Eradication Program

 

Global Eradication Campaign

The global campaign to eradicate Guinea worm disease (GWD) began in 1980 at the U.S. Centers for Disease Control and Prevention (CDC). CDC suggested that the eradication of GWD (also known as dracunculiasis) would be an ideal indicator of success for the United Nations International Drinking Water Supply and Sanitation Decade (IDWSSD) (1981–1990) because it was believed that people could only get GWD by drinking contaminated water. A year later, GWD eradication was adopted as a sub-goal of the IDWSSD[1, 2, 3]. In 1984, CDC was designated as the WHO Collaborating Center for Research, Training, and Eradication of Dracunculiasis. In 2017, the Collaborating Center changed its name to the WHO Collaborating Center for Dracunculiasis Eradication.

In 1986, there were 20 countries with GWD. These countries had about 3.5 million human cases per year. Most (90%) cases occurred in Africa. An additional 120 million people in Africa were at risk for GWD because of unsafe water supplies[2, 4]. That year, the World Health Assembly (WHA) adopted a formal resolution calling for the elimination of GWD, country by country[5]. The Carter Center, working closely with Ministries of Health, took the lead for the global Guinea Worm Eradication Program (GWEP) in 1986 and built local, national, and international partnerships. Support came from numerous donor agencies, foundations, institutions, and governments. Based on the success of the GWEP, the WHA adopted its first resolution to eradicate GWD from the world in 1991[6]. A country has successfully interrupted transmission and eliminated GWD when there have been no reports of GWD for three or more years[1, 2, 3]. When all countries are certified by WHO as having eliminated GWD or never having had GWD, then global eradication will be achieved.

Criteria for Eradication

WHA initially targeted GWD for eradication because it met the following specific criteria:

It was biologically and technically possible to eradicate this disease[2, 7, 8, 9].

  • There was no chance for the disease to return after the last human case occurs.
  • GWD was easily diagnosed because of its signs and symptoms. Few diseases could be confused with GWD and the public in affected communities knew and recognized the worm.
  • In each affected country the worms emerge from the skin during certain predicable times of the year.
  • GWD was previously eliminated from parts of the Former Soviet Union during the 1920s and from endemic areas of Iran in the 1970s.

The benefits of eradication outweighed the costs[2, 7, 8, 10].

  • The World Bank assessed the socio-economic impact of GWD in 1997. It concluded that the costs for GWD eradication and morbidity reduction would be significantly less than the continued costs of the disease.
  • Other direct benefits of eradication would include:
    • The development of a group of trained health workers who could provide both GWD management and other basic health services.
    • Improvements in water supplies
      • Water no longer contaminated with Guinea worm
      • Enhanced advocacy for new safe water sources
  • The global community would indirectly benefit from the enhanced culture of disease prevention and social equity afforded by this disease eradication program. Countries and organizations supporting GWD eradication would be helping to reduce the suffering of some of the world’s most underprivileged people.

While support for eradication was felt to be strong in endemic countries, there were political and societal barriers to eradication that were also considered by the WHA. Political support was and still is variable, even in endemic countries. International donor support was and is difficult to maintain for this neglected tropical disease (NTD). NTDs affect the poorest populations, including people living in remote rural areas or conflict zones who often have little political voice. Therefore, diseases such as GWD generally have a low profile and limited status in the list of public health priorities[1, 2, 3]. Nevertheless, in 1986 and again 1991 the WHA adopted the resolution to eliminate and then eradicate GWD.

Criteria for Certification of GWD Eradication

GWD transmission is interrupted in a country once no new GWD cases occur for 12 consecutive months (i.e., one incubation period). At this point, countries can apply for certification of GWD-free status from the International Commission for the Certification of Dracunculiasis Eradication (ICCDE)[11].

The ICCDE is a panel of international GWD specialists. It was established by WHO in 1995 to verify and confirm information from countries applying for certification. The ICCDE considers GWD eradication to be achieved in a country when

  • Adequate active surveillance systems have confirmed the absence of GWD for 3 or more years;
  • A rumor log of suspected cases has been maintained for a 3-year period detailing
    • The particulars of each case,
    • The origin of each case, and
    • The final diagnosis of each case (i.e., a true case of GWD or some other condition); and
  • All confirmed cases imported from endemic countries have been traced to their origins and have been fully contained*.

The ICCDE certifies a country as being free from GWD after it confirms these criteria have been met and receives a report detailing the history of GWD in that country[11].

Moving Forward with GWD Eradication

Extracting a Guinea worm from the ankle by wrapping it around a stick. Credit: Public Health Image Library/1968

Extracting a Guinea worm from the ankle by wrapping it around a stick. Credit: Public Health Image Library/1968

Great progress has been made in the last three decades. As of February 2019, the ICCDE has certifiedexternal icon 199 countries, territories, and areas as being free from GWD transmission, with only 7 countries remaining to be certified: Angola, Chad, Democratic Republic of the Congo, Ethiopia, Mali, South Sudan, and Sudan [12].

Thanks to the Guinea Worm Eradication Program, there were only 28 human cases reported worldwide in 2018. These human cases were reported in Angola (1 case), Chad (17 cases), and South Sudan (10 cases). Animals infected with D. medinensis, mostly domesticated dogs, have been reported since 2012. In 2018, Chad reported 1,040 infected dogs and 25 cats; Ethiopia reported 11 infected dogs, five cats, and one baboon; and Mali reported 18 infected dogs and two cats .[ 13 ]

Recent research has shown that certain aquatic animals can become infected by eating copepods (tiny “water fleas” too small to be clearly seen without a magnifying glass) that have been infected with Guinea worm larvae[14,15]. Larvae are immature forms of the Guinea worm that contaminate water. Animals (e.g., dogs) and humans who live in countries where GWD is occurring (such as Chad, Ethiopia, Mali, and South Sudan ) and consume raw or undercooked aquatic animals (such as small whole fish that have not been gutted, other fish, and frogs) may be at risk for GWD.

With the discovery of GWD in animals, mostly domestic dogs in Chad, the GWEP has augmented its interventions to address possible spread by aquatic animals. These include health education about burying or burning fish entrails left over from fish processing to prevent dogs from eating them and avoiding feeding fish entrails to dogs. People are also advised to cook well any fish and other aquatic animals before eating them to prevent themselves from becoming infected. A reward is also offered for persons who report GWD in their dogs before the dogs can contaminate water; the reward helps cover the cost of tethering, feeding, and caring for the dog with the help of the GWEP until the worm or worms are safely removed.

* Transmission from a patient or animal with dracunculiasis is contained only if all of the following conditions are met for each emerged worm: 1) the infected patient or animal is identified before or within 24 hours after worm emergence; 2) the patient or animal has not entered any water source since the worm emerged; 3) a village volunteer or other health care provider has managed the patient or animal properly, by cleaning and bandaging the wound until the worm has been fully removed and by providing health education to the patient or the animal’s owner to discourage the patient or animal from contaminating any water source (if two or more emerging worms are present, transmission is not contained until the last worm is removed); 4) the containment process, including verification of dracunculiasis, is validated by a Guinea Worm Eradication Program supervisor within 7 days of emergence of the worm; and 5) the approved chemical temephos (ABATE®†) is used to kill the copepods if any uncertainty about contamination of sources of drinking water exists, or if a source of drinking water is known to have been contaminated. [16]

† Use of trade names is for identification only and does not imply endorsement by the Public Health Service or by the U.S. Department of Health and Human Services.

References
  1. Hopkins, D.R., et al., Dracunculiasis eradication: neglected no longer. Am J Trop Med Hyg, 2008. 79(4): p. 474–9.
  2. Ruiz-Tiben, E. and D.R. Hopkins, Dracunculiasis (Guinea worm disease) eradication. Adv Parasitol, 2006. 61: p. 275–309.
  3. Hopkins DR, et al., Update: Progress Toward Global Eradication of Dracunculiasis, January 2007-June 2008. MMWR, 2008.Oct 31;57(43): p. 1173–6.
  4. Watts, S.J., Dracunculiasis in Africa in 1986: its geographic extent, incidence, and at-risk population. Am J Trop Med Hyg, 1987. 37(1): p. 119–25.
  5. World Health Assembly, Elimination of dracunculiasis, in 21.
  6. World Health Assembly, Eradication of dracunculiasis, in 5.
  7. Aylward, B., et al., When is a disease eradicable? 100 years of lessons learned. Am J Public Health, 2000. 90(10): p. 1515–20.
  8. Molyneux, D.H., D.R. Hopkins, and N. Zagaria, Disease eradication, elimination and control: the need for accurate and consistent usage. Trends Parasitol, 2004. 20(8): p. 347–51.
  9. Hopkins, D. and E.M. Hopkins, Guinea Worm: The End in Sight, in Medical and Health Annual, E. Bernstein ed. 1991, Encyclopedia Britanica Inc.: Chicago.
  10. Greenaway, C., Dracunculiasis (guinea worm disease). CMAJ, 2004. 170(4): p. 495–500.
  11. World Health Organization, Criteria for the Certification of Dracunculiasis Eradication, in WHO/FIL/96.187 Rev.1.
  12. World Health Organization. (2019). Certification–International Commission for the Certification of Dracunculiasis Eradication. [online] Available at: https://www.who.int/dracunculiasis/certification/en/external icon [Accessed 15 Feb. 2019].
  13. World Health Organization. Dracunculiasis Eradication: Global Surveillance Summary, 2017. Wkly Epidemiol Rec. 93(21): p. 305–20.
  14. Eberhard ML, Yabsley MJ, Zirimwabagabo H, Bishop H, Cleveland CA, Maerz JC, Bringolf R, Ruiz-Tiben E. Possible Role of Fish and Frogs as Paratenic Hosts of Dracunculus medinensis, Chad. Emerg Infect Dis. 2016. 22(8): p. 1428–30. doi: 10.3201/eid2208.160043.
  15. Eberhard ML, Cleveland CA, Zirimwabagabo H, Yabsley MJ, Ouakou PhPT, Ruiz-Tiben E. Guinea Worm (Dracunculus medinensis) Infection in a Wild-Caught Frog, Chad. Emerg Infect Dis, 2016. 22(11): p. 1961–2. doi: 10.3201/eid2211.161332.
  16. Hopkins DR, et al., Progress Toward Global Eradication of Dracunculiasis, January 2016–June 2017. MMWR, 2017 Dec 8. 66(48): p. 1327–31.

Page last reviewed: May 2, 2019