CHICAGO (AP) — Officials say one patient at a mental health facility in the southern Illinois has tested positive for Legionnaires' disease.

Illinois' Department of Human Services says in a Wednesday statement that the patient at the Chester Mental Health Center was being treated and is in stable condition. The agency received the test results Tuesday.

It says it's working with Illinois' Department of Public Health to determine the source of the bacteria, while also monitoring other patients. Legionnaires' is contracted by people who inhale vapor from infected water.

The IDHS statement says there are around 300 cases reported each year in Illinois.

Public attention in recent months has focused on the Illinois Veterans Home in Quincy, where Legionnaires' has contributed to the deaths of more than a dozen residents since 2015.