- Between 2009 and 2017, there were 444 cryptosporidiosis outbreaks reported in 40 states and Puerto Rico.
- The outbreaks resulted in 7,465 people falling ill.
- Recreational water — mostly swimming pools, but also kiddie pools and water playgrounds — were responsible for 156, more than a third of the cases.
- Untreated water (such as lakes) and drinking water caused 22 more cases.
- Eighty-six cases involved contact with animals, mostly cattle.
- Another 57 cases were associated with child care settings.
- Twenty-two cases were foodborne, most involving unpasteurized milk or apple cider.
- Most cases were reported in the months of July and August, and 2016 was a peak year for outbreaks with more than 80.
- The number of cases increased by an average of 12.8% annually between 2009 and 2017.