|
Legionnaire's disease |
| Definition: |
| An acuterespiratory infection caused by the bacterium Legionella pneumophila, which can cause a broad spectrum of disease from mild cough and fever to a serious pneumonia.
|
| Alternative Names: |
| Legionella pneumonia; Pontiac fever |
| Causes, incidence, and risk factors: |
| The bacteria have been found in water delivery systems and can survive in the warm, moist, air conditioning systems of large buildings including hospitals. The infection is transmitted through the respiratory route. Person to person spread has not been proven. From the onset of symptoms, a worsening of the condition is typical during the first 4 to 6 days, with improvement starting in another 4 to 5 days. Most infection occurs in middle-aged or older people, although it has been reported in children. Typically, the disease is less severe in children. Risk factors include cigarette smoking; underlying diseases such as renal failure, cancer, diabetes or chronic obstructive pulmonary disease; people with suppressed immune systems from chemotherapy, steroid medications or diseases such as cancer and leukemia; alcoholism; being middle-aged or elderly, and in chronically ventilated patients. |
| Symptoms: |
|
| Signs and tests: |
|
| Treatment: |
|
The goal of treatment is to eliminate the infection with antibiotics. Treatment is started as soon as Legionnaire's disease is suspected, without waiting for confirmation by culture results. Erythromycin is the drug of choice. Supportive treatment includes hospitalization for fluid and electrolyte replacement and oxygen administration by mask or by mechanical ventilation, if the respiratory system becomes severely compromised by the infection. |
| Expectations (prognosis): |
| The overall death rate for those with pneumonia is about 15%, and the death rate increases in those with underlying diseases. The mortality for patients who develop Legionnaire's disease while hospitalized is close to 50%, especially when antibiotics are started late. |
| Complications: |
|
Some complications include respiratory failure requiring mechanical ventilation (use of a respirator). |
| Calling your health care provider: |
| Call your health care provider if breathing difficulties develop. |
| Prevention: |
| Active surveillance of infections that were acquired within a hospital can lead to the treatment of contaminated water delivery systems. Detection and treatment of sources outside hospitals usually occurs during or after an epidemic has happened. |
Reviewed By: Camille Kotton, M.D., Infectious Diseases Division, Massachusetts General Hospital and Brigham and Women's Hospital, Boston, MA. Review provided by VeriMed Healthcare Network.
 |
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch). |
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2003 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
