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BMJ Open Aug 2021To quantify conflict events and access across countries that remain to be certified free of transmission of (Guinea worm disease) or require postcertification...
OBJECTIVES
To quantify conflict events and access across countries that remain to be certified free of transmission of (Guinea worm disease) or require postcertification surveillance as part of the Guinea Worm Eradication Programme (GWEP).
SETTING AND PARTICIPANTS
Populations living in Guinea worm affected areas across seven precertification countries and 13 postcertification sub-Saharan African countries.
OUTCOME MEASURES
The number of conflict events and rates per 100 000 population, the main types of conflict and actors reported to be responsible for events were summarised and mapped across all countries. Chad and Mali were presented as case studies. Guinea worm information was based on GWEP reports. Conflict data were obtained from the Armed Conflict Location and Event Data Project. Maps were created using ArcGIS V.10.7 and access was measured as regional distance and time to cities.
RESULTS
More than 980 000 conflict events were reported between 2000 and 2020, with a significant increase since 2018. The highest number and rates were reported in precertification Mali (n=2556; 13.0 per 100 000), South Sudan (n=2143; 19.4), Democratic Republic of Congo (n=7016; 8.1) and postcertification Nigeria (n=6903; 3.4), Central Africa Republic (n=1251; 26.4), Burkina Faso (n=2004; 9.7). Violence against civilians, protests and battles were most frequently reported with several different actors involved including Unidentified Armed Groups and Boko Haram. Chad and Mali had contracting epidemiological and conflict situations with affected regions up to 700 km from the capital or 10 hours to the nearest city.
CONCLUSIONS
Understanding the spatial-temporal patterns of conflict events, identifying hotspots, the actors responsible and their sphere of influence is critical for the GWEP and other public health programmes to develop practical risk assessments, deliver essential health interventions, implement innovative surveillance, determine certification and meet the goals of eradication.
Topics: Animals; Burkina Faso; Certification; Dracunculiasis; Dracunculus Nematode; Humans; Mali
PubMed: 34353803
DOI: 10.1136/bmjopen-2021-049732 -
MMWR. Morbidity and Mortality Weekly... Nov 2019Dracunculiasis (also known as Guinea worm disease) is caused by the parasite Dracunculus medinensis and is acquired by drinking water containing copepods (water fleas)...
Dracunculiasis (also known as Guinea worm disease) is caused by the parasite Dracunculus medinensis and is acquired by drinking water containing copepods (water fleas) infected with D. medinensis larvae. The worm typically emerges through the skin on a lower limb approximately 1 year after infection, resulting in pain and disability (1). There is no vaccine or medicine to treat the disease; eradication efforts rely on case containment* to prevent water contamination and other interventions to prevent infection, including health education, water filtration, chemical treatment of unsafe water with temephos (an organophosphate larvicide to kill copepods), and provision of safe drinking water (1,2). In 1986, with an estimated 3.5 million cases occurring each year in 20 African and Asian countries (3), the World Health Assembly called for dracunculiasis elimination (4). The global Guinea Worm Eradication Program (GWEP), led by The Carter Center and supported by the World Health Organization (WHO), CDC, the United Nations Children's Fund, and other partners, began assisting ministries of health in countries with dracunculiasis. This report, based on updated health ministry data, describes progress to eradicate dracunculiasis during January 2018-June 2019 and updates previous reports (2,4,5). With only five countries currently affected by dracunculiasis (Angola, Chad, Ethiopia, Mali, and South Sudan), achievement of eradication is within reach, but it is challenged by civil unrest, insecurity, and lingering epidemiologic and zoologic questions.
Topics: Disease Eradication; Dracunculiasis; Global Health; Humans
PubMed: 31671082
DOI: 10.15585/mmwr.mm6843a5 -
International Journal For Parasitology.... Dec 2023A new species of is described in wild neotropical otters, , occurring in Corrientes, Argentina, based on morphological and molecular characteristics. Worms were located...
A new species of is described in wild neotropical otters, , occurring in Corrientes, Argentina, based on morphological and molecular characteristics. Worms were located in the subcutaneous tissue from two of five investigated otters. n. sp. is differentiated from the 14 species of described from mammals and reptiles by the prominent dorsal and ventral papillae on the head; deirids posterior to nerve ring; male with long needlelike spicules and presence of gubernaculum; and long first stage larva. Phylogenetic analysis using the 18S rRNA positioned n. sp. in an anterior position to the rest of sequences available and COI positioned it in a separated clade sister to sequences. This is the first report on the presence of this nematode in in Argentina.
PubMed: 38045874
DOI: 10.1016/j.ijppaw.2023.11.002 -
Ghana Medical Journal Dec 2016
Topics: Animals; Disease Reservoirs; Dogs; Dracunculiasis; Dracunculus Nematode; Global Health; Humans; Neglected Diseases; Zoonoses
PubMed: 28579624
DOI: 10.4314/gmj.v50i4.1 -
Journal of Infection in Developing... Aug 2022Guinea worm disease is caused by Dracunculus medinensis. Transmission of the disease depends on vectors (copepods). Abate applications in targeted water sources to...
INTRODUCTION
Guinea worm disease is caused by Dracunculus medinensis. Transmission of the disease depends on vectors (copepods). Abate applications in targeted water sources to control copepod is the main intervention. The aim of this study was to assess vector control practice in the guinea worm endemic region of Gambela, Ethiopia and to identify elimination gaps.
METHODOLOGY
Retrospective analysis of routine program data recorded from 2016 to 2020 was performed. Pre-and post-copepod test is conducted on water ponds to determine the density of copepods. Based on the copepod density, the chemical is applied accordingly. The five years data was obtained from Ethiopian public health institute electronic database with permission.
RESULTS
A total of 22,131 water ponds were treated during the past five years. Out of the total treated in 2020, 4,669/7,266 (64%) were found with > 9 Copepods during pre-copepod test. 130/7,266 (1.79%) of water ponds which were post-tested after Abate application failed the requirement of scoring ≤ 9 copepods. Of the 130 water ponds, 115 (88.5%) were observed during the transmission season (April to November). Abate application trend had increased by 28.9% during the 5 years period. According to the database, some of the largest water sources found in infection reporting villages missed their 28 days regular treatment schedule.
CONCLUSIONS
A single water source that has not been treated effectively could be a source of infection for both humans and animals. The practice of Abate application should be enhanced and monitored regularly. The documenting system should be improved for quality, timely information and action.
Topics: Animals; Dracunculus Nematode; Ethiopia; Humans; Retrospective Studies; Temefos; Water
PubMed: 36156498
DOI: 10.3855/jidc.15972 -
PLoS Neglected Tropical Diseases Apr 2020Global eradication of human Guinea worm disease (dracunculiasis) has been set back by the emergence of infections in animals, particularly domestic dogs Canis...
Global eradication of human Guinea worm disease (dracunculiasis) has been set back by the emergence of infections in animals, particularly domestic dogs Canis familiaris. The ecology and epidemiology of this reservoir is unknown. We tracked dogs using GPS, inferred diets using stable isotope analysis and analysed correlates of infection in Chad, where numbers of Guinea worm infections are greatest. Dogs had small ranges that varied markedly among villages. Diets consisted largely of human staples and human faeces. A minority of ponds, mostly <200 m from dog-owning households, accounted for most dog exposure to potentially unsafe water. The risk of a dog having had Guinea worm was reduced in dogs living in households providing water for animals but increased with increasing fish consumption by dogs. Provision of safe water might reduce dog exposure to unsafe water, while prioritisation of proactive temephos (Abate) application to the small number of ponds to which dogs have most access is recommended. Fish might have an additional role as transport hosts for Guinea worm, by concentrating copepods infected with worm larvae.
Topics: Animals; Chad; Diet; Disease Reservoirs; Dog Diseases; Dogs; Dracunculiasis; Dracunculus Nematode; Ecology; Family Characteristics; Feces; Female; Fishes; Humans; Water
PubMed: 32310976
DOI: 10.1371/journal.pntd.0008170 -
MMWR. Morbidity and Mortality Weekly... Oct 2015Dracunculiasis (Guinea worm disease) is caused by Dracunculus medinensis, a parasitic worm. Approximately 1 year after a person acquires infection from contaminated...
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. The campaign to eradicate dracunculiasis worldwide began in 1980 at CDC. In 1986, the World Health Assembly called for dracunculiasis elimination, and the global Guinea Worm Eradication Program, led by the Carter Center and supported by the World Health Organization (WHO), United Nations Children's Fund (UNICEF), CDC, and other partners, began assisting ministries of health in countries where dracunculiasis was endemic. In 1986, an estimated 3.5 million cases occurred each year in 20 countries in Africa and Asia. Since then, although the goal of eradicating dracunculiasis has not been achieved, considerable progress has been made. Compared with the 1986 estimate, the annual number of reported cases in 2015 has been reduced by 99% and cases are confined to four endemic countries. This report updates published and unpublished surveillance data reported by ministries of health and describes progress toward dracunculiasis eradication from January 2014 through June 2015. During 2014, a total of 126 cases were reported from four countries (Chad [13 cases], Ethiopia [three], Mali [40], and South Sudan [70]), compared with 148 cases reported in 2013, from the same four countries. The overall 15% reduction in cases during 2013–2014 was less than that experienced in recent years, but the rate of decline increased again to 70% in the first 6 months of 2015 compared with the same period during 2014. Continued active surveillance with aggressive detection and appropriate management of cases are essential program components; however, epidemiologic challenges and civil unrest and insecurity pose potential barriers to eradication.
Topics: Disease Eradication; Dracunculiasis; Global Health; Humans
PubMed: 26492134
DOI: 10.15585/mmwr.mm6441a1 -
PLoS Neglected Tropical Diseases Jul 2021Guinea worm (Dracunculus medinensis) was detected in Chad in 2010 after a supposed ten-year absence, posing a challenge to the global eradication effort. Initiation of a...
BACKGROUND
Guinea worm (Dracunculus medinensis) was detected in Chad in 2010 after a supposed ten-year absence, posing a challenge to the global eradication effort. Initiation of a village-based surveillance system in 2012 revealed a substantial number of dogs infected with Guinea worm, raising questions about paratenic hosts and cross-species transmission.
METHODOLOGY/PRINCIPAL FINDINGS
We coupled genomic and surveillance case data from 2012-2018 to investigate the modes of transmission between dog and human hosts and the geographic connectivity of worms. Eighty-six variants across four genes in the mitochondrial genome identified 41 genetically distinct worm genotypes. Spatiotemporal modeling revealed worms with the same genotype ('genetically identical') were within a median range of 18.6 kilometers of each other, but largely within approximately 50 kilometers. Genetically identical worms varied in their degree of spatial clustering, suggesting there may be different factors that favor or constrain transmission. Each worm was surrounded by five to ten genetically distinct worms within a 50 kilometer radius. As expected, we observed a change in the genetic similarity distribution between pairs of worms using variants across the complete mitochondrial genome in an independent population.
CONCLUSIONS/SIGNIFICANCE
In the largest study linking genetic and surveillance data to date of Guinea worm cases in Chad, we show genetic identity and modeling can facilitate the understanding of local transmission. The co-occurrence of genetically non-identical worms in quantitatively identified transmission ranges highlights the necessity for genomic tools to link cases. The improved discrimination between pairs of worms from variants identified across the complete mitochondrial genome suggests that expanding the number of genomic markers could link cases at a finer scale. These results suggest that scaling up genomic surveillance for Guinea worm may provide additional value for programmatic decision-making critical for monitoring cases and intervention efficacy to achieve elimination.
Topics: Animals; Chad; DNA, Helminth; Dracunculiasis; Dracunculus Nematode; Genetic Markers; Genome, Helminth; Genome, Mitochondrial; Humans; Population Surveillance
PubMed: 34310598
DOI: 10.1371/journal.pntd.0009609 -
Emerging Infectious Diseases Sep 2017To inform Dracunculus medinensis (Guinea worm) eradication efforts, we evaluated the role of fish as transport hosts for Dracunculus worms. Ferrets fed fish that had...
To inform Dracunculus medinensis (Guinea worm) eradication efforts, we evaluated the role of fish as transport hosts for Dracunculus worms. Ferrets fed fish that had ingested infected copepods became infected, highlighting the importance of recommendations to cook fish, bury entrails, and prevent dogs from consuming raw fish and entrails.
Topics: Animals; Chad; Copepoda; Dog Diseases; Dogs; Dracunculiasis; Dracunculus Nematode; Ferrets; Fish Diseases; Fishes; Food Chain; Host Specificity; Humans; Larva
PubMed: 28820381
DOI: 10.3201/eid2309.161931 -
Scientific Reports Jan 2020Dracunculus medinensis, the causative agent of Guinea worm disease in humans, is being reported with increasing frequency in dogs. However, the route(s) of transmission...
Dracunculus medinensis, the causative agent of Guinea worm disease in humans, is being reported with increasing frequency in dogs. However, the route(s) of transmission to dogs is still poorly understood. Classical transmission to humans occurs via drinking water that contains cyclopoid copepods infected with third stage larvae of D. medinensis, but due to the method of dog drinking (lapping) compared to humans (suction and/or retrieval of water into containers), it seems unlikely that dogs would ingest copepods readily through drinking. We exposed lab raised beagles to varying densities of uninfected copepods in 2 liters of water to evaluate the number of copepods ingested during a drinking event. We confirmed dogs can ingest copepod intermediate hosts while drinking; however, low numbers were ingested at the densities that are typically observed in Chad suggesting this transmission route may be unlikely. Overall, the relative importance of the classic transmission route and alternate transmission routes, such as paratenic and transport hosts, needs investigation in order to further clarify the epidemiology of guinea worm infections in dogs.
Topics: Animals; Chad; Communicable Disease Control; Copepoda; Disease Vectors; Dogs; Dracunculiasis; Dracunculus Nematode; Eating; Female; Humans; Male
PubMed: 31996759
DOI: 10.1038/s41598-020-58191-4