Life Cycle


Life cycle of Cyclospora cayetanensis

  The unsporulated and non-infectious oocysts are deposited into the environment in human stool.


   Sporulation occurs after days or weeks at temperatures between 22˚C to 32˚C.  Sporulation divides the sporont into two sporocysts, each containing two elongate sporozoites.


  Food or Waterborne transmission follows.


  The oocysts are ingested!


  The oocysts excyst in the gastrointestinal tract, freeing the sporozoites which invade the epithelial cells of the jejunum


  Once the sporozoites are inside the cells they undergo asexual multiplication and then sexual development to mature into oocysts


  The mechanisms of contamination of food and water are still under investigation

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A Few Interesting Notes


Incubation Period


The period from infection to disease ranges from 2 to 11 days, with the average being one week.  The long incubation period has implications for transmission.  Because of this long incubation period, it is virtually impossible to have person-to-person transmission.



Why are there still life cycle mysteries?

Research into the possible modes of contamination is limited by the fact that it is difficult to detect the low levels of Cyclospora in the samples.  Additionally, the lack of an animal host also constrains life cycle research.