Dracunculus

  

Contents

  

Rev 09/04/2025

Guinea Worm Classification Hosts
Morphology and Anatomy Life Cycle
Return to Dracunculus Menu Economic Importance Damage
Distribution Management
Return to Dracunculidae Menu Feeding  References
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Classification:

              
Chromadorea
 Chromadoria

           Rhabditida 

                       Spirurina
             Dracunculoidea
                         
                   Dracunculidae
 
  •             Dracunculus Reichard, 1759
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    Morphology and Anatomy:

    Ref: Cleveland et al., 2018

       
    Body size range for the species of this genus in the database - Click:
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    Distribution:

     Varies with species, but worldwide, especially subtropical and tropical areas.  Guinea worms have been described fro 11 species of mammals (Crichton and Beverley-Burton,  1973).

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    Economic Importance:

     

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    Feeding:

    Food Sources and Feeding strategies for the genus Dracunculus

    Adult dracunculoid nematodes are parasites occurring in tissues and body cavities of mammals, fish, reptiles, amphibians and birds

    Nematodes in the genus Dracunculus are large subcutaneous parasites of mammals and reptiles (snakes and turtles) with most described species being from snakes

     

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    Hosts:

    Host Group Dracunculus species Definitive Hosts Intermediate Hosts Paratenic Hosts
             
    Mammals D. medinensis humans, dogs, ferrets copepods amphibians
      D. insignis raccoons, mink, opossum, dogs, cats copepods amphibians
      D. lutrae river otter unknown unknown
      D. fuelleborni opossum unknown unknown
    Reptiles D. ophidensis garter smake copepods tadpoles
      D. brasiliensis anaconda and water snake unknown unknown
      D. coluberensis trinket snake unknown unknown
      D. alii keelback snake unknown unknown
      D. houdemeri keelback snake unknown unknown
      D. doi Madagascar boa unknown unknown
      D. dahomensis African rock python unknown unknown
      D. oesophagus colubrid snakes copepod unknown
      D. mulbus pythons unknown unknown
    Turtles D. globocephalus snapping turtle copepod unckown

    Recent reportsa of host-switching in dracunculids will require further study of the biology of the genus.

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    Life Cycle:


    Definitive hosts are mammals; intermediate hosts are copepods and transport or paratenic hosts are amphibans and fish. Definitive hosts become infected by ingesting L3s within copepods when drinking water or, for some species, consumption of paratenic hosts or fish transport hosts

    Adults up to 1 meter long, typically extracted from the definitive host by winding slowly around a stick over a period of several days

    The biology and host-parasite relationships of the Guinea Worm (Dracunculus medinensis) are quite well known but there is a lack of general life history knowledge of many other species

    In many cases, species descriptions are based on characteristics of males, which are often difficult to find because of their smaller size and lower abundance than females.

    Once ingested, L3s migrate to subcutaneous and intramuscular connective tissues of the thoracic and abdominal musculature where they undergo an additional 2 molts. Nematodes parasitize connective tissue beneath latissimus dorsi or in subcutaneous and intermuscular connective tissue of thorax, abdomen, legs, and feet (Crichton and Beverley-Burton,  1973). When fully gravid and filled with larvae, females create an ulcerative-type lesion in the host epidermis.

    When the epidermal lesions are exposed to water, larvae are expelled from the female into the environment where they are consumed by the intermediate cyclopoid copepod host. Female nematodes then senesce and may be pulled out of tissue by the affected animal or will retreat subcutaneously and calcify.

    Male and female nematodes fully mature to adults after 60-70 days, with fertilization occurring after maturation.  Male and unfertilized female nematodes can survive for about a year  (Cleveland et al., 2018).
     

    For Ecophysiological Parameters for this genus, click 
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    Damage:

    Ingested infective larvae penetrate the gut and invade subcutaneous connective tissues, migrating mainly to the axillary and inguinal regions. Maturing female worms migrate from deep connective tissues to peripheral subsurface locations, particularly in the extremities of limbs (legs and arms) although they can occur elsewhere.



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    Management:

    There is a worldwide effort to eradicate the Guinea worm. Organizations such as the Task Force for Child Survival and Global 2000 list this as one of their primary objectives.

    Spread of the Guinea worm can be prevented by filtering drinking water through a cotton cloth or by treating drinking water with the chemical Abate (which has been tested to be safe for human consumption, and it is not known to harm birds or fish). 

    The best method for defeating dracunculiasis seems to be supplying villages with safe drinking water.

     
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    References:

    Cairncross, S., Muller, R., Zagaaria, N., 2002. Dracunculiasis (Guinea worm disease) and the eradication initiative. Clin. Microbiol. Rev. 15 (2), 223-246.

    Cleveland, C.A., Garrett, K.B., Cozad, R.A., Williams, B.M.. Murray, M.H., Yabsley, M.J. 2018. The wild world of Guinea Worms: A review of the genus Dracunculus in wildlife. Int. J. Parasitology: Parasites and wildlife 7:289-300.

    Crichton, V.F.J., Beverly-Burton, M., 1973. Dracunculus lutrae n. sp. (Nematoda: Dracunculoidea) from the otter, Lutra canadensis, in Ontario, Canada. Can. J. Zool. 51, 521-529.

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    For more information about nematodes, Go to Nemaplex Main Menu.

    Copyright 1999 by Howard Ferris.
    Revised: September 04, 2025.