What is the pathophysiology of cryptosporidiosis?

Updated: Nov 11, 2019
  • Author: Melinda B Tanabe, MD; Chief Editor: Michael Stuart Bronze, MD  more...
  • Print
Answer

Cryptosporidium oocysts are highly infectious, requiring fewer than 10 oocysts to cause human disease for some isolates. [12, 13] The oocysts are infectious immediately after excretion, and the life cycle of the parasite produces forms that reinvade the intestine. The location of the parasite in the intestine is intracellular but extracytoplasmic, which may contribute to the marked resistance of Cryptosporidium species to treatment. Large numbers of oocysts are excreted and are resistant to harsh conditions, including chlorine at levels usually applied in water treatment.

Cryptosporidiosis typically presents with watery diarrhea. The mechanism by which Cryptosporidium causes diarrhea includes a combination of increased intestinal permeability, chloride secretion, and malabsorption, which are all thought to be mediated by the host response to infection. [2, 14, 15] Severe disease is characterized by villous atrophy and crypto-hyperplasia. [15] In immunocompetent persons, the infection is usually limited to the small intestine. In persons with AIDS or certain congenital immunodeficiencies, the biliary and respiratory tracts may be involved. [16]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!