Cyclosporiasis

Reportable by Laboratories and Providers

About this Reportable Disease

Infectious agent: Protozoan parasite Cyclospora cayetanensis

Description of illness: Cyclospora infects the small intestine and typically causes watery diarrhea, with frequent, sometimes explosive, stools. Vomiting, body aches, low-grade fever, and other flu-like symptoms occur occasionally. If untreated, the illness may last for a few days to a month or longer, and may follow a remitting-relapsing course. Some infected persons are asymptomatic, particularly in settings where cyclosporiasis is endemic.

Interactive Disease Data


Laboratory Reporting for this Disease

Cyclospora

TEST NAME Cyclospora
DISEASE/DISORDER Cyclosporiaisis
ALTERNATE NAME(S)  
METHODOLOGY Genotyping
SPECIAL INSTRUCTIONS Specimens are only accepted from May 1 through the end of each calendar year.
ORDERING INFORMATION TDH DLS Requisition:  PH-4182 Clinical Submission Requisition Form

Specimen Requirements 

Patient Preparation
  • None
Specimen Collection
  • Acceptable specimen types:

-  Fixed stools in Intestinal Parasite (IP) Total Fix bottle (black cap)

-  Unfixed or preserved specimens (EXCEPT Formalin) - minimum                         volume 500 µL 
Specimen Labeling
  • Specimen must be labeled with at least two unique patient identifiers and match accompanying TDH-DLS Form PH-4182.
Specimen Processing
  • None
Specimen Storage and Preservation
  • Temperature storage temperatures prior to shipping:

    -Unfixed stools stored at 2 - 8°C

    -Intestinal Parasite (IP) Total Fix media at 17 - 25°C

    -Preserved specimens (EXCEPT Formalin) 2-30°C
Specimen Transportation
  • Ship samples at the following temperatures:

-Unfixed stools stored at 2 - 8°C

-Intestinal Parasite (IP) Total Fix media at 17 - 25°C

-Preserved specimens (EXCEPT Formalin) 2-30°C

-Ship specimens within 1 week of collection.

  • All infectious substance shipments must conform to U.S. Department of Transportation (DOT) Hazardous Materials Regulations (HMR 49 C.F.R. Parts 171-180). 
Specimen Acceptability and Rejection
  • Unsatisfactory specimens include but are not limited to:

 -  Specimen was broken or leaked in transit

-   Specimens with interfering substances present such as bismuth, barium, mineral oil, gall-bladder dyes, urine, water, or dirt

-   No specimen was in the container submitted

-   Stools submitted in formalin

-   Stools collected prior to May 1 of each calendar year

-   Specimens that are incorrectly labeled or contain discrepancies between the test requisition and the specimen container

-   Specimen containers that are overfilled 
Testing Location Specimens will be sent to reference laboratory.

Laboratory Reporting

Reporting requirements apply to all laboratories located within Tennessee, as well as laboratories outside of Tennessee that test residents of Tennessee, including laboratories located within healthcare facilities. Healthcare providers and laboratories in the same healthcare facility both have a duty to report. The type of organisms and analytes laboratories must report to TDH for 2026 are indicated, and there are several ways laboratories can report results to TDH.

Information about this Reportable Disease for Healthcare Providers

Clinical Summary

  • Cyclosporiasis is an intestinal infection caused by Cyclospora cayetanensis and is acquired by ingesting contaminated food or water (often fresh produce). The parasite’s oocysts typically need about 1–2+ weeks in the environment to become infectious, so direct person-to-person spread is unlikely.
  • Symptoms commonly include watery diarrhea (sometimes frequent/explosive) with loss of appetite, weight loss, abdominal cramping/bloating, gas, nausea, and prolonged fatigue. The incubation period averages about 1 week (range ~2 days to ≥2 weeks), and illness can last days to a month or longer and may relapse if untreated.
  • Diagnosis often requires specifically ordering Cyclospora testing because many U.S. laboratories do not routinely include it (special stool stains and/or PCR). Because shedding can be intermittent, more than one stool specimen collected on different days may be needed.
  • Recommended treatment is trimethoprim-sulfamethoxazole (TMP-SMX) (typical adult immunocompetent regimen: 160/800 mg by mouth twice daily for 7–10 days; longer courses may be needed for people with HIV). Prevention focuses on avoiding potentially stool-contaminated food and water; routine chemical disinfection methods may not reliably kill Cyclospora.

Healthcare Provider Reporting

Healthcare reporting requirements apply to all providers located within Tennessee, as well as providers whose patients reside in Tennessee.

Providers must report cases of all diseases and conditions listed through one of these methods:

• Mail or fax a completed PH-1600 form to your local health department or fax to the state health office at (615) 741-3857

• Send automatically via electronic case reporting (eCR). See this TDH webpage for more information on eCR, register at the Trader Partner Registration website, or contact MU.Health@tn.gov for assistance.

• Submit online via NBS. NBS is TDH's reportable disease system. To request an NBS account for reporting Complete this user survey to request an NBS account for reporting. 

• Blood lead levels can be sent via fax ( (615) 741-3857), entered online, or reported using the instructions at this link. 

Information about this Reportable Disease for the Public

What It Is and How People Get Infected

Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis (Cyclospora). People get infected by swallowing Cyclospora in contaminated food or water.

How It Spreads and Who Is at Risk (Including Travel)

Contamination happens when food or water is exposed to feces (stool). In the United States, outbreaks have been linked to fresh produce, and people can also become infected during travel outside the U.S.
For travel-related prevention and diarrhea guidance, see the CDC travel health reference, the CDC Yellow Book (international travel). 

Signs and Symptoms

Some people have no symptoms. When symptoms occur, they typically begin about 1 week after exposure (range: as soon as 2 days to 2 weeks or more). Common symptoms include watery diarrhea, loss of appetite, weight loss, stomach cramps/bloating, increased gas, nausea, and fatigue. 

Treatment and What to Do If You Think You’re Sick

Many healthy people will recover without treatment, but illness may be prolonged. The treatment of choice is the antibiotic trimethoprim-sulfamethoxazole (TMP-SMX). If you have symptoms (especially prolonged diarrhea), contact a healthcare provider for evaluation and possible testing and treatment.

This Page Last Updated: March 25, 2026 at 8:53 PM