391 research outputs found
Zoonotic nematodes of wild carnivores
No full textFor a long time, wildlife carnivores have been disregarded for their potential in transmitting zoonotic nematodes. However, human activities and politics (e.g., fragmentation of the environment, land use, recycling in urban settings) have consistently favoured the encroachment of urban areas upon wild environments, ultimately causing alteration of many ecosystems with changes in the composition of the wild fauna and destruction of boundaries between domestic and wild environments. Therefore, the exchange of parasites from wild to domestic carnivores and vice versa have enhanced the public health relevance of wild carnivores and their potential impact in the epidemiology of many zoonotic parasitic diseases. The risk of transmission of zoonotic nematodes from wild carnivores to humans via food, water and soil (e.g., genera Ancylostoma, Baylisascaris, Capillaria, Uncinaria, Strongyloides, Toxocara, Trichinella) or arthropod vectors (e.g., genera Dirofilaria spp., Onchocerca spp., Thelazia spp.) and the emergence, re-emergence or the decreasing trend of selected infections is herein discussed. In addition, the reasons for limited scientific information about some parasites of zoonotic concern have been examined. A correct compromise between conservation of wild carnivores and risk of introduction and spreading of parasites of public health concern is discussed in order to adequately manage the risk of zoonotic nematodes of wild carnivores in line with the ‘One Health’ approach
Review of “Echinococcus and Echinococcosis, Part A.” edited by R. C. Andrew Thompson, Alan J. Lymbery and Peter Deplazes
No full textBOOK DETAILS:
Thompson RCA, Deplazes P, Lymbery AJ, Editors. Echinococcus and Echinococcosis, Part A. Volume 95, Advances in Parasitology 95. Academic Press; 2017. 525 pages, ISBN 978-0-12-8114711 (hardcover); 9780128114728 (eBook)
Review of “Echinococcus and Echinococcosis, Part A.” edited by R. C. Andrew Thompson, Alan J. Lymbery and Peter Deplazes
No full textBook details Thompson RCA, Deplazes P, Lymbery AJ, Editors. Echinococcus and Echinococcosis, Part A. Volume 95, Advances in Parasitology 95. Academic Press; 2017. 525 pages, ISBN 978-0-12-8114711 (hardcover); 9780128114728 (eBook)
Ribosomal and mitochondrial DNA analysis of Trichuridae nematodes of carnivores and small mammals
No full textSeveral species of Trichuridae nematodes can infect dogs, cats and wild mammals. The diagnosis of these infections relies on the microscopic identification of eggs which are characterized by a similar "lemon" shape and polar plugs in all Trichuridae. Thus, morphological diagnosis to species level is challenging. The use of biomolecular diagnostic methods is desirable but very little genetic data are known from Trichuridae of carnivores and small mammals. The aim of this work was to genetically characterize several species of Trichuridae that can affect dogs, cats and wild mammals, as a basis to develop molecular diagnostic tests. Specimens (adult worms or eggs) of Eucoleus aerophilus (syn. Capillaria aerophila), Eucoleus boehmi (syn. Capillaria boehmi), Pearsonema plica (syn. Capillaria plica), Aonchotheca putorii (syn. Capillaria putorii), Calodium hepaticum (syn. Capillaria hepatica), Calodium splenaecum (syn. Capillaria splenaeca) and Trichuris vulpis were obtained from carcasses of red foxes, feces of dogs, the liver of a vole and from the spleen of Crocidura sp. Parts of the small subunit rRNA (18S rRNA) gene and of the mitochondrial cytochrome c oxidase subunit I (cox 1 mtDNA) gene were amplified from the above mentioned nematodes, yielding the first 18S rRNA gene sequences of all the capillariid nematodes and the first cox 1 mtDNA sequences of E. boehmi, P. plica, C. hepaticum, A. putorii and T. vulpis. The 18S rRNA gene is highly conserved among the different species and not suitable as a target for specific diagnostic oligonucleotides. However, these sequences contribute to a better understanding of the complex taxonomic relations among Trichuridae. Indeed, a dendrogram based on the 18S rRNA gene locus supports the latest taxonomic revision. Interspecies divergence was much higher at the cox 1 mtDNA gene locus, rendering it suitable for DNA barcoding and particularly valuable in resolving closely related species. Furthermore, the mitochondrial genetic markers defined in the present study are useful to develop Trichuridae species-specific primers
The occurrence of taeniids of wolves in Liguria (northern Italy)
No full textCanids are definitive hosts of Taenia and Echinococcus species, which infect a variety of mammals as intermediate or accidental hosts including humans. Parasite transmission is based on domestic, semi-domestic and wildlife cycles; however, little is known of the epidemiological significance of wild large definitive hosts such as the wolf. In this study, 179 scats of wolves (Canis lupus italicus) collected throughout the Italian region of Liguria were analyzed for the detection of taeniid infection. Taeniid egg isolation was performed using a sieving/flotation technique, and the species level was identified by PCR (gene target: 12S rRNA and nad 1) followed by sequence analyses. Based on sequence homologies of ≥99%, Taenia hydatigena was identified in 19.6%, Taenia krabbei in 4.5%, Taenia ovis in 2.2%, Taenia crassiceps in 0.6%, Hydatigera taeniaeformis in 0.6% and Echinococcus granulosus in 5.6% of the samples. According to these results, Canis lupus italicus can be considered as involved in the wild (including cervids and rodents) and semi-domestic cycles (including sheep and goats) of taeniids in this area
Alveolar echinococcosis: what triggers emergence in North America, Central Europe and Asia?
No full textPURPOSE OF REVIEW
Infection with the larval (metacestode) stage of Echinococcus multilocularis causes alveolar echinococcosis (AE), a serious hepatic disorder. The parasite has increased its infection extensity in wildlife and domestic dogs, mainly due to urbanization and spatial extension of wildlife hosts in Europe, Asia as well as North America, resulting in emerging infection risk for humans.
RECENT FINDINGS
In hyperendemic areas such as Kyrgyzstan and China, ecological and socioeconomic changes have been associated with the unpredictable increase of AE cases. In North America, the appearance of the European-like genotype is of concern. In Europe, the annual increase of human case numbers reached a plateau even in hyperendemic situations. Therefore, we conclude that most of the exposed individuals are resistant to parasite invasion and/or to disease development. Thus, AE develops in a few healthy individuals, but preferentially in immunosuppressed patients.
SUMMARY
In the future, improved diagnostic strategies will allow more precise estimations of transmission routes including the role of food, water and direct dog contact, which should yield improved public health recommendations. Finally, understanding protective innate and acquired immune mechanisms as well as parasite-driven immune-evasion processes will be essential to develop curative therapies in nonoperable patients and, futuristically, appropriate vaccines
Conquering Switzerland: the emergence of Angiostrongylus vasorum in foxes over three decades and its rapid regional increase in prevalence contrast with the stable occurrence of lungworms
No full textAngiostrongylus vasorum, Crenosoma vulpis and Capillaria aerophila are the most common lungworms of domestic and wild canids. We investigated the short- and long-term lungworm prevalence changes in the Swiss fox population with a focus on A. vasorum. Between 2012 and 2017, lungs and hearts of 533 foxes from north-eastern Switzerland were necropsied and blood samples tested for circulating A. vasorum antigen. Angiostrongylus vasorum prevalence increased steadily from 21.5% in 2012 to 81.8% in 2017. In contrast, C. aerophila and C. vulpis prevalences fluctuated between 41.8 and 74.7%, and 3.6 and 14.9%, respectively. Based on 3955 blood samples collected between 1986 and 2017 from three geographic areas and during four time periods, antigen seropositivity increased from 2.4 to 62.0%. In north-eastern Switzerland, seropositivity was initially low (1.9 and 1.7% in the first two time periods) but increased in the following two decades to 22.2 and 62.0%, respectively. Our findings depict the spectacular expansion of A. vasorum in the past three decades. Regionally, the prevalence in foxes increased 4-fold within 6 years in some regions. This underpins the important role of foxes as reservoir hosts, likely explaining the increasing number of cases of canine angiostrongylosis in Switzerland. Our findings are representative of central Europe and may help anticipating future developments in areas where A. vasorum is present but (still) infrequent
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