1
|
Holland CV. A walk on the wild side: A review of the epidemiology of Toxocara canis and Toxocara cati in wild hosts. Int J Parasitol Parasites Wildl 2023; 22:216-228. [PMID: 37964985 PMCID: PMC10641444 DOI: 10.1016/j.ijppaw.2023.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/15/2023] [Accepted: 10/15/2023] [Indexed: 11/16/2023]
Abstract
Toxocara species are cosmopolitan nematode parasites of companion, domestic and wild hosts. Of the 26 known species of Toxocara, only Toxocara canis and Toxocara cati are definitively zoonotic. The significance of wild carnivores as definitive hosts of T. canis and T. cati respectively, has received far less attention compared to domestic dogs and cats. Complex environmental changes have promoted increasing contact between wildlife, domestic animals and humans that can enhance the risk of pathogen spillover. This review lists a total of 19 species of wild canid host that have been shown to act as definitive hosts for T. canis and a total of 21 species of wild felid host. In general, the number of publications focusing on felid host species is fewer in number, reflecting the general paucity of data on T. cati. The wild canids that have received the most attention in the published literature include the red fox (Vulpes vulpes), the wolf (Canis lupus), and the golden jackal (Canis aureus). The wild felid species that has received the most attention in the published literature is the Eurasian lynx (Lynx lynx). Some non-canid and non-felid hosts also act as definitive hosts of Toxocara species. Certainly, red foxes would appear to be the most significant wild species in terms of their potential to transmit Toxocara to domestic dogs and humans via environmental contamination. This can be explained by their increasing population densities, encroachment into urban areas and their dietary preferences for a wide range of potential paratenic hosts. However, a major challenge remains to assess the relative importance of wild hosts as contributors to environmental contamination with Toxocara ova. Furthermore, one major constraint to our understanding of the significance of wildlife parasitism is a lack of access to samples, particularly from rare host species.
Collapse
Affiliation(s)
- Celia V. Holland
- Department of Zoology, School of Natural Sciences, Trinity College, Dublin 2, Ireland
| |
Collapse
|
2
|
Cowie RH, Malik R, Morgan ER. Comparative biology of parasitic nematodes in the genus Angiostrongylus and related genera. ADVANCES IN PARASITOLOGY 2023; 121:65-197. [PMID: 37474239 DOI: 10.1016/bs.apar.2023.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
The rise to prominence of some Angiostrongylus species through associated emerging disease in humans and dogs has stimulated calls for a renewed focus on the biology of this genus and three related genera. Although significant research efforts have been made in recent years these have tended to focus on individual species and specific aspects such as diagnosis and treatment of disease or new records of occurrence and hosts. This comprehensive review takes a comparative approach, seeking commonalities and differences among species and asking such questions as: Which species belong to this and to closely related genera and how are they related? Why do only some species appear to be spreading geographically and what factors might underlie range expansion? Which animal species are involved in the life cycles as definitive, intermediate, paratenic and accidental hosts? How do parasite larvae find, infect and develop within these hosts? What are the consequences of infection for host health? How will climate change affect future spread and global health? Appreciating how species resemble and differ from each other shines a spotlight on knowledge gaps and provides provisional guidance on key species characteristics warranting detailed study. Similarities exist among species, including the basic life cycle and transmission processes, but important details such as host range, climatic requirements, migration patterns within hosts and disease mechanisms differ, with much more information available for A. cantonensis and A. vasorum than for other species. Nonetheless, comparison across Angiostrongylus reveals some common patterns. Historically narrow definitive host ranges are expanding with new knowledge, combining with very broad ranges of intermediate gastropod hosts and vertebrate and invertebrate paratenic and accidental hosts to provide the backdrop to complex interactions among climate, ecology and transmission that remain only partly understood, even for the species of dominant concern. Key outstanding questions concern larval dynamics and the potential for transmission outside trophic relations, relations between infection and disease severity in different hosts, and how global change is altering transmission beyond immediate impacts on development rate in gastropods. The concept of encounter and compatibility filters could help to explain differences in the relative importance of different gastropod species as intermediate hosts and determine the importance of host community composition and related environmental factors to transmission and range. Across the group, it remains unclear what, physiologically, immunologically or taxonomically, delimits definitive, accidental and paratenic hosts. Impacts of infection on definitive host fitness and consequences for population dynamics and transmission remain mostly unexplored across the genus. Continual updating and cross-referencing across species of Angiostrongylus and related genera is important to synthesise rapid advances in understanding of key traits and behaviours, especially in important Angiostrongylus species that are emerging causative agents of disease in humans and other animals.
Collapse
Affiliation(s)
- Robert H Cowie
- Pacific Biosciences Research Center, University of Hawaii, Maile Way, Gilmore, Honolulu, HI, United States.
| | - Richard Malik
- Centre for Veterinary Education, The University of Sydney, NSW, Australia
| | - Eric R Morgan
- Institute for Global Food Security, Queen's University Belfast, Chlorine Gardens, Belfast, United Kingdom; School of Veterinary Science, University of Bristol, Langford House, Langford, North Somerset, United Kingdom
| |
Collapse
|
3
|
Globokar M, Pantchev N, Hinney B, Leschnik M, Peschke R, Schaper R, Schnyder M. Serological and faecal detection of Angiostrongylus vasorum in dogs from Austria. Vet Parasitol Reg Stud Reports 2021; 26:100641. [PMID: 34879952 DOI: 10.1016/j.vprsr.2021.100641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/10/2021] [Accepted: 09/16/2021] [Indexed: 11/18/2022]
Abstract
Canine angiostrongylosis is a potentially lethal parasitic disease that can manifest itself with a broad spectrum of clinical signs, including respiratory distress, neurological and bleeding disorders, or non-specific signs. The occurrence of Angiostrongylus vasorum is widely reported in Europe, but very little is known about its presence in Austria. In this first large-scale survey, 1279 sera were collected from Austrian dogs and tested by an ELISA for the detection of circulating antigen of A. vasorum (sensitivity: 95.7%, specificity 94.0%) and by a separate ELISA detecting specific antibodies (sensitivity 81.0%, specificity 98.8%). Furthermore, 1040 faecal samples were tested for the presence of lungworm first stage larvae (L1). One dog (0.1%, 95% confidence intervals [CI]: 0.0-0.4%) was positive in both ELISAs, while 1.2% (n = 15, CI: 0.7-1.9%) of the tested dogs were antigen-positive and 1.5% (n = 19, CI: 0.9-2.3%) were positive for specific antibodies. Overall, 13 dogs (1.3%; CI: 0.7-2.1%) were positive for A. vasorum L1 while 31 dogs were positive for Crenosoma vulpis L1 (3.0%; CI: 2.0-4.2%). One dog shed L1 from both A. vasorum and C. vulpis (0.1%, CI: 0.0-0.5%). Dogs positive for A. vasorum originated from northeast, southeast and south Austria (antigen and/or antibody detection), but also from north, west and southwest Austria (antibody detection) and from northeast and west Austria (L1 detection). One of 88 blood samples (1.1%, CI: 0.0-6.2%) submitted from the eastern part of Austria was positive by a rapid assay for A. vasorum antigen detection (Angio Detect™). Crenosoma vulpis positive samples originated from northwest, north, northeast, south and west Austria. These results confirm the very sporadic occurrence of A. vasorum in the investigated areas of the country. However, due to the substantial infectious pressure from the surrounding countries and the free circulation of dogs and foxes acting as wildlife reservoirs and due to clinical relevance for infected dogs, it is crucial to maintain disease awareness also in areas where the parasite has not yet been detected.
Collapse
Affiliation(s)
| | | | - Barbara Hinney
- Institute of Parasitology, Department of Pathobiology, Vetmeduni Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | - Michael Leschnik
- Clinical Unit of Internal Medicine Small Animals, University Hospital for Small Animals, Department/Hospital for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Roman Peschke
- Institute of Parasitology, Department of Pathobiology, Vetmeduni Vienna, Veterinärplatz 1, 1210 Vienna, Austria
| | | | - Manuela Schnyder
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zurich, Switzerland.
| |
Collapse
|
4
|
Fuehrer HP, Morelli S, Unterköfler MS, Bajer A, Bakran-Lebl K, Dwużnik-Szarek D, Farkas R, Grandi G, Heddergott M, Jokelainen P, Knific T, Leschnik M, Miterpáková M, Modrý D, Petersen HH, Skírnisson K, Vergles Rataj A, Schnyder M, Strube C. Dirofilaria spp. and Angiostrongylus vasorum: Current Risk of Spreading in Central and Northern Europe. Pathogens 2021; 10:1268. [PMID: 34684217 PMCID: PMC8537668 DOI: 10.3390/pathogens10101268] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
In the past few decades, the relevance of Dirofilaria immitis and Dirofilaria repens, causing cardiopulmonary and subcutaneous dirofilariosis in dogs and cats, and of Angiostrongylus vasorum, causing canine angiostrongylosis, has steadily increased in Central and Northern Europe. In this review, a summary of published articles and additional reports dealing with imported or autochthonous cases of these parasites is provided for Central (Austria, Czechia, Germany, Hungary, Luxemburg, Poland, Slovakia, Slovenia, and Switzerland) and Northern (Denmark, Finland, Iceland, Norway, and Sweden) Europe. Research efforts focusing on Dirofilaria spp. and A. vasorum have varied by country, and cross-border studies are few. The housing conditions of dogs, pet movements, the spread of competent vectors, and climate change are important factors in the spread of these nematodes. Dogs kept outside overnight are a major factor for the establishment of Dirofilaria spp. However, the establishment of invasive, diurnal, synanthropic, competent mosquito vectors such as Aedes albopictus may also influence the establishment of Dirofilaria spp. The drivers of the spread of A. vasorum remain not fully understood, but it seems to be influenced by habitats shared with wild canids, dog relocation, and possibly climatic changes; its pattern of spreading appears to be similar in different countries. Both Dirofilaria spp. and A. vasorum merit further monitoring and research focus in Europe.
Collapse
Affiliation(s)
- Hans-Peter Fuehrer
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.S.U.); (K.B.-L.)
| | - Simone Morelli
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy;
| | - Maria Sophia Unterköfler
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.S.U.); (K.B.-L.)
| | - Anna Bajer
- Department of Eco-Epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (A.B.); (D.D.-S.)
| | - Karin Bakran-Lebl
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (M.S.U.); (K.B.-L.)
| | - Dorota Dwużnik-Szarek
- Department of Eco-Epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (A.B.); (D.D.-S.)
| | - Róbert Farkas
- Department of Parasitology and Zoology, University of Veterinary Medicine, 1078 Budapest, Hungary;
| | - Giulio Grandi
- Section for Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences (SLU), 750 07 Uppsala, Sweden;
- Department of Microbiology, National Veterinary Institute (SVA), 756 51 Uppsala, Sweden
| | - Mike Heddergott
- Department of Zoology, Musée National d’Historire Naturelle, 25, Rue Münster, 2160 Luxembourg, Luxembourg;
| | - Pikka Jokelainen
- Department of Bacteria, Parasites and Fungi, Infectious Disease Preparedness, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark;
| | - Tanja Knific
- Institute of Food Safety, Feed and Environment, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia;
| | - Michael Leschnik
- Clinical Unit of Internal Medicine Small Animals, Department/Universitätsklinik für Kleintiere und Pferde, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria;
| | - Martina Miterpáková
- Institute of Parasitology, Slovak Academy of Sciences, Hlinkova 3, 040 01 Košice, Slovakia;
| | - David Modrý
- Biology Center, Institute of Parasitology, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic;
- Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources/CINeZ, Czech University of Life Sciences Prague, 16500 Praha-Suchdol, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic
| | - Heidi Huus Petersen
- Centre for Diagnostic, Department of Health Technology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark;
| | - Karl Skírnisson
- Institute for Experimental Pathology at Keldur, University of Iceland, Keldnavegur 3, 112 Reykjavik, Iceland;
| | - Aleksandra Vergles Rataj
- Institute of Microbiology and Parasitology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia;
| | - Manuela Schnyder
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, 8057 Zürich, Switzerland;
| | - Christina Strube
- Centre for Infection Medicine, Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
| |
Collapse
|
5
|
Tylkowska A, Pilarczyk B, Tomza-Marciniak A, Pilarczyk R. The prevalence of intestinal nematodes among red foxes (Vulpes vulpes) in north-western Poland. Acta Vet Scand 2021; 63:19. [PMID: 33952322 PMCID: PMC8100824 DOI: 10.1186/s13028-021-00584-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 04/24/2021] [Indexed: 11/16/2022] Open
Abstract
Background The red fox (Vulpes vulpes) is widely distributed in the Northern Hemisphere and Australia. The presence of nematode-infected foxes in urbanized areas increases the risk of transmission of nematodes to domestic dogs and thus, to humans. The aim of this study was to determine the prevalence and species composition of intestinal nematodiasis in red foxes in Western Pomerania, a province in north-western Poland. The intestinal contents of 620 red foxes killed during a government reduction shooting programme were examined for adult nematodes using the sedimentation and counting technique (SCT). Results Intestinal nematodes, including Toxocara canis, Toxascaris leonina, Uncinaria stenocephala and Trichuris vulpis, were found in 77.3% (95% CI 73.8–80.4%) of the examined foxes with a mean infection burden of 20.1 nematode per animal. Male and female foxes had similar infection burdens. Conclusions The nematodes are present in high prevalence and intensity among foxes in north-western Poland. Furthermore, this high prevalence of nematodes in foxes may likely constitute a health risk to humans and domestic animals due to increasing fox densities in urban and periurban areas.
Collapse
|
6
|
Kotwa JD, Schnyder M, Jardine CM, Deplazes P, Pearl DL, Berke O, Mercer N, Peregrine AS. Investigation of the occurrence of Angiostrongylus vasorum in coyotes in southern Ontario, Canada. J Vet Diagn Invest 2021; 33:664-669. [PMID: 33890522 PMCID: PMC8225693 DOI: 10.1177/10406387211011990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In North America, the only endemic focus for Angiostrongylus
vasorum (French heartworm) was historically thought to occur in the
southeastern part of the island of Newfoundland. However, reports of A.
vasorum infection in wild canids in West Virginia, USA, and Nova
Scotia, Canada, suggest the introduction of the parasite to mainland North
America. We screened for A. vasorum in coyotes from across
southern Ontario. Additionally, we evaluated the performance of ELISAs for
detection of circulating A. vasorum antigen (Ag-ELISA) and
antibodies against A. vasorum (Ab-ELISA) designed for use in
sera or blood of foxes for use with coyotes in this region. Autopsies were
performed on 397 coyotes, and lung tissue extract prepared from each carcass was
tested via both ELISAs. The sensitivity and specificity for both tests were
estimated in the absence of a gold standard using a 2-test single population
Bayesian model; sensitivity and specificity priors were based on the performance
of the assays in foxes in Switzerland. Eight coyotes tested positive for
A. vasorum antigen; no animal was antibody positive. The
estimated sensitivity and specificity of the Ag-ELISA were 90.8% (95% credible
interval [CrI]: 83.8–95.6%) and 95.5% (95% CrI: 93.4–97.2%), respectively. For
the Ab-ELISA, the estimated sensitivity and specificity were 41.9% (95% CrI:
32.1–51.9%) and 98.0% (95% CrI: 96.3–99.0%), respectively. Based on these
findings and negative postmortem data for the same animals, there is
insufficient evidence to suggest the presence of A. vasorum in
southern Ontario coyotes.
Collapse
Affiliation(s)
| | - Manuela Schnyder
- Institute of Parasitology, University of Zurich, Zürich, Switzerland
| | - Claire M Jardine
- Departments of Pathobiology, Guelph, Ontario, Canada.,Canadian Wildlife Health Cooperative, Guelph, Ontario, Canada
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Zürich, Switzerland
| | - David L Pearl
- Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Olaf Berke
- Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Nicola Mercer
- Wellington-Dufferin-Guelph Public Health, Guelph, Ontario, Canada
| | | |
Collapse
|
7
|
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. Parasitology 2020; 147:1071-1079. [PMID: 32372743 DOI: 10.1017/s0031182020000700] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Angiostrongylus 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.
Collapse
|