Life Cycle and Transmission of Cyclospora cayetanensis: Known and unknown

Authors: Dubey, Jitender; Khan, Asis; Rosenthal, Benjamin

Submitted to: Microorganisms
Publication Type: Literature Review
Publication Acceptance Date: 1/4/2022
Publication Date: 1/6/2022
Citation: Dubey, J.P., Khan, A., Rosenthal, B.M. 2022. Life Cycle and Transmission of Cyclospora cayetanensis: Known and unknown. Microorganisms. 10(118):1-12. https://doi.org/10.3390/microorganisms10010118.
DOI: https://doi.org/10.3390/microorganisms10010118

Interpretive Summary: Coccidia are single celled parasites of medical and veterinary importance. Economically and clinically Important genera include Eimeria, Cryptosporidium, Toxoplasma, Sarcocystis, Cystoisospora, and Cyclospora. Cyclosporosis is an emerging problem worldwide and the disease is caused by Cyclospora cayetanensis. It is fecally transmitted infection. Humans ae the only known hosts for C. cayetanensis. Lack of experimental animal models and inability to cultivate the parasite in vitro hampers progress on its risk assessment and to estimate environmental contamination. The objectives of this paper are to review known and unknown aspects of its life cycle and transmission, and to review the appropriateness of surrogates best capable of hastening progress in understanding its biology and developing mitigating strategies. This review will be of interest to biologists, public health workers and parasitologists.

Technical Abstract: Although infections with Cyclospora cayetanensis are prevalent worldwide, many aspects of its life cycle and transmission are unknown. Humans are the only known hosts of this parasite. Information on its endogenous development is derived from histological examination of few biopsy specimens. Its asexual and sexual stages occur in biliary-intestinal epithelium. In histological sections its stages are less than 10 microns, making definitive identification difficult. Asexual (schizonts) and sexual (gamonts) are located in epithelial cells. Male (microgamonts) have 2 flagella, and macrogamete (female) contain wall forming bodies. Oocysts are excreted in feces in unsporulated stage. Sporulation occurs in the environment but there are many unanswered questions concerning dissemination and survival of C. cayetanensis oocysts. Biologically and phylogenotypically, C. cayetanensis resembles closely with Eimeria species of chickens, especially E. acervulina. Here we review known and unknown aspects of its life cycle and transmission, and appropriateness of surrogates best capable of hastening progress in understanding its biology and developing mitigating strategies.