-
Le Infezioni in Medicina 2023Dracunculiasis (Guinea Worm Disease) is a chronic disease that is primarily found in the arid and poor areas of our planet where water supply systems consist of open... (Review)
Review
Dracunculiasis (Guinea Worm Disease) is a chronic disease that is primarily found in the arid and poor areas of our planet where water supply systems consist of open wells. This parasitic disease is transmitted to humans not only through the consumption of water contaminated with crustaceans harbouring larvae of , but also through the ingestion of paratenic (frogs) or transport hosts (fish). The natural progression of the disease is caused by adult worms invading connective tissues, leading to blistering and ulceration of the extremities, approximately one year after infection. In 1986, the Guinea Worm Eradication Program (GWEP) was launched and since then, the incidence of the disease has been reduced by over 99%. Indeed, the most recent global report from 2022 shows only 13 cases of human dracunculiasis worldwide, the lowest annual incidence ever reported. The new found knowledge of potential animal reservoirs and the recent discovery of possible edible paratenic hosts could pose challenges to the future eradication of this debilitating disease. Therefore, attempts to eradicate this parasitosis should not be postponed. Intensive research is needed in this neglected area of medicine, now that the goal is within reach.
PubMed: 38075414
DOI: 10.53854/liim-3104-9 -
Protein Science : a Publication of the... Sep 2023Nicotinic acetylcholine receptors (N-AChRs) mediate fast synaptic signaling and are members of the pentameric ligand-gated ion channel (pLGIC) family. They rely on a...
Nicotinic acetylcholine receptors (N-AChRs) mediate fast synaptic signaling and are members of the pentameric ligand-gated ion channel (pLGIC) family. They rely on a network of accessory proteins in vivo for correct formation and transport to the cell surface. Resistance to cholinesterase 3 (RIC-3) is an endoplasmic reticulum protein that physically interacts with nascent pLGIC subunits and promotes their oligomerization. It is not known why some N-AChRs require RIC-3 in heterologous expression systems, whereas others do not. Previously we reported that the ACR-16 N-AChR from the parasitic nematode Dracunculus medinensis does not require RIC-3 in Xenopus laevis oocytes. This is unusual because all other nematode ACR-16, like the closely related Ascaris suum ACR-16, require RIC-3. Their high sequence similarity limits the number of amino acids that may be responsible, and the goal of this study was to identify them. A series of chimeras and point mutations between A. suum and D. medinensis ACR-16, followed by functional characterization with electrophysiology, identified two residues that account for a majority of the receptor requirement for RIC-3. ACR-16 with R/K159 in the cys-loop and I504 in the C-terminal tail did not require RIC-3 for functional expression. Mutating either of these to R/K159E or I504T, residues found in other nematode ACR-16, conferred a RIC-3 requirement. Our results agree with previous studies showing that these regions interact and are involved in receptor synthesis. Although it is currently unclear what precise mechanism they regulate, these residues may be critical during specific subunit folding and/or assembly cascades that RIC-3 may promote.
Topics: Receptors, Nicotinic; Cholinesterases; Cell Membrane; Endoplasmic Reticulum
PubMed: 37417463
DOI: 10.1002/pro.4718 -
MMWR. Morbidity and Mortality Weekly... Nov 2023The effort to eradicate Dracunculus medinensis, the etiologic agent of dracunculiasis, or Guinea worm disease, commenced at CDC in 1980. In 1986, with an estimated 3.5...
The effort to eradicate Dracunculus medinensis, the etiologic agent of dracunculiasis, or Guinea worm disease, commenced at CDC in 1980. In 1986, with an estimated 3.5 million cases worldwide in 20 African and Asian countries, the World Health Assembly called for dracunculiasis elimination. The Guinea Worm Eradication Program (GWEP) was established to help countries with endemic dracunculiasis reach this goal. GWEP is led by The Carter Center and supported by partners that include the World Health Organization, UNICEF, and CDC. In 2012, D. medinensis infections were unexpectedly confirmed in Chadian dogs, and since then, infections in dogs, cats, and baboons have posed a new challenge for GWEP, as have ongoing civil unrest and insecurity in some areas. By 2022, dracunculiasis was endemic in five countries (Angola, Chad, Ethiopia, Mali, and South Sudan), with only 13 human cases identified, the lowest yearly total ever reported. Animal infections, however, were not declining at the same rate: 686 animal infections were reported in 2022, including 606 (88%) in dogs in Chad. Despite these unanticipated challenges as well as the COVID-19 pandemic, countries appear close to reaching the eradication goal. GWEP will continue working with country programs to address animal infections, civil unrest, and insecurity, that challenge the eradication of Guinea worm.
Topics: Humans; Animals; Dogs; Disease Eradication; Dracunculiasis; Pandemics; Global Health; World Health Organization
PubMed: 37943706
DOI: 10.15585/mmwr.mm7245a4 -
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 -
International Journal of Molecular... Sep 2023Among the plants that exhibit significant or established pharmacological activity, the genus L. deserves special attention. This genus comprises over 500 species...
Among the plants that exhibit significant or established pharmacological activity, the genus L. deserves special attention. This genus comprises over 500 species belonging to the largest family. Our study aimed at providing a comprehensive evaluation of the phytochemical composition of the ethanol extracts of five different L. species (collected from the southwest of the Russian Federation) and their antimicrobial and nematocide activity as follows: cv. Novichok., cv. Smaragd, cv. Citral, cv. Euxin, and cv. Tavrida. The study of the ethanol extracts of the five different L. species using the methods of gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-MS/MS) allowed establishing their phytochemical profile. The obtained data on the of five different L. species ethanol extracts' phytochemical composition were used to predict the antibacterial and antifungal activity against phytopathogenic microorganisms and nematocidal activity against the free-living soil nematode . The major compounds found in the composition of the L. ethanol extracts were monoterpenes, sesquiterpenes, flavonoids, flavonoid glycosides, coumarins, and phenolic acids. The antibacterial and antifungal activity of the extracts began to manifest at a concentration of 150 µg/mL. The cv. Smaragd extract had a selective effect against Gram-positive and bacteria, whereas the cv. Tavrida extract had a selective effect against Gram-negative and bacteria and , and fungi. The cv. Novichok, cv. Smaragd, and cv. Citral extracts in the concentration range of 31.3-1000 µg/mL caused the death of nematodes. It was established that cv. Novichok affects the UNC-63 protein, the molecular target of which is the nicotine receptor of the N-subtype.
Topics: Animals; Ethanol; Antifungal Agents; Artemisia; Tandem Mass Spectrometry; Anti-Infective Agents; Anti-Bacterial Agents; Antinematodal Agents; Araceae; Caenorhabditis elegans; Flavonoids; Plant Extracts
PubMed: 37762675
DOI: 10.3390/ijms241814372 -
Parasitology Research Dec 2023Nematode species of the genus Dracunculus (Spirurida: Dracunculoidea) infect tissues and body cavities of reptiles, domestic and wild carnivores, and humans. The...
Nematode species of the genus Dracunculus (Spirurida: Dracunculoidea) infect tissues and body cavities of reptiles, domestic and wild carnivores, and humans. The definitive hosts acquire the infection by ingesting intermediate (i.e., cyclopoid copepod) or paratenic (i.e., amphibians and fishes) hosts. Here we report the jaguar (Panthera onca) as a potential new host for Dracunculus sp. The nematode was collected from an ulcerated cutaneous nodule on the left anterior limb of a female jaguar in the municipality of Miranda, Mato Grosso do Sul state, Brazil. Based on the morphology of first stage larvae collected from a small fragment of the uterus of the adult nematode, the species was identified as Dracunculus sp. Reichard, 1759. Additionally, the morphological identification was molecularly confirmed by sequencing the cox1 gene. This report advocates for further investigations into the transmission cycle of this parasite in the Brazilian Pantanal wetland, considering the role of wildlife hosts and the zoonotic potential of Dracunculus species in that area.
Topics: Animals; Humans; Female; Panthera; Animals, Wild; Dracunculus Nematode; Dracunculoidea; Fishes; Brazil
PubMed: 37823992
DOI: 10.1007/s00436-023-07984-3 -
Chemistry & Biodiversity Jun 2024For decades, guinea worm disease, caused by the parasitic worm Dracunculus medinensis, has been a major public health concern, impacting vulnerable populations in Africa...
For decades, guinea worm disease, caused by the parasitic worm Dracunculus medinensis, has been a major public health concern, impacting vulnerable populations in Africa and Asia. This review gives an in-depth examination of the various therapeutic approaches used to combat guinea worm disease. This study seeks to provide a current and evidence-based summary of available treatment techniques by conducting an exhaustive examination of peer-reviewed literature, medical databases, and official health organisation publications. The current review intends to contribute to the knowledge base and influence plans for guinea worm disease control and eradication by critically evaluating the success and obstacles associated with various treatment approaches through standard heterocyclic medications, herbal sources, phytochemicals, and nanomedicines. The importance of integrating community engagement and collaboration among national and international stakeholders is emphasised to foster sustainable solutions and ensure a collective effort towards a guinea worm-free world.
PubMed: 38877685
DOI: 10.1002/cbdv.202400592 -
International Journal For Parasitology.... Apr 2024The genus contains numerous species of subcutaneous parasites of mammals and reptiles. In North America, there are at least three mammal-infecting species of . Reports...
The genus contains numerous species of subcutaneous parasites of mammals and reptiles. In North America, there are at least three mammal-infecting species of . Reports of infections have been reported from river otters () since the early 1900s; however, little is known about the species infecting otters or their ecology. Most reports of do not have a definitive species identified because females, the most common sex found due to their larger size and location in the extremities of the host, lack distinguishing morphological characteristics, and few studies have used molecular methods to confirm identifications. Thus, outside of Ontario, Canada, where both and have been confirmed in otters, the species of in river otters is unknown. In the current study, molecular characterization of nematodes from river otters revealed a high diversity of species. In addition to confirming infections, two new clades were detected. One clade was a novel species in any host and the other was a clade previously detected in Virginia opossums () from the USA and a domestic dog from Spain. No infections with were detected and neither new lineage was genetically similar to , which was recently described from a neotropical otter () from Argentina. These data also indicate that spp. infections in otters are widespread throughout Eastern North America. Currently the life cycles for most of the spp. infecting otters are unknown. Studies on the diversity, life cycle, and natural history of Dracunculidae parasites in wildlife are important because the related parasite, (human Guinea worm) is the subject of an international eradication campaign and there are increasing reports of these parasites in new geographic locations and new hosts, including new species in humans and domestic dogs.
PubMed: 38516639
DOI: 10.1016/j.ijppaw.2024.100922 -
The American Journal of Tropical... May 2024Chad has seen a considerable reduction in cases of Guinea worm disease (or dracunculiasis) in domestic dogs in recent years. Tethering of dogs and application of Abate®...
Chad has seen a considerable reduction in cases of Guinea worm disease (or dracunculiasis) in domestic dogs in recent years. Tethering of dogs and application of Abate® larvicide to water sources appear to have contributed to this progress, but with 767 reported dog cases in 2021, accelerating elimination of the disease in Chad may require additional tools. We investigate the potential benefits of a hypothetical diagnostic test that could be capable of detecting prepatent infections in dogs. We adapt an agent-based simulation model for forecasting the impact of interventions on guinea worm disease in dogs to examine the interaction of multiple test factors including test accuracy, when the test can detect infection, dog selection, and dog-owner compliance with tethering recommendations. We find that a diagnostic test could be successful if used in conjunction with existing interventions, and elimination can be achieved within 2 years with 80% or higher test sensitivity, 90% or higher specificity, systematic testing of each dog twice per year, and more than 90% long-term tethering compliance when a dog tests positive or a worm is emerging. Because of the long incubation period of Guinea worm disease (10-14 months) and the fact that no treatment exists, the benefits of the test rely on the testing rollout and response of dog owners. If the test could estimate the timing of worm emergence, long-term tethering could be eliminated and infected dogs could be tethered only when the worms are expected, minimizing the related resources (human and financial) to support the intervention.
Topics: Animals; Dogs; Dracunculiasis; Dog Diseases; Dracunculus Nematode; Chad; Diagnostic Tests, Routine; Sensitivity and Specificity
PubMed: 38579703
DOI: 10.4269/ajtmh.23-0534