History of Discovery


Ambunti, Papua New Guinea

The history of the discovery of Cyclospora begins with a publication by British parasitologist, Dr. Ashford, of three cases of a “coccidian-like” parasite in Papua New Guinea.  His publication went largely unnoticed for ten years until the first documented outbreak in a physician dormitory in the United States in 1990.  The parasite’s classification was discovered in 1992 when researchers in Peru claimed to have sporulated and excysted the oocysts which would place the parasite in the genus of Cyclospora. 

The complete morphology was described in 1994 and the species name cayetanensis was derived from the research university in Peru (Cayetano Heredia University).


From 1990-1999, there have been at least 11 food and waterborne outbreaks of cyclosporiasis in North America. The following figure from B. L. Herwaldt’s review on Cyclospora cayetanensis gives a summary of some of the major outbreaks of the parasite.





Increasing publicity and research has resulted in better documentation and diagnosis of the cyclospora parasite.  However, according to an informal survey conducted by the American society of Parasitologists, few physicians are adequately trained in parasitology and, as a result, cyclosporiasis infections largely go undiagnosed.




Phylum: Acomplexa

Class: Sporozoa

Subclass: Coccidia

Order: Eucoccidiorida

Family: Eimeriidae

Genus: Cyclospora

Species: cayentanensis