility for the entire 10 days before symptom onset) that resulted from 72 different health care facilities.

Additionally, 20 of 21 jurisdictions (95%) reported 468 (17%) possible health care-associated Legionnaires’ disease cases (as defined by any exposure to a health care facility for a portion of the 10 days before symptom onset) that resulted from approximately 415 different health care facilities.

While approximately 9% of Legionnaires’ disease cases overall are fatal, this report showed a case fatality of 25% for definite health care-associated cases.

MedicalResearch.com: What should clinicians and patients take away from your report?

Response: Legionnaires’ disease in U.S. health care facilities is widespread and deadly, but preventable. Additionally even though definite health care-associated cases only accounted for 3% of the total reported cases, we believe that this number just represents the tip of the iceberg with many more cases that were never diagnosed.

Through the collaboration of health care facility leaders, healthcare providers, and public health officials effective prevention and response activities can reduce the number of cases. In health care facilities, the prevention of the first case is likely best achieved by the implementation and maintenance of an effective water management program. ASHRAE standard 188 provides guidance on the development of such a program. CDC and its partners simplified this standard into a toolkit (https://www.cdc.gov/legionella/WMPtoolkit). Additionally, efforts such as rapid case identification through appropriate diagnostics testing and timely case reporting and investigations are need for case reduction.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Currently we do not have a clear understanding of how many U.S. health care facilities have already implemented an effective water management program. A better understanding of this number would be helpful as we continue to monitor disease trends over time. Most recently, the Centers for Medicare and Medicaid Services released a survey and certification memo requiring all health care facilities to have an ASHRAE-compliant water management program. This may aid in our understanding of this number.

MedicalResearch.com: Is there anything else you would like to add?

Response: Besides having an effective water management program in place, there are other important activities as part of Legionella prevention and response. For instance, when heath care providers know who to test and which tests to use when considering Legionella in the diagnosis, early case identification and likely subsequent prevention of future cases, can occur. Legionella should be considered in the differential diagnosis of health care-acquired pneumonia especially among groups known to be more vulnerable to developing Legionnaires’ disease, when other facility-related cases of Legionnaires’ disease have been identified, or when a facility’s water parameters are conducive to supporting the growth of Legionella. The recommend clinical testing procedure is obtaining (prior to antibiotic administration) both a lower respiratory sputum sample for culture on selective media and a Legionella urinary antigen test. While easy to obtain and perform, the urinary antigen test only detects Legionella pneumophila serogroup 1, and thus the use of culture is needed to identify other species and serogroups.

Last, we would like to emphasize the importance of public health reporting of Legionella both to state and local officials as well as to the national surveillance systems. For instance, with improved reporting to SLDSS we can continue to gain knowledge about Legionella exposures, testing, and outcomes on the national scale.

I have nothing to disclose.

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Citation:

Soda EA, Barskey AE, Shah PP, et al. Vital Signs: Health Care–Associated Legionnaires’ Disease Surveillance Data from 20 States and a Large Metropolitan Area — United States, 2015. MMWR Morb Mortal Wkly Rep 2017;66:584–589. DOI: http://dx.doi.org/10.15585/mmwr.mm6622e1

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

Last Updated on June 13, 2017 by Marie Benz MD FAAD