Encyclopedia of Parasitology

2016 Edition
| Editors: Heinz Mehlhorn

Opisthorchis felineus (syn. tenuicollis)

Reference work entry
DOI: https://doi.org/10.1007/978-3-662-43978-4_4131

Name

Greek: opisten = posterior position; orchis = testis. Latin: felis = catfish. English: cat liver fluke; however, several other fish eating animals are infected, too.

Geographic Distribution/Epidemiology

North East Europe, focally: in countries of the former UDSSR, India, Indo-China, Japan. In total about 10 millions of humans are infected; the parasite was already found in fresh water fish ponds around Berlin, Germany.

Morphology/Life Cycle

The adult hermaphroditic worms measure 8–12 mm × 2–3 mm and are able to stretch themselves in length and width (Fig. 1). These worms can be easily differentiated from   Clonorchis sinensis by help of their two testes, which are lobulated without deep imaginations. The anterior testis forms four lobes, and the posterior five (Fig. 1). The life cycle runs like that of Clonorchis sinensis or O. viverrini; however, snails of the genus Bythinia (syn. Bulimus) are first intermediate hosts, and carps and related species act as second intermediate hosts harboring the infectious metacercariae. The yellow-brownish eggs of O. felineus measure about 30 × 12 μm, and thus their width is smaller than that of C. sinensis (Fig. 2).
Opisthorchis felineus (syn. tenuicollis), Fig. 1

Diagrammatic representation of adult flukes including Opisthorchis felineus. Note the species specific shape of the two testes of O. felineus (HO)

Opisthorchis felineus (syn. tenuicollis), Fig. 2

Light micrograph of an adult worm of O. felineus (author: PD Dr. Schuster, Dubai)

Symptoms of Disease

Diagnosis

The eggs are found in feces when using concentration methods ( S.A.F.C. of  M.I.F.C.). They appear yellow brownish and possess (as the related Opisthorchis species) a typical operculum (Fig. 3).
Opisthorchis felineus (syn. tenuicollis), Fig. 3

Light micrograph of eggs of O. felineus; note the characteristic cover (operculum), which is blown off during hatch of the miracidium larva

Infection

Oral uptake of raw or undercooked meat of fresh water fish containing infectious metacercariae.

Prophylaxis

Avoiding to eat raw or undercooked fish in endemic regions; heating of up to 60 °C, however, is sufficient to kill the metacercariae.

Incubation Period

Three to four weeks, dependent on the amount of ingested metacercariae.

Prepatent Period

Two to three weeks.

Patency

Fifteen to twenty years (repeated infections are possible).

Therapy

Further Reading

  1. Nöckler K et al (2003) Indirect ELISA for the detection of antibodies against Opisthorchis felineus and Metorchis bilis. Vet Parasitol 110:207–215CrossRefPubMedGoogle Scholar
  2. Schuster RK et al (1999) Liver fluke finding in red foxes. Parasitol Res 85:142–146CrossRefPubMedGoogle Scholar
  3. Schuster RK et al (2003) Liver enzyme activity and histological changes in the liver of silver foxes. Parasitol Res 89:414–418PubMedGoogle Scholar
  4. Schuster RK (2010) Opisthorchiidosis: a review. Infect Disord Drug Targets 10:402–415CrossRefPubMedGoogle Scholar
  5. Schuster RK et al (2013) Liver flukes in dogs and treatment with praziquantel. Vet Parasitol 150:362–365CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Institut für Zoomorphologie, Zellbiologie und ParasitologieHeinrich-Heine-UniversitätDüsseldorfGermany