Legionellosis in Long-Term Care: An Update

Abstract

Recently, three cases of Legionnaires’ disease were reported in three separate nursing centers in my geographic area, the state of New York. Because this was the first time I had seen this occur during my many years of working in long-term care, I felt this would be a good time to discuss the issue. The Centers for Disease Control and Prevention (CDC) has a tool kit for Legionnaires disease, from which this update has been derived. The website and other resources are included in this article. Legionnaires’ disease, caused by the microorganisms Legionella spp., was first described after an outbreak in 1976 among attendees at an American Legion convention in Philadelphia. The disease — a type of pneumonia — is very serious, killing about 1 in 10 people who contract it. Since 2000, cases of Legionnaires’ disease have increased fourfold in the United States. In 2016, the U.S. Department of Health and Human Services reported 6,100 cases in the United States. Because Legionnaires’ disease is frequently underdiagnosed, this may not represent the true incidence. In the natural environment, Legionella occurs in fresh water but becomes a health hazard when it invades water systems in buildings. Legionnaires’ disease and Pontiac fever — another disease caused by Legionella — are transmitted via small droplets of water in the air, which can be inhaled. It is not usually transmitted from person to person. The risk factors for Legionnaires’ disease include age 50 and older, a history of smoking, chronic lung disease, immune system disorders, systemic cancer, diabetes, renal failure, or hepatic failure. A recent overnight stay outside the home — including stay in a health care facility — is also a risk factor, as is exposure to hot tubs. Of more than 60 pathogenic species of Legionella, Legionella pneumophila serogroup 1 causes most cases of legionellosis (the collective term for Legionnaires’ disease and Pontiac fever). In natural aquatic systems, Legionella microorganisms grow and multiply within protozoa, single-celled microorganisms such as amoebae. Human alveolar macrophages resemble protozoa, which makes them a suitable host for Legionella in the human lungs. After an incubation period of two to 10 days (with an average of five to six days) from the time of exposure, the symptoms that manifest include:•Fever•Myalgia•Cough•Shortness of breath•Headache•Delirium•Radiograph positive for pneumonia The preferred diagnostic tests for Legionnaires’ disease are concurrent culture of lower respiratory secretions (e.g., sputum, bronchoalveolar lavage) on selective media and the Legionella urinary antigen test. Ideally, sputum should be obtained before starting an antibiotic, but the treatment should not be delayed to accommodate this. Urinary antigen testing is effective in detecting Legionella infections for days to weeks after treatment. Serological assays are not recommended due to their low specificity. •Legionella should be considered in patients who do not respond to antibiotics or are immunocompromised. Be aware of any recent outbreaks.•Macrolides and respiratory fluoroquinolones are the preferred agents for treatment (see “CDC Resources”).•The patient may require hospitalization.•Respiratory isolation is not required because transmission is via water droplets.•Supportive treatment, such as hydration and oxygen therapy, should be provided.•Resident and family education about disease transmission and treatment is advised.•All cases should be reported to the public health department.CDC Resources•Legionella (Legionnaires’ Disease and Pontiac Fever): Diagnosis, Treatment, and Prevention; https://www.cdc.gov/legionella/clinicians/diagnostic-testing.html•Legionella (Legionnaires’ Disease and Pontiac Fever): Guidelines, Standards, and Laws; https://www.cdc.gov/legionella/resources/guidelines.html•Toolkit: Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings; https://www.cdc.gov/legionella/wmp/toolkit/ •Legionella (Legionnaires’ Disease and Pontiac Fever): Diagnosis, Treatment, and Prevention; https://www.cdc.gov/legionella/clinicians/diagnostic-testing.html•Legionella (Legionnaires’ Disease and Pontiac Fever): Guidelines, Standards, and Laws; https://www.cdc.gov/legionella/resources/guidelines.html•Toolkit: Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings; https://www.cdc.gov/legionella/wmp/toolkit/ Proper maintenance of water systems in which Legionella may grow is key to disease prevention. The CDC encourages all owners of health care facilities to develop a water management plan aimed at reducing the risk of Legionella contamination. If Legionella is found in a health care facility’s water system, it must be eliminated. A tool kit developed by the CDC can help facilities determine the sources of contamination (see “CDC Resources”). Preventive measures such as cleaning the distal outlets and removing “dead legs” in the plumbing system (Long Term Living Contin Care Prof 2014:63:36–40) are known to be expensive and, unfortunately, ineffective. An outbreak of Legionella in a skilled nursing center is a disaster for everyone involved. It is critically important to recognize the signs and symptoms of a possible Legionella infection and to have a clinical policy/protocol in place for management. From an administrative prospective, follow the CDC guidelines for determining if the water system in your building is at risk for growing and spreading Legionella and learn about the newly published standards for Legionella water management and how to monitor and respond to changes in water quality. This should be included in the facility’s policy and procedure manual.