Protozoa

Protozoa Table 

GI Infections 
ProtozoaDiseaseTreatment
Giardia lambliaGiardiasis (fatty diarrhea)Metronidazole 
Entamoeba histolyticaAmebiasis (bloody diarrhea and red liver abscesses)Metronidazole
Cryptosporidium (C. parvum, C. isospora belli, and C. cyclospora cayetanensis)Diarrhea  Supportive only  
MicrosporidiaDiarrheaSupportive only
CNS Infections 
Toxoplasma gondiiToxoplasmosis (brain abscesses in AIDS)Congenital toxoplasmosis SulfadiazinePyrimethamine
Naegleria fowleriPrimary amebic meningoencephalitis (PAM)Amphotericin B
Trypanosoma gambiense/rhodesienseAfrican sleeping sicknessSuraminMelarsoprol
AcanthamoebaGranulomatous amebic encephalitis (GAE)Keratitis (corneal infection)Azoles
Visceral Infections 
Trypanosoma cruziChagas’ diseaseNifurtimox
Leishmania donovaniLeishmaniasisSodium stibogluconate
Hematologic Infections 
Plasmodium (P. vivax,  P. ovale, P. malariae, and P. falciparum)MalariaChloroquinePrimaquineMefloquine
BabesiaBabesiosis (like mild malaria)Quinine
STDs 
Trichomonas vaginalisVaginitisMetronidazole

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