Asian Pacific Journal of Tropical Medicine (2012)505-510 505

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Asian Pacific Journal of Tropical Medicine

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Dracunculiasis eradication - Finishing the job before surprises arise

Benjamin Jelle Visser*
Academic Medical Centre, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands

ARTICLE INFO ABSTRACT

Article history: Dracunculiasis (Guinea worm disease) is a preventable waterborne parasitic disease that affects
Received 5 December 2011 the poorest people living in remote rural areas in sub-Saharan African countries, who do not have
Received in revised form 15 Feburary 2012 access to safe drinking water. The Guinea Worm Eradication Program, a 25-year old campaign to
Accepted 15 April 2012 rid the world of Guinea Worm disease has now reached its final stage accelerating to zero cases
Available online 20 July 2012 in all endemic countries. During the 19th and 20th centuries, dracunculiasis was common in
much of Southern Asia and the African continent. The overall number of cases has been reduced
Keywords: tremendously by ≥99%, from the 3.32 million cases estimated to have occurred in 1986 in Africa
Dracunculiasis to only 1 797 cases reported in 2010 reported in only five countries (Sudan, Mali, Ethiopia, Chad
Guinea worm disease and Ghana) and Asia free of the disease. This achievement is unique in its kind - the only
Eradication previously eradicated disease is smallpox, a viral infection for which vaccination was possible
- and it has been achieved through primary community-based prevention and health education
programs. Most efforts need to be taken in two countries, South Sudan (comprising 94% or 1 698
out of 1 797 of the cases reported world-wide in 2010) and Mali because of frequent movements of
nomads in a vast area inside and outside Mali’s borders. All factors favourable to dracunculiasis
eradication are available including adequate financial resources, community and political
support and high levels of advocacy. Thus there is no reason that this disabling parasitic disease
cannot be eradicated soon before surprises arise such as new civil conflicts in currently endemic
countries.

agricultural productivity, school attendance and maternal

1. Introduction and child health[2]. Although this neglected tropical disease
has a low mortality, morbidity is considerably high causing
Dracunculiasis [Guinea worm disease(GWD)] is a parasitic huge disabilities which are physically and economically
disease caused by the nematode (roundworm) Dracunculus devastating[3,4]. Since the start of the Dracunculiasis
medinensis. This worm is known to parasite on human since Eradication Program -25 years ago- conducted by several
at least ancient Egypt, where it has been identified in 3 organizations such as the C arter C enter, C enters for
000-year-old Egyptian mummies[1]. The disease affects Disease Control and Prevention, UNICEF, World Health
the poorest populations, often in remote rural areas, who Organization, Ministries of Health of affected countries,
do not have access to safe drinking water. Most endemic and numerous other non-governmental organizations,
areas now are conflict zones or is insecure; this constitute enormous progress has been made[5]. The overall number
a major challange to roll out full interventions to interrupt of cases has been reduced tremendously by more than 99%
transmission of dracunculiasis. from the 3.5 million cases estimated to have occurred in
Therefore, dracunculiasis is both a disease of poverty 1986 in 20 different countries in Africa and Asia, to 1797
and a cause of poverty. With sometimes more than half of cases reported in only 5 African countries in 2010, with
a village population being affected, it significantly affects most cases (94%) reported in Southern Sudan[6,7] (Figure 1).
In addition, cases have been reported in Chad which was
*Corresponding author: Benjamin Jelle Visser, MSc, Academic Medical Centre, considered as disease-free for the last decade. The target
University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
Tel: +31205669111 dates for eradication have been postponed several times
E-mail: bj.visser@amc.ura.nl and were usually over-optimistic and difficult to achieve.
506 Benjamin Jelle Visser/Asian Pacific Journal of Tropical Medicine (2012)505-510

This is due to the fact that target dates were mainly set up liquid into the water that contains millions of immature
for political reasons as it can strengthen the advocacy efforts larvae. When released in water, the larvae are ingested by
of the eradication program in endemic countries, rather than copepods where they moult twice and become infective
choosing a realistic evidence-based target date guided by larvae within two weeks[11]. This contaminates the drinking
estimates of the impact of interventions. This however, has water source and the cycle begins anew[12].
demonstrated to be difficult, because of the scarce number
of impact evaluations of control and surveillance programs[8].

1 000 000
900 000
800 000
700 000
600 000
500 000
400 000
300 000
No. of cracunculiasis
200 000
100 000
0
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011

Figure 1. Annual number of cases reported worldwide, 1989-2011.

*2011: Provisional: The 804 cases reported worldwide as of June
2011. Figure 2. Several Guinea worms emerging from a leg of a patient from
Ghana, photo by Dr. A. Tayeh.

2. Life cycle and clinical impact

3. Treatment
People become infected by drinking unfiltered water from
stagnant ponds or open shallow wells contaminated with There is no available curative drug or vaccine against
copepods (small water fleas) containing infective larvae. In dracunculiasis. Infected persons do not develop immunity.
the stomach, the copepods are killed by the digestive juices There is only the “traditional treatment”-gradually pulling
and consequently the larvae are released and then penetrate the worm out manually-, usually by winding a few inches/
their way through the digestive wall into the body cavity. centimetres of the worm each day on a small wooden stick,
The ovoviviparous female grows up to 1 meter (3 feet) length, which is a very painful process[12]. Thus, it can take weeks to
but only 1 to 2 mm thickness in the subcutaneous tissue, months for the entire worm to be removed, during which time
and can live up to 12 to 14 months, while the male worm dies the patient is often severely incapacitated. Moreover, nearly
within a few months[9]. No symptoms manifest until a year every infected person will be a victim of secondary bacterial
or so after the infection by which time the female worm has infection. If not treated with antibiotics, these lesions can
produced millions of eggs in its uterus, and is predominantly cause several complications such as erysipelas/cellulitis,
localized in the lower extremities (80%-90%). A sudden abscesses, sepsis, septic arthritis and even trismus (lock jaw
release of larvae causes a hot, painful sensation under the caused by tetanus infection)[11]. Patients ought to be careful
skin, creating a painful blister (1 to 6 cm diameter). The not to break the worm during manual extraction, because if
person may develop a slight fever, local redness, swelling the worm breaks it can cause intense inflammation as the
and severe pruritus around the blister. Also diarrhoea, remaining part of the dead worm disintegrates in the affected
nausea, vomiting and dizziness may be present. The blister limb.
will burst within 1 to 3 days. When one or more female
worms (1.8 worms per person on average, with as many
as 14 worms documented to emerge from a given person
4. Epidemiology and economic impact
in a season) slowly come out of the blister (Figure 2), an
excruciating burning sensation and pain is felt[10]. Immersing
Dracunculiasis affects people that depend on contaminated
or pouring water over the blister helps to relieve the pain,
drinking water sources, usually stored in unprotected
but also for sloughing-off the skin over the blister, allowing
stagnant water source such as ponds. Villages that depend
exposure of the worm to the outside environment[2]. This is
upon such water for drinking can have 15% to 70% of their
the moment that the female worm releases a milky white
 Benjamin Jelle Visser/Asian Pacific Journal of Tropical Medicine (2012)505-510
507

population infected. It threatens economic development[13], is low. Case containment programs are preventing infected
because it mainly affects the most productive people (12- people to enter drinking water sources in order to interrupt
50 year old), sustaining the disease-poverty-disease cycle. transmission completely. Case-containment centres have
Variation in incidence between age, gender and occupation been set up, where patients can be kept for about a week
is mainly determined by the type of water source from where and receive free medical treatment and food. To maintain
the people drink. GWD transmission has a seasonal pattern intensive surveillance, nationwide in-kind reward systems
and is closely related to rainfall. In arid areas, people get for informing on cases exists. Rewards vary from U.S. $ 10
infected during the rainy season, when surface water is to 100. All these grassroots public health initiatives have
available. In wet regions, people generally get infected been demonstrated to be extremely effective and suitable to
during the dry season, when sources of drinking water are be used in remote and less developed communities in the
scarce and becoming stagnant. The seasonal pattern of poorest countries on earth[12].
clinical manifestations of the disease, which occurs one year
after transmission, often coincides with harvest or planting
seasons and significantly affects agricultural productivity. 6. The road to eradication
I n N igeria for example, GWD was responsible for an
approximate 11.6% decrease in the total rice crop production. Shortly after the WHO declared the world free of smallpox
It is estimated that infected people lose 100 days of work per in 1977, the first disease ever eradicated, dracunculiasis
year. Furthermore, it affects school attendance because of was posed to be the ideal next candidate for eradication[16].
inability to walk to school, with children being absent for at It was stated that dracunculiasis, a disease only transmitted
least 25% of the school year. The World Bank has estimated via drinking water, would be an ideal indicator to measure
that the economic rate of return on the investment in GWEP the success of the U nited N ations declaration of the
will be about 29% per year once the disease is eradicated[3]. International Drinking Water Supply and Sanitation Decade
(IDWSSD) 1981-1990. In 1981 the possibility of elimination
of GWD by improving the quality of human drinking
5. Main strategies water was adopted by the IDWSSD as a sub-goal of their
endeavours. An international campaign led by the Carter
The main strategies of the GWEP are preceded by setting Center launched the battle against GWD in 1986. In addition,
up national surveillance programs, to identify cases other international partners including the United Nations
and consequently establish an appropriate policy and Development Program and UNICEF, together with countries
national plan for eradication[14]. After that, interventions endemic for GWD, joined the global effort. The WHO has
are implemented. Main strategies are early case detection been deeply involved from the start of the campaign; The
( within 24 hours of worm emergence ) to interrupt W orld H ealth A ssembly ( WHA ) accepted a resolution
transmission immediately, community mobilizations (WHA 34.25, 1981) linking drinking safe water supply to
and awareness campaigns including health education the prevalence of dracunculiasis, which could serve as a
such as village-by-village health education by village- unique visible and measurable indicator of the progress
based volunteers about the origin of the infection, mode of of the IDWSSD. In 1986 the WHA accepted a resolution
transmission and methods of prevention. Another important ( 39 . 21 ) calling for the elimination of dracunculiasis. A s
factor remains vector control by temephos application (a the campaign gained support, the World Health Assembly
chemical copecide which is not harmful to animals and in 1991 accepted a resolution calling for the eradication
humans)in contaminated drinking water sources to kill the of the disease by 1995 . I n addition, national programs
intermediate host. Filtering all unsafe water before drinking for dracunculiasis eradication in Asia started from 1983.
could be achieved by millions of cloth filters (e.g. personal Since then, the number of newly reported cases declined
special filter straws), hence preventing ingestion of the water tremendously (Figure 1), eliminating the disease in Asia
fleas containing infective larvae. Provision of safe water (Pakistan 1993, India 1996) and several African countries
sources such as bore-hole wells and deep dug wells were (Cameroon, Senegal and Yemen 1997[17-19]. It is estimated
proposed as the major contributor in combating GWD, but that one million cases each year are prevented due to the
appeared to be an extremely expensive option not affordable campaign. The global success of the GWEP is unprecedented
by most endemic countries[15]. One of the most effective because it is mainly achieved by involving thousands of
strategies, whatever the prevalence or incidence or setting village volunteers who disseminate health education for this
is so called “case containment”; unfortunately this is very disease, which has no drug based or vaccine therapies[17].
costly and is now only used in areas where the prevalence
508 Benjamin Jelle Visser/Asian Pacific Journal of Tropical Medicine (2012)505-510

7. Current status of the campaign compared with the number of cases in 2009 . A lthough
the number of cases is not high, the situation in Mali is
GWD remained endemic during 2010 in 5 African countries, considered an obstacle to GWEP due to the movement of
Sudan (1 698 cases), Mali (57 cases), Ethiopia (21 cases) nomadic populations in a vast area not only in Mali but
and Ghana (8 cases). In addition Niger, which reported also to neighbouring formerly endemic countries including
interruption of dracunculiasis in 2008, reported 3 cases Burkina Faso, Mauritania and Niger. It is no surprise that the
in 2010 all imported from Mali. Chad confirmed that 10 3 cases reported in Niger in 2010 were imported from Mali.
indigenous cases were detected in 2010. After more than ten years of stagnation in the number of
Sudan currently reports most cases. Within Sudan, the Guinea worm cases in Ghana that reported between 4 000
northern states already eradicated GWD , which is not to 8 000 cases annually before 2008, there was a dramatic
surprising since the civil war was being fought mostly in decrease in the number of detected cases during 2008-
the southern part of the country. Southern Sudan, where it 2009 and only 8 cases were reported in 2010. All of these 8
has been proved to be difficult to implement an eradication cases were contained. As the last case was reported in May
program, reported 94% (1 698/1 797) of global cases in 2010. 2010 and no more were reported to the end of July 2011 (14
This continuing transmission is not only a concern for South months with no cases) it is likely that the disease has been
Sudan, but also for neighbouring states such as Uganda, interrupted in the country[22].
because of cross-border travelling of indigenous nomads. The recent re-emergence of cases in the southern part
A 4-month cease-fire in 1995, negotiated by former US of C had, a decade after transmission was halted, is of
president Jimmy Carter, allowed health workers to establish concerned to all persons involved in GWEP. It is not possible
health education programs and distribution of cloth filters[17]. to ascertain whether this resurgence is a result of continuing
Currently, the eradication program in South Sudan is the last undetected low-level indigenous transmission over the
program that needs to be fully scaled up after the signing past 10 years or if it has originated from a recently imported
of the Comprehensive Peace Agreement in 2005, ending the case that was not detected[6]. It can also be considered a
longest-running, bloodiest and most neglected civil war in consequence of the delay in interrupting the disease in
Africa. It was acknowledged that this long-awaited peace countries that are neighbouring Chad including Niger,
agreement to bring peace in Southern Sudan removed the Nigeria, Cameroon and Sudan.
most important obstacle for eradication dracunculiasis[20].
Nevertheless, even after the peace agreement and the gain
of independence of South Sudan on July 9th 2011, the GWEP 8. Conclusion
is still not running at full speed. It will be a quite challenge
to maintain a high priority for this eradication program on With no more than 1 797 Guinea worm cases reported in
the political agenda in a newly formed nation with many 2010 from only 4 Sub-Saharan African countries endemic
other challenges ahead. Humanitarian agencies are now for GWD, there are indications that the number of endemic
still unable to freely access the civilian population, despite countries and the number of cases will be reduced further in
improvements in the security situation. Besides this, ongoing 2011. Ghana may have interrupted disease transmission as
fighting and inter-communal clashes displaced thousands discussed earlier. The number of reported cases in Ethiopia
of people, making it difficult to reach them[21]. It is hoped was low (6 cases) during the first half of 2011, which is half
that after a short period of the independence of South Sudan, the number of the cases reported during the same period
political stability and peace will prevail at last, which is in 2010[22]. As of June 2011, provisional data show a further
of vital importance to the success in the eradication of decline in GWD with a total of 804 cases; South Sudan
dracunculiasis in the region[14]. reported 99% (793/804) of all cases of GWD in the world.
The situation of dracunculiasis in Ethiopia is tied to that Thus, only two endemic countries will determine the future
of South Sudan, as the endemic areas in both countries of GWEP, Mali and South Sudan. Figure 3 shows the status of
are adjacent to each other. Twenty one cases from a small dracunculiasis cases during 1989 to 2011 for Mali and Sudan.
endemic zone, Gog District, have been reported nearer to There has been stagnation in the number of cases for Sudan
the border with South Sudan in 2010. Members of the main and Mali for 1993 to 2008. But there is a sign of decrease in
community frequently move across the Ethiopian-Sudanese the number of cases during 2009 to 2010 which is promising
border transmitting the disease from one side to another and if continues.
thus the disease transmission will be easier to interrupt if With ≥94% of the global cases concentrated in South
the number of cases in South Sudan is further reduced. Sudan, focused efforts of GWEP will be required in this
Mali reported 57 cases in 2010, that is a reduction of 69% newly born country that has been devastated after many
 Benjamin Jelle Visser/Asian Pacific Journal of Tropical Medicine (2012)505-510
509

1 000 000

100 000

10 000
Number of cases

1 000

100

10

1
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
Mali 12011 5581 4218 2402 1099 650 410 290 718 861 829 357 659 329 313 417 186 57 3
Sudan 2984 53271 64608 118578 43596 47977 66097 54890 49471 41493 20299 7266 5569 20582 5815 3618 2733 1692 793

Figure 3. Annual cases of GWD in Mali and Sudan.

* Provisional. Data as of June 2011; South Sudan reported 99% of all cases of Guinea Worm disease in the world.
Box 1 - Key papers in the field of Guinea worm eradication.
•Cairncross S, Muller R, Zagaria N. Dracunculiasis (Guinea worm disease) and the eradication initiative. Clin Microbiol Rev 2002; 15(2): 223-
246.
•Greenaway C. Dracunculiasis (guinea worm disease). CMAJ 2004; 170(4): 495-500.
•Ruiz-Tiben E, Hopkins DR. Dracunculiasis (Guinea worm disease) eradication. Adv Parasitol 2006; 61: 275-309.
•Tayeh A, Cairncross S. Editorial: Dracunculiasis eradication by 2009: will endemic countries meet the target? Trop Med Int Health 2007;
12(12): 1403-1408.
•Muller R. Guinea worm disease--the final chapter? Trends Parasitol 2005; 21(11): 521-524.
Box 2 - Learning points of this review.
•Dracunculiasis (Guinea worm disease) is a preventable waterborne parasitic disease which caused a enormous public health problem, however,
the disease has now reached its final stage accelerating to zero cases in all endemic countries.
•The Global Guinea Worm Eradication Program (GWEP) has reduced the overall number of cases by ≥ 99%, from the 3.32 million cases
estimated to have occurred in 1986 in Africa to only 1 797 cases reported in 2010. From 1 January to 30 June 2011 there have been only 814
confirmed cases of dracunculiasis. The majority of cases come from South Sudan (801), Mali (3), Ethiopia (8) and Chad (2).
•The success of the GWEP will be determined by only two endemic countries; Mali and South Sudan; The eradication program in South Sudan
is the program that needs to be fully scaled up because a long civil war impeded effective implantation of national public health initiatives. Mali
is considered an obstacle to GWEP mainly due to the high degree of movement of nomadic populations in vast areas bordering several countries.
If surprises arise, such as a new conflict in South Sudan or in Mali, interruption of dracunculiasis will be difficult and the disease may spread.
The utmost challenge for the next few years will be to increase and sustain the current eradication efforts using all the existing tools.

years of civil wars, which will now gradually and slowly determining the fate of success of GWEP with a high degree
rebuild itself. In South Sudan, there may be as many as 732 of movement of nomadic populations in vast areas bordering
villages endemic for dracunculiasis. As in other countries, several countries. Mali has for long been exporting cases to
eradication requires implementing a village-based program other endemic countries such as Burkina Faso and Niger and
in each endemic village, which is easier said than done with to non-endemic countries, namely Algeria[23]. The recent
the hundreds of villages in Southern Sudan with restricted re-introduction of dracunculiasis in Chad, which was free
access to particularly during the rainy season. South Sudan, from the disease since the year 2000, is a strong reminder
though it is now very rich in oil, remains one of the least of the significance of maintaining surveillance in areas that
developed regions on earth, with ethnic tensions, mass are considered to be free from the disease. It also can be
movements of displaced people, troubled relations with considered a consequence of the delay in interrupting the
the north, few roads or other infrastructure, and limited disease in countries that are neighbouring Chad including
communication possibilities [2]. A dditional difficulties Niger, Nigeria, Cameroon and Sudan.
caused by upheavals are disruptions in activities and loss of If surprises arise, such as a new conflict in South Sudan
personnel, and increased costs because of the need to airlift or in Mali, interruption of dracunculiasis will be difficult
supplies. and the disease may spread. The utmost challenge for the
Mali can prove that it is as crucial as South Sudan in next few years will be to increase and sustain the current
510 Benjamin Jelle Visser/Asian Pacific Journal of Tropical Medicine (2012)505-510

eradication efforts using all the existing tools[8]. Effective [6] W

 HO. Dracunculiasis eradication - global surveillance summary,
surveillance and case containment followed by reliable 2010. Weekly Epidemiological Record 2011; 86 (20): 189-204.
reporting will be crucial at this stage to ensure that disease [7] Lodge M. And then there were four: more countries beat guinea
transmission can be interrupted soon. Special attention worm disease. BMJ 2010; 340: c496.
should also be given to cross-border spread of the disease [8] Tayeh A, Cairncross S. Editorial: Dracunculiasis eradication by
particularly to northern Uganda which has already been 2009: will endemic countries meet the target? Trop Med Int Health
certified in 2009 as disease free; the zones where nomads 2007; 12(12): 1403-1408.
travel may pose a risk for re-introduction of the disease in [9] Greenaway C. Dracunculiasis (guinea worm disease). CMAJ 2004;
former endemic countries. Surveillance strategies focusing 170(4): 495-500.
on zones of transmission that cut across such boundaries [10]Müllner A, Helfer A, Kotlyar D, Oswald J, Efferth T. Chemistry
need to be implemented. Yet, given adequate resources and and pharmacology of neglected helminthic diseases. Curr Med
high level advocacy by national and international leaders Chem 2011; 18(5): 767-789.
in an environment of political stability and peace, there is [11]I r i e m e n a m N C , O y i b o W A , F a g b e n r o - B e y i o k u A F .
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plagued mankind since ancient times, cannot be eradicated 2008; 102(3): 343-347.
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We declare that we have no conflict of interest. [14]Breman JG, Arita I. The certification of smallpox eradication and
implications for guinea worm, poliomyelitis, and other diseases:
Confirming and maintaining a negative. Vaccine 2011 (Epub
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[15]Muller R. Guinea worm disease--the final chapter? Trends
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