Dracunculus medinensis

Everything you wanted to know about “Guinea Worms”

But, were afraid to askCrisAngel Presents

Guinea Worms and You

CDC estimates

• In 1986, there were 3.5 million cases worldwide• In 2009, there were fewer than 10,000 cases• Presently, there may be as few as 1,000 cases • Guinea worm disease is expected to be the next disease after smallpox to be eradicated

Classification/Taxonomy

Kingdom: Animalia

Phylum: Nematoda

Class: Secernentea

Order: Camallanida

Family: Dracunculidae

Genus: Dranunculus

Species: Meninensis

Geographic Distribution

• Predominantly in Africa. Also in India, Pakistan, Saudi Arabia, and Yemen

• Freshwater lakes and rivers

Who’s Your Host• Definitive host:

Humans, wolves, dogs, horses, cows, leopards, monkeys, and baboons (oh my!)

• Intermediate: Cyclops copepods

Morphology

• Female: 60 cm in length and can reach up to 3 ft• Male: much smaller 1.2-2.9 cm• Larvae: 500 and 700 micrometers

Life Cycle

Humans are infected by drinking unfiltered water containing copepods that are infected with larvae. After ingestion, the copepods die and release the larvae. The larvae then penetrate the stomach and intestinal wall and enter the abdominal cavity and retroperitoneal space. The larvae mature and reproduce. The males die while the females migrate into the subcutaneous tissue toward the skin. After about one year of infection, the female worm induces a blister, which will rupture. When the blister comes into contact with water, the female worm emerges and releases larvae. Larvae are ingested by copepods and infective larvae are developed after about two weeks.

Life Cycle

Pathogenesis

• Emergent Worms• Severe pain, allergic

reactions, and blisters

• Secondary Bacterial Infections:• Caused by retreating

worms• Entry of tetanus spores

• Nonemergent Worms• Arthritis, cellulitis, and

necrosis

Complications• Cellulitis• Boils• Infection (sepsis)• Joint infection and

severe joint pain• Lock jaw• Disability

The Fiery Serpent

Symptoms• Slight Fever• Itchy Rash• Nausea• Vomiting • Diarrhea

Diagnosis

• Blister Formation• The outline of worm under the

skin– Enhanced by reflected light

Treatment1. Immerse foot2. Extract worm3. Bandage4. Drugs: None

Control:GWEP

1. Patient Surveillance2. Provide Safe Water3. Vector Control: Abate 4. Education

Works Cited

CDC: http://www.cdc.gov/parasites/guineaworm/prevent.html

CMR: http://cmr.asm.org/cgi/content/full/15/2/223/F4

Nature: http://www.nature.com/embor/journal/v10/n3/full/embor200919.html

NIH: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2536457/pdf/bullwho00088-0065.pdf WHO: http://www.who.int/dracunculiasis/disease/disease_more/en/index.html

Supplemental Videoshttp://reels.creativecow.net/film/foul-water-fiery-serpent

http://www.youtube.com/watch?v=Qwk-THcjmlI

http://www.youtube.com/watch?v=omudJzeX4q0&feature=fvst

http://www.youtube.com/watch?v=u4kQWvUv_Ns