Cryptosporidium infection in Oregon public health clinic patients 1985-88: the value of statewide laboratory surveillance.

To evaluate the utility of statewide laboratory Cryptosporidium surveillance, we screened stools from all 5,256 patients evaluated at local health departments for parasitic disease from January 1985 through June 1988. Fifty-seven patients (1.1 percent) were found to have Cryptosporidium. Seasonal peaks in positivity were observed in the spring, summer, and early autumn months. In children, younger age was associated with higher positivity rate of cryptosporidiosis. As a result of these surveillance efforts, Oregon's first known outbreak of cryptosporidiosis was detected and investigated during 1988. Twenty-five persons were infected, including children, parents, and staff associated with two day care centers. The cost of routine screening for Cryptosporidium was $1.13 per specimen in our laboratory, and we consider it useful.