Protozoan infection

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Protozoan infection
Amoebic Ulcer Intestine.jpg
Amoebic ulcer of the intestine caused by E. histolytica
Classification and external resources
Specialty infectious disease
DiseasesDB 28851
eMedicine ped/1914
MeSH D011528

Protozoan infections are parasitic diseases caused by organisms formerly classified in the Kingdom Protozoa.[1] They include organisms classified in Amoebozoa, Excavata, and Chromalveolata.

Examples include Entamoeba histolytica, Plasmodium (some of which cause malaria), and Giardia lamblia.[2] Trypanosoma brucei, transmitted by the tsetse fly and the cause of African sleeping sickness, is another example.[3]

The species traditionally collectively termed "protozoa" are not closely related to each other, and have only superficial similarities (eukaryotic, unicellular, motile, though with exceptions). The terms "protozoa" (and protist) are usually discouraged in the modern biosciences. However, this terminology is still encountered in medicine. This is partially because of the conservative character of medical classification, and partially due to the necessity of making identifications of organisms based upon appearances and not upon DNA.

Protozoan infections in animals may be caused by organisms in the sub-class Coccidia (disease: Coccidiosis) and species in the genus Besnoitia (disease: Besnoitiosis).

Several pathogenic protozoans appear to be capable of sexual processes involving meiosis (or at least a modified form of meiosis).[4] Included among these protozoans are Plasmodium falciparum (malaria), Toxoplasma gondii (toxoplasmosis), Leishmania species (leishmaniases), Trypanosoma brucei (African sleeping sickness), Trypanosoma cruzi (Chagas disease) and Giardia intestinalis (giardiasis).[4]


They are treated with antiprotozoal agents.[1] Recent papers have also proposed the use of viruses to treat infections caused by protozoa.[5][6]


  1. ^ a b Protozoan+Infections at the US National Library of Medicine Medical Subject Headings (MeSH)
  2. ^ "Intestinal and Luminal Protozoa".
  3. ^ "Sleeping Sickness".
  4. ^ a b Bernstein H, Bernstein C, Michod RE (2018). Sex in microbial pathogens. Infection, Genetics and Evolution volume 57, pages 8-25.
  5. ^ Keen, E. C. (2013). "Beyond phage therapy: Virotherapy of protozoal diseases". Future Microbiology. 8 (7): 821–823. doi:10.2217/FMB.13.48. PMID 23841627.
  6. ^ Hyman, P.; Atterbury, R.; Barrow, P. (2013). "Fleas and smaller fleas: Virotherapy for parasite infections". Trends in Microbiology. 21 (5): 215–220. doi:10.1016/j.tim.2013.02.006. PMID 23540830.