Additional Information

Legionella infection is associate with 2 clinically and epidemiologically distinct illnesses, Legionnaires disease and Pontiac fever.

Legionnaires disease is characterized by fever, cough, myalgia, and pneumonia, whereas, Pontiac fever is a milder illness without pneumonia.

Inhaling aerosols of water contaminated with Legionella species is believed to be the primary mode of infection; the incubation period is generally 2 - 10 days.

A 4 fold rise in IgG IFA antibody titer to >1:128 between acute and convalescent sera may be used in the laboratory confirmation of Legionella infection.