DracunculiasisDracunculiasisGuinea Worm DiseaseGuinea Worm Disease

DracunculiasisDracunculiasis Commonly as the Guinea worm diseaseCommonly as the Guinea worm disease Causes by the largest of tissue parasites Causes by the largest of tissue parasites

affecting humans, the parasitic round affecting humans, the parasitic round worm worm Dracunculus medinensisDracunculus medinensis

Transmitted to people when they drink Transmitted to people when they drink water containing copepods that are water containing copepods that are infected with infected with Dracunculus medinensisDracunculus medinensis

Rarely fatal but often incapacitating for Rarely fatal but often incapacitating for several monthsseveral months

Not currently possible to drugs prevent Not currently possible to drugs prevent or treat withor treat with

Historical:Historical:

Thought to be referred Thought to be referred to in a book written in to in a book written in Egypt 3,500 years ago Egypt 3,500 years ago (the Ebers' Papyrus). (the Ebers' Papyrus).

Probably the "fiery Probably the "fiery serpent" referred to in serpent" referred to in the Bible. the Bible.

Also may be the coiled Also may be the coiled serpents on the serpents on the "Caduceus" the symbol "Caduceus" the symbol of a physician. of a physician.

Dracunculus medinensisDracunculus medinensis

EpidemiologyEpidemiology . In 1986, there were an estimated . In 1986, there were an estimated

3.5 million cases of Guinea worm in 20 3.5 million cases of Guinea worm in 20 endemic nations in Asia and Africa.endemic nations in Asia and Africa. The The number of cases has been reduced by more number of cases has been reduced by more than 99% to 3,190 in 2009, 3,185 of them in than 99% to 3,190 in 2009, 3,185 of them in the four remaining endemic nations of the four remaining endemic nations of Africa: Sudan, Ghana, Mali and Ethiopia. Africa: Sudan, Ghana, Mali and Ethiopia.

Map-2002Map-2002

The life cycleThe life cycle

Life Cycle Life Cycle

Adult females in subcutaneous tissues of the Adult females in subcutaneous tissues of the legs and arms. legs and arms.

Blister forms over nematode. Breaks when Blister forms over nematode. Breaks when exposed to water. exposed to water.

Nematode uterus ruptures and discharges first Nematode uterus ruptures and discharges first stage juveniles into the water (ovoviviparous). stage juveniles into the water (ovoviviparous).

Juveniles ingested by copepod (intermediate Juveniles ingested by copepod (intermediate host, 2 molts within copepod). host, 2 molts within copepod).

Copepod swallowed by human. Copepod swallowed by human. Juveniles migrate via lymph system. Juveniles migrate via lymph system. Develop to adults in subcutaneous tissues. Develop to adults in subcutaneous tissues.

MORPHOLOGYMORPHOLOGY

MorphologMorphology y

Dracunculus medinensis is usually Dracunculus medinensis is usually

whitewhite

The adult female is among the The adult female is among the

longest nematodeslongest nematodes

Often measures one meter in lengthOften measures one meter in length

No more than 1-2 mm wide (thin like No more than 1-2 mm wide (thin like

spaghetti)spaghetti)

The male is generally much smaller The male is generally much smaller

and raerly recovered from humans and raerly recovered from humans

because he dies shortly afer matingbecause he dies shortly afer mating

SymptomsSymptoms

Symptoms/Symptoms/Pathogenicity Pathogenicity None until blister forms and toxic fluids None until blister forms and toxic fluids

result in - result in - – a rash accompanied by severe itching a rash accompanied by severe itching – nausea nausea – vomiting vomiting – diarrhea diarrhea – dizziness. dizziness.

Secondary bacterial infections of opening Secondary bacterial infections of opening are possible. are possible.

There may be later symptoms--fibrosis of There may be later symptoms--fibrosis of the skin, muscles, tendons and joints ( may the skin, muscles, tendons and joints ( may interfere with locomotion or use of limbs). interfere with locomotion or use of limbs).

SymptomsSymptoms On occasion worms migrate to On occasion worms migrate to

joints , die prematurely, & calcifyjoints , die prematurely, & calcify The calcified worms can trigger The calcified worms can trigger

arthritis, locked joints, or permanent arthritis, locked joints, or permanent crippling & deformitiescrippling & deformities

DiagnosisDiagnosis

Made by observing visible Made by observing visible characteristics of the disease & characteristics of the disease & communicating with the infected communicating with the infected personperson

Possible to discover infection up to Possible to discover infection up to six months befor emergence six months befor emergence

Enzyme-linked Enzyme-linked immunoelectrotransfer Blot (EITB)immunoelectrotransfer Blot (EITB)

Treatment Treatment There is no cure. The only treatment is to remove the There is no cure. The only treatment is to remove the

worm over many weeks by winding it around a small stick worm over many weeks by winding it around a small stick

and pulling it out a tiny bit at a time. Sometimes the and pulling it out a tiny bit at a time. Sometimes the

worm can be pulled out completely within a few days, but worm can be pulled out completely within a few days, but

the process usually takes weeks or months.the process usually takes weeks or months.

No medication is available to end or prevent infection. No medication is available to end or prevent infection.

However, the worm can be surgically removed before the However, the worm can be surgically removed before the

wound begins to swell. Antihistamines and antibiotics can wound begins to swell. Antihistamines and antibiotics can

reduce swelling and ease removal of the wormreduce swelling and ease removal of the worm

Prevention Prevention To stop the infection of the Guinea worm you To stop the infection of the Guinea worm you

must keep Guinea worm larvae out of the must keep Guinea worm larvae out of the drinking water. Use only water that has been drinking water. Use only water that has been filtered or obtained from a safe source.filtered or obtained from a safe source.

Water can be boiled, filtered through tightly Water can be boiled, filtered through tightly woven nylon cloth, or treated with a larvae-woven nylon cloth, or treated with a larvae-killing chemical. People with an open Guinea killing chemical. People with an open Guinea worm wound should not enter ponds or wells worm wound should not enter ponds or wells used for drinking water.used for drinking water.