Legionnaires' disease: an update.

Legionella pneumophila is transmitted by aerosolization of water or dust from soil. There are six serotypes and four newly recognized related organisms. Sporadic cased of Legionnaires; disease are more common than epidemic case and are less likely to be suspected . Most reporters cases are characterized by severe pneumonia. Bacteriologic culture is the preferred method of diagnosis, but most cases are identified by the indirect fluorescent antibody method. Erythromycin is the drug of choice.