MARSHALL COUNTY, Iowa — Reported Legionnaires’ disease cases slowed over the weekend with the Iowa HHS reporting just two new cases across a several day period.

Earlier in the week, Iowa Health and Human Services reported two separate large jumps in Legionnaires’ disease cases. Totaling 68 cases, and still just one death, on Wednesday.

Over the past several days the number of reported cases slowed, with only two new cases reported across a four day period. Bringing the total numbers of cases to 70 since August 2025.

Legionnaires’ disease is caused by legionella bacteria which is inhaled through water vapor droplets which can come from cooling towers, water fountains, or hot tubs. Legionnaires’ is not spread from person to person.

Marshall County Public Health Department and Iowa HHS announced the cluster of cases and their investigation three weeks ago, saying they were working with the CDC to identify the local cause of the disease.

Over the course of the investigation, the Marshall County Health Department says several area cooling towers have been tested and cleaned. However, the source of the outbreak has not been identified by health officials.

Though not usually deadly, individuals affected will require treatment through antibiotics. People who are in or have visited the Marshalltown area and experience the following symptoms should seek treatment:

• High fever
• Cough
• Fatigue
• Shortness of breath
• Headaches
• Chest pain
• Nausea or diarrhea

For more information on Legionnaires’ disease and the investigation visit the Iowa HHS website.