Data and Surveillance

Disease Trends

Reported cases of Legionnaires' disease have increased since the early 2000s, peaking in 2018. While reported cases dropped during the first year of the COVID-19 pandemic, they rebounded starting in 2021.

Legionnaires' disease incidence has been increasing since 2000. Click the image to enlarge.

 Some groups have higher incidence rates. Rates of reported cases of Legionnaires' disease are highest among:

• Black persons
• Males
• Older adults
• Northeast and Midwest regions
• Summer and fall months