Advances in Cyclosporiasis Diagnosis and Therapeutic Intervention

Abstract

Cyclosporiasis is caused by the coccidian parasite Cyclospora cayetanensis and is associated with large and complex food-borne outbreaks worldwide. Associated symptoms include severe watery diarrhea, particularly in infants, and immune dysfunction. With the globalization of human food supply, the occurrence of cyclosporiasis has been increasing in both food growing and importing countries. As well as being a burden on the health of individual humans, cyclosporiasis is a global public health concern. Currently, no vaccine is available but early detection and treatment could result in a favorable clinical outcome. Clinical diagnosis is based on cardinal clinical symptoms and conventional laboratory methods, which usually involve microscopic examination of wet smears, staining tests, fluorescence microscopy, serological testing, or DNA testing for oocysts in the stool. Detection in the vehicle of infection, which can be fresh produce, water, or soil is helpful for case-linkage and source-tracking during cyclosporiasis outbreaks. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX) can evidently cure C. cayetanensis infection. However, TMP-SMX is not suitable for patients having sulfonamide intolerance. In such case ciprofloxacin, although less effective than TMP-SMX, is a good option. Another drug of choice is nitazoxanide that can be used in the cases of sulfonamide intolerance and ciprofloxacin resistance. More epidemiological research investigating cyclosporiasis in humans should be conducted worldwide, to achieve a better understanding of its characteristics in this regard. It is also necessary to establish in vitro and/or in vivo protocols for cultivating C. cayetanensis, to facilitate the development of rapid, convenient, precise, and economical detection methods for diagnosis, as well as more effective tracing methods. This review focuses on the advances in clinical features, diagnosis, and therapeutic intervention of cyclosporiasis.

Seasonal Differences in Cyclospora cayetanensis Prevalence in Colombian Indigenous People

“…Primary site of human infection is the upper small intestinal tract [ 6 ]. While C. cayetanensis -associated gastroenteritis is usually self-limiting after partly prolonged courses in immunocompetent individuals, long-lasting severe diarrhea may occur in immunocompromised patients, sometimes with relapses despite cotrimoxazole therapy [ 2 , 3 , 7 , 8 ]. Clinical courses about several weeks or months have been described without antimicrobial treatment.…”

“…In particular, individuals with low socio-economic status are at risk of getting infected with C. cayetanensis [ 15 , 16 ] as impressively indicated by a prevalence of 22.2% in slum dwellers in South Chennai, India [ 17 ]. However, imported and insufficiently cleaned raw fruit and vegetables imported from areas of endemicity are sources of infection even in non-endemic countries and irrespective of socio-economic status [ 2 , 8 , 9 , 18 ]. Accordingly, large foodborne cyclosporiasis outbreaks have been described in industrialized countries as well [ 19 , 20 ].…”

Applications in Which Aptamers Are Needed or Wanted in Diagnostics and Therapeutics

“…Detection of this parasite on fresh produce and in soils and large volumes of irrigation water is truly a "needle in a haystack" problem; thus, high affinity receptors (i.e., antibodies or aptamers) are required to capture and perhaps concentrate the oocysts. However, Linscott's directory shows no hits for antibodies against Cyclospora, and the lack of commercial antibodies is acknowledged in the literature [9]. Additionally, in private discussions with academic researchers who have tried to develop antibodies against Cyclospora oocysts, the author has been informed that it is a very difficult task, and the resulting antibody affinities have been poor.…”

Life Cycle and Transmission of Cyclospora cayetanensis: Knowns and Unknowns

“…Cyclosporiasis is a problem worldwide. Several recent papers review prevalence, clinical symptoms, diagnosis, epidemiology, and treatment of cyclosporiasis [1][2][3][4][5][6]. The objectives of this paper are to review known and unknown aspects of its life cycle and transmission, and to review the appropriateness of surrogates best capable of hastening progress in understanding its biology and developing mitigating strategies.…”