Approach to severe legionellosis a: “Severe community acquired pneumònia”.

Since its first isolation more than twenty years agoLegionella pneumophilahas become a well-established etiologic agent of both community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) (1). The reported incidence of legionellosis in those cases of CAP in which a microbiologic diagnosis may be made ranges from 2 to 27%, depending on the geographical area under consideration and the inclusion criteria of the study (2). The percentage tends to be greater in series of CAP that require hospitalization than in those that can be treated on an outpatient basis. The highest percentages have been reported in series characterized by the severity of the illness.