Evaluation of nested PCR for diagnosis of Cyclospora cayetanensis in a sample of immunosuppressed and diarrheic patients in Turkey

Abstract

Background: Cyclospora cayetanensis is a food-borne coccidian parasite that causes cyclosporiasis inhumans and possibly in other animals. It presents with watery diarrhea and other related symptoms.Since detection of oocysts may be difficult with histological stains, a negative result should not exclude thepossibility of C. cayetanensis. PCR methods can achieve more sensitive detection of the parasite.Objective: The presence of C. cayetanensis was investigated in an immunosuppressed patient group,diarrhea patient group, and in both immunosuppressed and diarrhea patient group using the modifiedacid-fast staining and nested polymerase chain reaction (nPCR) methods.Subjects and Methods: Included in the study were 80 patients with immune suppression, 50 patientswith diarrhea, and 70 patients with both immune suppression and diarrhea. The clinical findings of thesepatients were recorded, stool samples were collected and examined using both the modified acid-fast (AF)staining and nPCR methods.Results: The overall detection rate of C. cayetanensis was 8% and 12% using the modified AF and nPCR,respectively. C. cayetanensis was detected in 5% of immunosuppressed patients, 12%, in patients withdiarrhea and 20% in patients with both immune suppression and diarrhea. Statistically significantrelationships were identified between the frequency of C. cayetanensis and abdominal pain (P<0.01),nausea (P<0.01), fatigue (P<0.01), diarrhea (P<0.05), and weight loss (P<0.01).Conclusion: nPCR gave a higher rate of cyclosporiasis, and it is more appropriate especially in cases withrecurrent prolonged symptoms.