-
Parasitology Research Dec 2023The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals... (Review)
Review
The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.
Topics: Animals; Humans; Helminthiasis; Soil; One Health; Anthelmintics; Helminths
PubMed: 38114766
DOI: 10.1007/s00436-023-08088-8 -
International Journal For Parasitology.... Dec 2022Anthelmintic resistance is reported in equine nematodes with increasing frequency in recent years, and no new anthelmintic classes have been introduced during the past... (Review)
Review
Anthelmintic resistance is reported in equine nematodes with increasing frequency in recent years, and no new anthelmintic classes have been introduced during the past 40 years. This manuscript reviews published literature describing anthelmintic resistance in cyathostomins, Parascaris spp., and Oxyuris equi with special emphasis on larvicidal efficacy against encysted cyathostomin larvae and strongylid egg reappearance periods (ERP). Resistance to benzimidazoles and pyrimidines is highly prevalent in cyathostomin populations around the world, and macrocyclic lactone resistance has been documented in cyathostomins in recent years as well. Two recent studies have documented resistance to the larvicidal regimen of fenbendazole, whereas the larvicidal efficacy of moxidectin is variable, but with no evidence of a reduction from historic levels. In the 1990s, ERP estimates were 8-10 and 12-16 weeks for ivermectin and moxidectin, respectively, while several studies published after year 2000 found ERPs to be 5 weeks for both compounds. This is a clear change in anthelmintic performance, but it remains unclear if this is due to development of anthelmintic resistance or selection for other biological traits leading to a quicker resumption of strongylid egg shedding following anthelmintic treatment. Macrocyclic lactone resistance is common in Parascaris spp. around the world, but recent reports suggests that resistance to the two other classes should be monitored as well. Finally, O. equi has been reported resistant to ivermectin and moxidectin in countries representing four continents. In conclusion, multi-drug resistance is becoming the norm in managed cyathostomin populations around the world, and a similar pattern may be emerging in Parascaris spp. More work is required to understand the mechanisms behind the shortened ERPs, and researchers and veterinarians around the world are encouraged to routinely monitor anthelmintic efficacy against equine nematodes.
Topics: Horses; Animals; Horse Diseases; Anthelmintics; Fenbendazole; Macrolides; Ivermectin; Ascaridoidea; Drug Resistance; Parasite Egg Count; Feces
PubMed: 36342004
DOI: 10.1016/j.ijpddr.2022.10.005 -
Trends in Parasitology Dec 2019There is increasing attention on the complex interactions occurring between schistosome parasites and their hosts. However, little is known about the occurrence,... (Review)
Review
There is increasing attention on the complex interactions occurring between schistosome parasites and their hosts. However, little is known about the occurrence, epidemiology, and mechanisms of schistosomiasis-associated infertility. In this article, we argue that an in-depth understanding of the interplay between parasites and the host endocrine system may significantly enhance current knowledge of infertility in infected individuals. We discuss the basic hormonal mechanisms that may lead to the discovery of entirely novel anthelmintic interventions against schistosomiasis.
Topics: Animals; Anthelmintics; Endocrine System; Host-Parasite Interactions; Humans; Infertility; Schistosoma; Schistosomiasis
PubMed: 31623951
DOI: 10.1016/j.pt.2019.09.001 -
Trends in Parasitology Sep 2021Most anthelmintics were discovered through in vivo screens using animal models of infection. Developing in vitro assays for parasitic worms presents several challenges.... (Review)
Review
Most anthelmintics were discovered through in vivo screens using animal models of infection. Developing in vitro assays for parasitic worms presents several challenges. The lack of in vitro life cycle culture protocols requires harvesting worms from vertebrate hosts or vectors, limiting assay throughput. Once worms are removed from the host environment, established anthelmintics often show no obvious phenotype - raising concerns about the predictive value of many in vitro assays. However, with recent progress in understanding how anthelmintics subvert host-parasite interactions, and breakthroughs in high-content imaging and machine learning, in vitro assays have the potential to discern subtle cryptic parasite phenotypes. These may prove better endpoints than conventional in vitro viability assays.
Topics: Animals; Anthelmintics; Drug Evaluation, Preclinical; Helminthiasis; Helminths; Host-Parasite Interactions
PubMed: 34092518
DOI: 10.1016/j.pt.2021.05.004 -
Trends in Parasitology Aug 2018Anthelmintic resistance in human and animal pathogenic helminths has been spreading in prevalence and severity. Multidrug resistance is a widespread problem in livestock... (Review)
Review
Anthelmintic resistance in human and animal pathogenic helminths has been spreading in prevalence and severity. Multidrug resistance is a widespread problem in livestock animals. The use of available pharmacology-based information is critical to the design of successful future approaches for parasite control. Relevant scientific work supporting the main strategies to optimize anthelmintic therapy in ruminants under the current drug-resistance scenario is described here. We emphasize the need for further integrated pharmaco-parasitological knowledge to extend the lifespan of both traditional and novel anthelmintic compounds, and to progress in the identification of complementary/alternative measures of parasite control in livestock animals.
Topics: Animal Husbandry; Animals; Anthelmintics; Communicable Disease Control; Helminthiasis, Animal; Ruminants
PubMed: 29960843
DOI: 10.1016/j.pt.2018.05.005 -
International Journal For Parasitology.... Dec 2020For more than four decades, the free-living nematode Caenorhabditis elegans has been extensively used in anthelmintic research. Classic genetic screens and heterologous... (Review)
Review
For more than four decades, the free-living nematode Caenorhabditis elegans has been extensively used in anthelmintic research. Classic genetic screens and heterologous expression in the C. elegans model enormously contributed to the identification and characterization of molecular targets of all major anthelmintic drug classes. Although these findings provided substantial insights into common anthelmintic mechanisms, a breakthrough in the treatment and control of parasitic nematodes is still not in sight. Instead, we are facing increasing evidence that the enormous diversity within the phylum Nematoda cannot be recapitulated by any single free-living or parasitic species and the development of novel broad-spectrum anthelmintics is not be a simple goal. In the present review, we summarize certain milestones and challenges of the C. elegans model with focus on drug target identification, anthelmintic drug discovery and identification of resistance mechanisms. Furthermore, we present new perspectives and strategies on how current progress in C. elegans research will support future anthelmintic research.
Topics: Animals; Anthelmintics; Caenorhabditis elegans; Drug Discovery; Nematoda
PubMed: 33249235
DOI: 10.1016/j.ijpddr.2020.09.005 -
Trends in Parasitology Jul 2018Fifty years after anthelmintic resistance in livestock parasites was first reported, the prevalence of resistance has increased globally, and is of increasing... (Review)
Review
Fifty years after anthelmintic resistance in livestock parasites was first reported, the prevalence of resistance has increased globally, and is of increasing significance in animal industries. It is now timely to reflect on what we have learnt, how research has unfolded, and what we hope to learn in the future. This Opinion paper examines ten important research events that were pivotal in resistance research. The moments include the discovery, description, and diagnosis of parasite resistance, as well as important physiological and genetic findings, and the development of online tools to help manage resistance. Despite our efforts, resistance remains the greatest challenge in parasite control. The future directions for research, including people and funding, are discussed.
Topics: Animals; Anthelmintics; Drug Resistance; Helminthiasis, Animal; Helminths; Parasitology; Research
PubMed: 29803755
DOI: 10.1016/j.pt.2018.05.001 -
Research in Veterinary Science Dec 2022The objective of this study was to conduct research of the literature available in electronic media on anthelmintic intoxication in sheep and goats. The search for... (Review)
Review
The objective of this study was to conduct research of the literature available in electronic media on anthelmintic intoxication in sheep and goats. The search for primary studies was carried out in five electronic databases: ScienceDirect, PubMed, Scopus, Web of Science, and SciELO. The search terms used were (antihelmintic OR antiparasitic OR vermifuge) AND (poisoning OR toxicity OR overdose OR intoxication) AND (goat OR sheep). A total of 2361 articles were identified from the five databases: Science Direct (n = 1869), PubMed (n = 434), Scopus (n = 37), Web of Science (n = 16), and SciELO (n = 5). As 111 articles were found in duplicates, 2250 were left for review of the title and abstracts, of which 115 were read in full, and 28 were included in the systematic review. Of the 28 articles, 16 involved sheep, 9 involved goats, and 3 involved both species. Twelve drugs were identified in intoxication reports: albendazole (2), closantel (14), disophenol (1), ivermectin (1), levamisole (2), moxidectin (1), netobimin (1), nitroxinil (1), oxfendazole (2), parbendazole (2), tetramizole (1), and thiabendazole (1). The most prevalent symptoms of anthelmintic intoxication reported were showed involvement of the nervous, locomotor, and renal systems, as well as teratogenic influences. Data from this review underscore the need of the care required in the control of parasitic infections through the safe use of antiparasitic drugs to avoid cases of intoxication.
Topics: Sheep; Animals; Goats; Parasite Egg Count; Sheep Diseases; Anthelmintics; Albendazole; Antiparasitic Agents; Drug Resistance; Goat Diseases; Feces
PubMed: 36219891
DOI: 10.1016/j.rvsc.2022.09.038 -
Biology Letters May 2022Wild ruminants are susceptible to infection from generalist helminth species, which can also infect domestic ruminants. A better understanding is required of the... (Review)
Review
Wild ruminants are susceptible to infection from generalist helminth species, which can also infect domestic ruminants. A better understanding is required of the conditions under which wild ruminants can act as a source of helminths (including anthelmintic-resistant genotypes) for domestic ruminants, and vice versa, with the added possibility that wildlife could act as for drug-susceptible genotypes and hence buffer the spread and development of resistance. Helminth infections cause significant productivity losses in domestic ruminants and a growing resistance to all classes of anthelmintic drug escalates concerns around helminth infection in the livestock industry. Previous research demonstrates that drug-resistant strains of the pathogenic nematode can be transmitted between wild and domestic ruminants, and that gastro-intestinal nematode infections are more intense in wild ruminants within areas of high livestock density. In this article, the factors likely to influence the role of wild ruminants in helminth infections and anthelmintic resistance in livestock are considered, including host population movement across heterogeneous landscapes, and the effects of climate and environment on parasite dynamics. Methods of predicting and validating suspected drivers of helminth transmission in this context are considered based on advances in predictive modelling and molecular tools.
Topics: Animals; Anthelmintics; Drug Resistance; Haemonchus; Livestock; Ruminants
PubMed: 35506237
DOI: 10.1098/rsbl.2022.0057 -
Trends in Parasitology Jun 2021Helminth secretomes comprise many potential immunomodulators. The molecular and functional diversity of these entities and their importance at the host-parasite... (Review)
Review
Helminth secretomes comprise many potential immunomodulators. The molecular and functional diversity of these entities and their importance at the host-parasite interface have been increasingly recognized. It is now common to hypothesize that parasite-derived molecules (PDMs) are essential mediators used by parasites to establish and remain in their hosts. Suppression of PDM release has been reported for two anthelmintic drug classes, the benzimidazoles and macrocyclic lactones, the mechanisms of action of which remain incompletely resolved. We propose that bringing together recent insights from different streams of parasitology research, for example, immunoparasitology and pharmacology, will stimulate the development of new ways to alter the host-parasite interface in the search for novel anthelmintic strategies.
Topics: Animals; Anthelmintics; Helminthiasis; Helminths; Host-Parasite Interactions
PubMed: 33563557
DOI: 10.1016/j.pt.2021.01.007