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Peter Atem - One of the best experts on this subject based on the ideXlab platform.

  • not every worm wrapped around a stick is a guinea worm a case of onchocerca volvulus mimicking Dracunculus medinensis
    Parasites & Vectors, 2015
    Co-Authors: E N Mbong, Gerald Etapelong Sume, Flaubert Danbe, Andre Arsene Bita Fouda, Peter Atem
    Abstract:

    Background Despite being certified guinea worm free in 2007, Cameroon continues surveillance efforts to ensure rapid verification of any suspected reoccurrence. This includes the investigation of every rumor and confirmation of each suspicious expulsed worm. This paper presents fieldwork carried out to investigate a guinea worm rumor in Cameroon which turned out to be an Onchocerca volvulus mimicking Dracunculus medinensis.

  • Not every worm wrapped around a stick is a guinea worm: a case of Onchocerca volvulus mimicking Dracunculus medinensis
    Parasites & Vectors, 2015
    Co-Authors: E N Mbong, Gerald Etapelong Sume, Flaubert Danbe, Andre Arsene Bita Fouda, Peter Atem
    Abstract:

    Background Despite being certified guinea worm free in 2007, Cameroon continues surveillance efforts to ensure rapid verification of any suspected reoccurrence. This includes the investigation of every rumor and confirmation of each suspicious expulsed worm. This paper presents fieldwork carried out to investigate a guinea worm rumor in Cameroon which turned out to be an Onchocerca volvulus mimicking Dracunculus medinensis . Methods The investigation included a field visit to the subsistence farming community where the rumor was reported. During the visit, interviews were conducted with health staff who managed the case and the elderly farmer from whom the worm was retrieved. An investigation of any potential missed guinea worm cases was also conducted through interviews with community residents and reviews of the health facility’s medical records. This was combined with laboratory analyses of water samples from the community’s water sources and the retrieved worm which was removed from the patient via wrapping it around a stick. Results Microscopy and molecular analyses of the retrieved worm revealed a female Onchocerca volvulus whose expulsion strongly mimicked guinea worm. In addition to presenting findings of our investigation, this paper discusses distinguishing elements between the two parasites and gives an overview of guinea worm eradication efforts in Cameroon as well as current challenges to the worm’s eradication globally. Conclusions The investigation findings suggest the evolving Onchocerca volvulu s worm tropisms’ adaptive survival behavior worth further investigation. Strategies used to successfully control guinea worm in Cameroon could be adapted for Onchocerca volvulus control.

Mark L Eberhard - One of the best experts on this subject based on the ideXlab platform.

  • A search for tiny dragons (Dracunculus medinensis third-stage larvae) in aquatic animals in Chad, Africa
    Scientific Reports, 2019
    Co-Authors: Christopher A Cleveland, Mark L Eberhard, Hubert Zirimwabagabo, Alec T. Thompson, Kayla B. Garrett, Liandrie Swanepoel, Tchonfienet Moundai, Philippe T. Ouakou, Ernesto Ruiz-tiben, Michael J Yabsley
    Abstract:

    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. Since 2012, an increase in GW infections in domestic dogs, cats and baboons has been reported. Because these infections have not followed classical GW epidemiological patterns resulting from water-borne transmission, it has been hypothesized that transmission occurs via a paratenic host. Thus, we investigated the potential of aquatic animals to serve as paratenic hosts for D . medinensis in Chad, Africa. During three rainy and two dry season trips we detected no GW larvae in 234 fish, two reptiles and two turtles; however, seven GW larvae were recovered from 4 (1.4%) of 276 adult frogs. These data suggest GW infections may occur from ingestion of frogs but the importance of this route is unknown. Additional studies are needed, especially for other possible routes (e.g., ingestion of fish intestines that were recently shown to be a risk). Significantly, 150 years after the life cycle of D . medinensis was described, our data highlights important gaps in the knowledge of GW ecology.

  • Possible Role of Fish as Transport Hosts for Dracunculus spp. Larvae.
    Emerging Infectious Diseases, 2017
    Co-Authors: Christopher A Cleveland, Mark L Eberhard, Hubert Zirimwabagabo, Robert B Bringolf, Alec T. Thompson, Stephen J. Smith, Michael J Yabsley
    Abstract:

    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.

  • guinea worm Dracunculus medinensis infection in a wild caught frog chad
    Emerging Infectious Diseases, 2016
    Co-Authors: Mark L Eberhard, Christopher A Cleveland, Hubert Zirimwabagabo, Michael J Yabsley, Philippe Tchindebet Ouakou, Ernesto Ruiztiben
    Abstract:

    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.

  • possible role of fish and frogs as paratenic hosts of Dracunculus medinensis chad
    Emerging Infectious Diseases, 2016
    Co-Authors: Mark L Eberhard, Christopher A Cleveland, Hubert Zirimwabagabo, Michael J Yabsley, Henry S Bishop, John C Maerz, Robert B Bringolf, Ernesto Ruiztiben
    Abstract:

    : 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. Two ferrets (Mustela putorius furo) were fed fish or tadpoles that had been exposed to infected copepods. Only the ferret fed tadpoles harbored developing Dracunculus larvae at necropsy 70-80 days postexposure. These observations confirm that D. medinensis, like other species in the genus Dracunculus, can readily survive and remain infective in potential paratenic hosts, especially tadpoles.

  • Thirty-Seven Human Cases of Sparganosis from Ethiopia and South Sudan Caused by Spirometra Spp.
    American Journal of Tropical Medicine and Hygiene, 2015
    Co-Authors: Mark L Eberhard, Elizabeth A Thiele, Gole E. Yembo, Makoy S. Yibi, Vitaliano Cama, Ernesto Ruiz-tiben
    Abstract:

    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. Age of cases ranged between 7 and 70 years (mean 25 years); 21 (57%) patients were male and 16 were female. The presence of spargana in open skin lesions is somewhat atypical, but does confirm the fact that populations living in these remote areas are either ingesting infected copepods in unsafe drinking water or, more likely, eating poorly cooked paratenic hosts harboring the parasite.

Michael J Yabsley - One of the best experts on this subject based on the ideXlab platform.

  • Dogs and the classic route of Guinea Worm transmission: an evaluation of copepod ingestion
    Scientific Reports, 2020
    Co-Authors: Kayla B. Garrett, Christopher A Cleveland, Ania A. Majewska, Michael J Yabsley
    Abstract:

    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.

  • A search for tiny dragons (Dracunculus medinensis third-stage larvae) in aquatic animals in Chad, Africa
    Scientific Reports, 2019
    Co-Authors: Christopher A Cleveland, Mark L Eberhard, Hubert Zirimwabagabo, Alec T. Thompson, Kayla B. Garrett, Liandrie Swanepoel, Tchonfienet Moundai, Philippe T. Ouakou, Ernesto Ruiz-tiben, Michael J Yabsley
    Abstract:

    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. Since 2012, an increase in GW infections in domestic dogs, cats and baboons has been reported. Because these infections have not followed classical GW epidemiological patterns resulting from water-borne transmission, it has been hypothesized that transmission occurs via a paratenic host. Thus, we investigated the potential of aquatic animals to serve as paratenic hosts for D . medinensis in Chad, Africa. During three rainy and two dry season trips we detected no GW larvae in 234 fish, two reptiles and two turtles; however, seven GW larvae were recovered from 4 (1.4%) of 276 adult frogs. These data suggest GW infections may occur from ingestion of frogs but the importance of this route is unknown. Additional studies are needed, especially for other possible routes (e.g., ingestion of fish intestines that were recently shown to be a risk). Significantly, 150 years after the life cycle of D . medinensis was described, our data highlights important gaps in the knowledge of GW ecology.

  • Possible Role of Fish as Transport Hosts for Dracunculus spp. Larvae.
    Emerging Infectious Diseases, 2017
    Co-Authors: Christopher A Cleveland, Mark L Eberhard, Hubert Zirimwabagabo, Robert B Bringolf, Alec T. Thompson, Stephen J. Smith, Michael J Yabsley
    Abstract:

    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.

  • guinea worm Dracunculus medinensis infection in a wild caught frog chad
    Emerging Infectious Diseases, 2016
    Co-Authors: Mark L Eberhard, Christopher A Cleveland, Hubert Zirimwabagabo, Michael J Yabsley, Philippe Tchindebet Ouakou, Ernesto Ruiztiben
    Abstract:

    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.

  • possible role of fish and frogs as paratenic hosts of Dracunculus medinensis chad
    Emerging Infectious Diseases, 2016
    Co-Authors: Mark L Eberhard, Christopher A Cleveland, Hubert Zirimwabagabo, Michael J Yabsley, Henry S Bishop, John C Maerz, Robert B Bringolf, Ernesto Ruiztiben
    Abstract:

    : 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. Two ferrets (Mustela putorius furo) were fed fish or tadpoles that had been exposed to infected copepods. Only the ferret fed tadpoles harbored developing Dracunculus larvae at necropsy 70-80 days postexposure. These observations confirm that D. medinensis, like other species in the genus Dracunculus, can readily survive and remain infective in potential paratenic hosts, especially tadpoles.

E N Mbong - One of the best experts on this subject based on the ideXlab platform.

  • not every worm wrapped around a stick is a guinea worm a case of onchocerca volvulus mimicking Dracunculus medinensis
    Parasites & Vectors, 2015
    Co-Authors: E N Mbong, Gerald Etapelong Sume, Flaubert Danbe, Andre Arsene Bita Fouda, Peter Atem
    Abstract:

    Background Despite being certified guinea worm free in 2007, Cameroon continues surveillance efforts to ensure rapid verification of any suspected reoccurrence. This includes the investigation of every rumor and confirmation of each suspicious expulsed worm. This paper presents fieldwork carried out to investigate a guinea worm rumor in Cameroon which turned out to be an Onchocerca volvulus mimicking Dracunculus medinensis.

  • Not every worm wrapped around a stick is a guinea worm: a case of Onchocerca volvulus mimicking Dracunculus medinensis
    Parasites & Vectors, 2015
    Co-Authors: E N Mbong, Gerald Etapelong Sume, Flaubert Danbe, Andre Arsene Bita Fouda, Peter Atem
    Abstract:

    Background Despite being certified guinea worm free in 2007, Cameroon continues surveillance efforts to ensure rapid verification of any suspected reoccurrence. This includes the investigation of every rumor and confirmation of each suspicious expulsed worm. This paper presents fieldwork carried out to investigate a guinea worm rumor in Cameroon which turned out to be an Onchocerca volvulus mimicking Dracunculus medinensis . Methods The investigation included a field visit to the subsistence farming community where the rumor was reported. During the visit, interviews were conducted with health staff who managed the case and the elderly farmer from whom the worm was retrieved. An investigation of any potential missed guinea worm cases was also conducted through interviews with community residents and reviews of the health facility’s medical records. This was combined with laboratory analyses of water samples from the community’s water sources and the retrieved worm which was removed from the patient via wrapping it around a stick. Results Microscopy and molecular analyses of the retrieved worm revealed a female Onchocerca volvulus whose expulsion strongly mimicked guinea worm. In addition to presenting findings of our investigation, this paper discusses distinguishing elements between the two parasites and gives an overview of guinea worm eradication efforts in Cameroon as well as current challenges to the worm’s eradication globally. Conclusions The investigation findings suggest the evolving Onchocerca volvulu s worm tropisms’ adaptive survival behavior worth further investigation. Strategies used to successfully control guinea worm in Cameroon could be adapted for Onchocerca volvulus control.

James Zingeser - One of the best experts on this subject based on the ideXlab platform.

  • ecology of domestic dogs canis familiaris as an emerging reservoir of guinea worm Dracunculus medinensis infection
    PLOS Neglected Tropical Diseases, 2020
    Co-Authors: Robbie A Mcdonald, Tchonfienet Moundai, Dieudonné P. Sankara, Gautam Biswas, Jared K Wilsonaggarwal, George J F Swan, Cecily E D Goodwin, James Zingeser
    Abstract:

    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.

  • ecology of domestic dogs canis familiaris as an emerging reservoir of guinea worm Dracunculus medinensis infection
    bioRxiv, 2020
    Co-Authors: Robbie A Mcdonald, Tchonfienet Moundai, Dieudonné P. Sankara, Gautam Biswas, Jared K Wilsonaggarwal, George J F Swan, Cecily E D Goodwin, James Zingeser
    Abstract:

    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