Dracunculiasis

 

Dracunculiasis: Guinea Worm Disease

About the Disease  

Dracunculiasis
Disease caused by  Dracunculus medinensis


by Meredith Maxey [Honors Tutorial College/BIOS]    

REFERENCES

History:
  • Documented since antiquity
  • “fiery serpent” mentioned in Old Testament
  • Calcified worm found in Egyptian mummies

Picture:  Egyptian Mummy  Source

  • Sanskrit verses allude to the worm (14 th  century BC)
  • Called “dracontiasis” during the Graeco-Roman period
  • Arab-Persian physicians described in 9 th  century AD
 A little more recently…
  • 1624-1677: Persian physicians remove worm from patients’ legs
  • Through 18 th  century: varying opinions on the nature of the condition (nerve vs. dead tissue)
  • 1870: Role of intermediate host in life cycle determined by Alesaj Pavlovich Fedchenko
  • End of 19 th  century: Scientific community aware of how it was transmitted; protective measures taken
  • 1905: Life cycle also demonstrated by Robert Thomas Leiper
  • 1913: Life cycle documented yet again by Dyneshvar Atmaran Turkhud
  • 1926-1931: Eradicated in Uzbekistan
  • 1972: Eradicated in Iran
  • 1984-1991: Eradication in India
  • 1986-present: Cooperation of Carter Center, WHO, CDC, and UNICEF
Symptoms of Infection
  • No symptoms for up to one year
  • Symptoms preceding emergence of worm:
    • Chills/fever and vomiting
    • Swelling
  • During emergence of worm
    • Burning sensation
    • Secondary bacterial infections
    • Locked joints
Treatment     

Picture:  Emerging worm being wrapped around a stick  Source

Wind the worm around a small stick -- a few centimeters (of up to 100) a day.  That can take weeks to months but…anaphylaxis is likely if the worm breaks.

  • No medication to end/prevent infection
  • Analgesics for pain/swelling
  • Antibiotic ointment to prevent secondary infections
  • Surgical removal is possible before ulcer formation
Dracunculus: The parasite

  Picture:  Dracunculus medinensis, the cause of dracunculiasis  Source

  • Genus of nematode parasites
  • Latin for “little dragon”
  • Family - Dracunculidae
  • 7 main species
    • D. insignis  – dogs and wild carnivores
    • D. medinensis --  humans, dogs, cattle, horses
  • Also known as “Guinea Worm”
Life Cycle of  D. medinensis    

Picture source

D. medinensis  emerges through an ulcer on the skin after one or two years of infection.  When the person with the emergent worm enters drinking water, the worm releases larvae into the water.  Microscopic water fleas ( Cyclops ) then ingest the larvae.

Cyclops
The larvae develop into the infective stage within 10-14 days.

Humans become infected by drinking water.  Human stomach acid digests flea, but not the guinea worm.  Then the worm can enter body cavity via small intestine and develop further.

  • Male worm = 1-3 cm
  • Female worm = 60-100 cm long (like a strand of spaghetti)

During next 10-14 months, the male and female will copulate.  The male dies and is absorbed into female.

  • Female can contain 1000s of larvae and resides in the connective tissues of limbs and trunk.
  • Generally no pathological conditions

Finally, the female migrates to part of body where it will emerge

  • 90% of cases = lower limbs

 

Death of female responsible for the following…  

Picture:  Emerging  D. medinensis  Source

  • Blister develops on skin and ruptures within 72 hours – thus, exposing the worm
  • Blister becomes an ulcer
  • Immersion in water to relieve burning
  • Female is capable of releasing larvae for several days and the cycle repeats.  Repeat Infection is quite common

  Eradication  

“Hopefully Guinea worm will be the first parasitic disease ever eradicated.  If and when that happens, we will have done it without a drug and without a vaccine to treat or prevent the disease.  If we can do that, it will be one of the greatest achievements in public health.”

~Dr. Ernesto Ruiz-Tiben, technical director of the Guinea Worm Eradication Program

Why is eradication possible?
  • Diagnosis is unambiguous because of the emerging worm
  • Transmission vector is not mobile
  • Interventions, like cloth filters, are effective, low cost, and simple to use
  • Limited geographical distribution
  • Political commitment from governments
Who is involved?     
  • The Carter Center of Emory University 
     
    • President Jimmy Carter
  • Carter Center’s Guinea Worm Eradication Program
  • UNICEF
  • Centers for Disease Control and Prevention  
  • World Health Organization                           
Did you know?

Dracunculiasis has been around for a long time (found in the remains of  Egyptian mummies).  But in just 20 years, through the collaboration of these organizations, it is likely to be eradicated.

WHO Strategy - 1997
  • about us itdi Implement containment measures in all endemic villages
  • Establish community-based surveillance systems

  • Target implementation of specific interventions

  • Map all endemic villages and maintain dracunculiasis databases

  • Manage certification process

Containment Measures
  • Cases identified prior to emergence or at least within 24 hours after
  • Containment measures initiated immediately
  • Then…clean wound
  • Bandage for 2-3 weeks
  • Avoid contact with water
  • 2004 – only 34% endemic cases were contained
Surveillance       

Click here for a detailed look   at surveillance efforts  

 

Specific Interventions
  • Provide safe water
  • Health education
  • Community mobilization
  • Filter distribution
  • Treatment of infected water sources
Who is most affected?

Rural communities in sub-Saharan Africa 

  Map:  Countries in sub-Saharan Africa  Source

  • Limited access to medical care
  • Secondary bacterial infections common
  • Incapacitated for several months
  • Can lead to permanent crippling
  • Usually emerges during planting or harvesting season
  • Huge negative impact on the local economies
Impacts of Infection
  • Heavy crop losses
  • Parents unable to care for children
  • Children unable to attend school
  • Financial problems
  • Resultant economic and social burden on affected communities
    • *For example, $20 million lost in one year by rice farmers in Nigeria
Problems still faced: local resistance to treatment   

Picture:  A sacred pond  Source

2001: Jacob Ogebe (field officer for Carter Center) was trying to treat all ponds in the village of Ogi with Abate.  The villagers lied about on of the ponds because it was sacred to them.  His life was threatened, but he offered payment to those that would secretly treat the pond.  In another instance, a dog was killed and put in pond so the villagers would consider it unclean.  The villagers did not drink the water anymore, and the Guinea worm cases went down.

Prevention          
  • Education about transmission
  • Drink only water from underground sources
  • Prevent people with open ulcers from entering potential drinking water
  • Filter drinking water (removes disease vector)                         

Picture:  Filtering water through cloth  Source

  • Carter Center donation: $30 = 100 portable filters
  • Treat unsafe sources with larvicides such as Abate ® 
Cyclops: Vector of Dracunculus  

       

Picture Source

One of the most common genera of freshwater copepods

  • 100 species
  • 0.5-5mm long with large red or black eye
  • They have even made it into popular culture

Sheldon J. Plankton of SpongeBob SquarePants

Picture Source

Affected Communities
  • Generally tropical regions that have one or more annual dry seasons
  • Infection acquired from a stagnant drinking water source like ponds and shallow wells
  • In 2005, all known infections in sub-Saharan Africa (Ghana, Sudan, Nigeria)
In those countries…                                   

58% bed-ridden for at least one month after emergence  

Nigeria = half of adult members of family suffered from dracunculiasis in one year                                      Nigeria Map Source

Sudan = children of stricken parents 3x as likely to be malnourished 

Eradication efforts, however, are still considered to be extremely successful

Right Sudan  Source

 
Epidemiology
  • 11 endemic countries in 2004
  • 9 endemic countries in 2005 (Benin and Mauritania dropped off list)
Endemic countries reported
10, 674 cases in 2005:
  • Burkina Faso
  • Cote d’Ivoire
  • Ethiopia
  • Ghana
  • Mali Niger
  • Nigeria
  • Sudan
  • Togo

Ghana and Sudan reported 9550 (90% total)

  • Ghana – 3981 (37%)
  • Sudan – 5569 (52%)

Non-endemic cases (brings tally to 12)

  • Uganda (9)
  • Kenya (2)
  • Benin (1)

Last cases remain most difficult

Mapping and Databases

1993 – WHO/UNICEF created HealthMap

  • Created to service the mapping/monitoring needs of the Dracunculiasis Eradication Program
  • Assists national eradication programs in the successful use of GIS
  • Maps produced allow for easy visualization of problem (magnitude and location)
  • Use of system requires no special training or software
HealthMap                                   

Picture:  Sample screens from HealthMap  Source

The maps include information on the following:

  • Number of cases
  • Distribution of safe water supply
  • Historical maps show trends
  • New software in 1997
  • Monthly data input and results are automatically available for viewing
  • Facilitates certification process
Certification 

International Commission for the Certification of Dracunculiasis Eradication (ICCDE) was  e stablished in May 1995

  • Verify and confirm information from countries claiming absence of indigenous dracunculiasis
  • So far, 168 countries have received certification.   This includes ALL of Asia.  

Picture:  Family seeking information on dracunculiasis  Source

Carter Center Involvement

1986 – provided technical and financial assistance to eradication programs

  • Unique in its ability to provide and mobilize the necessary components of a successful eradication campaign
  • Also, they have the political will, financial support, technical expertise, and strong partnerships necessary to perpetuate the campaign.

99.5% reduction in the past twenty years!!

1986 = 3.5 million cases worldwide

2005 = 10,000 reported cases worldwide

Currently, dracunculiasis is present in 12 countries in sub-Saharan Africa -- not all of those are considered endemic…Sudan is a main concern due to its ongoing civil war (7275 cases in 2004).  The civil war has taken a toll on, among other things, dracunculiasis eradication efforts.  All other countries, however, are attempting to eradicate dracunculiasis as soon as possible!