Attempts to establish experimental Cyclospora cayetanensis infection in laboratory animals

Attempts were made to develop an animal model for Cyclospora cayetanensis t o identify a practical laboratory host for studying human cyclosporiasis. O ocysts collected from stool of infected humans in the United States, Haiti, Guatemala, Peru, and Nepal were held in potassium dichromate solution to a llow development of sporozoites. The following animal types were inoculated : 9 strains of mice, including adult and neonatal immunocompetent and immun e-deficient inbred and outbred strains, rats, sandrats, chickens, ducks, ra bbits, jirds, hamsters, ferrets, pigs, dogs, owl monkeys, rhesus monkeys, a nd cynomolgus monkeys. Most animals were inoculated by gavage, although som e of the primates were fed oocysts on food items. The animals were examined for signs of infection, particularly diarrhea, and stool samples were exam ined for 4-6 wk after inoculation. None of the animals developed patent inf ections or signs of infection. We conclude that none of the animals tested is susceptible to infection with C. cayetanensis.