A study from the Centers for Disease Control and Prevention find a third of all recreational waterborne disease outbreaks occurred in hotel pools or hot tubs and water play venues.
Between 2000 and 2014 the CDC recorded nearly 500 disease outbreaks related to recreational water use that resulted in more than 27,000 illnesses and eight deaths. Hotels were the leading setting, associated with 157 of the outbreaks
Of the outbreaks with a confirmed cause, most were due to pathogens in the pool while the rest were caused by chemicals. A parasite that causes diarrhea and other gastrointestinal issues caused most of the illnesses.
Outbreaks spiked during June, July and August but they were observed to take place all year long with March being another month with a spike in cases.
Chlorine is the primary barrier to the transmission of pathogens in treated recreational water. At CDC-recommended concentrations of at least 1 ppm, free available chlorine inactivates most pathogens within minutes.