During 2002, 206 confirmed cases of Cryptosporidium parvum infection (4.2 per 100,000 population) were reported.
This is similar to the 198 cases reported in 2001 and represents an 8% increase from the median number of cases reported annually from 1997 to 2001 (median, 190 cases; range, 91 to 242). The median age among casepatients in 2002 was 10 years (range, 4 months to 81 years). Children 10 years of age or younger accounted for 52% of cases. Sixty percent of cases occurred during July through September. The incidence of cryptosporidiosis in the West Central, Southeastern, and Southwestern districts (16.6, 10.6, and 7.8 cases per 100,000 population, respectively) was significantly higher than the statewide incidence. Only 44 (21%) reported cases occurred among residents of the seven-county Twin Cities metropolitan area (1.6 per 100,000 population). Twenty-nine (14%) case-patients required hospitalization, for a median of 2 days (range, 1 to 9 days).
Six outbreaks of cryptosporidiosis were identified in 2002, including two outbreaks in child daycare settings (three and two cases, respectively) with person-to-person transmission. Three recreational water-borne outbreaks occurred, including 52 cases (16 laboratory-confirmed) associated with a community-based swimming pool, 41 cases (14 laboratory- confirmed) associated with a hotel swimming pool, and 16 cases (two laboratory-confirmed) associated with a resort swimming pool. One outbreak with two confirmed cases resulted from contact with calves from a dairy farm.