PetriKey

Parasite

Dracunculus medinensis

Guinea worm from copepod-contaminated water

druh-KUNK-yoo-lus meh-dih-NEN-sis

nematoderoundwormwaterbornecopepoderadication

High-yield clue

Drinking water with copepods (Cyclops) leads a meter-long female worm to emerge through a painful skin blister on the lower leg.

Overview

The guinea worm, a tissue nematode acquired by drinking water containing infected copepods, famous as a near-eradicated disease and for its dramatic skin emergence.

Classification

  • Nematode (roundworm)
  • Waterborne via copepod intermediate host
  • Very long adult female worm
  • No mosquito/fly vector

Lab & identification clues

  • Adult worm visible emerging from a skin blister
  • Larvae released when the lesion contacts water
  • Clinical recognition, not stool eggs

Associations

  • Ingestion of copepod-contaminated drinking water
  • Painful lower-limb blister and ulcer vocabulary
  • Slow worm extraction over weeks
  • Global eradication public-health framing

Commonly confused with

  • Wuchereria bancrofti
  • Onchocerca volvulus

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource