DracunculiasisDracunculiasis(Guinea Worm Disease):(Guinea Worm Disease):

A ReportA Report

Shelly Beard, Nicole Corder, and Majken Kiyohara

Dracunculiasis – In Brief:Dracunculiasis – In Brief: Commonly known as the guinea worm disease Caused by the largest of tissue parasites

affecting humans, the parasitic roundworm Dracunculus medinensis

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

Rarely fatal but often incapacitating for several months

Not currently possible to prevent or treat with drugs

The Report:The Report:

Historical highlights The lifecycle Morphology Symptoms Diagnosis Treatment Prevention Socioeconomic impact, past and present The eradication initiative

Old Testament:

021:006 And the LORD sent fiery serpents among the people, and theybit the people; and much people of Israel died.

021:007 Therefore the people came to Moses, and said, We have sinned,for we have spoken against the LORD, and against thee; prayunto the LORD, that he take away the serpents from us.And Moses prayed for the people.

021:008 And the LORD said unto Moses, Make thee a fiery serpent, andset it upon a pole: and it shall come to pass, that every one thatis bitten, when he looketh upon it, shall live.

Historical HighlightsHistorical Highlights

Historical Highlights:Historical Highlights:

The 'fiery serpent' mentioned in the Old Testament

The serpents coiled around the staff of Hermes, the symbol of a physician

Believed to be anything from exposed nerves to dead tissue in the Middle Ages

It was suggested that they were worms in mid 1700s

1905: The life cycle was described

1986: Dracunculiasis was chosen as the next diseaseto be targeted for worldwide eradication

ClassificationClassification

Dracunculus medinensis:

Nematode (also known as roundworms)

Superfamily: Dracunculoidea

Order: Spirurida

• Mammalian tissue parasites

• Eggs or larvae require arthropods (insects or crustaceans) as intermediate hosts

The LifecycleThe Lifecycle

The LifecycleThe LifecycleFirst-stage larvae (L1) are released into water by a mature female worm

ŒL1 remain active in the water up to 1 week until they are ingested by a suitable copepod

The transformation to infectious third stage larvae (L3) occurs within 2 weeks

Ž

The LifecycleThe LifecycleInfection of man is effected when swallowing infected copepods

After 3 month the worms mate and the male dies. The female continues to grow and travel down the muscle planes.

Œ

Ž

The female emergesafter 10-14 months to release larvae in waterand completes the cycle…

Œ

MorphologyMorphology

MorphologyMorphology

Dracunculus medinensis is usually white

The adult female is among the longest of

nematodes:

• Often measures one meter in length

• No more than 1-2 mm wide

(thin like spaghetti or angel hair pasta)

The male is generally much smaller and

rarely recovered from humans, because

he dies shortly after mating

Male

Female

Techniques used to evade the Techniques used to evade the Human Immune System: Human Immune System:

Roundworms have an outer protective cuticle layer; some worms can even survive in pure vinegar

Opiates from Dracunculus medinensis lowerthe sensation of pain in the human host and significantly decrease the immune systems’ responsiveness

Antigen cloaking, disguises itself as human Manipulate the humans' immune system to

prevent acquisition of immunity

SymptomsSymptoms

Symptoms:Symptoms:

Most often asymptomatic from time of infection until days before emergence

Pre-partum Immune response:• Fever, ulceration, and a painful burning

sensation in the area where the worm will present

Post-partum susceptibility to secondary infections in open wounds

Symptoms:Symptoms:

On occasion worms migrate to joints, die prematurely, and calcify.

The calcified worms can trigger arthritis, locked joints, or permanent crippling and deformities

DiagnosisDiagnosis

Patent DiagnosisPatent Diagnosis

Made by observing visible characteristics of the disease and communicating with the infected person

Prepatent DiagnosisPrepatent Diagnosis Desirable in an effort to achieve containment of

the disease Possible to discover infection up to six months

before emergence• Falcon Assay Screening Test-Enzyme-Linked

Immunosorbent Assay (FAST-ELISA)• Enzyme-linked Immunoelectrotransfer Blot (EITB)

technique However, testing is complex, expensive and not well

suited for the socioeconomically challenged areas where Dracunculiasis still occurs

TreatmentTreatment

Traditional TreatmentTraditional Treatment

Traditional treatment starts when the worm begins to emerge from the body

The worm is wrapped around a small stick in order to prevent retraction and facilitate the extraction which can take weeks

For the ones fortunate enough to afford it:• An analgesic can be taken to reduce the swelling

associated with the blister• Antibiotic ointment and proper cleansing can be used to

prevent secondary bacterial infections

MedicationsMedications

The medications generally used for parasitic worm infections do not work to eliminate Dracunculus medinensis:

• Treatment with drugs such as diethylcarbamazine, albendazole, and invermectin don’t display a statistically significant reduction in worm burdenwhen compared with controls

• Mebendazole usage increased the chance of the worm emerging in locations other than the feet and legs

Vaccines are currently not available, and immunity isn’t acquired (re-infections are possible)

Invasive TreatmentInvasive Treatment

Surgical removal of the worm (before a blister forms) shortens the duration of the debilitating pain and prevents further contamination of water sources

However, this form of treatment is rarely desirable or even an option in socioeconomically challenged areas

PreventionPrevention

PreventionPrevention

Lack of treatment options and the burden of care during the long infectious process brings the focus to prevention

Preventative measures:• Treating contaminated water sources with larvicide

• Providing drinking water from underground sources

• Filtering to remove copepods from surface waterused for drinking

• Education, education, education !

ChallengesChallenges

Cultural and religious practices• Chemicals should not be added to sacred ponds

• Fear of “filtering off the power” of sacred water

• Belief that Dracunculiasis is a result of witchcraft

Getting to all the rural locations with occurrences

Social unrest, such as ongoing war in Sudan

This pond serves 1,500 peoplewith drinking water

Socioeconomic ImpactSocioeconomic Impact

Socioeconomic ImpactSocioeconomic Impact

It has been estimated that infected people lose 100 days of work per year

Children are absent from school for 25% of the school year, if they or members of their family are infected

The cost in lost revenue for the individual and the community can be very high

Historical ImpactHistorical Impact

Written and pictorial documents indicate that Dracunculus medinensis has affected mankind for many centuries

The titles “Guinea” and “Medina” stem from areas with significant incidences of the disease

A finding of a male worm in a mummy indicates that the wealthy were also susceptible to infection

Current ImpactCurrent Impact

Dracunculiasis is currently limited to remote, rural villages in 13 sub-Saharan African countries without access to safe drinking water

The vast majorityof current casesinflict citizens ofthe war-torn nationof Sudan

Distribution by Country of 10,674 Cases of Distribution by Country of 10,674 Cases of Dracunculiasis, 2005 – Dracunculiasis, 2005 – Includes imported casesIncludes imported cases

The last known indigenous case occurred in Kenya in 1994, but this country has been kept in the stage of pre-certification of eradication because of annual importations of cases from Sudan.

The last known indigenous case occurred in Kenya in 1994, but this country has been kept in the stage of pre-certification of eradication because of annual importations of cases from Sudan.

Dracunculiasis in the USA?Dracunculiasis in the USA?

A case history from 1995: Nine year old emigrant from Sudan. Before leaving

Sudan, a Dracunculus medinensis worm was extracted successfully from her right leg

After arriving in the United States another worm began to emerge from her left leg

She presented to a clinic in Tennessee with a secondary infection; treatment with antibiotics was unsuccessful

Surgical intervention facilitated removal of the fragmented worm, pus, and necrotic tissue

With proper outpatient therapy, the girl was able to walk and returned to normal

The Eradication The Eradication InitiativeInitiative

The Eradication InitiativeThe Eradication Initiative

In the 1980s a global campaign was launched to eradicate Dracunculiasis worldwide

• At that time Dracunculiasis was known to inflict India, Pakistan, 16 sub-Saharan countries in Africa, as well as Yemen

• Eradication efforts began in 1982 in India and shortly thereafter in Pakistan, Ghana, Nigeria, and Cameroon

By 1995, all of the known endemic countries established eradication programs

Between 1980 and now, the cases worldwide have been reduced by more than 99.5%

Pakistan: An Example of EradicationPakistan: An Example of Eradication

Village-wide search for cases of Dracunculiasis in 1987• Reached 47,401 of the 50,000 suspected endemic villages

The main interventions: monofilament nylon or polyester cloth filters, and chemical treatment of drinking water sources with temephos

Trained healthcare workers in villages to identify and report cases of Dracunculiasis

Case containment began in 1990 Incentive rewards were offered in 1991 to any health

worker or individual reporting a case of Dracunculiasis in a village

Pakistan has been free from Dracunculiasis since 1994

Thank YouThank You

Shelly Beard

Nicole Corder

Majken Kiyohara