|Classification and external resources|
Legionnaires disease is a potentially fatal pneumonia caused most commonly by Legionella pneumophila, a gram negative, aerobic bacteria that is carried by amoeba that thrive in stagnant water. During infection, the bacterium invades macrophages and lung epithelial cells and replicates intracellularly. It belongs to the genus Legionella.
Legionella pneumophila was first identified in 1976. National surveillance systems and research studies were established early, and in recent years improved ascertainment and changes in clinical methods of diagnosis have contributed to an upsurge in reported cases in many countries. Environmental studies continue to identify novel sources of infection, leading to regular revisions of guidelines and regulations. There are about 8,000 to 18,000 cases of Legionnaires' disease each year in the United States, according to the Bureau of Communicable Disease Control.
Between 1995 and 2005 over 32,000 cases of Legionnaires' disease and more than 600 outbreaks were reported to the European Working Group for Legionella Infections There is a shortage of data on Legionella in developing countries and it is likely that Legionella-related illness is underdiagnosed worldwide. Improvements in diagnosis and surveillance in developing countries would be expected to reveal far higher levels of morbidity and mortality than are currently recognised. Similarly, improved diagnosis of human illness related to legionella species and serogroups other than Legionella pneumophila would improve knowledge about their incidence and spread.
A 2011 study successfully used modeling to predict the likely number of cases during Legionnaires’ outbreaks based on symptom on-set dates from past outbreaks. In this way, the eventual likely size of an outbreak can be predicted, enabling efficient and effective use of public health resources in managing an outbreak.
The first recognized cases of Legionnaires' disease occurred in 1976 in Philadelphia, Pennsylvania among attendees of a Legionnaires' convention held at the Bellevue-Stratford Hotel. 182 Legionnaires contracted the disease and 29 of them died.
In Summer of 2013, a outbreak in at an assisted living center in Reynoldsburg, Ohio, resulted in 6 dead and 39 ill.
Legionella pneumophila thrives in aquatic systems where it is established within amoeba in a symbiotic relationship. In the built environment, central air conditioning systems in office buildings, hotels, and hospitals are sources of contaminated water. Other places it can dwell include cooling towers used in industrial cooling systems as well as evaporative coolers, nebulizers, humidifiers, whirlpool spas, hot water systems, showers, windshield washers, fountains, room-air humidifiers, ice making machines, and misting systems typically found in grocery store produce sections.
- 1976 Philadelphia legionellosis outbreak
- Legionella pneumophila
- American Legion
- List of Legionellosis outbreaks
- Winiecka-Krusnell, J; Linder, E (1999). "Free-living amoebae protecting Legionella in water: the tip of an iceberg?". Scandinavian journal of infectious diseases 31 (4): 383–5. PMID 10528878.
- Takamatsu, R; Teruya, H; Takeshima, E; Ishikawa, C; Matsumoto, K; Mukaida, N; Li, JD; Heuner, K; Higa, F; Fujita, J; Mori, N (2010 Jan 5). "Molecular characterization of Legionella pneumophila-induced interleukin-8 expression in T cells.". BMC microbiology 10: 1. PMID 20051107.
- Ryan, KJ; Ray CG (editors) Sherris Medical Microbiology (4th ed.) McGraw-Hill.
- "Legionellosis.". Massachusetts Department of Public Health. Bureau of Communicable Disease Control. Nov. 2011. Retrieved 2012-11-12.
- World Health Organization 2007. Legionella and the prevention of legionellosis. Geneva, Switzerland: WHO. Available at http://www.who.int/water_sanitation_health/emerging/legionella.pdf
- Egan, JR; Hall, IM; Lemon, DJ; Leach, S (2011 Mar). "Modeling Legionnaires' disease outbreaks: estimating the timing of an aerosolized release using symptom-onset dates.". Epidemiology (Cambridge, Mass.) 22 (2): 188–98. PMID 21242803.
- "Legionnaire disease". Encyclopaedia Britannica. Retrieved 30 October 2013.
- "Legionellosis Guideline: Best Practices for Control of ''Legionella'' (WTP-148) (06)". Cooling Technology Institute. Retrieved 2010-09-11..
- Mahoney, F. J.; Hoge, C. W.; Farley, T. A.; Barbaree, J. M.; Breiman, R. F.; Benson, R. F.; McFarland, L. M. (1 April 1992). "Communitywide Outbreak of Legionnaires' Disease Associated with a Grocery Store Mist Machine". Journal of Infectious Diseases 165 (4): 736–739. doi:10.1093/infdis/165.4.xxxx. PMID 1552203.
- "Legionnaires' disease link to lack of windscreen wash". Physorg.com. 2010-06-15. Retrieved 2010-09-11.