Iowa health officials investigating 21 cases of Legionnaires’ disease in Marshalltown

State health officials are investigating a cluster of Legionnaires’ disease diagnoses in Marshalltown that have affected 21 people and led to one death.

The people diagnosed with the disease live in north central Marshalltown, according to a news release issued Thursday by the Iowa Department of Health and Human Services.

Legionnaires’ disease is caused by Legionella bacteria, which thrive in warm water and typically spread when a person inhales aerosolized water droplets, such as mist from cooling towers, hot tubs or decorative fountains.

The disease is not contagious and most healthy people who are exposed do not get sick, according to the release. The person who died as a result of the Marshalltown infection had underlying health conditions, the state reported.

“Iowans should know that Legionnaires’ disease can be effectively treated with antibiotics if diagnosed early,” Robert Kruse, Iowa HHS medical director, said in the news release. “Adults aged 50 and older, those who smoke or individuals with chronic lung conditions should seek medical care promptly if they develop flu-like or respiratory symptoms.”

The state reports that the risk to people living in or visiting Marshalltown is low, but health officials recommend that anyone who lives and works in that area and becomes ill with a pneumonia-like illness should visit their primary care doctor.

HHS is working with health care providers to advise them to test for Legionnaires’ disease if a patient who develops pneumonia lives in, works in, or has spent significant time in north central Marshalltown the 14 days before symptom onset.

Symptoms of Legionnaires’ disease include:

People who are more likely to experience severe illness from Legionnaires’ disease include individuals 50 years and older, those with weakened immune systems, those with chronic respiratory conditions such as asthma and COPD, and smokers.

Iowa HHS also is asking business and property owners to review their water management practices.