Flatworms of medical importance are divided into flukes (Class Turbellaria and Class Trematoda) and tapeworms (Class Cestoda). Flukes and tapeworms and constitute more than 56% of the currently known ~30 000 species of platyhelminths. These flatworms are considered to be among the most successful of metazoan parasites, as measured by their numerical abundance, their geographical reach and host (habitat) diversity. Their complex life-cycles involve one or more intermediate hosts from mollusks (particularly for trematodes), arthropods (particularly for cestodes), annelids, ctenophores, echinoderms, hexapods and vertebrates, before reaching sexual maturity in a definitive (almost exclusively vertebrate) host.
The species of trematodes reported to be incriminated in human infections
Class Turbellaria
Among all turbellarians only three species belong to the Family Geoplanidae were reported as human pseudoparasites.
Family Geoplanidae
Bipalium fuscatum
Bipalium kewense
Bipalium venosum
Class Trematoda
Trematodes comprise two subclasses: the Aspidogastrea and the Digenea. The Aspidogastrea includes only four families and perhaps 80 species. They are parasites of freshwater and marine mollusks, and vertebrates (cartilaginous and bony fish, and turtles). They may reach maturity in the mollusk or vertebrate host. None of them has any economic importance, but because they have several characters which appear to be archaic, they are of very great interest to biologists . The Digenea is the major group with 18,000 to 24,000 nominal species in more than 2,500 genera and over 150 families. Digeneans mature exclusively as internal parasites of vertebrates. They infect all classes of vertebrates and represent the largest group of internal metazoan parasites. They are among the most prevalent parasitic worms, second only to nematodes in their abundance. Some digeneans are serious parasites of humans and many of them cause great economic losses through infections of domestic animals.
Family Brachylaimidae
Brachylaima cribbi
Family Cyathocotylidae
Prohemistomum vivax
Family Strigeidae
Cotylurus japonicus
Family Diplostomidae
Diplostomum spathaceum
Neodiplostomum seoulense
Fibricola cratera
Alaria americana
Alaria marcianae
Alaria alata
Family Schistosomatidae
This family includes 14 genera: Allobilharzia, Austrobilharzia, Bilharziella, Bivitellobilharzia, Dendritobilharzia, Gigantobilharzia, Griphobilharzia, Heterobilharzia, Macrobilharzia, Orientobilharzia, Ornithobilharzia, Schistosoma, Schistosomatium and Trichobilharzia. One genus, Schistosoma, has a major public health importance as the causative agent of human schistosomiasis. Different species that belong to other genera of the family are incriminated in a pathogenic condition called cercarial dermatitis. The following species are incriminated in causing human schistosomiasis:
Schistosoma japonicum
Schistosoma mekongi
Schistosoma malayensis
Schistosoma mansoni
Schistosoma haematobium
Schistosoma intercalatum
Schistosoma guineensis
Schistosoma mattheei
Schistosoma bovis
Schistosoma margrebowiei
Schistosoma curassoni
Schistosoma rodhaini
Schistosoma sinensium
Schistosoma incognitum
Family Clinostomidae
Clinostomum complanatum
Family Isoparorchiidae
Isoparorchis hypselobagri
Family Gymnophallidae
Gymnophalloides seoi
Family Gastrothylacidae
Fischoederius elongatus
Family Gastrodiscidae
Gastrodiscoides hominis
Watsonius watsoni
Family Echinostomatidae
Acanthoparyphium tyosenense
Artyfechinostomum malayanum
Artyfechinostomum oraoni
Echinochasmus fujianensis
Echinochasmus japonicus
Echinochasmus jiufoensis
Echinochasmus liliputanus
Echinochasmus perfoliatus
Echinoparyphium recurvatum
Echinostoma angustitestis
Echinostoma cinetorchis
Echinostoma echinatum
Echinostoma hortense
Echinostoma ilocanum
Echinostoma macrorchis
Echinostoma revolutum
Episthmium caninum
Hypoderaeum conoideum
Isthmiophora melis
Himasthla muehlensi
Family Cathaemasiidae
Cathaemasia cabrerai
Family Fasciolidae
Fasciolopsis buski
Fasciola hepatica
Fasciola gigantica
Family Philophthalmidae
Philophthalmus lacrymosus
Philophthalmus palpebrarum
Philophthalmus spp.
Family Heterophyidae
Heterophyes heterophyes
Heterophyes nocens
Heterophyopsis continua
Metagonimus yokogawai
Metagonimus takahashii
Metagonimus miyatai
Metagonimus minutus
Apophallus donicus
Centrocestus armatus
Centrocestus caninus
Centrocestus formosanus
Centrocestus cuspidatus
Centrocestus kurokawai
Cryptocotyle lingua
Haplorchis taichui
Haplorchis pleurolophocerca
Haplorchis pumilio
Haplorchis vanissimus
Haplorchis yokogawai
Procerovum calderoni
Procerovum varium
Pygidiopsis summa
Stellantchasmus pseudocirratus
Stellantchasmus falcatus
Stellantchasmus formosanus
Stictodora fuscata
Stictodora lari
Family Opisthorchiidae
Clonorchis sinensis
Opisthorchis viverrini
Opisthorchis felineus
Opisthorchis noverca
Amphimerus pseudofelineus
Metorchis conjunctus
Pseudamphistomum truncatum
Pseudamphistomum aethiopicum
Family Dicrocoeliidae
Dicrocoelium dendriticum
Dicrocoelium hospes
Eurytrema pancreaticum
Eurytrema coelomaticum
Family Paragonimidae
Paragonimus westermani
Paragonimus africanus
Paragonimus uterobilateralis
Paragonimus kellicotti
Paragonimus mexicanus
Paragonimus heterotremus
Paragonimus skrjabini
Paragonimus ohirai
Family Orchipedidae
Achillurbainia nouveli
Achillurbainia ratti
Achillurbainia recondita
Achillurbainia congolensis
Family Troglotrematidae
Nanophyetus salmincola
Family Plagiorchiidae
Plagiorchis vespertilionis
Plagiorchis muris
Plagiorchis philippinensis
Plagiorchis javensis
Plagiorchis harinasutai
Family Microphallidae
Microphallus minus
Carneophallus brevicaeca
Family Lecithodendriidae
Phaneropsolus bonnei
Phaneropsolus spinicirrus
Prosthodendrium molenkampi
Paralecithodendrium obtusum
Paralecithodendrium glandulosum
The species of cestodes reported to be incriminated in human infections
Class Cestoda
Cestodes are ubiquitous among humans and animals worldwide. They are unique among all worms because they are perfectly specialized for the parasitic life and are incapable of living independently. Adult cestodiasis is far less pathogenic to humans than other helminthic infections. Only heavy infections are able to cause physical damage of the gut wall, and possible blockage of the intestines. However, larval infections of few species of cestodes may cause serious clinical complications as in sparganosis or cysticercosis. Recent reports confirm that some cestodes may behave as opportunistic parasites in immunocompromised individuals.
Family Tentaculariidae
Nybelinia surmenicola
Family Sphyriocephalidae
Hepatoxylon trichiuri
Family Diphyllobothriidae
Diphyllobothrium latum
Diphyllobothrium nihonkaiense
Diphyllobothrium dendriticum
Diphyllobothrium dalliae
Diphyllobothrium pacificum
Diphyllobothrium cameroni
Diphyllobothrium cordatum
Diphyllobothrium hians
Diphyllobothrium lanceolatum
Diphyllobothrium orcini
Diphyllobothrium scoticum
Diphyllobothrium stemmacephalum
Diphyllobothrium ursi
Diphyllobothrium alascense
Diphyllobothrium elegans
Diplogonoporus balaenopterae
Ligula intestinalis
Ligula brauni
Pyramicocephalus anthocephalus
Schistocephalus solidus
Spirometra erinaceieuropaei
Spirometra mansonoides
Spirometra theileri
Sparganum proliferum
Family Mesocestoididae
Mesocestoides lineatus
Mesocestoides variabilis
Family Anoplocephalidae
Bertiella studeri
Bertiella mucronata
Moniezia expansa
Mathevotaenia symmetrica
Inermicapsifer madagascariensis
Family Davaineidae
Raillietina (Raillietina) celebensis
Raillietina (R.) demerariensis
Raillietina (R.) asiatica
Family Dipylidiidae
Dipylidium caninum
Family Hymenolepididae
Rodentolepis nana
Rodentolepis microstoma
Hymenolepis diminuta
Drepanidotaenia lanceolata
Family Taeniidae
Echinococcus granulosus
Echinococcus multilocularis
Echinococcus vogeli
Echinococcus oligarthrus
Echinococcus shiquicus
Taenia saginata
Taenia solium
Taenia asiatica
Taenia taeniaeformis
Taenia crassiceps
Taenia hydatigena
Taenia ovis
Taenia multiceps
Taenia serialis
In addition some cestodes of uncertain taxonomic position were reported!
For detailed information please refer to my publications:
1. Lotfy WM. Tapeworms and human health: A comprehensive overview. 2013. LAP Lambert Academic Publishing AG & Co. KG. Saarbrücken, Germany. ISBN 978-3659324604.
2. Lotfy WM. Digeneans and human health: A comprehensive overview. 2010. LAP Lambert Academic Publishing AG & Co. KG. Saarbrücken, Germany. ISBN 978-3-8433-8919-8.