History and Disease Patterns
Español: Historia y patrones de la enfermedad
Legionellosis, which includes Legionnaires' (LEE-juh-nares) disease and Pontiac fever, is a respiratory disease caused by a type of bacteria called Legionella.
Legionella was discovered after an outbreak in 1976 among people who went to a Philadelphia convention of the American Legion. Those who were affected suffered from a type of pneumonia (lung infection) that eventually became known as Legionnaires’ disease.
The pictured magazine covers feature the work of public health professionals in 1976 as they raced to trace the origin of the first documented outbreak of Legionnaires’ disease in Philadelphia, Pennsylvania.1
The first identified cases of Pontiac fever occurred in 1968 in Pontiac, Michigan, among people who worked at and visited the city’s health department. It wasn’t until Legionella was discovered after the 1976 outbreak in Philadelphia that public health officials were able to show that the same bacteria causes both diseases.
Illness caused by Legionella continues to be detected, now more than ever. Each year, it is estimated that between 8,000 and 18,000 people in the United States need care in a hospital due to Legionnaires' disease.2 More illness is usually found in the summer and early fall, but it can happen any time of year.
- Magazine story covers related to the 1976 outbreak of Legionnaire’s disease. From Centers for Disease Control and Prevention (CDC) Public Health Library, #1185. Copyright 1976 by CDC. Reprinted with permission.
- Marston BJ, Plouffe JF, File TM Jr, Hackman BA, Salstrom SJ, Lipman HB, et al. Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group. Arch Intern Med. 1997;157(15):1709–18.
- Page last reviewed: October 28, 2015
- Page last updated: January 22, 2016
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