What is Legionnaires’ disease?
Legionnaires’ disease is a serious condition that is caused by Legionella bacteria. Legionella is naturally found in bodies of water such as lakes and streams but is dangerous when it manifests in water systems that people are exposed to. This disease is a form of pneumonia or lung infection that requires immediate attention and treatment.
The disease got its name from an outbreak that occurred in 1976 in Philadelphia. An outbreak of pneumonia affected 221 people, killing 34. Many of those infected were members of the American Legion attending a convention at a hotel, thus the name Legionnaires’ disease.
Outbreaks most often occur in the water systems of large buildings where the bacteria can easily multiply and spread. It is not spread by person to person contact; instead it is contracted by breathing in microscopic water droplets containing Legionella bacteria. For example, this can happen by breathing in the spray from a shower or mist from the ventilation system. Outbreaks have been linked to water systems, air conditioning units, physical therapy equipment, decorative fountains, hot tubs and more. Legionnaires’ disease outbreaks are local and occur in hospitals, long term care facilities and assisted living facilities. In these environments germs can spread easily, people are vulnerable and prone to infection. When not treated effectively Legionnaires’ disease can be fatal.
Not all people are at risk of contracting Legionnaires’ disease. People most susceptible are those over 50 years old, current or past smokers, have chronic lung disease or a weakened immune system. In ten days after exposure symptoms start with headache, muscle pain, chills and fever. After 2-3 days symptoms worsen to shortness of breath, coughing, chest pain, nausea, vomiting, diarrhea and confusion. This disease can lead to multiple life threatening complications such as respiratory failure, septic shock and acute kidney failure if not treated properly. Diagnosing and treating the disease as soon as possible can help shorten the recovery time and prevent more serious complications. A mild form of Legionnaires’ disease called Pontiac fever is also known to cause flu like systems such as fever, chills, headache and muscle aches. Pontiac fever does not infect the lungs and symptoms normally clear within 5 days. The Centers for Disease Control and Prevention (CDC) reports between 8,000 and 18,000 cases of Legionnaires' disease annually in the United States, but it also estimates that more than 90 percent of cases go unreported.
If you think you have been exposed to Legionella you should see your doctor immediately. Most likely you will be tested for the bacteria using a urine test. More in depth tests such as a blood test, a chest x-ray, a lung tissue sample, a CT brain scan or a spinal tap may be necessary. Treatment includes antibiotics and often requires a hospital stay.
There is no vaccine for Legionnaires’ disease. It can only be prevented by effectively maintaining water systems. Water should be tested regularly and systems should be cleaned frequently. People can also personally reduce their risk of contracting the disease by avoiding smoking.