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Otranto D, Mendoza-Roldan JA, Beugnet F, Baneth G, Dantas-Torres F. New paradigms in the prevention of canine vector-borne diseases. Trends Parasitol 2024:S1471-4922(24)00091-6. [PMID: 38744542 DOI: 10.1016/j.pt.2024.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/12/2024] [Accepted: 04/14/2024] [Indexed: 05/16/2024]
Abstract
The prevention of canine vector-borne diseases (CVBDs) is pivotal for the health and welfare of dogs as well as for reducing their zoonotic risk to humans. Scientific knowledge gained in recent years contributed to the development of new strategies for the control of these diseases in different social and cultural contexts. Here, we discuss recent advances in the prevention of vector-borne pathogens (VBPs) affecting dogs with a focus on those of zoonotic relevance.
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Affiliation(s)
- Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy; Department of Veterinary Clinical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong, China.
| | | | | | - Gad Baneth
- Koret School of Veterinary Medicine, Hebrew University, Rehovot, Israel
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Huggins LG, Koehler AV, Gasser RB, Traub RJ. Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond. ADVANCES IN PARASITOLOGY 2023; 120:1-85. [PMID: 36948727 DOI: 10.1016/bs.apar.2022.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.
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Affiliation(s)
- Lucas G Huggins
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia.
| | - Anson V Koehler
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Robin B Gasser
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, The University of Melbourne, Parkville, VIC, Australia
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Ehrlichiosis in Dogs: A Comprehensive Review about the Pathogen and Its Vectors with Emphasis on South and East Asian Countries. Vet Sci 2022; 10:vetsci10010021. [PMID: 36669021 PMCID: PMC9863373 DOI: 10.3390/vetsci10010021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/17/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Ehrlichiosis in dogs is an emerging vector borne rickettsial zoonotic disease of worldwide distribution. In general, three Ehrlichial species (Ehrlichia canis, E. ewingii, and E. chaffeensis) are involved in infecting dogs. Among them, E. canis is the well-known etiological pathogen affecting platelets, monocytes, and granulocytes. Dogs act as a reservoir, while the main vector responsible for disease transmission is Rhipicephalus sanguineus. However, in east Asian countries, Haemaphysalis longicornis is considered the principal vector for disease transmission. This disease affects multiple organs and systems and has three clinical manifestations, including acute, subclinical, and chronic. Definitive diagnosis involves visualization of morulae on cytology, detection of antibodies through an indirect immunofluorescence test (IFAT), and DNA amplification by polymerase chain reaction (PCR). In canine ehrlichiosis, no predilection of age or sex is observed; however, Siberian Huskies and German Shepherds are more likely to develop severe clinical manifestations. Doxycycline, rifampicin, and minocycline are proven to be effective drugs against canine ehrlichiosis. This review is intended to describe a brief overview of Ehrlichia infection in dogs, its reported prevalence in east and south Asian countries, and the latest knowledge regarding chemotherapy and associated vectors responsible for the disease transmission. This manuscript also identifies the prevailing knowledge gaps which merit further attention by the scientific community.
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Chaber A, Easther R, Cumming B, Irving R, Keyburn AL, Smart C, O'Handley R, Lignereux L. Ehrlichia canis rapid spread and possible enzooty in northern South Australia and distribution of its vector Rhipicephalus linnaei. Aust Vet J 2022; 100:533-538. [PMID: 36053779 PMCID: PMC9804231 DOI: 10.1111/avj.13201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 06/24/2022] [Accepted: 07/31/2022] [Indexed: 01/05/2023]
Abstract
Recent concerns have arisen in Australia regarding detections of the exotic bacterium Ehrlichia canis which has resulted in ehrlichiosis outbreaks. In Australia, it is spread by the tropical brown dog tick Rhipicephalus linnaei, formerly Rhipicephalus sanguineus sensu lato tropical lineage. Previously, the tick has been recorded in South Australia in the Coober Pedy and the Oodnadatta areas. This study, which includes historical specimens data held in historical Australian arthropod collections, along with 10 sampled remote communities, confirms the wide distribution range of this species within the State. E. canis was detected by PCR in the ticks. The percentage of dogs hosting PCR-positive ticks increased from 2.8% (95% confidence interval [CI]: 0.3 to 9.7) in November-December 2020 to 62.9% (95% CI: 44.9 to 78.5) end of February 2021, initially in two then in seven Anangu Pitjantjatjara Yankunytjatjara lands communities in the far northern regions of South Australia. Our results suggest a rapid spread of the pathogen. No evidence of E. canis was found in nine regional communities. The extended tropical brown dog tick distribution indicates a greater area where E. canis may occur and may require management to minimise the impacts of ehrlichiosis outbreaks. Without the implementation of effective detection and control programs, this extended distribution of R. linnaei is likely to result in the spread of the bacterium to other regions.
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Affiliation(s)
- A‐L Chaber
- School of Animal and Veterinary Sciences, Roseworthy CampusThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - R Easther
- School of Animal and Veterinary Sciences, Roseworthy CampusThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - B Cumming
- Animal Management in Rural and Remote Indigenous Communities (AMRRIC)4/41 Sadgroves Crescent, Winnellie, Larrakia CountryNorthern Territory0820Australia
| | - R Irving
- Animal Management in Rural and Remote Indigenous Communities (AMRRIC)4/41 Sadgroves Crescent, Winnellie, Larrakia CountryNorthern Territory0820Australia,Adelaide Northern Veterinary Group854 North East Road, ModburySouth Australia5092Australia
| | - AL Keyburn
- Bioassay Research and Development TeamCommonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease PreparednessPrivate Bag 24, GeelongVictoria3220Australia
| | - C Smart
- Animal Management in Rural and Remote Indigenous Communities (AMRRIC)4/41 Sadgroves Crescent, Winnellie, Larrakia CountryNorthern Territory0820Australia
| | - R O'Handley
- School of Animal and Veterinary Sciences, Roseworthy CampusThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - L Lignereux
- School of Animal and Veterinary Sciences, Roseworthy CampusThe University of AdelaideAdelaideSouth AustraliaAustralia
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Huggins LG, Stevenson M, Baydoun Z, Mab R, Khouri Y, Schunack B, Traub RJ. Field trial investigating the efficacy of a long-acting imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto®, Elanco) compared to monthly topical fipronil for the chemoprevention of canine tick-borne pathogens in Cambodia. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2022; 2:100095. [PMID: 35865719 PMCID: PMC9294050 DOI: 10.1016/j.crpvbd.2022.100095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/19/2022] [Accepted: 06/22/2022] [Indexed: 11/26/2022]
Abstract
The tropical brown dog tick, Rhipicephalus linnaei, commonly infests canines in the tropics and is an important vector for disease-causing and sometimes lethal pathogens including Babesia spp., Ehrlichia canis, Hepatozoon canis and Anaplasma platys. In tropical climates ticks and their pathogens exert an extremely high infection pressure on unprotected dogs. To protect canines in such regions, effective acaricidal products possessing a speed of kill that blocks pathogen transmission is paramount. We conducted a 12-month community trial to compare the chemoprophylactic efficacy of two topical commercial acaricidal formulations: an imidacloprid 10% and flumethrin 4.5%, 8-month acting collar (Seresto®) against a monthly spot-on containing 12% w/v fipronil (Detick, Thailand). In a separate analysis, we used baseline data collected at the start of the trial to quantify tick-borne pathogen (TBP) infection status in dogs with a prior history of being administered a systemically-acting (isoxazoline) versus a topically-acting ectoparasiticide. We found that both topical products in the community trial demonstrated high efficacy at protecting dogs from ticks and TBP, with Seresto® demonstrating a moderate increase in protection at 3 (95% confidence interval (CI): 1–5) TBP-positive dogs per 100 dog-years at risk compared to 11 (95% CI: 4–26) TBP-positive dogs per 100 dog-years at risk for those on fipronil. Additionally, at baseline dogs treated with commercial systemic isoxazoline acaricides prior to the trial’s commencement were 2.7 (95% CI: 0.5–15.0) times more likely to be TBP-positive compared to dogs that had been topically treated, highlighting such isoxazoline products as being less efficacious than topical products at preventing canine TBP acquisition in a tropical setting. Chemopreventive products against ectoparasite infestation are essential for dog health in the tropics. Prevalence of canine tick-borne pathogens was higher in dogs on systemic ectoparasiticides than those on topical ones. Seresto® demonstrated better protection against canine tick-borne pathogen infection than a fipronil formulation.
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Morelli S, Gori F, Colombo M, Traversa D, Sarrocco G, Simonato G, Nespeca C, Di Cesare A, Frangipane di Regalbono A, Veronesi F, Russi I, Schnyder M. Simultaneous Exposure to Angiostrongylus vasorum and Vector-Borne Pathogens in Dogs from Italy. Pathogens 2021; 10:1200. [PMID: 34578232 PMCID: PMC8472057 DOI: 10.3390/pathogens10091200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/05/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022] Open
Abstract
Several drivers have recently fostered the expansion of Angiostrongylus vasorum throughout Europe, where Vector-Borne Pathogens (VBPs) are also spreading. However, the level of simultaneous risk of infection is still unknown in canine populations. This study evaluated the simultaneous exposure to A. vasorum and major canine VBPs in dogs of Italy. Sera of 294 dogs were subjected to two ELISAs, detecting A. vasorum circulating antigens and antibodies against the parasite, and to the following assays: (i) SNAP® 4DX (IDEXX Laboratories Inc.) detecting Dirofilaria immitis antigens, and antibodies vs. Borrelia burgdorferi, Anaplasma spp. and Ehrlichia spp. and (ii) IFAT for the detection of antibodies vs. Leishmania infantum, Babesia canis and Rickettsia conorii. Twenty-two (7.5%, CI: 4.8-11.1%) and six (2%, CI: 0.7-4.4%) dogs scored positive for circulating A. vasorum antibodies and antigens, respectively. Seventeen dogs (5.8%, CI: 3.4-9.1%) were positive for A. vasorum antibodies + at least one VBP, three (1%, CI: 0.2-3%) for A. vasorum antigen + at least one VBP, while one dog (0.3%, CI: 0.01-1.88%) was positive for A. vasorum antigen + A. vasorum antibodies + B. canis antibodies. These results show that dogs living in different regions of Italy are at risk of simultaneous infections with both A. vasorum and VBPs. Despite the same scenario being likely in other countries of Europe, the current knowledge is scant. Therefore, further studies are warranted to amplify current epizootiological information and to understand whether control programs should be improved.
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Affiliation(s)
- Simone Morelli
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Francesca Gori
- Institute of Parasitology, Vetsuisse-Faculty, University of Zurich, 8057 Zurich, Switzerland; (F.G.); (M.S.)
| | - Mariasole Colombo
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Donato Traversa
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Giulia Sarrocco
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Giulia Simonato
- Department of Animal Medicine, Production and Health, University of Padua, 35020 Lengaro, Italy; (G.S.); (A.F.d.R.)
| | - Chiara Nespeca
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Angela Di Cesare
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | | | - Fabrizia Veronesi
- Department of Veterinary Medicine, University of Perugia, 06123 Perugia, Italy;
| | - Ilaria Russi
- Faculty of Veterinary Medicine, University of Teramo, 64100 Teramo, Italy; (M.C.); (D.T.); (G.S.); (C.N.); (A.D.C.); (I.R.)
| | - Manuela Schnyder
- Institute of Parasitology, Vetsuisse-Faculty, University of Zurich, 8057 Zurich, Switzerland; (F.G.); (M.S.)
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Otranto D, Dantas-Torres F, Fourie JJ, Lorusso V, Varloud M, Gradoni L, Drake J, Geurden T, Kaminsky R, Heckeroth AR, Schunack B, Pollmeier M, Beugnet F, Holdsworth P. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for studies evaluating the efficacy of parasiticides in reducing the risk of vector-borne pathogen transmission in dogs and cats. Vet Parasitol 2021; 290:109369. [PMID: 33548595 DOI: 10.1016/j.vetpar.2021.109369] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 01/04/2023]
Abstract
These guidelines are intended to provide an in-depth review of current knowledge and assist the planning and implementation of studies for evaluating the efficacy of parasiticides in reducing transmission of vector-borne pathogens (VBPs) to dogs and cats. At present, the prevention of VBP transmission in companion animals is generally achieved through the administration of products that can repel or rapidly kill arthropods, thus preventing or interrupting feeding before transmission occurs. The present guidelines complement existing guidelines, which focus on efficacy assessment of parasiticides for the treatment, prevention and control of flea and tick infestations, but also give guidance for studies focused on other vectors (i.e. mosquitoes and phlebotomine sand flies). The efficacy of parasiticides in reducing VBP transmission can be evaluated through laboratory or field studies. As such, the present guidelines provide recommendations for these studies, representing a tool for researchers, pharmaceutical companies and authorities involved in the research, development and registration of products with claims for reducing VBP transmission in dogs and cats, respecting the overall principles of the 3Rs (replacement, reduction and refinement). Gaps in our current understanding of VBP transmission times are herein highlighted and the need for further basic research on related topics is briefly discussed.
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Affiliation(s)
- Domenico Otranto
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, 70010, Valenzano, Italy.
| | - Filipe Dantas-Torres
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, 70010, Valenzano, Italy; Department of Immunology, Aggeu Magalhães Institute (Fiocruz-PE), Pernambuco, Brazil
| | | | - Vincenzo Lorusso
- Global Research and Intellectual Property, Vetoquinol, 37 Rue de la Victoire, 75009, Paris, France; School of Science, Engineering and Environment, Peel Building, University of Salford, Greater Manchester, M5 4WT, United Kingdom
| | | | - Luigi Gradoni
- Unit of Vector-Borne Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Jason Drake
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN, 46140, USA
| | - Thomas Geurden
- Zoetis, Veterinary Medicine Research and Development, Hoge Wei 10, B-1930, Zaventem, Belgium
| | - Ronald Kaminsky
- ParaC-Consulting for Parasitology and Drug Discovery, 79685, Haeg-Ehrsberg, Germany
| | - Anja R Heckeroth
- MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany
| | - Bettina Schunack
- Bayer Animal Health GmbH: an Elanco Animal Health Company, 51368, Leverkusen, Germany
| | - Matthias Pollmeier
- Bayer Animal Health GmbH: an Elanco Animal Health Company, 51368, Leverkusen, Germany
| | - Frédéric Beugnet
- Boehringer-Ingelheim Animal Health, 29 Av Tony Garnier, Lyon, 69007, France
| | - Peter Holdsworth
- PAH Consultancy Pty Ltd, Wanniassa, 2903, Canberra, ACT, Australia
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Lappin MR, Tasker S, Roura X. Role of vector-borne pathogens in the development of fever in cats: 2. Tick- and sandfly-associated diseases. J Feline Med Surg 2020; 22:41-48. [PMID: 31916874 DOI: 10.1177/1098612x19895942] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PRACTICAL RELEVANCE There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite. AIM The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens vectored by ticks or sandflies, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats associated with pathogens known or suspected to be vectored by fleas was discussed within Part 1 of this two-part article series.
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Affiliation(s)
- Michael R Lappin
- Department of Clinical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, CO 80523, USA
| | - Séverine Tasker
- Bristol Veterinary School, University of Bristol, Langford, Bristol BS40 5DU, UK.,The Linnaeus Group, Shirley B90 4BN, UK
| | - Xavier Roura
- Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
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Huggins LG, Koehler AV, Ng-Nguyen D, Wilcox S, Schunack B, Inpankaew T, Traub RJ. Assessment of a metabarcoding approach for the characterisation of vector-borne bacteria in canines from Bangkok, Thailand. Parasit Vectors 2019; 12:394. [PMID: 31395073 PMCID: PMC6686542 DOI: 10.1186/s13071-019-3651-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/01/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Globally, bacterial vector-borne disease (VBD) exerts a large toll on dogs in terms of morbidity and mortality but nowhere is this more pronounced than in the tropics. Tropical environments permit a burgeoning diversity and abundance of ectoparasites some of which can transmit an extensive range of infectious agents, including bacteria, amongst others. Although some of these vector-borne bacteria are responsible for both animal and human diseases in the tropics, there is a scarcity of epidemiological investigation into these pathogens' prevalence. The situation is further exacerbated by frequent canine co-infection, complicating symptomatology that regular diagnostic techniques may miss or be unable to fully characterise. Such limitations draw attention to the need to develop screening tools capable of detecting a wide range of pathogens from a host simultaneously. RESULTS Here, we detail the employment of a next-generation sequencing (NGS) metabarcoding methodology to screen for the spectrum of bacterial VBD that are infecting semi-domesticated dogs across temple communities in Bangkok, Thailand. Our NGS detection protocol was able to find high levels of Ehrlichia canis, Mycoplasma haemocanis and Anaplasma platys infection rates as well as less common pathogens, such as "Candidatus Mycoplasma haematoparvum", Mycoplasma turicensis and Bartonella spp. We also compared our high-throughput approach to conventional endpoint PCR methods, demonstrating an improved detection ability for some bacterial infections, such as A. platys but a reduced ability to detect Rickettsia. CONCLUSIONS Our methodology demonstrated great strength at detecting coinfections of vector-borne bacteria and rare pathogens that are seldom screened for in canines in the tropics, highlighting its advantages over traditional diagnostics to better characterise bacterial pathogens in environments where there is a dearth of research.
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Affiliation(s)
- Lucas G. Huggins
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052 Australia
| | - Anson V. Koehler
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052 Australia
| | - Dinh Ng-Nguyen
- Faculty of Animal Sciences and Veterinary Medicine, Tay Nguyen University, Buon Ma Thuot, Dak Lak 630000 Vietnam
| | - Stephen Wilcox
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052 Australia
| | | | - Tawin Inpankaew
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok, 10900 Thailand
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3052 Australia
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Fourie JJ, Evans A, Labuschagne M, Crafford D, Madder M, Pollmeier M, Schunack B. Transmission of Anaplasma phagocytophilum (Foggie, 1949) by Ixodes ricinus (Linnaeus, 1758) ticks feeding on dogs and artificial membranes. Parasit Vectors 2019; 12:136. [PMID: 30909972 PMCID: PMC6434881 DOI: 10.1186/s13071-019-3396-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/11/2019] [Indexed: 11/16/2022] Open
Abstract
Background The interplay of speed of activity of acaricidal products and tick-borne pathogen transmission time is the major driver for disease prevention. This study aimed to investigate the time required for transmission of Anaplasma phagocytophilum by adult Ixodes ricinus ticks in vivo on dogs, and to confirm the time required for transmission observed in vivo, in vitro. Methods Nymphs of I. ricinus were experimentally infected with an A. phagocytophilum strain of canine origin. Dogs were allocated to 6 groups of 3 dogs each. Groups 1–5 were infested with 50 A. phagocytophilum-infected female adult ticks on Day 0. Ticks were removed post-infestation at 3, 6, 12, 24 and 48 h. Dogs in Group 6 were infested with 60 A. phagocytophilum-infected female adult ticks (left on dogs until engorged). Dogs were observed daily for general health and clinically examined on Day 0, and weekly from Day 14. Blood was collected for qPCR and serological analysis on Day 0 (pre-challenge) and weekly thereafter. In the in vitro study each artificial feeding chamber was seeded with 10 adult ticks (5 male/5 female), attachment assessed, and blood pools sampled for qPCR at 6 h intervals up to 72 h after first tick attachment. Results Anaplasma phagocytophilum specific antibodies and DNA were detected in all 3 dogs in Group 6. No A. phagocytophilum-specific antibodies or DNA were detected in any dogs in Groups 1–5. All dogs remained healthy. Female tick attachment in 60 artificial feeding chambers over 72 h ranged between 20–60%. Anaplasma phagocytophilum DNA was detected in the blood collected from 5% of chambers sampled at 6 h, with the highest number of positive samples (16.3%) observed at 36 h. Conclusions Transmission of A. phagocytophilum by I. ricinus ticks starts within a few hours after attachment but establishment of infections in dogs is apparently dependent on a minimum inoculation dose that was only observed when ticks attached for greater than 48 h. These findings highlight the need for acaricidal products to exert a repellent and/or rapid killing effect on ticks to forestall transmission and subsequent disease.
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Arthropod-borne pathogens of dogs and cats: From pathways and times of transmission to disease control. Vet Parasitol 2017; 251:68-77. [PMID: 29426479 DOI: 10.1016/j.vetpar.2017.12.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 12/25/2017] [Accepted: 12/26/2017] [Indexed: 11/21/2022]
Abstract
Vector-borne pathogens have developed a close relationship with blood feeding arthropod ectoparasites (e.g., mosquitoes, ticks, phlebotomine sand flies, black flies, fleas, kissing bugs, lice) and exploited a huge variety of vector transmission routes. Therefore, the life cycles of these pathogens result in a long evolved balance with the respective arthropod biology, ecology and blood feeding habits, instrumentally to the infection of several animal species, including humans. Amongst the many parasite transmission modes, such as ingestion of the arthropod, with its faeces or secretions, blood feeding represents the main focus for this article, as it is a central event to the life of almost all arthropod vectors. The time frame in which pathogens are transmitted to any animal host is governed by a large number of biological variables related to the vector, the pathogen, the host and environmental factors. Scientific data available on transmission times for each pathogen are discussed relative to their impact for the success of vector-borne disease control strategies. Blocking pathogen transmission, and thus preventing the infection of dogs and cats, may be achievable by the use of chemical compounds if they are characterised by a fast onset of killing activity or repellence against arthropods. The fast speed of kill exerted by systemic isoxazoline, as well as the repellent effect of pyrethroids have renewed the interest of the scientific community and pharmaceutical companies towards reducing the burden of vector-borne diseases under field conditions. However, endosymbionts and vaccines targeting arthropods or pathogen antigens should be further investigated as alternative strategies towards the goal of achieving an effective integrated control of vector-borne diseases.
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Murphy M, Cavalleri D, Seewald W, Drake J, Nanchen S. Laboratory evaluation of the speed of kill of lotilaner (Credelio™) against Ixodes ricinus ticks on dogs. Parasit Vectors 2017; 10:541. [PMID: 29089039 PMCID: PMC5664588 DOI: 10.1186/s13071-017-2467-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 10/11/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND With the geographical expansion of tick species and increased recognition of pathogens they transmit, there is a requirement for safe and rapidly effective control measures for dogs. Lotilaner, a novel isoxazoline, is rapidly absorbed following administration of a flavored chewable tablet formulation (Credelio™), providing at least 98% efficacy for at least 1 month following assessments at 48 h post-treatment, and following subsequent challenges. A study was conducted to determine the speed with which lotilaner kills ticks. METHODS From 38 dogs, the 32 with the highest Ixodes ricinus counts from a Day -4 infestation were randomized among four groups: two groups were untreated controls, two received lotilaner tablets at a minimum dose rate of 20 mg/kg. Infestations with I. ricinus were performed on Days -2, 7, 14, 21, 28 and 35. Counts were completed 4 and 8 h post-treatment (Day 0), and 8 and 12 h following subsequent infestations. All live ticks were incubated for 24 h following removal from study dogs. RESULTS At 4 h post-treatment, there was a 69.8% reduction in geometric mean live tick counts in treated dogs compared to controls. After incubation, the reduction increased to 97.2%. At 8 h after treatment, pre- and post-incubation reductions were 99.2 and 100%, respectively. Following post-treatment challenges, post-incubation efficacy through Day 28 at 8 and 12 h was at least 94.3 and 98.0%, respectively, and was 85.7 and 94.2% at 8 and 12 h after the Day 35 challenge. Mean live tick counts in the lotilaner groups were significantly lower than in the control groups at all assessments through Day 35 at 8 (t (7) ≥ 9, P < 0.0001, Days 0 to 28; t (7) = 3.54, P ≤ 0.0095, Day 35) and 12 h post-treatment and after subsequent infestations (t (7) ≥ 10, P < 0.0001, all days). There were no treatment-related adverse events. CONCLUSION Lotilaner at a minimum dose rate of 20 mg/kg began to kill ticks on dogs within 4 h of treatment and efficacy was 100% within 8 h. Lotilaner sustained a rapid kill of newly infesting I. ricinus through 35 days. By quickly killing ticks that infest dogs, lotilaner has potential to help limit the transmission of tick-borne pathogens.
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Affiliation(s)
- Martin Murphy
- Elanco Animal Health, Mattenstrasse 24a, 4058, Basel, Switzerland
| | | | - Wolfgang Seewald
- Elanco Animal Health, Mattenstrasse 24a, 4058, Basel, Switzerland
| | - Jason Drake
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN, 46140, USA.
| | - Steve Nanchen
- Elanco Animal Health, Mattenstrasse 24a, 4058, Basel, Switzerland
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13
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Little SE. Lotilaner - a novel systemic tick and flea control product for dogs. Parasit Vectors 2017; 10:539. [PMID: 29089062 PMCID: PMC5664799 DOI: 10.1186/s13071-017-2471-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 10/11/2017] [Indexed: 11/16/2022] Open
Affiliation(s)
- Susan E Little
- Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK, 74074, USA.
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14
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Mylonakis ME, Theodorou KN. Canine Monocytic Ehrlichiosis: An Update on Diagnosis and Treatment. ACTA VET-BEOGRAD 2017. [DOI: 10.1515/acve-2017-0025] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Abstract
Canine monocytic ehrlichiosis (CME) is a tick-borne disease of worldwide distribution. The major causative agent is Ehrlichia canis, a gram-negative, obligate intracellular, pleomorphic bacterium of the genus Ehrlichia, which infects monocytes, macrophages and lymphocytes, forming intracytoplasmic, membrane-bound bacterial aggregates, called morulae. After an incubation period of 8-20 days, the course of E. canis infection, can be sequentially divided into acute, subclinical and chronic phases, although these phases can hardly be distinguished in the clinical setting. Clinical recovery is the typical outcome of acutely infected dogs, entering the subclinical phase, during which they show no or minimal clinical signs and/or mild hematological abnormalities. Immunocompetent dogs may eliminate the infection during the acute or subclinical phases, but an unpredictable proportion of dogs will eventually develop the chronic phase, characterized by aplastic pancytopenia and high mortality, due to septicemia and/or severe bleeding. This article outlines briefly the pathogenesis of CME due to E. canis, and more thoroughly reviews the recent scientific literature pertaining to the diagnosis and treatment of this devastating disease.
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Affiliation(s)
- Mathios E. Mylonakis
- Konstantina N. Companion Animal Clinic, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki , Greece
| | - Konstantina N. Theodorou
- Companion Animal Clinic, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki , Greece
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15
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Schorderet-Weber S, Noack S, Selzer PM, Kaminsky R. Blocking transmission of vector-borne diseases. Int J Parasitol Drugs Drug Resist 2017; 7:90-109. [PMID: 28189117 PMCID: PMC5302141 DOI: 10.1016/j.ijpddr.2017.01.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/22/2017] [Indexed: 12/16/2022]
Abstract
Vector-borne diseases are responsible for significant health problems in humans, as well as in companion and farm animals. Killing the vectors with ectoparasitic drugs before they have the opportunity to pass on their pathogens could be the ideal way to prevent vector borne diseases. Blocking of transmission might work when transmission is delayed during blood meal, as often happens in ticks. The recently described systemic isoxazolines have been shown to successfully prevent disease transmission under conditions of delayed pathogen transfer. However, if the pathogen is transmitted immediately at bite as it is the case with most insects, blocking transmission becomes only possible if ectoparasiticides prevent the vector from landing on or, at least, from biting the host. Chemical entities exhibiting repellent activity in addition to fast killing, like pyrethroids, could prevent pathogen transmission even in cases of immediate transfer. Successful blocking depends on effective action in the context of the extremely diverse life-cycles of vectors and vector-borne pathogens of medical and veterinary importance which are summarized in this review. This complexity leads to important parameters to consider for ectoparasiticide research and when considering the ideal drug profile for preventing disease transmission.
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Affiliation(s)
| | - Sandra Noack
- Boehringer Ingelheim Animal Health GmbH, Binger Str. 173, 55216 Ingelheim, Germany.
| | - Paul M Selzer
- Boehringer Ingelheim Animal Health GmbH, Binger Str. 173, 55216 Ingelheim, Germany.
| | - Ronald Kaminsky
- ParaC Consulting for Parasitology and Drug Discovery, Altenstein 13, 79685 Haeg-Ehrsberg, Germany.
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