Legionnaires' disease (the most severe form of Legionellosis) is a form of pneumonia that is caused by inhalation or aspiration of bacteria that belong to the family Legionellaceae. This family includes 48 species and 70 serogroups. Legionellosis is most commonly linked to exposure to Legionella pneumophila, however, other species (i.e., L. micdadei, L. anisa) can cause the disease as well. The name Legionella pneumophila was coined after the original outbreak of the disease at the American Legion convention in Philadelphia in 1976. L. pneumophila has many sub-groups called serotypes. L. pneumophila serotype 1 and 6 are commonly associated with Legionnaires disease.
Legionella are commonly found in aquatic environments and some species have been found in soil. The organisms are found in a wide range of environmental conditions and are relatively resistant to low pH, dissolved oxygen levels, and routine chlorination techniques for drinking water. Temperatures above 104° F promote rapid multiplication of the organism. The organisms are consistently found in the biofilm that forms in aquatic environments, cooling towers and potable water systems.
The risk factors for Legionellosis in decreasing order of importance are heavy smoking, chronic lung disease, the elderly, and the immunosuppressed. A recent study has documented 76 cases of pediatric Legionellosis in children under 1 year of age or children with underlying medical conditions such as malignancy or immunosuppression. Legionellosis is not contagious; there is no evidence that the disease can be transmitted form person to person. Exposure must be thru inhalation or aspiration of contaminated, aerosolized water. Once a person has Legionnaires disease, getting it a second time is extremely rare.
The US Centers for Disease Control (CDC) recommends routine monitoring for Legionella in all bone marrow and organ transplant hospitals nationwide. Routine monitoring in healthcare facilities is recommended or required in several states such as NY, TX, MD, Los Angeles County and Allegheny County PA. Canada has guidelines for monitoring healthcare facilities. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) recommends routine monitoring of building water supply systems.
Legionellaceae are ubiquitous in fresh water and estuarine environments. Most outbreaks of disease are due to Legionella found in contaminated water and biofilm found in potable water distribution systems, whirlpool spas, and cooling towers. Transmission occurs from contaminated water that becomes aerosolized and inhaled by a susceptible host. We have a variety of different test methods depending upon the information you need:
Sample retention time - 1 week
For further information, visit our dedicated Legionella Testing website at www.legionellatesting.com or contact Diane Miskowski, MPH, at 1-800-220-3675 ext. 2528.
>> Legionella Sampling Location Guide