Moxley 1 Logan Moxley BIO 112 Mrs. Caplan Legionnaire’s Disease Legionnaire’s disease was first identified and described in January 1977. Even today it is often regarded as an unusual or exotic disease, when in fact it is a very common form of community and nosocomial acquired pneumonia (Lane, 2004). By the fall of 1976 the Swine Flu had been excluded as the cause of the Philadelphia outbreak and several other theories were beginning to emerge, including conspiracies against American veterans. The Centers for Disease Control and Prevention (CDC) interviewed over 4,000 Legionnaires and their families, and collected hundreds of environmental samples from the hotel and its surroundings. Then January 1977, a CDC team isolated the bacterium that was isolated responsible for the outbreak. Further investigation into the hotel’s environmental systems revealed the bacterium thrived in the air-conditioning unit. The organism was named Legionella pneumophila: Legionella for the persons from whom they isolated the bacterium and pneumophila because the organism “likes the lungs” (Lane, 2004). The elusive and previously unrecognized bacterium acts as an intracellular pathogen that invades and replicates within free-living protozoa and mammalian cells. The bacterium is found commonly in many fresh water environments including rivers, lakes, ponds, potable water systems, soil and aerosolizing devices, such as cooling towers, showers, whirlpools, and spas Microbiologists have identified at least 28 different types of the bacterium, but Legionella pneumophila stereotype 1 is responsible for most cases in the United States (Lane, 2004). Moxley 2 In the United States, Legionnaire’s Disease is consistently ranked among the top cases of community acquired pneumonia, accounting for an estimated 2% to 15% of cases annually. It is estimated that over 25,000 cases of community-acquired Legionnaire’s Disease occur in the United States and cause more than 4,000 deaths every year. More than 95% of actual cases may go undetected. Because outbreaks are widely publicized, the disease enjoys a false, but ongoing reputation as an exotic plague (Lane, 2004). The diagnosis for Legionnaire’s disease at this time is recognized by four laboratory methods. The four methods are urine antigen test, culture of the organism, direct fluorescent antibody staining, and serology. The urine antigen test provides rapid and accurate diagnosis of disease caused by L. pneumophila. It has been reported to be one of the most powerful methods used. However 80% to 90% of the clinically diagnosed cases are caused by serogroup 1 and the urine test is being used increasingly (Lane, 2004). It is estimated that in the United States there are between 10,000 and 50,000 cases each year. For someone to get Legionnaire’s disease they must be exposed to water contaminated with Legionella bacteria. This exposure may happen by inhaling or drinking water contaminated with Legionella bacteria. Legionnaire’s disease is not contagious and cannot be transmitted from one person to another. Legionnaire’s disease is not easy to diagnose the pneumonia caused by Legionella is not easy to distinguish from other forms of pneumonia. A number of diagnostic test allow a physician to identify the disease (Lane, 2004). Legionnaire’s disease is a disease that can be prevented. Avoiding water conditions that allow the organism to grow high levels is the best means of prevention. Specific preventive steps include: Regularly maintain and clean cooling towers, evaporate condensers to prevent growth of Legionella. Maintain domestic water heaters at 140 F. Avoid conditions that allow Moxley 3 water to stagnate. Large water-storage tanks exposed to sunlight can produce warm conditions favorable to high levels of Legionella. Frequent flushing of unused water lines will help alleviate stagnation (Lane, 2004). Moxley 4 La n e , G eo r ge . (2 00 4) . Le gi o nn ai r e. M E DS UR G N urs i n g , 13 (6 ), 4 09 -4 14.