The colon shows altered glandular morphology secondary to chronic infection (cystic change, villous surface).

The spherical organisms reside along the surface as 2-5 micron basophilic structures. Note the villous tranformation of colonic mucosa.

Cryptosporidium spp. are a major cause of diarrheal disease in immunodeficient individuals, but it also may affect immunocompetent individuals as well. The infection can be spread either from person to person, from animals, via food, and by water.

In healthy individuals, Cryptosporidium spp. usually causes watery or mucoid diarrhea and abdominal pain that persists for several days and occasionally several weeks. Immunocompromised hosts often experience chronic or intractable disease which in addition to severe intestinal disease, also may suffer from atypical and extra-intestinal disease. The entire GI tract including the gall bladder, pancreatic duct and even the bronchial tree can be affected.

In the otherwise healthy host, spontaneous recovery is typical, and there is no effective specific therapeutic agent. Those with immunocompromise should be administered drugs with biliary excretion (such as nitazoxanide).

In the otherwise healthy host, spontaneous recovery is typical, and there is no effective specific therapeutic agent.