Legionella

Abstract

Legionella species were first described in 1943 and 1947 using procedures developed for the isolation of Ricksettsia. However, it wasn't until 1976 that this bacteria was described as a significant pathogen in humans following an outbreak of respiratory illness at an American Legion Conference in a Philadelphia hotel, although Legionella was not determined to be the causative agent until almost a year later. More recently, there is evidence that cases of legionellosis are on the rise and an estimated 8000–18, 000 people are hospitalized resulting in a 5%–30% fatality rate. To date, a significant amount of research, new diagnostic methods, and surveillance activities have been described that have impacted the current investigation of Legionella disease. This chapter describes all the diagnostic approaches, from culture methods to the advanced molecular methods and protocols used for both clinical specimens and environmental samples.