Epidemiological and molecular investigations of a point-source outbreak of Dracunculus medinensis infecting humans and dogs in Chad: a cross-sectional study.

Background: Dracunculiasis (also known as Guinea worm disease), caused by the Dracunculus medinensis nematode, is progressing towards eradication, with a reduction in cases from 3·5 million cases in the mid-1980s to only 54 human cases at the end of 2019. Most cases now occur in Chad. On April 19, 2019, a 19-year-old woman presented with D medinensis in an area within the Salamat region of Chad, where the disease had not been previously reported.

Surveillance of Human Guinea Worm in Chad, 2010-2018.

The total number of Guinea worm cases has been reduced by 99.9% since the mid-1980s when the eradication campaign began. Today, the greatest number of cases is reported from Chad.

Correlates of Variation in Guinea Worm Burden among Infected Domestic Dogs.

The Guinea Worm Eradication Program has been extraordinarily successful-in 2019, there were 53 human cases reported, down from the estimated 3.5 million in 1986. Yet the occurrence of Guinea worm in dogs is a challenge to eradication efforts, and underlying questions about transmission dynamics remain.

Investigation of Dracunculiasis Transmission among Humans, Chad, 2013-2017.

Dracunculiasis, slated for global eradication, typically is acquired by drinking stagnant water containing microscopic crustaceans (copepods) infected with Dracunculus medinensis larvae, causing clusters of case persons with worms emerging from the skin. Following a 10-year absence of reported cases, 9-26 sporadic human cases with few epidemiologic links have been reported annually in Chad since 2010; dog infections have also been reported since 2012. We conducted an investigation of human cases in Chad to identify risk factors.

Population genomic evidence that human and animal infections in Africa come from the same populations of Dracunculus medinensis.

Background: Guinea worm-Dracunculus medinensis-was historically one of the major parasites of humans and has been known since antiquity. Now, Guinea worm is on the brink of eradication, as efforts to interrupt transmission have reduced the annual burden of disease from millions of infections per year in the 1980s to only 54 human cases reported globally in 2019. Despite the enormous success of eradication efforts to date, one complication has arisen.

Identifying correlates of Guinea worm (Dracunculus medinensis) infection in domestic dog populations.

Few human infectious diseases have been driven as close to eradication as dracunculiasis, caused by the Guinea worm parasite (Dracunculus medinensis). The number of human cases of Guinea worm decreased from an estimated 3.5 million in 1986 to mere hundreds by the 2010s.

Agent-Based Simulation for Seasonal Guinea Worm Disease in Chad Dogs.

The campaign to eradicate dracunculiasis (Guinea worm [GW] disease) and its causative pathogen (GW) in Chad is challenged by infections in domestic dogs, which far outnumber the dwindling number of human infections. We present an agent-based simulation that models transmission of GW between a shared water source and a large population of dogs. The simulation incorporates various potential factors driving the infections including external factors and two currently used interventions, namely, tethering and larvicide water treatments.

Guinea worm in domestic dogs in Chad: A description and analysis of surveillance data.

After a ten-year absence of reported Guinea worm disease in Chad, human cases were rediscovered in 2010, and canine cases were first recorded in 2012. In response, active surveillance for Guinea worm in both humans and animals was re-initiated in 2012. As of 2018, the Chad Guinea Worm Eradication Program (CGWEP) maintains an extensive surveillance system that operates in 1,895 villages, and collects information about worms, hosts (animals and humans), and animal owners.

A search for tiny dragons (Dracunculus medinensis third-stage larvae) in aquatic animals in Chad, Africa.

Dracunculus medinensis, or human Guinea worm (GW), causes a painful and debilitating infection. The global Guinea Worm Eradication Program (GWEP) has successfully reduced human GW cases from 3.5 million in 21 countries in 1986 to only 30 cases in three remaining countries in 2017.

Achieving the endgame: Integrated NTD case searches.

Trachoma and Guinea Worm Disease (GWD) are neglected tropical diseases (NTD) slated for elimination as a public health problem and eradication respectively by the World Health Organization. As these programs wind down, uncovering the last cases becomes an urgent priority. In 2010, Ghana Health Services, along with The Carter Center, Sightsavers, and other partners, conducted integrated case searches for both GWD and the last stage of trachoma disease, trachomatous trichiasis (TT), as well as providing surgical treatment for TT to meet elimination (and eradication targets).

Progress Toward Global Eradication of Dracunculiasis - January 2017-June 2018.

Dracunculiasis (Guinea worm disease), caused by the parasite Dracunculus medinensis, is acquired by drinking water containing copepods (water fleas) infected with its larvae. The worm typically emerges through the skin on a lower limb approximately 1 year after infection, causing pain and disability (1). The worldwide eradication campaign began at CDC in 1980.

Population genetic analysis of Chadian Guinea worms reveals that human and non-human hosts share common parasite populations.

Following almost 10 years of no reported cases, Guinea worm disease (GWD or dracunculiasis) reemerged in Chad in 2010 with peculiar epidemiological patterns and unprecedented prevalence of infection among non-human hosts, particularly domestic dogs. Since 2014, animal infections with Guinea worms have also been observed in the other three countries with endemic transmission (Ethiopia, Mali, and South Sudan), causing concern and generating interest in the parasites' true taxonomic identity and population genetics. We present the first extensive population genetic data for Guinea worm, investigating mitochondrial and microsatellite variation in adult female worms from both human and non-human hosts in the four endemic countries to elucidate the origins of Chad's current outbreak and possible host-specific differences between parasites.

Dracunculiasis Eradication: Are We There Yet?

This report summarizes the status of the global Dracunculiasis Eradication Program as of the end of 2017. Dracunculiasis (guinea worm disease) has been eliminated from 19 of 21 countries where it was endemic in 1986, when an estimated 3.5 million cases occurred worldwide.

What It Means to Be Guinea Worm Free: An Insider's Account from Ghana's Northern Region.

Despite several periods of stagnating guinea worm disease (GWD) incidence in Ghana during its national eradication campaign in the 1990s and early 2000s, the last reported case of GWD was in May 2010. In July 2011, Ghana celebrated the interruption of guinea worm (GW) transmission. Although it has been established that GWD causes disability, pain, and socioeconomic hardship, there is a dearth of population-based evidence collected in post-GW-endemic countries to document the value attributed to GWD eradication by residents in formerly endemic communities.

Progress Toward Global Eradication of Dracunculiasis, January 2016-June 2017.

Dracunculiasis (Guinea worm disease) is caused by Dracunculus medinensis, a parasitic worm. Approximately 1 year after a person acquires infection from contaminated drinking water, the worm emerges through the skin, usually on a lower limb (1). Pain and secondary bacterial infection can cause temporary or permanent disability that disrupts work and schooling.

The cost-effectiveness of an eradication programme in the end game: Evidence from guinea worm disease.

Background: Of the three diseases targeted for eradication by WHO, two are so-called Neglected Tropical Diseases (NTDs)-guinea worm disease (GWD) and yaws. The Guinea Worm Eradication Programme (GWEP) is in its final stages, with only 25 reported in 2016. However, global eradication still requires certification by WHO of the absence of transmission in all countries.

Recurrence of Guinea Worm Disease in Chad after a 10-Year Absence: Risk Factors for Human Cases Identified in 2010-2011.

A decade after reporting its last case of Guinea worm disease (GWD), a waterborne parasitic disease targeted for eradication, Chad reported 20 confirmed human cases from 17 villages-10 cases in 2010 and 10 cases in 2011. In 2012, the first GWD dog infections were diagnosed. We conducted a case-control study during April-May 2012 to identify human transmission risk factors and epidemiologic links.

Guinea Worm (Dracunculus medinensis) Infection in a Wild-Caught Frog, Chad.

A third-stage (infective) larva of Dracunculus medinensis, the causative agent of Guinea worm disease, was recovered from a wild-caught Phrynobatrachus francisci frog in Chad. Although green frogs (Lithobates clamitans) have been experimentally infected with D. medinensis worms, our findings prove that frogs can serve as natural paratenic hosts.

Progress Toward Global Eradication of Dracunculiasis -January 2015-June 2016.

Dracunculiasis (Guinea worm disease) is caused by Dracunculus medinensis, a parasitic worm. Approximately 1 year after a person acquires infection from drinking contaminated water, the worm emerges through the skin, usually on the leg. Pain and secondary bacterial infection can cause temporary or permanent disability that disrupts work and schooling.

Possible Role of Fish and Frogs as Paratenic Hosts of Dracunculus medinensis, Chad.

Copepods infected with Dracunculus medinensis larvae collected from infected dogs in Chad were fed to 2 species of fish and tadpoles. Although they readily ingested copepods, neither species of fish, Nile tilapia (Oreochromis niloticus) nor fathead minnow (Pimephalis promelas), were found to harbor Dracunculus larvae when examined 2-3 weeks later. Tadpoles ingested copepods much more slowly; however, upon examination at the same time interval, tadpoles of green frogs (Lithobates [Rana] clamitans) were found to harbor small numbers of Dracunculus larvae.

Progress Toward Global Eradication of Dracunculiasis, January 2014-June 2015.

Dracunculiasis (Guinea worm disease) is caused by Dracunculus medinensis, a parasitic worm. Approximately 1 year after a person acquires infection from contaminated drinking water, the worm emerges through the skin, usually on the lower limb. Pain and secondary bacterial infection can cause temporary or permanent disability that disrupts work and schooling.

Thirty-Seven Human Cases of Sparganosis from Ethiopia and South Sudan Caused by Spirometra Spp.

Thirty-seven unusual specimens, three from Ethiopia and 34 from South Sudan, were submitted since 2012 for further identification by the Ethiopian Dracunculiasis Eradication Program (EDEP) and the South Sudan Guinea Worm Eradication Program (SSGWEP), respectively. Although the majority of specimens emerged from sores or breaks in the skin, there was concern that they did not represent bona fide cases of Dracunculus medinensis and that they needed detailed examination and identification as provided by the World Health Organization Collaborating Center (WHO CC) at Centers for Disease Control and Prevention (CDC). All 37 specimens were identified on microscopic study as larval tapeworms of the spargana type, and DNA sequence analysis of seven confirmed the identification of Spirometra sp.

Progress toward global eradication of dracunculiasis--January 2013-June 2014.

Dracunculiasis (Guinea worm disease) is caused by Dracunculus medinensis, a parasitic worm. Approximately 1 year after a person acquires infection from contaminated drinking water, the worm will emerge through the skin, usually on the lower limb. Pain and secondary bacterial infection can cause temporary or permanent disability that disrupts work and schooling.

Logistics of Guinea worm disease eradication in South Sudan.

From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical-logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities.