Parasite Classification

Hi:

I’ve seen many classifications of parasites, but this seems to be the best one that I’ve come across. I counted that there are approximately 144 parasites that harm humans under their classification table; of course, there are a lot more parasites that affect people (hundreds into thousands) and yet many are “unidentified” by the establishment. Most likely, this table of classification is still being used by the medical community today (we know how slow they are with updates). Some parasites that are listed as an intestinal parasite (Ascaris, as an example) can also be found in the liver, lungs, and etc.

For anyone seeking to find out what kind of parasites they have through their doctor or wherever, it’s best not to narrow the choices for testing based off of assumptions. For instance, people may assume that they have Ascaris in the nose, but it could be one of the others listed below or something else entirely different. 

Best of Health!

DD

 

 

http://www.journals.uchicago.edu/CID/journal/issues/v29n4/CIDv29p734/CIDv29p7...

Correspondence: Lynne S. Garcia, UCLA Clinical Laboratories, 10833 Le-Conte Ave., Los Angeles, California 90095-1713(lgarcia1@ucla.edu).

Clinical Infectious Diseases 1999; 29:734–6

This article is in the public domain.

 

Classification of Human Parasites, Vectors, and Similar Organisms

Lynne S. Garcia

From the Department of Pathology and Laboratory Medicine, UCLA

Medical Center, Los Angeles, California
 

When common names are used to describe parasites and parasitic infections, these names may refer to different parasites in different parts of the world. To eliminate these problems in interpretation of names, a binomial system of nomenclature is used in which the scientific name consists of the genus and species.

Classification systems have been developed to indicate the relationship among the various species of parasites, and these schemes have been based primarily on life cycles and morphology of the organism. Closely related species are placed in the same genus, related genera in the same family, related families in the same order, related orders in the same class, and related classes in the same phylum, one of the major categories in the animal kingdom. Organisms in each category will have characteristics in common.

Parasites of humans are classified in six major divisions. These include the Protozoa (amebae, flagellates, ciliates, sporozoans, coccidia, microsporidia), the Nematoda or roundworms, the Platyhelminthes or flatworms (cestodes, trematodes), the Pentastomids or tongue worms (may be grouped with the arthropods), the Acanthocephala or thorny-headed worms, and the Arthropoda (e.g., insects, spiders, mites, ticks). Although these categories appear to be clearly defined, there may be confusion in attempting to classify parasites, often due to the lack of known specimens or the presence of strains or races of the same species with slightly different characteristics.

Reproductive mechanisms have been used as a basis for determining definitions of species, but there are many exceptions within parasite groups. Another difficulty in recognition of species is the ability and tendency of the organisms to alter their morphological forms according to age, host, or nutrition, which may result in different names for the same organism. In many cases, there may be alternation of parasitic and freeliving phases in the life cycle. These organisms may be very different and difficult to recognize as belonging to the same species. However, newer molecular methods of grouping organisms have often confirmed taxonomic conclusions reached hundreds of years before by experienced taxonomists. As studies continue in parasitic genetics, immunology, and biochemistry, the species designation will be defined more clearly by use of highly sophisticated molecular techniques.

No attempt has been made to include every possible organism, but only those considered to be clinically relevant in the context of human parasitology. Not every organism listed below is a human pathogen. Also, although new classification names are proposed frequently and there may be some disagreement among scientists, this list is designed to provide nomenclature that is currently in use.

 

Protozoa Amebae (Intestinal)

Entamoeba histolytica

Entamoeba dispar*

Entamoeba hartmanni

Entamoeba coli

Entamoeba polecki

Endolimax nana

Iodamoeba bu¨tschlii

Blastocystis hominis

 

Flagellates (Intestinal)

Giardia lamblia†

Chilomastix mesnili

Dientamoeba fragilis

Trichomonas hominis

Enteromonas hominis

Retortamonas intestinalis

 

Ciliates (Intestinal)

Balantidium coli

 

Coccidia, Microsporidia (Intestinal)

Coccidia

Cryptosporidium parvum

Cyclospora cayetanensis

Isospora belli

Sarcocystis hominis

Sarcocystis suihominis

 

Microsporidia

Enterocytozoon bieneusi

Encephalitozoon intestinalis

 

 

Sporozoa, Flagellates (Blood, Tissue)

Sporozoa (Malaria and Babesiosis)

Plasmodium vivax

Plasmodium ovale

Plasmodium malariae

Plasmodium falciparum

Babesia species

 

Flagellates (Leishmaniae, Trypanosomes)

Leishmania tropica complex

Leishmania mexicana complex

Leishmania braziliensis complex

Leishmania donovani complex

Leishmania peruviana

Trypanosoma brucei gambiense

Trypanosoma brucei rhodesiense

Trypanosoma cruzi

Trypanosoma rangeli

 

Amebae, Flagellates (Other Body Sites)

Amebae

Naegleria fowleri

Acanthamoeba species

Entamoeba gingivalis

Balamuthia mandrillaris (Leptomyxid ameba)

 

Flagellates

Trichomonas vaginalis

Trichomonas tenax

 

Coccidia, Sporozoa, Microsporidia (Other Body Sites)

Coccidia

Toxoplasma gondii

Sarcocystis “lindemanni”

 

Sporozoa

Pneumocystis carinii‡

 

Microsporidia

Nosema connori

Vittaforma corneae

Pleistophora

Trachipleistophora hominis

Brachiola

Encephalitozoon hellum

Encephalitozoon cuniculi

Encephalitozoon intestinalis

Encephalitozoon bieneusi

 

“Microsporidium”

Enterocytozoon bieneusi

 

Nematodes (Roundworms) Intestinal

Ascaris lumbricoides

Enterobius vermicularis

Ancylostoma duodenale

Necator americanus

Strongyloides stercoralis

Trichostrongylus species

Trichuris trichiura

Capillaria philippinensis

 

Tissue

Trichinella spiralis

Visceral larva migrans (Toxocara canis or Toxocara cati)

Ocular larva migrans (Toxocara canis or Toxocara cati)

Cutaneous larva migrans (Ancylostoma braziliense or Ancylostoma caninum)

Dracunculus medinensis

Angiostrongylus cantonensis

Angiostrongylus costaricensis

Gnathostoma spinigerum

Anisakis species (larvae from saltwater fish)

Phocanema species (larvae from saltwater fish)

Contracaecum species (larvae from saltwater fish)

Eustrongylides species

Capillaria hepatica

Thelazia species

Gnathostoma species

 

Blood and Tissues (Filarial Worms)

Wuchereria bancrofti

Brugia malayi

Brugia timori

Loa loa

Onchocerca volvulus

Mansonella ozzardi

Mansonella streptocerca

Mansonella perstans

Dirofilaria immitis (usually lung lesion; in dogs, heartworm)

Dirofilaria species (may be found in subcutaneous nodules)

 

Cestodes (Tapeworms) Intestinal

Diphyllobothrium latum

Dipylidium caninum

Hymenolepis nana

Hymenolepis diminuta

Taenia solium

Taenia saginata

 

Tissue (Larval Forms)

Taenia solium

Echinococcus granulosus

Echinococcus multilocularis

Taenia multiceps (formerly Multiceps multiceps)

Taenia serialis

Spirometra mansonoides

Spirometra mansoni

Diphyllobothrium species

 

Trematodes (Flukes) Intestinal

Fasciolopsis buski

Echinostoma ilocanum

Heterophyes heterophyes

Metagonimus yokogawai

 

Liver/Lung

Clonorchis (Opisthorchis) sinensis

Opisthorchis viverrini

Fasciola hepatica

Paragonimus westermani

Paragonimus mexicanus

Paragonimus species

 

Blood

Schistosoma mansoni

Schistosoma haematobium

Schistosoma japonicum

Schistosoma intercalatum

Schistosoma mekongi

 

Pentastomids (Tongue Worms)

Tissue (Larval Forms)

Armillifer species

Linguatula serrata

Sebekia species

 

Nasopharyngeal (Adult Worms)

Armillifer species

Linguatula serrata

 

Acanthocephalans (Thorny-Headed Worms) Intestine

Macrocanthorynchus hirudinaceus

Moniliformis moniliformis

 

Arthropods

 

Diplopoda

Millipedes

 

Chilopoda

Centipedes

 

Crustacea

Copepoda: copepods (Cyclops)

Decapoda: crayfish, lobsters, crabs

 

Arachnida

Scorpiones: scorpions

Araneae: spiders (black widow, brown recluse)

Acari: ticks (Dermacentor, Ixodes, Argas, Ornithodoros)

Mites (Sarcoptes)

 

Insecta

Anoplura: sucking lice (Pediculus, Phthirus)

Siphonaptera: fleas (Pulex, Xenopsylla, etc.)

Dictyoptera: cockroaches

Hemiptera: true bugs (Triatoma)

Hymenoptera: bees, wasps, etc.

Coleoptera: beetles

Lepidoptera: butterflies, caterpillars, moths, etc.

Diptera: flies, mosquitoes, gnats, midges (Phlebotomus,

Aedes, Anopheles, Glossina, Simulium, etc.)

 

Pentastomida

Tongue worms (see above)

* Entamoeba histolytica is being used to designate pathogenic zymodemes, while Entamoeba dispar is now being used to designate nonpathogenic zymodemes. However, unless trophozoites containing ingested red blood cells (E. histolytica) are seen, the two organisms cannot be differentiated on the basis of morphology. The laboratory report should indicate: Entamoeba histolytica/Entamoeba dispar.

† Although some individuals have changed the species designation for the genus Giardia to Giardia intestinalis or Giardia duodenalis, there is no general agreement. Therefore, for this listing, we will retain the name Giardia lamblia.

‡ Pneumocystis carinii has now been reclassified with the fungi.

 

Suggested Reading

Beaver CB, Jung RC, Cupp EW. Clinical parasitology. Philadelphia: Lea & Febiger, 1984.

Garcia LS, Bruckner DA. Diagnostic medical parasitology. 3rd ed. Washington, DC: ASM Press, 1997.

Gibson DI. Nature and classification of parasitic helminths. In: Collier L, Balows A, Susman M, eds. Topley & Wilson’s microbiology and microbial infections. New York: Oxford University Press, 1998.

Goddard J. Arthropods of medical importance. 2nd ed. New York: CRC Press, 1996.

Murray PR, Baron EJ, Pfaller MA, Tenover FC, Yolken RH, eds. Manual of clinical microbiology. 7th ed. Washington, DC: American Society for Microbiology, 1999.
 

CID 1999;29 (October)

 

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