(Legionnaires' disease, Pontiac fever, and extrapulmonary legionellosis)

Legionellosis includes three clinically distinct illnesses, Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, that are all caused by exposure to Legionella bacteria. Legionnaires’ disease most commonly presents as pneumonia. Pontiac fever is a milder, influenza-like illness, and extrapulmonary legionellosis happens when there is disease outside the lungs, (e.g., heart) and diagnostic testing reveals evidence of Legionella at that site.

About Legionella

Surveillance in Connecticut

Information for Patients and the Public

Information for Healthcare Providers and Facilities

Healthcare-Associated Legionnaires' Disease

Epidemiologic Investigation

Environmental Investigation

Information for Building Owners

Water Management Program 


Yale EIP logo

Legionella  Legionella Activities





This page last updated 3/19/2021.