Legionnaires' disease that occur globally is not known. Legionnaires' disease is the cause of an estimated 2-9% of pneumonia cases that are acquired outside of hospital. An estimated 8,000 to 18,000 cases a year in the United States require hospitalization. Outbreaks of disease account for a minority of cases. While it can occur any time of the year, it is more common in the summer and fall. The disease is named after the outbreak where it was first identified, at a 1976 American Legion convention in Philadelphia. The length of time between exposure to the bacteria and the appearance of symptoms is
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,