The Illinois Department of Public Health (IDPH), working closely with the DuPage County Health Department, is investigating a cluster of two Legionnaires’ disease cases, with illness onsets within one month of each other, in individuals who were at or near the Alden Valley Ridge Rehabilitation and Health Center in Bloomingdale, Illinois. Both individuals have recovered from their illnesses. IDPH Environmental Health staff conducted an onsite investigation at Alden Valley on September 22, 2025, and collected environmental samples. Testing performed by the IDPH Laboratory detected the presence of Legionella pneumophilia bacteria within the facility in samples collected from the case’s room and the facility’s cooling tower.
IDPH has communicated remediation procedures and water restrictions, as well as requirements for a comprehensive assessment of the facility’s water systems and additional testing requirements to confirm successful remediation. IDPH has also recommended the facility provide notification to residents/families and employees. In addition, IDPH recommended the facility conduct surveillance to identify other potential cases and to ensure appropriate human testing and clinical management. The facility is cooperating with the investigation.