The Illinois Department of Public Health (IDPH), in collaboration with the DuPage County Health Department, is investigating a cluster of two Legionnaires’ disease cases. Both individuals became ill within one month of each other and had spent time at or near a nursing home in Bloomingdale, Illinois. Both individuals have since recovered.
On September 22, 2025, IDPH Environmental Health staff conducted an onsite investigation and collected environmental samples. Testing by the IDPH Laboratory detected the presence of Legionella pneumophila—the bacteria that causes Legionnaires’ disease—in samples taken from the case’s room and the facility’s cooling tower.
IDPH has issued guidance to the facility, including remediation procedures, water restrictions, and requirements for a comprehensive assessment of the facility’s water systems. Follow-up environmental testing will be required to confirm successful remediation. IDPH has also recommended that the facility notify residents, families, and staff, and conduct active surveillance for potential additional cases. Appropriate clinical management and testing are also being encouraged. The facility is cooperating with the investigation.
According to preliminary 2025 data from IDPH, 287 cases of Legionnaires’ disease have been reported statewide. In Illinois, Legionnaires’ disease is a reportable condition and must be reported to the local health department within three days. Timely reporting is essential for identifying additional cases and helping control potential sources of exposure.
Legionella bacteria occur naturally in freshwater environments but can become a health concern when they grow and spread in man-made water systems. These systems may include hot tubs, cooling towers, hot water tanks, large plumbing systems, and decorative fountains. When aerosolized water droplets containing Legionella are inhaled, they can cause Legionnaires’ disease—a serious type of pneumonia. The disease is not spread from person to person.
Outbreaks are most often linked to buildings with complex water systems, such as hospitals, hotels, long-term care facilities, and cruise ships. Healthcare providers and facility operators should remain vigilant and ensure proper maintenance and monitoring of water systems, especially in high-risk environments.
Compliance Perspective
Issue
Transmission of Legionella can occur through aerosolized water or ingestion of contaminated drinking water. The Centers for Medicare & Medicaid Services (CMS) requires each facility to establish and maintain a comprehensive Infection Prevention and Control Program (IPCP). CMS also expects that nursing facilities have written policies and procedures designed to reduce the risk of growth and spread of Legionella and other opportunistic pathogens in the building’s water system. Each facility must develop a water management plan and maintain documentation that demonstrates, at a minimum:
- A facility-wide risk assessment identifying where Legionella and other opportunistic waterborne pathogens (e.g., Pseudomonas, Acinetobacter, Burkholderia, Stenotrophomonas, nontuberculous mycobacteria, and fungi) could grow and spread in the water system;
- A water management program that incorporates CDC and ASHRAE guidance;
- Testing protocols with acceptable control limits, documentation of results, and evidence of corrective actions when limits are not maintained;
- Ongoing compliance with applicable federal, state, and local regulations.
Discussion Points
- Review the facility’s Infection Control Plan and the water management policies and procedures designed to minimize the risk of Legionella and other waterborne pathogens. Ensure that procedures reflect current CDC and ASHRAE guidance. Consider engaging with an external consultant to assist with risk assessments, policy development, and mock surveys that can identify potential regulatory gaps in infection control practices.
- Ensure all staff receive education and training on the Infection Control Plan, with specific emphasis on the facility’s water management program. Med-Net Academy offers the course Legionella and Facility Water System Safety, which helps facilities meet CMS expectations for providing a safe, sanitary, and healthful environment for residents and staff. The course addresses risk factors for Legionella, how it grows and spreads, symptoms and treatment, and CMS expectations related to water management. It outlines the seven key activities of an effective water management program, proper disinfection methods, testing protocols, and immediate control measures in the event of positive results.
- Periodically audit the facility’s water management practices to ensure proper implementation. Confirm that water samples are being collected and tested according to the defined protocol, and that results and corrective actions are thoroughly documented. Staff responsible for collecting and submitting samples should be trained and periodically evaluated for competency. Consider using a third-party expert or consultant to assist with audit preparation or mock survey exercises, especially when internal resources are limited or if recent changes have occurred in personnel or protocols. Also ensure that a designated, trained registered nurse is competently serving as the facility’s Infection Preventionist.
*This news alert has been prepared by Med-Net Concepts, Inc. for informational purposes only and is not intended to provide legal advice.*