Cyclospora PCR test

Test code: X0043 - Ultrasensitive qualitative detection of Cyclospora species by real time PCR

Cyclospora is a genus of apicomplexan parasites characterized as having oocysts with two sporocysts, each containing two sporozoites. The most common species of Cyclospora is Cyclospora cayetanensis, a protozoan that infects the human small intestine and causes an illness known as cyclosporiasis.

Other, non-cayetanensis Cyclospora species infect a diverse range of animal hosts, exhibiting strong host specificity.  These non-cayetanensis Cyclospora species are found in non-human primates, reptiles, insectivores, and rodents.

Cyclosporiasis occurs upon ingestion of food or water contaminated with Cyclospora oocysts (the infectious form of the parasite). Common sources of human infection include fresh produce like berries, herbs like basil or cilantro which are consumed uncooked, lettuce, or other fruits and vegetables that have been exposed to fecal matter containing the parasite. Unlike some parasites, Cyclospora is not directly transmitted from person to person because the oocysts need time (days to weeks) in the environment to become infectious. Outbreaks are often linked to contaminated water or foods imported from tropical or subtropical regions, though cases occur worldwide.

The infection typically leads to watery diarrhea, which can be frequent and explosive, along with other gastrointestinal symptoms. Additional signs may include loss of appetite, weight loss, stomach pain, nausea, vomiting, fatigue, low-grade fever, bloating, and increased gas. Symptoms usually begin about a week after exposure and can last from a few days to over a month if untreated, especially in people or animals with weakened immune systems.

Cyclospora infection is traditionally diagnosed by microscopic examination of fecal material. However, this method has low sensitivity. PCR is increasingly being used instead to diagnose Cyclospora infection. PCR can detect low levels of Cyclospora DNA in stool samples, when the parasite burden is minimal or in cases where microscopy yields negative results. PCR is especially valuable for early-stage infections, when oocysts may be scarce. Studies have shown PCR to identify infections that traditional microscopic examination misses, improving overall detection rates (Murphy et al., 2017; Sow et al., 2017).

Utilities:

• Check for Cyclospora in water sources, food, soil, and other environmental samples
• Selection of appropriate remediation regimens
• Check for post-remediation absence of this parasite
• Help confirm the presence of this parasite in animals
• Help minimize human exposure to this agent

References:

Murphy HR, Lee S, da Silva AJ. Evaluation of an Improved U.S. Food and Drug Administration Method for the Detection of Cyclospora cayetanensis in Produce Using Real-Time PCR. J Food Prot. 2017 Jul;80(7):1133-1144.

Sow D, Parola P, Sylla K, Ndiaye M, Delaunay P, Halfon P, Camiade S, Dieng T, Tine RCK, Faye B, Ndiaye JL, Dieng Y, Gaye O, Raoult D, Bittar F. Performance of Real-Time Polymerase Chain Reaction Assays for the Detection of 20 Gastrointestinal Parasites in Clinical Samples from Senegal. Am J Trop Med Hyg. 2017 Jul;97(1):173-182.

Specimen requirements: 2 ml of feces, or fecal swab, or 2 ml of water, or used water filter media; or 2 ml of soil; or 2 ml food, or environmental swab or swipe.

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time polymerase chain reaction

Normal range: Nondetected