Outbreak of Legionnaires' disease at the American Legion convention in Philadelphia in 1976 (PDF)

Essay from the year 2018 in the subject Medicine - Epidemiology, Oxford University, course: International health and tropical medicine, language: English, abstract: Legionnaires disease (LD) is a bacterial pneumonia dated back to the mid of 20th century. Its name came from the fact that it was first described within the legionnaires in Philadelphia, United States of America (USA) in the 1970s. It is a debilitating infection and causes many complications which, if not taken care of, are lethal. The causative bacteria are called Legionella pneumophila; they are also associated with a non-pneumonic form called Pontiac disease.

LD is thought to be transmitted through a mist of aerosols from contaminated water sources like respiratory therapy equipment, showers, decorative fountains, cooling systems, potting soil, humidifiers, and ice machines. The bacteria replicate in the water, and the vulnerable individual gets infected by inhaling the small water droplets called aerosols which get into the body through respiratory tract. The vulnerable individuals have been identified to be those with weakened immune system like smokers, alcohol abusers, cancer patients, patients with final stage renal disease and diabetes mellitus, advanced age, people living with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) and those receiving drugs which suppress the immune system like steroids.