Establish a Correlative Dose-Response Model for Human Cryptosporidiosis

The goal of this proposal is to provide data to confirm strain variation effects on illness severity of volunteers challenged with different Cryptosporidium parvum strains, and to investigate whether these same differences are observed in animal models, using the gamma interferon knockout (GO) mouse model. Three strains previously used to challenge volunteers will be tested in the GO mouse model. In addition, two more strains will be tested both in volunteers and in the mice. Volunteer studies will be performed at the University of Texas medical Center, and the animal work at Tufts University.