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When
freshly passed in stools, the oocyst is not infective
(thus, direct fecal-oral transmission cannot occur; this differentiates
Cyclospora from another important coccidian parasite, Cryptosporidium).
In the environment
,
sporulation occurs after days or weeks at temperatures between 22°C to 32°C,
resulting in division of the sporont into two sporocysts, each containing
two elongate sporozoites
. Fresh
produce and water can serve as vehicles for transmission
and the
sporulated oocysts are ingested (in contaminated food or water)
. The
oocysts excyst in the gastrointestinal tract, freeing the sporozoites which
invade the epithelial cells of the small intestine
.
Inside the cells they undergo asexual multiplication and sexual development
to mature into oocysts, which will be shed in stools
.
The potential mechanisms of contamination of food and water are still under
investigation.
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