Protozoa Introduction Protozoa are single-celled eukaryotes Cyst vs. trophozoite forms in stressed environments, protozoa secrete a protective coat and shrink to a cyst form cysts are ingested by humans, leading to disease once inside a host, the protozoa convert back to their motile feeding form, the trophozoite form Protozoa Table GI Infections Protozoa Disease Treatment Giardia lamblia Giardiasis (fatty diarrhea) Metronidazole Entamoeba histolytica Amebiasis (bloody diarrhea and red liver abscesses) Metronidazole Cryptosporidium (C. parvum, C. isospora belli, and C. cyclospora cayetanensis) Diarrhea Supportive only Microsporidia Diarrhea Supportive only CNS Infections Protozoa Disease Treatment Toxoplasma gondii Toxoplasmosis (brain abscesses in AIDS) Congenital toxoplasmosis Sulfadiazine Pyrimethamine Naegleria fowleri Primary amebic meningoencephalitis (PAM) Amphotericin B Trypanosoma gambiense/rhodesiense African sleeping sickness Suramin Melarsoprol Acanthamoeba Granulomatous amebic encephalitis (GAE) Keratitis (corneal infection) Azoles Visceral Infections Protozoa Disease Treatment Trypanosoma cruzi Chagas' disease Nifurtimox Leishmania donovani Leishmaniasis Sodium stibogluconate Hematologic Infections Protozoa Disease Treatment Plasmodium (P. vivax, P. ovale, P. malariae, and P. falciparum) Malaria Chloroquine Primaquine Mefloquine Babesia Babesiosis (like mild malaria) Quinine STDs Protozoa Disease Treatment Trichomonas vaginalis Vaginitis Metronidazole