2 Legionnaires' disease cases reported at Northwestern Hospital in Chicago

CHICAGO (WLS) -- Two cases of Legionnaires' disease in patients treated at Northwestern Memorial Hospital several months apart are linked, the Illinois Department of Public Health (IDPH) said Saturday.

On Thursday, the Centers for Disease Control and Prevention (CDC) notified the health department of one case of an out-of-state patient who received treatment at Northwestern in November. IDPH linked that case with a separate patient who was at NMH in May, the health department said in a statement.

IDPH is working with Northwestern, the Chicago Department of Public Health and the CDC providing guidance on what patients to test and when, reviewing all pneumonia cases that occurred on the floors where the two patients stayed, discuss flushing protocols on the floors where the two patients stayed, discuss expanding use of filters for shower heads and sink on the floors where the two patients stayed and reviewing environmental water testing logs and water sampling approaches, the health department said.

Legionnaires' disease is a serious lung infection (pneumonia) that people can get by breathing in small droplets of water containing Legionella bacteria. In general, people do not spread Legionnaires' disease to other people. However, this may be possible in rare cases. Legionella is found naturally in fresh water environments, like lakes and streams. It can become a health concern when it grows and spreads in human-made water system, IDPH said.

In a statement, Northwestern said: "We are working closely with IDPH while also conducting an internal review to determine if these two cases are related. The safety and health of our patients is our top priority. We will have no additional comments until the review is completed."