AN OUTBREAK OF CRYPTOSPORIDIOSIS ASSOCIATED WITH A RESORT SWIMMING POOL

An outbreak of cyptosporidiosis occurred in late April 1993 among reso rt hotel guests which was temporally associated with, but geographical ly distant from, a massive waterborne outbreak of cryptosporidiosis in Milwaukee. Wisconsin, that occurred in late March and early April of 1983. A case-control study was performed among: groups with members wh o reported illness and among a systematic sample of groups who stayed at the resort hotel during the risk period. Of 120 persons interviewed , 51 (43%) met the case definition. Swimming in the resort hotel's poo l was significantly associated with case status (OR = 9.8; 95% Cl 3.4, 29.7), as was consumption of ice from the hotel's ice machines (OR = 2.3; 95% Cl 1.01, 5.2). When analysis was restricted only to laborator y-confirmed cases and controls, swimming pool use was the only risk fa ctor significantly associated with illness (OR = 13.0; 95% Cl 2.6, 88. 7). Following waterborne outbreaks of cryptosporidiosis associated wit h water supplies, swimming pools should be considered as possible ongo ing sources for transmission regionally.