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| Cryptosporidiosis of Colon |
| Etiology •Cryptosporidiosis is caused by the protozoan parasite Cryptosporidium parvum |
| Pathogenesis •The disease is acquired by ingestion of an oocyst •Trophozoites are liberated and attach themselves to the surface of small and large intestinal mucosal cells by destroying the microvilli and lying extracytoplasmically beneath the luminal enterocyte membrane •The intestinal mucosal cells are not destroyed, and the malabsorption and profuse diarrhea characteristic of the disease are produced by destruction of the microvilli, |
| Epidemiology •Crytosporidiosis is acquired through ingestion of fecally contaminated material with water being the usual source in epidemics •It is most commonly seen in immunocompromised individuals particularly those with AIDS •Milder cases of Cryptosporidiosis are also being seen in immunologically competent patients particularly those working on farms and in day care centers |
| General Gross Description •Endoscopically the intestinal mucosa is red, non-friable and without ulceration |
| General Microscopic Description •The organisms are seen as spherical 2-5mm basophilic bodies that line up on the surface of intestinal mucosal cells •No intracellular organisms are seen •Electron microscopy can demonstrate the trophozoites attached to the mucosal cell surfaces as well as oocysts •While the organisms are easily seen on H&E, silver and Giemsa stains can aid in the diagnosis •Mild nonspecific inflammation of the lamina propria can been seen in most cases with severe cases showing some acute inflammation •There is an absence of necrosis or ulceration |
| Clinical Correlation •The symptoms are crampy pain and profuse watery diarrhea which may be accompanied by low grade fever and nausea •Hyperactive bowel sounds may be heard and more severe cases have abdominal tenderness •In experimental animals the symptoms occur 3-5 days after ingestion of the oocysts •While examination of stool can reveal the parasites, the most common mode of diagnosis is mucosal biopsy of the colon •The disease can be self limited in patients competent to produce anti-parasite IGA, but in immunocompromised patients it can remain a difficult to treat chronic illness |
| References • Sleisenger MH, Fordtran JS. Gastrointestinal disease. 5th ed. Philadelphia: Saunders, 1993, pp. 1203-1204 |
| Cryptosporidiosis of Colon |
| Synopsis by: Martin Nadel M.D. (T67000E54800)[341] |
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