Cyclosporiasis PDF

Cyclosporiasis PREPARED BY: DR. SHIRLEY TANG GEE HOON CYCLOSPORIASIS Infection by Cyclospora spp. A coccidian parasite causing prolonged diarrhea and traveller’s diarrhea Cyclospora cayetanensis CYCLOSPORIASIS DISTRIBUTION Infection has been reported from South E Asia, Papua Ne...

Cyclosporiasis PREPARED BY: DR. SHIRLEY TANG GEE HOON CYCLOSPORIASIS Infection by Cyclospora spp. A coccidian parasite causing prolonged diarrhea and traveller’s diarrhea Cyclospora cayetanensis CYCLOSPORIASIS DISTRIBUTION Infection has been reported from South E Asia, Papua New Guinea, Indonesia, India, Pakistan, Nepal, Middle east, Afrika, UK, USA, South and central America and the Carribean. MORPHOLOGY- OOCYST (in feces) Spherical, size 8-10 um Morphology of sporulated (matured) oocyst: mature oocyst is round, 8–10 μm size, contains two sporocysts, each containing two sporozoites MORPHOLOGY-OOCYST Unsporulated (immature) when passed out in feces, contains central morula with 6-9 refractile globules. LIFE CYCLE Not clearly understood, possibly with asexual and sexual cycle in intestine Transmission through ingestion of sporulated oocysts that contaminate food or water LIFE CYCLE Oocyst shed in feces sporulates outside the host. The sporulated oocysts are infectious to humans. Man acquires infection by ingestion of food and water contaminated with feces- containing oocysts.  LIFE CYCLE Excystation of the sporocyst releases crescentic sporozoites in the human intestine. The sporozoites infect enterocytes in the small intestine. The sporozoites develop into unsporulated oocysts, which are excreted in feces.  PATHOGENICITY & CLINICAL FEATURES Incubation period is of 1- 7 days. diarrhea, fatigue, loss of appetite, nausea, vomiting, cramps, fever. (usually severe in the immunocompromised) Sometimes asymptomatic esp. immunocompetent person.  PATHOGENICITY & CLINICAL FEATURES Intestinal biopsy shows: - shortening of villous - lymphocyte infiltration of lamina propria - increase lymphocytes in the intestinal epithelial cell. DIAGNOSIS  DIAGNOSIS Stool Examination Diagnosis is by direct wet mount demonstration of oocysts in feces. The oocysts can be stained by a modified ziehl-neelsen stain. Oocysts of Cyclospora are acid-fast and stain red in color. Under ultraviolet illumination, unstained oocysts of C. cayetanensis are autofluorescent.  DIAGNOSIS Histopathology Biopsy specimen from jejunum shows villous atrophy and blunting of villi along with other inflammatory changes. The parasite can also be seen in small bowel biopsy material by electron microscopy.  TREATMENT Rehydration in serious cases, in mild cases no treatment needed Cotrimoxazole, tetracycline and folic acid have been used before HIV-infected patients may require long-term suppressive maintenance therapy.