Negative Environmental Testing Results for Legionella Bacteria in Findlay

The Illinois Department of Public Health (IDPH) and Shelby County Health Department announced that testing on environmental samples following three cases of Legionnaires’ disease in Findlay has not identified a definitive source of the exposure. Public health officials are continuing to monitor for additional cases, but none have been reported to date.

It was announced August 16 that IDPH was working with the county and the Illinois Environmental Protection Agency (Illinois EPA) to investigate a cluster of three Legionnaires’ disease cases among individuals living in Findlay that reported onset of symptoms between July 30 and August 4.

Water and swab samples were collected from potential sources of exposure for all three individuals identified during the epidemiological investigation and environmental assessment. However, Legionella pneumophila, the cause of all three individuals’ illnesses, was not detected in any of the environmental samples. IDPH officials noted that a definitive source of Legionella is rarely determined through environmental investigation.

As previously announced, Illinois EPA conducted testing and evaluation of the public water supply serving Findlay on August 11 and found no cause for concern with chlorine levels, an effective disinfection for Legionella. Illinois EPA has also requested daily sampling for chlorine residual within the system.

Legionnaires’ disease is a serious lung infection (pneumonia). Disease transmission primarily occurs through breathing in Legionella-contaminated, aerosolized water. People do not spread Legionnaires’ disease to other people. Outbreaks are most commonly associated with buildings or structures that have complex water systems like hotels, hospitals, long-term care facilities, and cruise ships. The bacterium can become a health concern when it grows and spreads in human-made water systems, like hot tubs, cooling towers, hot water tanks, large plumbing systems, and decorative fountains.

Most healthy people do not get Legionnaires’ disease after being exposed to Legionella bacteria. People at increased risk of Legionnaire’s disease are those 50 years of age or older, or those who have certain risk factors such as being a current or former smoker, having a chronic disease, or having a weakened immune system.

In 2022, Illinois reported 381 cases of Legionnaires’ disease statewide with 237 confirmed to date in 2023.

Additional information about Legionnaires’ disease can be found on the IDPH website and the CDC website.