Giardiasis associated with the use of a water slide.

Although Giardia lamblia cysts are an important contaminant of surface water supplies, only one swimming pool outbreak, involving an infant and toddler swim class, has been reported. We describe an outbreak of giardiasis associated with a hotel's new water slide pool which was cleansed by both bromination and sand filtration. Among the 107 hotel guests and their visitors surveyed, 29 probable and 30 laboratory-confirmed cases of Giardia infection were found. Cases ranged from 3 to 58 years of age, with a mean age of 21 years. The 5-year modal age grouping was 5 to 10 years of age. Symptoms in the 59 cases included: diarrhea (48), cramps (38), foul smelling stools (29), loss of appetite (23), fatigue (20), vomiting (18), greasy stools (15), fever (11) and weight loss (10). Four children and 2 adults were hospitalized. Significant associations were found for staying at the hotel, using the water slide pool and swallowing pool water. A possible contributing factor was the emptying of an adjacent toddlers' wading pool, a potential source of fecal material, into the water slide pool. Transmission of Giardia can occur in water slide pools and therefore should be considered in cases of protracted diarrhea among users of such pools.