Legionellosis can present as two types of illness: Legionnaires’ (LEE-juh-nares) disease and Pontiac fever. The two illnesses can be diagnosed with similar tests, but are treated differently.

Legionnaires’ disease is a serious type of pneumonia (lung infection) frequently requiring hospitalization, whereas Pontiac fever is a less serious illness that is self-limiting and does not require treatment. People can get sick with Legionnaire's disease or Pontiac fever when they breathe in mist or accidently swallow water into the lungs containing Legionella (LEE-juh-nell-a) bacteria.

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Legionellosis Reporting

For Clinical Questions or to Report Suspect Cases, Contact:

The CDPH Disease Reporting Hotline at 312-743-9000

*After hours, weekends, and holidays, call 311 and ask for the communicable disease physician on-call (or 312-744-5000 if outside the City of Chicago).

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Legionellosis Contacts

During normal business hours, Monday through Friday (excluding holidays)

Phone: 312-746-6152

Fax: 312-746-6388

Email: karrie-ann.toews@cityofchicago.org

CDPH disease reporting line: 312-743-9000  or call 311 after business hours and ask for the communicable disease physician on-call.