Infectious Disease Epidemiology Program

Airborne and Direct Contact Diseases - Legionellosis

Legionellosis is an infection caused by the bacterium Legionella pneumophila. Legionnaires’ disease acquired its name in 1976 when an outbreak of pneumonia occurred among persons attending a convention of the American Legion in Philadelphia. Later, the bacterium causing the illness was named Legionella. Maine monitors the incidence of Legionellosis through mandatory reporting by health care providers, clinical laboratories and other public health partners.

Numbers of cases of travel-associated Legionnaires' disease is increasing. It is important to report diagnosed cases of Legionnaires’ Disease as its identification implies the presence of an environmental source to which other susceptible individuals are likely to be exposed. Legionella testing should be performed for those who have traveled in the 2 weeks before onset of symptoms. All cases of Legionellosis should be reported to Maine CDC 1-800-821-5921.