RESUMO
In the last years Cyclospora sp. has been increasingly associated to human intestinal diseases. The first studies have been reported to this parasite as a Cyanobacterium-like body, large Cryptosporidium or coccidian-like body. The ultrastructural characteristic and the "in vitro" sporulation have revealed the existence of oocyst constituted for two sporocysts with two sporozoites per sporocyst. This evidence has allowed its classification as a coccidian within the genus Cyclospora and its designation as a new pathogen species in humans, Cyclospora cayetanensis. Recently phylogenetic analysis based on rDNA sequences suggested that Cyclospora sp. was closely related to the Eimeria genus. The identification, morphological characteristics, clinical evaluation and chemotherapy of the human intestinal disease asssociated to Cyclospora sp. are commented in the present paper