In July 2015 Lord Fairfax Health District (LFHD) officials investigated an outbreak of Cryptosporidium infections among campers at a local campground. LFHD used an electronic survey to conduct a retrospective cohort study of affected campers. Stool samples were collected from ill persons and tested for parasites. The LFHD conducted a campground inspection including detailed assessments of the swimming pools.

Eighty-seven gastrointestinal illnesses were reported among 745 campers surveyed. No one was hospitalized and no one died. The leading risk factor was swallowing any pool water. Eight human specimens were positive for Cryptosporidium. Four were typed as Cryptosporidium hominis. Initial distribution system and raw well water samples were positive for total coliforms. Raw well water was also positive for E. coli.