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CDC Revises Number of Reported Legionellosis Cases Upward for 2018


CDC Revises Number of Reported Legionellosis Cases Upward for 2018

Key Takeaways:

  • The CDC revised upward the number of 2018 Legionellosis cases, the majority of which were for Legionnaires’ disease, which has been on the rise since 2000

  • Nineteen percent of Legionnaires’ disease outbreaks between 2000-2014 were associated with long-term care facilities and another 15 percent with hospitals, according to a recent survey

  • In July 2018, the Centers for Medicare and Medicaid Services issued a memorandum to certified health care facilities regarding their expectations for mitigation of Legionella risks, including a properly documented water management plan


The original number of cases of Legionellosis reported by the CDC for 2018 was already a record 8,356 cases. This November, that number was revised upward by 1,577 cases to 9,933 representing an increase of 18.8 percent. Although Legionellosis includes both Legionnaires’ disease and Pontiac fever, the vast majority of these newly reported cases were for the more serious diagnosis of Legionnaires’ disease.

Legionnaires’ disease is a serious type of pneumonia caused by a waterborne pathogen known as legionella. It is contracted when susceptible individuals inhale water droplets or mist containing elevated levels of legionella bacteria. Even for those persons exposed to virulent strains of this pathogen, only about five percent contract Legionnaires’ disease. Those contracting the disease are susceptible due to age, some pre-existing condition or compromised immune system. Smoking, obesity and diabetes are also risk factors. The death rate from Legionnaires’ disease is approximately 10 percent but approaches 25 percent in susceptible nosocomial settings. Foremost among such settings are hospitals, nursing homes and senior living facilities. A recent survey of Legionnaires’ disease outbreaks between 2000-2014 revealed that 19 percent were associated with long-term care facilities and another 15 percent with hospitals. Those who survive the disease may have been comatose, intubated and may have sustained serious permanent injury such as partial paralysis, brain injury or amputated extremities following prolonged sepsis and organ failure.

Without question, the number of Legionnaires’ disease cases reported to the CDC has been on the rise since 2000, increasing at a rate 286 percent for the period of 2000 through 2014. Health departments reported about 6,100 and 7,500 cases of Legionnaires’ disease in the United States in 2016 and 2017, respectively. Clearly, there is consensus that even these numbers do not reflect the full story. The CDC has stated that it believes the actual number approaches 18,000 cases. In August 2019, the National Academies of Sciences, Engineering and Medicine (NASEM) published that it believes the real number approaches 70,000 cases per year in the United States. There appears to be no relief in sight as reported cases in 2019 create national headlines, with outbreaks in Atlanta, Georgia, and Asheville, North Carolina alone, sickening over 210 people.

In July 2018, the Centers for Medicare and Medicaid Services (CMS) issued a clarifying memorandum to certified healthcare facilities regarding CMS’s expectations for mitigation of legionella risks. Specifically, CMS’s letter revises prior memoranda issued June 2 and 9, 2017 to clarify that the CMS requirement to reduce legionella risks in health care facility water systems included hospitals, critical access hospitals, long-term care facilities and was intended to provide general awareness for all health care organizations.

CMS has made it clear that it expects all providers to have a properly documented water management plan which, at a minimum, conducts a facility risk assessment that:

  • Identifies where legionella and other opportunistic waterborne pathogens could grow and spread in the facility water system
  • Develops and implements a water management program that considers the ASHRAE 188 industry standard: ASHRAE Standard 188-2015: Legionellosis: Risk Management for Building Water Systems June 26, 2015. ASHRAE: Atlanta. and the CDC toolkit; “Legionella” Centers for Disease Control and Prevention, September 14, 2017.
  • Specifies testing protocols and acceptable ranges for control measures, and documents the results of testing and corrective actions taken when control limits are not maintained
  • Maintains compliance with other applicable federal, state and local requirements. (CMS does not require water cultures for Legionella)

Notably, this protocol stops short of requiring testing specifically for Legionella bacteria, a position currently inapposite to testing requirements supported by the American Industrial Hygiene Association (AIHA), NASEM, The U.S. Department of Veterans Affairs (DVA) and the New York cooling tower regulations enacted in 2015.

Even when facilities have water management plans in place, Legionella bacteria can still inoculate a water system and amplify to dangerous levels. A 2018 investigation conducted by the state health officials in Missouri sampled water in a collection of 61 hospitals, nursing homes and hotels over a one-year period. Documents obtained through public record requests showed that seven of those facilities tested positive for Legionella despite having active water management plans.

In light of upward trending numbers of reported cases of Legionellosis and the continuing difficulty in remediating Legionella from even well managed building water systems, the revised CMS policy should be communicated with all facility managers and staff associated with facility water management for any hospital, critical access hospital, nursing home, post-acute care provider or assisted living facility subject to the CMS guidelines. Those facilities unable to demonstrate measures to minimize the risk of Legionnaires’ disease are at risk of citation for non-compliance. Beyond citations for noncompliance, the incidence of litigation arising out of Legionnaires’ disease outbreaks is rapidly increasing. Verdicts and reported settlements often exceed seven figures. Remediation costs following a full-blown outbreak are high and a complete shutdown of affected areas can be ordered by local health officials. Over and above the potential economic losses is the damage caused by bad publicity.

Navigating proper water management policies, remediating contaminated systems and defending lawsuits arising out of outbreaks requires significant experience. Goldberg Segalla’s toxic tort and health care attorneys are thought leaders throughout the country on compliance, remediation and litigation associated with Legionella infections in facilities subject to CMS oversight. We are knowledgeable of the current statutes, laws, regulations, standards and guidelines along with the latest scientific and medical literature. We regularly work and consult with many of the foremost experts on water management policy, Legionella prevention, remediation and infectious disease throughout the country, including addressing the conundrum of whether to specifically test for Legionella. For more information, please contact: