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Wilson LA, Marr M, Logie C, Beckmann K, Lurz P, Ogden R, Milne E, Everest DJ. Squirrelpox in a red squirrel in Fife. Vet Rec 2024; 194:312. [PMID: 38639234 DOI: 10.1002/vetr.4182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Affiliation(s)
- L A Wilson
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - M Marr
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - C Logie
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - K Beckmann
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - Pww Lurz
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - R Ogden
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - E Milne
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG
| | - D J Everest
- APHA Weybridge, Addlestone, Surrey, KT15 3NB
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2
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Everest DJ, Green C, Dastjerdi A, Davies H, Cripps R, McKinney C, Podgornik G, Stinson M, O'Hare S, Sapsford B, Mill A, Van der Waal Z, Robinson N, Trotter S, Shuttleworth CM. Opportunistic viral surveillance confirms the ongoing disease threat grey squirrels pose to sympatric red squirrel populations in the UK. Vet Rec 2023; 192:e2834. [PMID: 37024300 DOI: 10.1002/vetr.2834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/29/2022] [Accepted: 03/01/2023] [Indexed: 04/08/2023]
Abstract
BACKGROUND Red Squirrels United was a UK landscape-scale grey squirrel management programme undertaken between 2016 and 2020. METHODS A total of 11034 grey squirrels were removed by culling, with 1506 necropsied and 1405 suitable for adenovirus (AdV) or squirrelpox virus (SQPV) quantitative PCR (qPCR) analysis. Spleen, lip or hair were extracted, and DNA was isolated, with samples tested in duplicate by qPCR. RESULTS Of 1378 tissue samples, 43% were positive for AdV and 10% for SQPV. Of 1031 hair samples, 11% were positive for AdV and 10% for SQPV. Overall, 762 of 1405 (54%) animals were positive for one or both viruses. LIMITATIONS Ad hoc sampling was undertaken from limited geographical areas but provided the only dataset from that period, instead of extrapolating from historical data. CONCLUSIONS The grey squirrel is an asymptomatic reservoir host for AdV and SQPV. Interspecific infection transmission potential is demonstrated. Grey squirrel management by culling is essential for mainland red squirrel viability until other suitable management tools are available.
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Affiliation(s)
| | - Chalin Green
- Animal and Plant Health Agency-Weybridge, Addlestone, UK
| | | | - Hannah Davies
- Animal and Plant Health Agency-Weybridge, Addlestone, UK
| | - Rachel Cripps
- Lancashire Wildlife Trust, Seaforth Nature Reserve, Liverpool, UK
| | | | | | | | - Simon O'Hare
- Northumberland Wildlife Trust, Newcastle Upon Tyne, UK
| | | | - Aileen Mill
- Centre for Wildlife Management, School of Biology, Newcastle University, Newcastle Upon Tyne, UK
| | - Zelda Van der Waal
- Centre for Wildlife Management, School of Biology, Newcastle University, Newcastle Upon Tyne, UK
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3
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Wauters LA, Lurz PWW, Santicchia F, Romeo C, Ferrari N, Martinoli A, Gurnell J. Interactions between native and invasive species: A systematic review of the red squirrel-gray squirrel paradigm. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1083008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
The eastern gray squirrel (Sciurus carolinensis) has been labeled as one of the 100 worst invasive alien species by the IUCN. In Europe, the species has been introduced to Britain, Ireland and Italy, and its subsequent spread has resulted in wide-scale extinction of native Eurasian red squirrels (Sciurus vulgaris) from the areas colonized by the gray squirrel. This replacement of a native by an alien competitor is one of the best documented cases of the devastating effects of biological invasions on native fauna. To understand how this replacement occurs, we present a systematic review of the literature on competition and interactions between red and gray squirrels. We describe the patterns of red and gray squirrel distribution in those parts of Europe where gray squirrels occur and summarize the evidence on the different processes and mechanisms determining the outcome of competition between the native and alien species including the influence of predators and pathogens. Some of the drivers behind the demise of the red squirrel have been intensively studied and documented in the past 30 years, but recent field studies and mathematical models revealed that the mechanisms underlying the red-gray paradigm are more complex than previously thought and affected by landscape-level processes. Therefore, we consider habitat type and multi-species interactions, including host-parasite and predator-prey relationships, to determine the outcome of the interaction between the two species and to better address gray squirrel control efforts.
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Cruciani D, Crotti S, Paoloni D, La Morgia V, Felici A, Papa P, Cosseddu GM, Moscati L, Gobbi P. Health Status of the Eastern Grey Squirrel ( Sciurus carolinensis) Population in Umbria: Results of the LIFE Project 'U-SAVEREDS'. Animals (Basel) 2022; 12:ani12202741. [PMID: 36290127 PMCID: PMC9597752 DOI: 10.3390/ani12202741] [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: 09/01/2022] [Revised: 09/09/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022] Open
Abstract
Simple Summary Invasive alien species are non-native species introduced deliberately or unintentionally beyond their past or present natural distribution, and their introduction and spread threatens local biological diversity. The Eastern grey squirrel is native to North America and was introduced to the British Islands, Italy, and South Africa. Around the year 2000, a new population of grey squirrels was recorded in Perugia, central Italy, where the species populated an area of approximately 50 km2, both in woodland and urban areas. The Eastern grey squirrel represents a huge threat to the conservation of the native Eurasian red squirrel when the two species coexist. Moreover, given their confident behaviour with humans, the non-native squirrels can negatively impact public health. The U-SAVEREDS Project was set up for Eurasian red squirrel conservation in Umbria through the eradication of the alien species and it also provided information on the health status of the Eastern grey squirrel to identify any infectious agents. The recovery of zoonotic pathogens allowed to assess the Eastern grey squirrel’s impact on human and domestic and wild animals’ health, provide helpful feedback for the management and eradication procedures, and raise public awareness through environmental education. Abstract The introduction of the Eastern grey squirrel (Sciurus carolinensis) in Europe is one of the best-known cases of invasive alien species (IAS) colonisation, that poses a severe risk to the conservation of biodiversity. In 2003, it was released in a private wildlife park near the city of Perugia (Italy), where it is replacing the native Eurasian red squirrel (Sciurus vulgaris). The LIFE13 BIO/IT/000204 Project (U-SAVEREDS) was set up for the Sciurus vulgaris conservation in Umbria through an eradication campaign of grey squirrels. One hundred and fifty-four animals were analysed for bacteriological, mycological, virological, and serological investigations (C4 action). Sanitary screening showed that Sciurus carolinensis is a dermatophyte carrier, and therefore, it could cause public health issues for humans, considering its confident behaviour. Moreover, it has been marginally responsible for the spreading of Candida albicans, Coxiella burnetii, and Borrelia lusitaniae. Health status evaluation conducted on the Sciurus carolinensis population indicated that it is necessary to raise awareness of its impacts on biodiversity and human health. Moreover, the health status and behaviours of the IAS must be considered when control or eradication campaigns are planned.
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Affiliation(s)
- Deborah Cruciani
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
- Correspondence:
| | - Silvia Crotti
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
| | | | - Valentina La Morgia
- Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Via Vitaliano Brancati 48, 00144 Roma, Italy
| | - Andrea Felici
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
| | - Paola Papa
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
| | - Gian Mario Cosseddu
- Istituto Zooprofilattico Sperimentale del Lazio e della Toscana “M. Aleandri” (IZSLT), Via Appia Nuova 1411, 00178 Roma, Italy
- Istituto Zooprofilattico Sperimentale Abruzzo e Molise “G. Caporale” (IZSAM), Campo Boario, 64100 Teramo, Italy
| | - Livia Moscati
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
| | - Paola Gobbi
- Istituto Zooprofilattico Sperimentale dell’Umbria e delle Marche “Togo Rosati” (IZSUM), Via G. Salvemini 1, 06126 Perugia, Italy
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5
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Shuttleworth CM, Everest D, Holmes P, Bell S, Cripps R. An Opportunistic Assessment of the Impact of Squirrelpox Disease Outbreaks upon a Red Squirrel Population Sympatric with Grey Squirrels in Wales. Animals (Basel) 2022; 12:ani12010099. [PMID: 35011205 PMCID: PMC8749610 DOI: 10.3390/ani12010099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary In Europe, squirrelpox virus is carried by non-native grey squirrels and spread into native red squirrel populations. The virus causes a large proportion of infected red squirrels to die and contributes to local declines and the replacement by grey squirrels. There are relatively few published studies quantifying the impact of disease amongst red squirrels. We present findings from a short-term study in north Wales, United Kingdom. Abstract Native red squirrels (Sciurus vulgaris) persisted in the coastal mainland woodlands of northern Gwynedd whilst sympatric with an invasive grey squirrel (Sciurus carolinensis) population suppressed by culling. Squirrelpox disease in the red squirrel population was recorded in 2017 and 2020/21. An autumn 2020 outbreak was associated with only 17.4% of animals caught and marked in the preceding June known to be present in March 2021. Despite an opportunistic data collection lacking the rigour of empirical experimental design, we observed low local survival rates similar to previously published accounts reported during major squirrelpox outbreaks. The use of a conservation dog to detect red squirrel carcasses resulted in positive detection and confirmation of a temporal and spatial expansion of one disease outbreak. The study is the first in Wales to use conservation dogs and the findings reinforce the vital strategic importance of geographical isolation reducing sympatry of red with grey squirrels in European regions where the introduced congener is a source of the squirrelpox infection.
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Affiliation(s)
| | | | - Paul Holmes
- APHA Shrewsbury, Veterinary Investigation Centre, Shrewsbury SY1 4HD, UK; (P.H.); (S.B.)
| | - Suzi Bell
- APHA Shrewsbury, Veterinary Investigation Centre, Shrewsbury SY1 4HD, UK; (P.H.); (S.B.)
| | - Rachel Cripps
- Lancashire Wildlife Trust, Bamber Bridge PR5 6BY, UK;
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6
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Roberts MG, Heesterbeek JAP. Infection dynamics in ecosystems: on the interaction between red and grey squirrels, pox virus, pine martens and trees. J R Soc Interface 2021; 18:20210551. [PMID: 34637641 PMCID: PMC8513127 DOI: 10.1098/rsif.2021.0551] [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: 12/13/2022] Open
Abstract
Ecological and epidemiological processes and interactions influence each other, positively and negatively, directly and indirectly. The invasion potential of pathogens is influenced by the ecosystem context of their host species' populations. This extends to the capacity of (multiple) host species to maintain their (common) pathogen and the way pathogen dynamics are influenced by changes in ecosystem composition. This paper exemplifies these interactions and consequences in a study of red and grey squirrel dynamics in the UK. Differences and changes in background habitat and trophic levels above and below the squirrel species lead to different dynamic behaviour in many subtle ways. The range of outcomes of the different interactions shows that one has to be careful when drawing conclusions about the mechanisms and processes involved in explaining observed phenomena concerning pathogens in their natural environment. The dynamic behaviour also shows that planning interventions, for example for conservation purposes, benefits from understanding the complexity of interactions beyond the particular pathogen and its threatened host species.
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Affiliation(s)
- M G Roberts
- School of Natural and Computational Sciences, New Zealand Institute for Advanced Study and the Infectious Disease Research Centre, Massey University, Private Bag 102 904, North Shore Mail Centre, Auckland, New Zealand
| | - J A P Heesterbeek
- Department of Population Health Sciences, Faculty of Veterinary Medicine, University of Utrecht, Yalelaan 7, Utrecht 3584 CL, The Netherlands
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7
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Fingland K, Ward SJ, Bates AJ, Bremner‐Harrison S. A systematic review into the suitability of urban refugia for the Eurasian red squirrel
Sciurus vulgaris. Mamm Rev 2021. [DOI: 10.1111/mam.12264] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Kathryn Fingland
- School of Animal Rural and Environmental Sciences Nottingham Trent University Southwell NottinghamshireNG25 0QFUK
| | - Samantha J. Ward
- School of Animal Rural and Environmental Sciences Nottingham Trent University Southwell NottinghamshireNG25 0QFUK
| | - Adam J. Bates
- School of Animal Rural and Environmental Sciences Nottingham Trent University Southwell NottinghamshireNG25 0QFUK
| | - Samantha Bremner‐Harrison
- School of Animal Rural and Environmental Sciences Nottingham Trent University Southwell NottinghamshireNG25 0QFUK
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8
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DIAGNOSING AND CATEGORIZING LEPROSY IN LIVE EURASIAN RED SQUIRRELS ( SCIURUS VULGARIS) FOR MANAGEMENT, SURVEILLANCE, AND TRANSLOCATION PURPOSES. J Zoo Wildl Med 2021; 52:648-659. [PMID: 34130408 DOI: 10.1638/2020-0066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 11/21/2022] Open
Abstract
The presence of Mycobacterium lepromatosis and Mycobacterium leprae in Eurasian red squirrel (Sciurus vulgaris, ERS) carcasses throughout the British Isles, and leprosy as a disease, have recently been reported using histological and molecular diagnostic methods. In 2016, the first longitudinal study of ERS affected by leprosy was initiated. One of the main challenges was the reliable diagnosis of leprosy in live ERS, which is important for (a) welfare and case management and (b) surveillance or pretranslocation screening efforts. We explored diagnostic methods ranging from detailed clinical assessment and informative categorization of observed lesions, thermal imaging, serology (antiphenolic glycolipid-I antibody [αPGL-I] detection) to molecular methods (polymerase chain reaction [PCR]). For PCR the ear was established as the optimal sampling site. Based on the experiences from this 2-yr study we propose an objective categorization system for clinical lesions and a diagnostic framework for the combination of the diagnostic tools we found to be effective in live ERS: clinical assessment, αPGL-I serology, and PCR. Thermal imaging did not offer additional information for leprosy diagnostics in ERS. We propose an amended definition of leprosy lesions in ERS as "skin areas of local hair loss, in which a firm-rubbery, glossy swelling develops, that may ulcerate" and standardized terminology for describing ERS leprosy status. The information presented forms the basis of a consistent, reliable diagnostic and reporting system for leprosy cases in ERS.
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9
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Sainsbury AW, Chantrey J, Ewen JG, Gurnell J, Hudson P, Karesh WB, Kock RA, Lurz PWW, Meredith A, Tompkins DM. Implications of squirrelpox virus for successful red squirrel translocations within mainland
UK. CONSERVATION SCIENCE AND PRACTICE 2020. [DOI: 10.1111/csp2.200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
| | - Julian Chantrey
- School of Veterinary Science, University of Liverpool Liverpool UK
| | - John G. Ewen
- Institute of Zoology, Zoological Society of London Regent's Park, London UK
- IUCN SSC Conservation Translocation Specialist Group UK
| | | | - Peter Hudson
- Nelson Mandela African Institute—Arusha, A co‐hire of The Huck Institutes & The Institutes of Energy & The Environment Penn State University Pennsylvania USA
| | - William B. Karesh
- IUCN SSC Wildlife Health Specialist Group Chair, EcoHealth Alliance New York New York USA
| | | | - Peter W. W. Lurz
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh Roslin, Midlothian UK
| | - Anna Meredith
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh Roslin, Midlothian UK
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne Parkville VIC Australia
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10
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Blackett TA, Simpson VR, Haugland S, Everest DJ, Muir CF, Smith KC, Mill AC. Mortalities, amyloidosis and other diseases in free-living red squirrels ( Sciurus vulgaris) on Jersey, Channel Islands. Vet Rec 2018; 183:503. [PMID: 30181130 DOI: 10.1136/vr.104779] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 06/14/2018] [Accepted: 07/06/2018] [Indexed: 11/04/2022]
Abstract
Between 2007 and 2014, 337 free-living red squirrels (Sciurus vulgaris) on Jersey, Channel Islands, were examined post mortem as part of a mortality and disease surveillance scheme. Road traffic accidents (RTAs) were attributable for 50.7 per cent (171/337) of the casualties, 34.4 per cent (116/337) succumbed to diseases including fatal exudative dermatitis (FED), 7.1 per cent (24/337) to predation, 6.5 per cent (22/337) to other trauma and 1.2 per cent (4/337) to suspected poisoning. Cat predation accounted for 5 per cent (17/337) of mortalities. Pathologies were diverse and individual animals were often identified with more than one disease process. Squirrelpox virus (SQPV) particles were not detected in selected cases examined by transmission electron microscopy (TEM). Amyloid was identified in 19.3 per cent (65/337) of squirrels, often in conjunction with inflammatory lesions like hepatic capillariasis. A consistent cause of amyloid accumulation was not identified, although there was a significant association of amyloidosis with hepatic capillariasis and FED. In addition to RTAs, amyloidosis and FED have been identified as important causes of squirrel morbidity and mortality on Jersey, while the underlying aetiology and predisposing factors for these two disease complexes are presently unclear. Disease, fragmented woodlands, an increasingly suburban habitat, along with various anthropogenic factors, may jeopardise the long-term viability of this island red squirrel population.
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Affiliation(s)
| | | | | | | | - Clare F Muir
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, UK
| | - Kenneth C Smith
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, UK
| | - Aileen C Mill
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
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11
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Dale TD, Watts PC, Jones D, Pounder K, Everest DJ, Begon ME, Chantrey J. Enhancement of wildlife disease surveillance using multiplex quantitative PCR: development of qPCR assays for major pathogens in UK squirrel populations. EUR J WILDLIFE RES 2016; 62:589-599. [PMID: 32214943 PMCID: PMC7088385 DOI: 10.1007/s10344-016-1031-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/22/2016] [Accepted: 07/03/2016] [Indexed: 11/22/2022]
Abstract
Rapid development in polymerase chain reaction (PCR) technology has revolutionised the speed and accuracy of many diagnostic assays. However, comparatively few wildlife epidemiological studies use quantitative PCR (qPCR) for pathogen detection, even fewer employ an internal control, to ensure confidence in negative results, and PCR's ability to multiplex and therefore detect several targets in a single reaction is underutilised. Here, we describe the development of two multiplex qPCR assays for the red and grey squirrel that detect the pathogens squirrelpox virus (SQPV) and adenovirus in squirrels (SADV), both of which cause mortality in the red squirrel. Both assays use a section of the squirrel phosphoglycerate kinase gene as an endogenous internal control that identifies and compensates for both, inadequate sampling or PCR inhibition. Tests on infected squirrel tissue demonstrate that simple swab samples (particularly from distal antebrachial skin) are sufficient to detect and identify the relative quantity of SQPV DNA in both squirrel species, while rectal swabs and blood cell pellets can be used to reliably indicate SADV infection. These assays are sensitive and specific with an endogenous internal control providing confidence in negative results and allowing comparison across laboratories. Using such assays should prove advantageous in wildlife studies with limited resources while allowing the maximum data yield.
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Affiliation(s)
- Timothy D. Dale
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | | | - David Jones
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Kieran Pounder
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - David J. Everest
- Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, Surrey, KT15 3NB UK
| | - Michael E. Begon
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Julian Chantrey
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
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12
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Fiegna C, Dagleish M, Coulter L, Milne E, Meredith A, Finlayson J, Di Nardo A, McInnes C. Host-pathogen dynamics of squirrelpox virus infection in red squirrels (Sciurus vulgaris). Vet Microbiol 2016; 182:18-27. [DOI: 10.1016/j.vetmic.2015.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/12/2015] [Accepted: 10/13/2015] [Indexed: 11/15/2022]
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13
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Tompkins DM, Carver S, Jones ME, Krkošek M, Skerratt LF. Emerging infectious diseases of wildlife: a critical perspective. Trends Parasitol 2015; 31:149-59. [PMID: 25709109 DOI: 10.1016/j.pt.2015.01.007] [Citation(s) in RCA: 173] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 01/07/2015] [Accepted: 01/22/2015] [Indexed: 12/20/2022]
Abstract
We review the literature to distinguish reports of vertebrate wildlife disease emergence with sufficient evidence, enabling a robust assessment of emergence drivers. For potentially emerging agents that cannot be confirmed, sufficient data on prior absence (or a prior difference in disease dynamics) are frequently lacking. Improved surveillance, particularly for neglected host taxa, geographical regions and infectious agents, would enable more effective management should emergence occur. Exposure to domestic sources of infection and human-assisted exposure to wild sources were identified as the two main drivers of emergence across host taxa; the domestic source was primary for fish while the wild source was primary for other taxa. There was generally insufficient evidence for major roles of other hypothesized drivers of emergence.
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Affiliation(s)
| | - Scott Carver
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - Menna E Jones
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - Martin Krkošek
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St, Toronto, ON, M5S 3G5, Canada
| | - Lee F Skerratt
- One Health Research Group, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
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14
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Chantrey J, Dale TD, Read JM, White S, Whitfield F, Jones D, McInnes CJ, Begon M. European red squirrel population dynamics driven by squirrelpox at a gray squirrel invasion interface. Ecol Evol 2014; 4:3788-99. [PMID: 25614793 PMCID: PMC4301051 DOI: 10.1002/ece3.1216] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/03/2014] [Accepted: 07/13/2014] [Indexed: 11/17/2022] Open
Abstract
Infectious disease introduced by non-native species is increasingly cited as a facilitator of
native population declines, but direct evidence may be lacking due to inadequate population and
disease prevalence data surrounding an outbreak. Previous indirect evidence and theoretical models
support squirrelpox virus (SQPV) as being potentially involved in the decline of red squirrels
(Sciurus vulgaris) following the introduction of the non-native gray squirrel
(Sciurus carolinensis) to the United Kingdom. The red squirrel is a major UK
conservation concern and understanding its continuing decline is important for any attempt to
mitigate the decline. The red squirrel–gray squirrel system is also exemplary of the
interplay between infectious disease (apparent competition) and direct competition in driving the
replacement of a native by an invasive species. Time series data from Merseyside are presented on
squirrel abundance and squirrelpox disease (SQPx) incidence, to determine the effect of the pathogen
and the non-native species on the native red squirrel populations. Analysis indicates that SQPx in
red squirrels has a significant negative impact on squirrel densities and their population growth
rate (PGR). There is little evidence for a direct gray squirrel impact; only gray squirrel presence
(but not density) proved to influence red squirrel density, but not red squirrel PGR. The dynamics
of red SQPx cases are largely determined by previous red SQPx cases, although previous infection of
local gray squirrels also feature, and thus, SQPV-infected gray squirrels are identified as
potentially initiating outbreaks of SQPx in red squirrels. Retrospective serology indicates that
approximately 8% of red squirrels exposed to SQPV may survive infection during an epidemic.
This study further highlights the UK red squirrel – gray squirrel system as a classic example
of a native species population decline strongly facilitated by infectious disease introduced by a
non-native species. It is therefore paramount that disease prevention and control measures are
integral in attempts to conserve red squirrels in the United Kingdom.
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Affiliation(s)
- Julian Chantrey
- Institute of Integrative Biology, University of Liverpool Biosciences Building, Crown Street, Liverpool, L69 7ZB, U.K
| | - Timothy D Dale
- Institute of Integrative Biology, University of Liverpool Biosciences Building, Crown Street, Liverpool, L69 7ZB, U.K
| | - Jonathan M Read
- Institute of Infection and Global Health, University of Liverpool Leahurst Campus, Neston, CH64 7TE, U.K
| | - Steve White
- Lancashire Wildlife Trust, Seaforth Nature Reserve Liverpool, L21 1JD, U.K
| | - Fiona Whitfield
- Lancashire Wildlife Trust, Seaforth Nature Reserve Liverpool, L21 1JD, U.K
| | - David Jones
- Institute of Infection and Global Health, University of Liverpool Leahurst Campus, Neston, CH64 7TE, U.K
| | - Colin J McInnes
- Moredun Institute, Pentlands Science Park Bush Loan, Penicuik, Midlothian, EH26 0PZ, U.K
| | - Michael Begon
- Institute of Integrative Biology, University of Liverpool Biosciences Building, Crown Street, Liverpool, L69 7ZB, U.K
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15
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Novel host-related virulence factors are encoded by squirrelpox virus, the main causative agent of epidemic disease in red squirrels in the UK. PLoS One 2014; 9:e96439. [PMID: 24983354 PMCID: PMC4077651 DOI: 10.1371/journal.pone.0096439] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 04/08/2014] [Indexed: 01/16/2023] Open
Abstract
Squirrelpox virus (SQPV) shows little evidence for morbidity or mortality in North American grey squirrels (Sciurus carolinensis), in which the virus is endemic. However, more recently the virus has emerged to cause epidemics with high mortality in Eurasian red squirrels (S. vulgaris) in Great Britain, which are now threatened. Here we report the genome sequence of SQPV. Comparison with other Poxviridae revealed a core set of poxvirus genes, the phylogeny of which showed SQPV to be in a new Chordopoxvirus subfamily between the Molluscipoxviruses and Parapoxviruses. A number of SQPV genes were related to virulence, including three major histocomaptibility class I homologs, and one CD47 homolog. In addition, a novel potential virulence factor showing homology to mammalian oligoadenylate synthetase (OAS) was identified. This family of proteins normally causes activation of an endoribonuclease (RNaseL) within infected cells. The putative function of this novel SQPV protein was predicted in silico.
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16
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Strauss A, White A, Boots M. Invading with biological weapons: the importance of disease-mediated invasions. Funct Ecol 2012. [DOI: 10.1111/1365-2435.12011] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Alex Strauss
- Department of Biology; Indiana University; Bloomington Indiana 47405 USA
| | - Andy White
- Department of Mathematics; Maxwell Institute for Mathematical Sciences; Heriot-Watt University; Edinburgh EH14 4AS UK
| | - Mike Boots
- Biosciences; College of Life and Environmental Sciences; University of Exeter; Cornwall Campus, Treliever Road Penryn Cornwall TR10 9EZ UK
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17
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McInnes CJ, Coulter L, Dagleish MP, Deane D, Gilray J, Percival A, Willoughby K, Scantlebury M, Marks N, Graham D, Everest DJ, McGoldrick M, Rochford J, McKay F, Sainsbury AW. The emergence of squirrelpox in Ireland. Anim Conserv 2012. [DOI: 10.1111/j.1469-1795.2012.00570.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - L. Coulter
- Moredun Research Institute; Edinburgh; UK
| | | | - D. Deane
- Moredun Research Institute; Edinburgh; UK
| | - J. Gilray
- Moredun Research Institute; Edinburgh; UK
| | | | | | - M. Scantlebury
- Queen's University Belfast; Belfast; Northern Ireland; UK
| | - N. Marks
- Queen's University Belfast; Belfast; Northern Ireland; UK
| | - D. Graham
- Animal Health Ireland; Carrick on Shannon; Eire
| | - D. J. Everest
- Animal Health and Veterinary Laboratories Agency; Surrey; UK
| | | | | | - F. McKay
- Zoological Society of London; London; UK
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18
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LaRose JP, Meredith AL, Everest DJ, Fiegna C, McInnes CJ, Shaw DJ, Milne EM. Epidemiological and postmortem findings in 262 red squirrels (Sciurus vulgaris) in Scotland, 2005 to 2009. Vet Rec 2010; 167:297-302. [PMID: 20729517 DOI: 10.1136/vr.c4196] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Postmortem and virological examinations for squirrelpox virus (SQPV) were carried out on 262 red squirrels (Sciurus vulgaris) found dead or moribund in Scotland between September 2005 and July 2009, to determine the likely causes of death and highlight factors that might be threats to the red squirrel population. Most of the squirrels were submitted from Dumfries and Galloway, and 71 per cent of them were adults. Road traffic accidents, squirrelpox, trauma or starvation were responsible for death in a large proportion (73 per cent) of the squirrels. Thin or emaciated body condition was associated with deaths resulting from pneumonia SQPV infection and starvation, and with the presence of external parasites. There were differences between age groups with regard to the cause of death; a large proportion of juveniles died of starvation, whereas a large proportion of subadults and adults died in road traffic accidents. SQPV infection was associated with the presence of external parasites, but was not associated with the sex of the animals.
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Affiliation(s)
- J P LaRose
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK
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19
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Simpson VR, Hargreaves J, Everest DJ, Baker AS, Booth PA, Butler HM, Blackett T. Mortality in red squirrels (Sciurus vulgaris) associated with exudative dermatitis. Vet Rec 2010; 167:59-63. [PMID: 20622205 DOI: 10.1136/vr.b4887] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Red squirrels (Sciurus vulgaris) found dead or dying on the Isle of Wight and the island of Jersey were suffering from exudative, ulcerative dermatitis and superficial staphylococcal pyoderma. The principal gross lesions were on the lips, eyelids and feet and showed similarities to those of squirrelpox. The histopathological lesions were also similar and, although there was no ballooning degeneration of epidermal cells, intracytoplasmic inclusions resembling those seen in poxvirus infections were present. Examination of lesions by electron microscopy failed to identify any virions, and PCR analysis for squirrelpox virus proved negative. The skin lesions also resembled those of mange, but although numerous mites were present in the fur these were mostly Dermacarus sciurinus with small numbers of Metalistrophorus pagenstecheri. The occurrence of these species on red squirrels in Britain is confirmed, but neither is pathogenic and they were not considered to have been involved in the pathogenesis of the dermatitis, the primary cause of which was not established.
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Affiliation(s)
- V R Simpson
- Wildlife Veterinary Investigation Centre, Chacewater, Truro, Cornwall TR4 8PB.
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20
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Detection of squirrel poxvirus by nested and real-time PCR from red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels. BMC Vet Res 2010; 6:33. [PMID: 20529323 PMCID: PMC2887832 DOI: 10.1186/1746-6148-6-33] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 06/08/2010] [Indexed: 11/10/2022] Open
Abstract
Background Squirrel poxvirus (SQPV) is highly pathogenic to red squirrels (Sciurus vulgaris), and is a significant contributing factor to the local extinction of the species in most parts of England and Wales, where infection is endemic in Eastern grey squirrel (Sciurus carolinensis) populations. Although a nested PCR assay has been used successfully to study the epidemiology of SQPV, samples have a long processing time and the assay is not quantifiable. Results This project describes the design and optimization of a real-time PCR for SQPV. Comparison with the nested PCR showed the real-time assay to be more sensitive by one log and able to detect approximately 144 genome copies per mg of tissue. Conclusions The real-time PCR has been used to quantify viral genome load in tissues from diseased and apparently healthy red and grey squirrels, and suggests that the titre of virus in tissues from diseased red squirrels is considerably higher than that found even in a grey squirrel with cutaneous lesions.
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21
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Abstract
SUMMARYThe dramatic decline of the native red squirrel in the UK has been attributed to both direct and disease-mediated competition with the grey squirrel where the competitor acts as a reservoir host of squirrelpox virus (SQPV). SQPV is threatening red squirrel conservation efforts, yet little is known about its epidemiology. We analysed seroprevalence of antibody against SQPV in grey squirrels from northern England and the Scottish Borders in relation to season, weather, sex, and body weight using Generalized Linear Models in conjunction with Structural Equation Modelling. Results indicated a heterogeneous prevalence pattern which is male-biased, increases with weight and varies seasonally. Seroprevalence rose during the autumn and peaked in spring. Weather parameters had an indirect effect on SQPV antibody status. Our findings point towards a direct disease transmission route, which includes environmental contamination. Red squirrel conservation management options should therefore seek to minimize squirrel contact points.
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