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Legionnaire disease
Legionella pneumonia; Pontiac fever; Legionellosis
Legionnaire disease is an infection of the lungs and airways. It is caused by Legionella bacteria.
Causes
The bacteria that cause Legionnaire disease have been found in water delivery systems. They can survive in the warm, moist air conditioning systems of large buildings, including hospitals.
Most cases are caused by the bacteria Legionella pneumophila . The rest of the cases are caused by other Legionella species.
Spread of the bacteria from person to person has not been proven.
Most infections occur in middle-aged or older people. In rare cases, children can get the infection. When they do, the disease is less severe.
Risk factors include:
- Alcohol abuse
- Cigarette smoking
-
Chronic illnesses, such as
kidney failure
or
diabetes
Kidney failure
Acute kidney failure is the rapid (less than 2 days) loss of your kidneys' ability to remove waste and help balance fluids and electrolytes in your b...
ImageRead Article Now Book Mark ArticleDiabetes
Diabetes is a chronic disease in which the body cannot regulate the amount of sugar in the blood.
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Long-term (chronic) lung disease, such as
COPD
COPD
Chronic obstructive pulmonary disease (COPD) is a common lung disease. Having COPD makes it hard to breathe. There are two main forms of COPD:Chroni...
ImageRead Article Now Book Mark Article - Long-term use of a breathing machine (ventilator)
- Medicines that suppress the immune system, including chemotherapy and steroid drugs
- Older age
Symptoms
Symptoms tend to get worse during the first 4 to 6 days. They most often improve in another 4 to 5 days.
Symptoms may include:
- Chest pain
- Cough that does not produce much sputum or mucus (dry cough)
- Coughing up blood
- Diarrhea, nausea, vomiting, and abdominal pain
- Fever, shaking chills
-
General discomfort, uneasiness, or ill feeling (
malaise
)
Malaise
Malaise is a general feeling of discomfort, illness, or lack of well-being.
Read Article Now Book Mark Article - Headache
- Joint pain
- Loss of energy
- Muscle aches and stiffness
- Problems with balance
- Shortness of breath
Exams and Tests
The health care provider will perform a physical exam. Abnormal sounds called crackles may be heard when listening to the chest with a stethoscope.
Tests that may be done include:
-
Arterial blood gases
Arterial blood gases
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
ImageRead Article Now Book Mark Article - Blood cultures
-
Bronchoscopy
Bronchoscopy
Bronchoscopy is a test to view the airways and diagnose lung disease. It may also be used during the treatment of some lung conditions.
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Chest x-ray
Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.
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Complete blood count (
CBC
), including
white blood cell count
CBC
A complete blood count (CBC) test measures the following:The number of red blood cells (RBC count)The number of white blood cells (WBC count)The tota...
ImageRead Article Now Book Mark ArticleWhite blood cell count
A WBC count is a blood test to measure the number of white blood cells (WBCs) in the blood. WBCs help fight infections. They are also called leukocy...
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ESR
(sed rate)
ESR
ESR stands for erythrocyte sedimentation rate. It is commonly called a "sed rate. "It is a test that indirectly measures how much inflammation is in...
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Liver blood tests
Liver blood tests
Liver function tests are common tests that are used to see how well the liver is working. Tests include:AlbuminAlpha-1 antitrypsin Alkaline phosph...
ImageRead Article Now Book Mark Article - Tests and cultures on sputum to identify the Legionella bacteria
- Urine tests to check for Legionella pneumophila bacteria
Treatment
Antibiotics are used to fight the infection. Treatment is started as soon as Legionnaire disease is suspected, without waiting for results of any lab test.
Other treatments may include receiving:
- Fluids through a vein (IV)
- Oxygen, which is given through a mask or breathing machine
Outlook (Prognosis)
Legionnaire disease can be life-threatening. The risk of dying is higher in people who:
- Have chronic diseases
- Become infected while in the hospital
- Are elderly
When to Contact a Medical Professional
Make an appointment with your health care provider if you have any type of breathing problem.
References
Edelstein PH, Roy CR. Legionnaires' disease and Pontiac fever. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases . 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 234.
Marrie TJ. Legionella infections. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 314.
-
Legionnaires' disease organism, legionella - illustration
Legionnaire's disease was first described in 1976 after an outbreak of fatal pneumonia at a Legionnaires convention. The newly described organism which caused the disease was named Legionella pneumophila, shown in this picture. (Image courtesy of the Centers for Disease Control and Prevention.)
Legionnaires' disease organism, legionella
illustration
-
Legionnaires' disease organism, legionella - illustration
Legionnaire's disease was first described in 1976 after an outbreak of fatal pneumonia at a Legionnaires convention. The newly described organism which caused the disease was named Legionella pneumophila, shown in this picture. (Image courtesy of the Centers for Disease Control and Prevention.)
Legionnaires' disease organism, legionella
illustration
Review Date: 2/2/2015
Reviewed By: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
