Legionnaire's Disease is an infection caused by the Legionella pneumophilia bacterium which manifests as a severe type of pneumonia. The disease was first identified in the United States in 1976--and was subsequently named--when more than 200 Legionnaires participating in America's bicentennial celebrations in Philadelphia became ill. Thirty-four of those infected died. Authorities were at a loss to identify the cause. Only after prolonged and intense investigations did researchers discover a previously unidentified bacteria which they believe was introduced into the air conditioning system through contaminated water supply. The disease is contracted through airborne transmission of the bacteria and progresses rapidly. Because it proves fatal in approximately 15-25% of reported cases, hospitalization is recommended in almost all instances.

Following identification of the Legionella bacterium, it is now known that the outbreak of a disease in Pontiac, Michigan in 1968, named "Pontiac Fever," was caused by the same species, as...