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Questions About Legionella

What is Legionella?


            A.  Simply put, Legionella is a bacterium made up of many different species.  The specific strain of concern in New York is L. pneumophila which is capable of producing illnesses such as Pontiac Fever or Legionnaire’s Disease. 


What is Legionnaire’s Disease?


            A.  Legionnaire’s Disease is a type of pneumonia.  It was named after a convention that was held by the American Legion at a hotel in Philadelphia in 1976.  The bacteria that causes this disease is not spread from person-to-person.  Typically, someone who contracts this disease has been exposed to airborne water particles that were inhaled, usually through a mist.  Sources of this mist can include hot tubs, showers and air-conditioning units and cooling towers used to cool large buildings such as hospitals, high rises and hotels.  Most people will be exposed to Legionnaire’s at some point in time but will usually not be infected with the disease.  This disease is of most concern to those who fall into a certain risk category such as the elderly, smokers or those with a compromised immune system such as cancer or aids patients, someone suffering from COPD or someone who is taking immunosuppressants after receiving an organ transplant.  Symptoms of the disease usually include fever, chills and a cough.  The appearance of symptoms is typically two to ten days after exposure but on rare occasions up to twenty days.  Those who fall into these groups and have contracted the disease usually require in-patient treatment at a hospital where they will be given a course of strong antibiotics.  Most people diagnosed with this disease will survive but treatment must begin quickly.  Mortality rates have dropped down to around 5% but during an outbreak can range from 5 – 30%.


Can legionella and Legionnaire’s disease be prevented?


            A.  In short, no.  This is a very common bacteria found in many places all around the world.  It can, however, be greatly reduced if a strong water treatment plan has been into place.  New York City and State have enacted new regulations that specifically list what must be included within the treatment plan.  Along with the required weekly and/or monthly preventative maintenance visits, additional steps must be taken including two (2) annual tower cleanings, quarterly legionella tests while the tower(s) is in operation and weekly heterotrophic tests to monitor for an increase in the presence of any harmful bacteria.  If any tests indicate a presence of bacteria, additional steps must be taken within a very specific time limit to bring the bacteria levels back under control.  If all steps in the regulations are followed, the chance of an outbreak of legionella can be significantly reduced.

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