1976 Philadelphia Legionnaires' disease outbreak States Center for Disease Control and Prevention (CDC) in 2017 only use the term Legionnaires' disease to refer to the serious version with pneumonia. CDC investigators quickly discovered outbreaks of respiratory disease caused by "L. pneumophila" dating back to 1959. An outbreak of what was dubbed Pontiac fever occurred in a health department in Pontiac, Michigan in July 1967. No one died. Although caused by the same bacterium, Pontiac fever is a milder ailment than Legionnaires' disease. Pneumonia is absent in those with Pontiac fever. An outbreak of pneumonia in July–August, 1965, at St. Elizabeths Hospital in Washington, DC, which
Epidemiology of pneumonia pneumonia occurred in approximately 156 million children (151 million in the developing world and 5 million in the developed world). It caused in 1.6 million deaths or 28–34% of all deaths in those under five years of age of which 95% occur in the developing world. Countries with the greatest burden of disease include: India (43 million), China (21 million) and Pakistan (10 million). Children in developing countries are at a significantly higher risk for developing pneumonia because malnutrition, overcrowding, and the lack of proper housing are prevalent risk factors. Other illnesses can also worsen the chances for developing pneumonia,