Equine Cryptosporidium parvum infections in western Poland.

A total of 564 fecal specimens from 318 horses used for recreational riding, child hippotherapy, and racing at ten commercial and government-run stables in western Poland were tested for Cryptosporidium parvum oocysts by microscopic examination of Ziehl-Neelsen stained smears, enzyme immunoassay, and combined direct immunofluorescent antibody and fluorescent in situ hybridization. Also, seven stool specimens from five personnel who had repeated contact with these horses were tested for C. parvum oocysts. Eleven horses that shed C. parvum oocysts were found in five of ten stables (50%). The prevalence of infection varied from 0% to 11.5%. The overall prevalence of equine C. parvum-associated cryptosporidiosis in the Wielkopolska region of western Poland was 3.5%. C. parvum oocysts were found only in fecal samples from mature horses, the number of oocysts was low, and infections were not associated with clinical signs. Oocysts were not found in human fecal specimens.