TOPICS: Cryptosporidium, parasite, protozoa, fecal-oral, O & P, ova and parasite test, sporozoites, cysts, stool, immunocompromised, AIDS, CD4 less that 100, vomiting, diarrhea, biopsy, intestinal epithelium, stool antigen test, acid fast stain, nitazoxanide, paromomycin, water filter