Epidemiology

The global eradication campaign has made steady progress. Both the number of cases and endemic villages has fallen significantly since the launch of the eradication efforts in the 1980s when 20 countries were endemic for the disease.

In 1986, an estimate of 3.5 million new cases occurred. In 1989, based on active village-based searches, 892 055 cases were reported to have occurred in 15 out of the 20 endemic countries (not included are data from Chad, Central African Republic, Senegal and Sudan).

In 2011, 4 countries remain with local transmission of dracunculiasis: Chad, Ethiopia, Mali and South Sudan*. Distribution of the disease is isolated to sub-Saharan Africa.

By 2011, a total of 1058 cases were reported. A reduction of 41% as compared to the 1797 cases reported in 2010, and more than 99% reduction from the cases reported in 1989.

In 2011, South Sudan reported 1028 cases, which represented more than 97% of the global total cases. The rest of the 2011 cases were reported in Ethiopia 8 cases, Chad 10 cases and Mali 12 cases.

The number of villages which reported cases reduced from 779 in 2010 to 483 in 2011; a 38% reduction. The number of endemic villages declined from 261 in 2010 to 142 in 2011, a 45% reduction.

Of these 1058 cases reported in 2011, 349 cases were women and 411 cases were children under 15 years old. Together women and children under 15 years old represented about 72% of all dracunculiasis cases reported in 2011.

Ghana, with the second highest number of dracunculiasis cases ever reported annually in the world (>179 000 cases reported in 1989) the first being Nigeria (>653 000 cases in 1988), reported its last indigenous case in May 2010 in Diare village in the Savelugu–Nanton district. Since then, no cases were reported in Ghana; the country is now in the pre-certification phase.

After reporting zero cases to WHO for more than 10 consecutive years, Chad, a country in the precertification phase, reported an outbreak in 2010 when10 cases were reported in 8 villages from 5 districts in 4 regions. In 2011, 10 additional cases were reported from 9 villages in 3 districts of 2 regions.

Investigations conducted in Chad did not reveal a definitive link between cases reported in 2010 and 2011; except the locality of Camp-Sara (1 case in 2011) which is a section of Matassi village (1 case in 2010), none of the remaining 8 localities that reported cases in 2011 had reported a case in 2010. None of the 20 cases reported in 2010 and 2011 had a history of travel out of Chad.

Of the 20 cases reported in 2010 and 2011, specimens from 6 cases and 10 cases respectively were confirmed positive for Dracunculus medinensis by the WHO Collaborating Centre for Research, Training and Eradication of Dracunculiasis at the US Centers for Disease Control and Prevention (CDC) by parasitological examination and/or molecular testing.

By the end of 2011, a total of 192 countries and territories representing 180 WHO Member States were certified free of dracunculiasis. Fourteen countries remain to be certified, of which 4 countries (Angola, Democratic Republic of the Congo, Somalia and South Africa) have no recent history of dracunculiasis. The 10 other countries are either endemic-Ethiopia, Mali, and South Sudan or in pre certification phase -Chad, Côte d’Ivoire, Ghana, Kenya, Nigeria, Niger, and Sudan

Online atlas on Dracunculiasis Eradication

This atlas shows the certification status of dracunculiasis eradication and the epidemiological status of the 20 countries considered endemic during the 1980s.

• Global figures
• Chad
• Ethiopia
• Mali
• South Sudan

The last stage of the programme is the most difficult; it requires more concentrated and focused efforts on surveillance, not only in endemic areas but also in areas free of transmission but at risk of importation from endemic areas.