Multiple choice The protist associated with HIV-positive patients presenting with diarrhea is Acanthamoeba Balamuthia mandrillaris Babesia Balantidium coli Cryptosporidium Reveal answer Fill a bubble to check yourself E Correct answer Explanation Cryptosporidium is a genus of apicomplexan protozoans that can cause gastrointestinal illness with diarrhea in humans. Cryptosporidium is the organism most commonly isolated in HIV-positive patients presenting with diarrhea.