Pathogen Safety Data Sheets: Infectious Substances – Cyclospora spp.



NAME: Cyclospora spp.

SYNONYM, OR CROSS REFERENCE: Cyclosporiasis, Cyclosporidiosis and Cyclospora cayetanensis.

CHARACTERISTICS: Cyclospora are coccidian in a genus isopora Footnote 1. Cyclospora are in phylum Apicomplexa Footnote 2, subclass Coccidiasina, and family Eimeriidae Footnote 1. Cyclospora has spherical, thick walled spores Footnote 3, oocyst with a diameter of 8-10 µm and contains two sporocysts, each of which contains two sporozoites Footnote 1. Cyclospora have been previously described as cyanobacterium-like body, blue-green algae and large flagellate Footnote 1. Cyclospora oocysts, when freshly passed in the stool are not sporulated and therefore are not infective. Oocysts require a few days to weeks to develop and mature in the environment into the infective sporulated oocyst, thus precluding direct fecal-oral transmission.Footnote 4 Upon ingested oocysts excyst in the gut and release the sporozoites, which invade the epithelial cells of the small intestine. Sporozoites undergo two generations of asexual reproduction in the cell and become meronts, which initiate the macro and micro gametocyte sexual cycle Footnote 4.


PATHOGENICITY/TOXICITY: Cyclospora causes opportunistic infection among AIDS patients Footnote 1. Cyclospora infections cause diarrhea Footnote 1, abdominal cramps or bloating, nausea, low grade fever and weight loss Footnote 1.

EPIDEMIOLOGY: Cyclospora spp. are present worldwide Footnote 3. Cyclospora is endemic to Peru, Haiti, and Nepal Footnote 3. In a Haitian AIDS clinic, 34% of patients seeking attention for chronic diarrhea were infected with Cyclospora Footnote 1. An epidemiological investigation in a Haitian community showed that Cyclospora infections were higher in the month of February Footnote 1. Children were five times more likely to show cyclosporiasis than adults and AIDS patients also had significantly higher rates of infection Footnote 1. In the United States, there is 0.1Footnote 1 case reported for 100,000 people Footnote 3 and most are likely travelers and inhabitants of areas where this protozoan is endemic Footnote 1. One outbreak in 1996 is reported in Canada and USA with Cyclospora Footnote 3.

HOST RANGE: Human and animals Footnote 1.

INFECTIOUS DOSE: Very low infectious dose of 10-100 oocysts Footnote 2.

MODE OF TRANSMISSION: Direct person-to-person transmission of Cyclospora is unlikely to occur because the organism is not immediately infectious when shed Footnote 2Footnote 6Footnote 5. Consumption of untreated water or contaminated food Footnote 1Footnote 5, or direct or indirect contact of contaminated soil can cause infection Footnote 5.

INCUBATION PERIOD: The oocysts are excreted unsporulated, requiring 7-13 days of optimal conditions outside of the host to mature Footnote 6. After an incubation of 2-11 days, immunocompetent patients experience a self-limited, but prolonged, relapsing watery diarrhea Footnote 6.

COMMUNICABILITY: No person to person transmission has been reported Footnote 3.


RESERVOIR: Cyclospora has been found in domestic animals Footnote 1, feces of chicken (oocysts) Footnote 1, and the intestines of mammals and birds Footnote 2Cyclospora-like oocysts have also been found in zoo animals (nonhuman primates, carnivores, and artiodactyla) Footnote 1.




DRUG SUSCEPTIBILITY: Trimethoprim-sulfamethoxazole (TMP-SMX) and ciprofloxacin (treatment failures occur more frequently with this quinolone) Footnote 1.

DRUG RESISTANCE: Azithromycin, norfloxacin, tinidazole, nalidixic acid, diloxanide furoate, and quinacrine Footnote 1.

SUSCEPTIBILITY TO DISINFECTANTS: Cyclospora are resistant to chemicals such as chlorine used for treating water Footnote 7.

PHYSICAL INACTIVATION: The Cyclospora oocysts are inactivated after heating at 60°C for 1 h Footnote 8. Oocysts cannot be induced to sporulate at minus 18°C for 24 h Footnote 8. Desiccation for 15 minutes causes the oocysts walls to rupture Footnote 8.

SURVIVAL OUTSIDE HOST: Cyclospora spp. require 7-15 days in the environment to sporulate, showing that they are able to survive in soil Footnote 5. Oocysts have been noted to survive in water for 2 months at 4°C and 7 days at 37°C Footnote 8.


SURVEILLANCE: Monitor for symptoms. Can be diagnosed by identification of the Cyclospora oocyst in fresh or iodine-preserved stool, duodenal aspirates, or small-bowel biopsiesFootnote 6Footnote 1. With acid-fast or safranin O staining, oocysts can be seen as 10 µm spheres with clusters of refractile globules Footnote 6.Diagnosis can be performed using modified Ziehl-Neelsen (MZN) and auramine-rhodamine stainsFootnote 1.

FIRST AID TREATMENT: Trimethoprim-sulfamethoxazole, TMP-SMX, is the first-line treatment for cyclosporiasis, with symptom resolution noted 2-3 days into therapy Footnote 6. 160-800 mg of TMP-SMX should be taken twice a day for 7 days Footnote 1.


PROPHYLAXIS: Patients re-experiencing symptoms of diahrrea 7 month following infection are given trimethoprim-sulfamethoxazole 3 times a week as a secondary prophylaxis Footnote 9.



SOURCES / SPECIMENS: Contaminated chicken feces, human feces Footnote 3, water Footnote 1, food products Footnote 5 , lettuce Footnote 6, uncooked meat Footnote 6 and raspberries Footnote 1Footnote 2Footnote 6.

PRIMARY HAZARD: Ingestion of contaminated food Footnote 3.

SPECIAL HAZARD: Working with infected lab mice or primates can be hazardous Footnote 3.


RISK GROUP CLASSIFICATION: Risk Group 2. This risk group applies to the genus as a whole, and may not apply to every species within the genus.

CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 12.

These containment requirements apply to the genus as a whole, and may not apply to each species within the genus.

PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 12.

OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 12.


SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover spill with paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up.

DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 13.

STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled Footnote 13.


REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

UPDATED: September 2016

PREPARED BY: Centre for Biosecurity, Public Health Agency of Canada
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright © Public Health Agency of Canada, 2016 Canada

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