About Legionella


Most knowledge regarding Legionnaires’ disease comes from outbreak investigations; however, only 4% of cases are associated with known outbreaks and are thoroughly investigated. In the United States, the rate of reported cases of Legionnaires’ disease has grown by nearly nine times since 2000. Outbreaks of Legionnaires’ disease are associated with inhalation or aspiration of aerosolized water from a variety of sources. Major risk factors include older age, a history of smoking, chronic lung disease, and a compromised immune system. Closing research and policy gaps around Legionnaires’ disease is imperative to preventing further increases in disease.  Because this disease is tied so closely with built water systems, successful efforts will require collaboration between partners in public health, microbiology, environmental health, and engineering, among others.

Selected References

  1. Gamage SD, Ross N, Kralovic SM, Simbartl LA, Roselle GA, Berkelman RL, Chamberlain AT. Health after Legionnaires' disease: A description of hospitalizations up to 5 years after Legionella pneumonia. PLoSONE 2021; 16(1): e0245262.
  2. Nelson KN, Binney ZO, Chamberlain AT. Excess Pneumonia Mortality During a 2014-2015 Legionnaires’ Disease Outbreak in Genessee County, Michigan. Epidemiology 2020; 31(6): 823-831.
  3. Ehret KM, Chamberlain AT, Berkelman RL, Fridkin SK. Preventing hospital-acquired Legionnaires’ disease: A snapshot of clinical practices and water management approaches in US acute-care hospitals. Infect Control Hosp Epidemiol 2018; 39(12): 1470-1472.
  4. Chamberlain AT, Lehnhart JD, Berkelman RL. The 2015 New York City Legionnaires’ Disease Outbreak: A Case Study on a History-Making Outbreak. J Public Health Manag Pract 2017; 23(4):410-416.
  5. Parr A, Whitney EA, Berkelman RL. Legionellosis on the Rise: A Review of Guidelines for Prevention in the United States. Journal of Public Health Management and Practice 2015;21(5):E17-E26.
  6. Lu J, Struewing I, Vereen E, Kirby AE, Levy K, Moe C, et al. Molecular Detection of Legionella spp. and their associations with Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system. J Appl Microbiol 2016;120(2):509-21.
  7. Barker KA, Whitney EA, Blake S, Berkelman RL. A Review of Guidelines for the Primary Prevention of Legionellosis in Long-Term Care Facilities. J Am Med Dir Assoc 2015;16(10):832-6.
  8. Berkelman RL. Letter: Consideration of prophylactic antibiotic therapy during an outbreak of Legionnaires' disease. Clin Infect Dis 2014;58(1):144-5.
  9. Flanders WD, Kirkland KH, Shelton BG. Effects of holding time and measurement error on culturing Legionella in environmental water samples. Water Res 2014;62:293-301.
  10. Whitney EA, Berkelman RL. Legionella hospital laboratory testing practices in georgia. Infect Control Hosp Epidemiol 2014;35(11):1441-2.
  11. Brzozowski AK, Silk BJ, Berkelman RL, Loveys DA, Caliendo AM. Use, location, and timeliness of clinical microbiology testing in Georgia for select infectious diseases. J Public Health Manag Pract 2012;18(4):E4-E10.