Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayetanesis. The parasite is found in countries with tropical and sub-tropical climates and is not endemic in Ontario. As a result, cases reported in Ontario are either travel-related or associated with imported food. Past outbreaks have been linked to imported produce and herbs. Cyclosporiasis causes watery diarrhea that can be treated with antibiotics.
After an average incubation period of 1 week, symptomatic infections typically manifest as watery diarrhea, which can be severe.
Other symptoms include:
Untreated infections typically last for 6 to 7 weeks and may follow a relapsing course. Infections, especially in disease-endemic settings, can be asymptomatic.
Cyclospora oocysts, when freshly passed in the stool, are not sporulated. Therefore, they are not infective. Oocysts require 7 to 15 days outside the host to develop and mature into the infective sporulated oocyst. Thus, direct fecal-oral transmission (i.e. person to person transmission) is unlikely.
When ingested, Cyclospora oocysts excyst in the gut and release sporozoites, which invade the epithelial cells of the small intestine.
Follow Public Health Ontario (PHO) Enteric Protozoa (Cryptosporidium, Cyclospora, Dientamoeba, Entamoeba, and Giardia) – PCR which provides routine PCR testing information for the main enteric parasitic protozoa at PHO. These parasitic protozoa include Cryptosporidium, Cyclospora, Dientamoeba, Entamoeba, and Giardia.
Enteric protozoa PCR is indicated for the diagnosis of patients with unexplained diarrhea lasting for 7 days or longer associated with recent travel, untreated water exposure (e.g. well water or streams), impaired immune system, or a suspected outbreak cluster.1
Trimethoprim-sulfamethoxazole (TMP-SMX) is the first-line treatment for cyclosporiasis, with symptom resolution usually noted 2 to 3 days into therapy.
No highly effective alternative antibiotic regimen has been identified yet for patients who:
Report all suspect or confirmed cases of cyclosporiasis to TPH at 416-392-7411 during business hours (8:30 a.m. to 4:30 p.m., Monday to Friday) or 311 after hours.