Legionnaires Disease – The What, Why & Where

Legionella Control International are Legionella experts and help and advise organisations across most commercial, industrial, healthcare, governmental and non-profit sectors.

What is Legionella? How did it come about?
Legionnaires disease was first discovered in 1976 after an outbreak in Philadelphia at a convention. Since then there have been approximately 10,000 to 50,000 people infected annually. Symptoms usually appear 2 to 10 days after exposure to the bacteria. Once infected, Legionnaires disease causes fever, cough and chills. As the disease progresses it may also cause muscle aches and headaches. Some people with Legionnaires disease develop a fatal type of pneumonia.

Why is it named Legionnaires disease?
This disease got its name because it was first contracted by a group of legionnaires attending a convention. About 200 people fell ill and approximately 25 died. After the bacteria was discovered it was called Legionella pneumophila; named after the legionnaires infected.

Who discovered it?
Legionnaires disease was discovered by a group of scientists. After obtaining a lung tissue sample the scientists were able to discover and name the bacteria responsible. They determined this specific type of bacteria commonly lives in water reservoirs. It can be contracted through drinking contaminated water or breathing in aerosolized particles. Sometimes people in office buildings are infected with Legionnaires after breathing contaminated air from air conditioners.

Where was it first found?
Legionnaires disease was first found in 1976 in the Bellevue-Stratford Hotel. It is commonly found in cooling towers and central air conditioning. Since then the bacteria has been found in ponds, creeks and other bodies of water. It can also be found in hotels, on cruise ships and in hot tubs. Luckily, most cases of Legionnaires disease can be prevented by scheduling regular maintenance on water system. Legionnaires is usually found in the water systems of large office buildings and home water systems are not common sources of contamination. Although outbreaks of Legionnaires gain national attention, most people are not at high risk of developing symptoms after coming in contact with the bacteria. People with underlying health problems are at higher risk. Less than 5 out of every 100 who are exposed will ever develop symptoms.