What is already known about this topic?
Outbreaks associated with treated recreational water in pools, hot tubs, and water playgrounds can be caused by pathogens or chemicals.
What is added by this report?
For the period 2015–2019, a total of 208 outbreaks associated with treated recreational water were reported to CDC.
Cryptosporidium caused 76 outbreaks, resulting in 2,492 cases.
Legionella caused 65 outbreaks, resulting in 13 deaths.
What are the implications for public health practice?
To help prevent outbreaks, operators of public aquatic venues and U.S. jurisdictions can voluntarily adopt CDC’s Model Aquatic Health Code,
Legionella Control Toolkit, and Water Management Program Toolkit recommendations, and swimmers can follow CDC’s healthy swimming steps.