Multistate Cyclospora outbreak – IDPH and CDC alert

The following is an IDPH alert released on July 26th 2013:

There has been an increase in Cyclospora cases in the United States during the months of June and July. At least 285 cases have been reported to CDC. The food item responsible for the outbreak is not yet known but steps are being made to identify a source. It is not known if all cases reported during this time frame are linked to the same outbreak. There are no subtyping techniques that can better establish which cases may be linked to a common source. More information on the multi-state investigation can be found at:

Illinois is currently reporting three cases of Cyclospora in the months of June and July that did not travel outside the country. Cases from Lake County and Montgomery County likely acquired infection within Illinois. A third case from Sangamon County likely acquired infection in Iowa.

Cyclospora cayetanensis is most commonly spread by contaminated food or water. The incubation period is a median of seven days. Cyclospora causes a watery diarrhea with frequent sometimes explosive bowel movements. Other common symptoms include loss of appetite, weight loss, abdominal cramps, bloating, increase gas and fatigue. Symptoms can be relapsing and last for a few days to two months. Symptoms are more severe in persons who are immunocompromised, including persons with HIV/AIDS.

Persons who call the local health department with clinically compatible symptoms should be advised to see a health care provider who can determine if testing for Cyclospora is needed. Cyclospora is diagnosed with stool testing that requires a specific request of the commercial laboratory or hospital laboratory for Cyclospora testing. Cyclospora cayetanensis oocysts can be detected by modified acid-fast staining of stool (8 to 10 microns in diameter). It is important to distinguish the Cyclospora oocysts from those of Cryptosporidium, which are also acid-fast but smaller (5 microns in diameter). Fluorescence microscopy can also be used for detection of oocysts, which are autofluorescent. Laboratories who have questions about Cyclospora testing should call the IDPH Springfield laboratory at 217-782-6562 and ask to speak to the Clinical Microbiology unit.

Health care providers are asked to consider the diagnosis of cyclosporiasis in persons with clinically compatible symptoms. Cyclosporiasis is reportable to the local health department by the health care provider and laboratory. Local health departments should interview laboratory confirmed cases reported in June and July with the standard questions for this disease. If the person does not report travel overseas during the incubation period they should also interview with a specific standardized outbreak questionnaire provided on the Sharepoint site under cyclosporiasis. This questionnaire should be faxed to the IDPH Communicable Disease control section at 217-524-0962.

Depending on the information gathered from the case patient, local health department environmental staff may be asked to collect additional information such as invoices from stores or shopper card information.


  1. What is Cyclospora?
  2. Surveillance for Laboratory-Confirmed Sporadic Cases of Cyclosporiasis — United States, 1997–2008
  3. Cyclospora infection