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Wirth W, Schwarzkopf L, Schaffer J, Ariel E. No Ranaviral DNA Found in Australian Freshwater Turtles, 2014-19, Despite Previous Serologic Evidence. J Wildl Dis 2024; 60:683-690. [PMID: 38741369 DOI: 10.7589/jwd-d-23-00051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 02/27/2024] [Indexed: 05/16/2024]
Abstract
Ranaviruses are pathogens of ectothermic vertebrates (fish, amphibians, and reptiles). Turtles are the most common group of reptiles reported with ranaviral infections. However, there have been no surveys for wild ranaviral infection in any turtles from the suborder Pleurodira, despite ranaviral distributions and experimentally susceptible pleurodiran turtle populations overlapping in several areas, including Australia. We assayed 397 pooled blood samples from six Australian freshwater turtle species collected from five different sites in northern Australia between 2014 and 2019. Historical serologic surveys in the area had found antiranaviral antibodies; however, we did not detect any ranaviral DNA in our samples. Discrepancies between historical serologic and our molecular results may be explained by low viral prevalence during the years that these samples were collected, survivorship bias, or possibly an age class bias in sampling.
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Affiliation(s)
- Wytamma Wirth
- College of Public Health, Medical and Veterinary Sciences, 1 James Cook Drive, James Cook University, Townsville, Queensland 4814, Australia
| | - Lin Schwarzkopf
- College of Science and Engineering, 1 James Cook Drive, James Cook University, The Science Place, Townsville, Queensland 4814, Australia
| | - Jason Schaffer
- Centre for Tropical Water and Aquatic Ecosystem Research, 1 James Cook Drive, Building 145, James Cook University, Townsville, Queensland 4814, Australia
| | - Ellen Ariel
- College of Public Health, Medical and Veterinary Sciences, 1 James Cook Drive, James Cook University, Townsville, Queensland 4814, Australia
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2
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Parrish K, Kirkland PD, Skerratt LF, Ariel E. Nidoviruses in Reptiles: A Review. Front Vet Sci 2021; 8:733404. [PMID: 34621811 PMCID: PMC8490724 DOI: 10.3389/fvets.2021.733404] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/19/2021] [Indexed: 12/17/2022] Open
Abstract
Since their discovery in 2014, reptile nidoviruses (also known as serpentoviruses) have emerged as significant pathogens worldwide. They are known for causing severe and often fatal respiratory disease in various captive snake species, especially pythons. Related viruses have been detected in other reptiles with and without respiratory disease, including captive and wild populations of lizards, and wild populations of freshwater turtles. There are many opportunities to better understand the viral diversity, species susceptibility, and clinical presentation in different species in this relatively new field of research. In captive snake collections, reptile nidoviruses can spread quickly and be associated with high morbidity and mortality, yet the potential disease risk to wild reptile populations remains largely unknown, despite reptile species declining on a global scale. Experimental studies or investigations of disease outbreaks in wild reptile populations are scarce, leaving the available literature limited mostly to exploring findings of naturally infected animals in captivity. Further studies into the pathogenesis of different reptile nidoviruses in a variety of reptile species is required to explore the complexity of disease and routes of transmission. This review focuses on the biology of these viruses, hosts and geographic distribution, clinical signs and pathology, laboratory diagnosis and management of reptile nidovirus infections to better understand nidovirus infections in reptiles.
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Affiliation(s)
- Kate Parrish
- Virology Laboratory, Elizabeth Macarthur Agricultural Institute, New South Wales (NSW) Department of Primary Industries, Menangle, NSW, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Peter D Kirkland
- Virology Laboratory, Elizabeth Macarthur Agricultural Institute, New South Wales (NSW) Department of Primary Industries, Menangle, NSW, Australia.,College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
| | - Lee F Skerratt
- Faculty of Veterinary and Agricultural Sciences, Melbourne Veterinary School, University of Melbourne, Melbourne, VIC, Australia
| | - Ellen Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD, Australia
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3
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Marschang RE, Salzmann E, Pees M. Diagnostics of Infectious Respiratory Pathogens in Reptiles. Vet Clin North Am Exot Anim Pract 2021; 24:369-395. [PMID: 33892892 DOI: 10.1016/j.cvex.2021.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Methods for the detection of pathogens associated with respiratory disease in reptiles, including viruses, bacteria, fungi, and parasites, are constantly evolving as is the understanding of the specific roles played by various pathogens in disease processes. Some are known to be primary pathogens with high prevalence in captive reptiles, for example, serpentoviruses in pythons or mycoplasma in tortoises. Others are very commonly found in reptiles with respiratory disease but are most often considered secondary, for example, gram-negative bacteria. Detection methods as well as specific pathogens associated with upper- and lower-respiratory disease are discussed.
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Affiliation(s)
| | | | - Michael Pees
- Department for Birds and Reptiles, University Veterinary Teaching Hospital, University of Leipzig, Clinic for Birds and Reptiles, An den Tierkliniken 17, Leipzig 04103, Germany
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4
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Page-Karjian A, Rafferty K, Xavier C, Stacy NI, Moore JA, Hirsch SE, Clark S, Manire CA, Perrault JR. Comprehensive health assessment and blood analyte reference intervals of gopher tortoises ( Gopherus polyphemus) in southeastern FL, USA. CONSERVATION PHYSIOLOGY 2021; 9:coab015. [PMID: 33815802 PMCID: PMC8009552 DOI: 10.1093/conphys/coab015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/20/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The gopher tortoise (Gopherus polyphemus), a keystone species, is declining throughout its geographic range. Lack of knowledge with respect to the potential infectious diseases present within wild populations creates a dilemma for wildlife biologists, conservationists and public policy makers. The objective of this study was to conduct a health assessment of two previously unstudied gopher tortoise aggregations located at two sites in southeastern FL. Samples were collected from 91 tortoises (48 adults, 35 juveniles, 8 hatchlings) captured at Florida Atlantic University's Harbor Branch Oceanographic Institute, in Fort Pierce, FL, USA in 2019, and Loggerhead Park in Juno Beach, FL, USA, during 2018-2019. Samples of blood, nasal swabs and oral/cloacal swabs were analyzed for hematology, plasma protein electrophoretic profiles and infectious disease testing including Mycoplasma spp. serology and polymerase chain reaction (PCR) assays for Ranavirus, Herpesvirus and Anaplasma spp. Hematological and plasma protein electrophoresis reference intervals are presented for adult and juvenile tortoises from both sites combined. Clinical signs consistent with upper respiratory tract disease (URTD) were observed in 18/91 (20%) tortoises, and antibodies to Mycoplasma agassizii were detected in 33/77 (42.9%) tortoises. Adult tortoises were significantly more likely than juveniles to have URTD clinical signs, and statistically significant, positive relationships were observed between the presence of antibodies to Mycoplasma spp. and carapace length, packed cell volume and plasma globulin concentrations. Anaplasma spp. inclusions were observed in 8/82 (10%) tortoises, but PCR detected Anaplasma sp. in 21/83 (25%) tortoises. Herpesvirus and Ranavirus were not detected in any blood or swab samples. This work contributes important baseline information on the health of gopher tortoises toward the southern end of the species' range.
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Affiliation(s)
- Annie Page-Karjian
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL 34946, USA
| | - Kathleen Rafferty
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL 34946, USA
| | - Clerson Xavier
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL 34946, USA
| | - Nicole I Stacy
- University of Florida College of Veterinary Medicine, Gainesville, FL 32609, USA
| | - Jon A Moore
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, FL 34946, USA
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
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5
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Adamovicz L, Allender MC, Gibbons PM. Emerging Infectious Diseases of Chelonians: An Update. Vet Clin North Am Exot Anim Pract 2020; 23:263-283. [PMID: 32327035 DOI: 10.1016/j.cvex.2020.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chelonians are increasingly challenged by anthropogenic threats and disease. This article summarizes recent literature and clinical experiences regarding 4 emerging infectious diseases in turtles and tortoises: ranaviruses, cryptosporidiosis, intranuclear coccodiosis of Testudines, and Emydomyces testavorans.
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Affiliation(s)
- Laura Adamovicz
- Wildlife Epidemiology Laboratory, University of Illinois College of Veterinary Medicine, 2001 South Lincoln Avenue, Urbana, IL 61802, USA.
| | - Matthew C Allender
- Wildlife Epidemiology Laboratory, University of Illinois College of Veterinary Medicine, 2001 South Lincoln Avenue, Urbana, IL 61802, USA
| | - Paul M Gibbons
- Avian and Exotic Veterinary Care, 7826 Northeast Sandy Boulevard, Portland, OR 97213, USA
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6
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Maclaine A, Wirth WT, McKnight DT, Burgess GW, Ariel E. Ranaviruses in captive and wild Australian lizards. Facets (Ott) 2020. [DOI: 10.1139/facets-2020-0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ranaviral infections have been associated with mass mortality events in captive and wild amphibian, fish, and reptile populations globally. In Australia, two distinct types of ranaviruses have been isolated: epizootic haematopoietic necrosis virus in fish and a Frog virus 3-like ranavirus in amphibians. Experimental studies and serum surveys have demonstrated that several Australian native fish, amphibian, and reptile species are susceptible to infection and supported the theory that ranavirus is naturally circulating in Australian herpetofauna. However, ranaviral infections have not been detected in captive or wild lizards in Australia. Oral-cloacal swabs were collected from 42 wild lizards from northern Queensland and 83 captive lizards from private collections held across three states/territories. Samples were tested for ranaviral DNA using a quantitative PCR assay. This assay detected ranaviral DNA in 30/83 (36.1%) captive and 33/42 (78.6%) wild lizard samples. This is the first time molecular evidence of ranavirus has been reported in Australian lizards.
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Affiliation(s)
- Alicia Maclaine
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Wytamma T. Wirth
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Donald T. McKnight
- College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Graham W. Burgess
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Ellen Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
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Carstairs SJ. Evidence for low prevalence of ranaviruses in Ontario, Canada's freshwater turtle population. PeerJ 2019; 7:e6987. [PMID: 31149410 PMCID: PMC6532614 DOI: 10.7717/peerj.6987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/19/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Ontario, Canada is home to eight native species of turtles; all eight are federally listed as Species At Risk, due to anthropogenic threats. However, until recently, reports of infectious disease have been lacking. Ranavirus is seen as an emerging threat for ectotherms globally, with mass die-offs most often reported in amphibians. Ranavirus has been detected in Ontario's amphibian populations, can be transmitted via water, and can be transmitted from amphibians to turtles. However, no studies on the prevalence of this virus in Ontario's turtles have previously been carried out. With recent reports of two confirmed positive case of ranavirus in turtles in Ontario, a knowledge of the ecology of ranavirus in Ontario's turtles has become even more important. This study estimates the prevalence of ranavirus in Ontario's turtles, and investigates the hypothesis that this is a newly emergent disease. METHODS Sixty-three samples were tested for ranavirus via PCR. These included a variety of turtle species, across their home range in Southern Ontario. Fifty-two of the samples originated from the liver and kidney of turtles who had succumbed to traumatic injuries after being admitted to the Ontario Turtle Conservation Centre; ten of the samples were taken from cloacal swabs, lesion swabs, or tail clips collected from live turtles showing signs of clinical disease. One of the live turtles was later euthanized for humane reasons and PCR was also carried out on the liver/kidney. RESULTS None of the 63 samples were found to be positive for ranavirus via PCR. The zero prevalence found in this study translates into a population prevalence estimate of less than 5%, with no change in prevalence from 2014-2018. DISCUSSION This is the first report on the prevalence of ranavirus in Ontario's turtles, and will help build an understanding of the ecology of this virus in Ontario. Ranavirus has historically been underreported in reptiles, but there has been an increase in global reports recently, most likely due to increased awareness. A carrier state is thought to exist in reptiles which makes surveillance in the population via random sampling a viable method of detection of prevalence. The first report of ranavirus in Ontario turtles occurred in 2018. This study suggests a continued low population prevalence for the years 2014-2018, however. Ongoing surveillance is necessary, as well as investigation of the eDNA presence in waterways as compared to the PCR of resident turtles, to further understand the sensitivity of these species to ranavirus infection. The utilization of qPCR would be helpful, to better quantify any positives encountered.
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Affiliation(s)
- Sue J. Carstairs
- Ontario Turtle Conservation Centre (Kawartha Turtle Trauma Centre), Selwyn, Ontario, Canada
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8
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Marschang RE. Virology. MADER'S REPTILE AND AMPHIBIAN MEDICINE AND SURGERY 2019. [PMCID: PMC7173601 DOI: 10.1016/b978-0-323-48253-0.00030-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wirth W, Schwarzkopf L, Skerratt LF, Ariel E. Ranaviruses and reptiles. PeerJ 2018; 6:e6083. [PMID: 30581674 PMCID: PMC6295156 DOI: 10.7717/peerj.6083] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 11/06/2018] [Indexed: 01/22/2023] Open
Abstract
Ranaviruses can infect many vertebrate classes including fish, amphibians and reptiles, but for the most part, research has been focused on non-reptilian hosts, amphibians in particular. More recently, reports of ranaviral infections of reptiles are increasing with over 12 families of reptiles currently susceptible to ranaviral infection. Reptiles are infected by ranaviruses that are genetically similar to, or the same as, the viruses that infect amphibians and fish; however, physiological and ecological differences result in differences in study designs. Although ranaviral disease in reptiles is often influenced by host species, viral strain and environmental differences, general trends in pathogenesis are emerging. More experimental studies using a variety of reptile species, life stages and routes of transmission are required to unravel the complexity of wild ranavirus transmission. Further, our understanding of the reptilian immune response to ranaviral infection is still lacking, although the considerable amount of work conducted in amphibians will serve as a useful guide for future studies in reptiles.
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Affiliation(s)
- Wytamma Wirth
- College of Public Health, Medical and Veterinary Sciences, James Cook University of North Queensland, Townsville, QLD, Australia
| | - Lin Schwarzkopf
- College of Science and Engineering, James Cook University of North Queensland, Townsville, QLD, Australia
| | - Lee F Skerratt
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Australia
| | - Ellen Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University of North Queensland, Townsville, QLD, Australia
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10
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Investigation of multiple mortality events in eastern box turtles (Terrapene carolina carolina). PLoS One 2018; 13:e0195617. [PMID: 29621347 PMCID: PMC5886585 DOI: 10.1371/journal.pone.0195617] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 03/26/2018] [Indexed: 11/19/2022] Open
Abstract
Wildlife mortality investigations are important for conservation, food safety, and public health; but they are infrequently reported for cryptic chelonian species. Eastern box turtles (Terrapene carolina carolina) are declining due to anthropogenic factors and disease, and while mortality investigations have been reported for captive and translocated individuals, few descriptions exist for free-living populations. We report the results of four natural mortality event investigations conducted during routine health surveillance of three Illinois box turtle populations in 2011, 2013, 2014, and 2015. In April 2011, over 50 box turtles were found dead and a polymicrobial necrotizing bacterial infection was diagnosed in five survivors using histopathology and aerobic/anaerobic culture. This represents the first reported occurrence of necrotizing bacterial infection in box turtles. In August 2013, paired histopathology and qPCR ranavirus detection in nine turtles was significantly associated with occupation of moist microhabitats, identification of oral plaques and nasal discharge on physical exam, and increases in the heterophil count and heterophil to lymphocyte ratio (p < 0.05). In July 2014 and 2015, ranavirus outbreaks reoccurred within a 0.2km radius of highly-disturbed habitat containing ephemeral ponds used by amphibians for breeding. qPCR ranavirus detection in five individuals each year was significantly associated with use of moist microhabitats (p < 0.05). Detection of single and co-pathogens (Terrapene herpesvirus 1, adenovirus, and Mycoplasma sp.) was common before, during, and after mortality events, but improved sample size would be necessary to determine the impacts of these pathogens on the occurrence and outcome of mortality events. This study provides novel information about the causes and predictors of natural box turtle mortality events. Continued investigation of health, disease, and death in free-living box turtles will improve baseline knowledge of morbidity and mortality, identify threats to survival, and promote the formation of effective conservation strategies.
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Ariel E, Elliott E, Meddings JI, Miller J, Santos MB, Owens L. Serological survey of Australian native reptiles for exposure to ranavirus. DISEASES OF AQUATIC ORGANISMS 2017; 126:173-183. [PMID: 29160216 DOI: 10.3354/dao03172] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ranaviruses have been isolated from many ectothermic vertebrates, and serological surveys of both amphibians and reptiles have shown the presence of ranaviral antibodies in a proportion of these populations. An enzyme-linked immunosorbent assay (ELISA) was developed to measure serum antibodies against ranavirus in Australian reptiles. The ELISA was validated with serum from challenge trials with Bohle iridovirus (BIV) in 6 reptilian species. A preliminary sero-survey of northern Queensland riparian reptile fauna (saw-shelled turtles Myuchelys latisternum, Krefft's river turtles Emydura macquarii krefftii, freshwater crocodiles Crocodylus johnstoni, as well as the snakes Boiga irregularis, Dendrelaphis punctulatus, Tropidonophis mairii, Morelia spilota, Liasis childreni and L. fuscus) revealed evidence of past exposure to Bohle iridoviral antigens in part of the population at several locations sampled. Furthermore, in Krefft's river turtles and freshwater crocodiles, a statistically significant trend was apparent for larger reptiles to be more likely to have BIV-reactive sera than smaller individuals. The use of adult tortoise populations as sentinels can assist in monitoring the presence of BIV in northern Australian freshwater streams, and thereby the potential dangers to native fauna from this agent.
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Affiliation(s)
- E Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, 4811 QLD, Australia
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12
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From fish to frogs and beyond: Impact and host range of emergent ranaviruses. Virology 2017; 511:272-279. [PMID: 28860047 DOI: 10.1016/j.virol.2017.08.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/29/2017] [Accepted: 08/01/2017] [Indexed: 11/21/2022]
Abstract
Ranaviruses are pathogens of ectothermic vertebrates, including amphibians. We reviewed patterns of host range and virulence of ranaviruses in the context of virus genotype and postulate that patterns reflect significant variation in the historical and current host range of three groups of Ranavirus: FV3-like, CMTV-like and ATV-like ranaviruses. Our synthesis supports previous hypotheses about host range and jumps: FV3s are amphibian specialists, while ATVs are predominantly fish specialists that switched once to caudate amphibians. The most recent common ancestor of CMTV-like ranaviruses and FV3-like forms appears to have infected amphibians but CMTV-like ranaviruses may circulate in both amphibian and fish communities independently. While these hypotheses are speculative, we hope that ongoing efforts to describe ranavirus genetics, increased surveillance of host species and targeted experimental assays of susceptibility to infection and/or disease will facilitate better tests of the importance of hypothetical evolutionary drivers of ranavirus virulence and host range.
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Goessling JM, Guyer C, Mendonça MT. More than Fever: Thermoregulatory Responses to Immunological Stimulation and Consequences of Thermoregulatory Strategy on Innate Immunity in Gopher Tortoises (Gopherus polyphemus). Physiol Biochem Zool 2017; 90:484-493. [DOI: 10.1086/692116] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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14
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Agha M, Price SJ, Nowakowski AJ, Augustine B, Todd BD. Mass mortality of eastern box turtles with upper respiratory disease following atypical cold weather. DISEASES OF AQUATIC ORGANISMS 2017; 124:91-100. [PMID: 28425422 DOI: 10.3354/dao03122] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Emerging infectious diseases cause population declines in many ectotherms, with outbreaks frequently punctuated by periods of mass mortality. It remains unclear, however, whether thermoregulation by ectotherms and variation in environmental temperature is associated with mortality risk and disease progression, especially in wild populations. Here, we examined environmental and body temperatures of free-ranging eastern box turtles Terrapene carolina during a mass die-off coincident with upper respiratory disease. We recorded deaths of 17 turtles that showed clinical signs of upper respiratory disease among 76 adult turtles encountered in Berea, Kentucky (USA), in 2014. Of the 17 mortalities, 11 occurred approximately 14 d after mean environmental temperature dropped 2.5 SD below the 3 mo mean. Partial genomic sequencing of the major capsid protein from 1 sick turtle identified a ranavirus isolate similar to frog virus 3. Turtles that lacked clinical signs of disease had significantly higher body temperatures (23°C) than sick turtles (21°C) during the mass mortality, but sick turtles that survived and recovered eventually warmed (measured by temperature loggers). Finally, there was a significant negative effect of daily environmental temperature deviation from the 3 mo mean on survival, suggesting that rapid decreases in environmental temperature were correlated with mortality. Our results point to a potential role for environmental temperature variation and body temperature in disease progression and mortality risk of eastern box turtles affected by upper respiratory disease. Given our findings, it is possible that colder or more variable environmental temperatures and an inability to effectively thermoregulate are associated with poorer disease outcomes in eastern box turtles.
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Affiliation(s)
- Mickey Agha
- Department of Wildlife, Fish, and Conservation Biology, University of California, One Shields Avenue, Davis, CA 95616, USA
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15
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EXPERIMENTAL CHALLENGE STUDY OF FV3-LIKE RANAVIRUS INFECTION IN PREVIOUSLY FV3-LIKE RANAVIRUS INFECTED EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) TO ASSESS INFECTION AND SURVIVAL. J Zoo Wildl Med 2015; 46:732-46. [DOI: 10.1638/2015-0022.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Effects of mycoplasmal upper-respiratory-tract disease on movement and thermoregulatory behavior of gopher tortoises (Gopherus polyphemus) in Georgia, USA. J Wildl Dis 2014; 50:745-56. [PMID: 25121399 DOI: 10.7589/2013-11-306] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract From 2011-12, we studied a gopher tortoise (Gopherus polyphemus) population with a historically high prevalence of antibodies to Mycoplasma agassizii to assess long-term effects of upper-respiratory-tract disease (URTD) on tortoise behavior. We radiotracked 30 adult tortoises (16 males, 14 females) from a long-term study site with the use of mark-recapture methods to determine site fidelity and to compare home-range size to that of a study in 1997. An additional 10 tortoises (six males, four females) with severe clinical signs of URTD from elsewhere in the study area were radiotracked and compared to tortoises that were asymptomatic or had only mild clinical signs. We also monitored thermoregulatory behavior of tortoises with the use of data loggers affixed to the carapace. There was no significant difference in home-range size between the asymptomatic tortoises and those with mild symptoms. Home ranges of tortoises with severe URTD were significantly larger than asymptomatic or mildly affected tortoises. Tortoises with severe clinical signs moved long distances over short periods, contradicting a hypothesis that chronically infected tortoises are less likely to emigrate. Prevalence of M. agassizii antibodies was similar among the three groups (98% overall), but prevalence of antibodies to a second pathogen associated with URTD, Mycoplasma testudineum, was lower in the asymptomatic (n=14, 7%) and mild-symptoms (n=7, 14%) groups than the severe-symptoms group (n=8, 50%). Variation in the average carapacial temperatures of tortoises with severe URTD was significantly different from carapacial temperatures of mild and asymptomatic tortoises, suggesting differences in thermoregulatory behavior of severely ill tortoises. Our 15-yr recapture data suggest that, despite high prevalence of M. agassizii, population density has not decreased over time. However, emigration, especially of tortoises with severe clinical disease, may play an important role in dispersal and persistence of pathogens.
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Surveillance for upper respiratory tract disease and Mycoplasma in free-ranging gopher tortoises (Gopherus polyphemus) in Georgia, USA. J Wildl Dis 2014; 50:733-44. [PMID: 25098305 DOI: 10.7589/2013-11-300] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract Upper respiratory tract disease (URTD) in the gopher tortoise (Gopherus polyphemus) is highly contagious and has been implicated in the reduction of populations throughout the range. With the exception of a few limited studies, the prevalence of URTD in Georgia, USA tortoise populations is poorly known. We found that exposure to Mycoplasma agassizii and Mycoplasma testudineum, associated with URTD, varied geographically among 11 Georgia tortoise populations. The prevalence of antibodies to M. agassizii in individual populations was either very low (0-3%, n=7 populations) or very high (96-100%, n=4 populations), whereas there was variation in the prevalence of antibodies to M. testudineum among populations (20-61%, n=10) with only one site being negative. Five sites had tortoises with antibodies to both pathogens, and these were the only sites where we observed tortoises with clinical signs consistent with URTD. We did not find tortoises with clinical signs of URTD at sites with tortoises with antibodies only to M. testudineum, which provides evidence that this organism may be of limited pathogenicity for gopher tortoises. Collectively, these data indicate that both M. agassizii and M. testudineum are present in Georgia populations of gopher tortoises and that clinical disease is apparent in populations where both pathogens are present. Additional research is needed to better understand the role of these two pathogens, and other potential pathogens, in the overall health of tortoise populations, especially if future conservation efforts involve translocation of tortoises.
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Brenes R, Miller DL, Waltzek TB, Wilkes RP, Tucker JL, Chaney JC, Hardman RH, Brand MD, Huether RR, Gray MJ. Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes. JOURNAL OF AQUATIC ANIMAL HEALTH 2014; 26:118-126. [PMID: 24895866 DOI: 10.1080/08997659.2014.886637] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ranaviruses have been associated with mortality of lower vertebrates around the world. Frog virus 3 (FV3)-like ranaviruses have been isolated from different ectothermic vertebrate classes; however, few studies have demonstrated whether this pathogen can be transmitted among classes. Using FV3-like ranaviruses isolated from the American bullfrog Lithobates catesbeianus, eastern box turtle Terrapene carolina carolina, and Pallid Sturgeon Scaphirhynchus albus, we tested for the occurrence of interclass transmission (i.e., infection) and host susceptibility (i.e., percent mortality) for five juvenile fish and three juvenile turtle species exposed to each of these isolates. Exposure was administered via water bath (10(3) PFU/mL) for 3 d and survival was monitored for 28 d. Florida softshell turtles Apalone ferox experienced no mortality, but 10% and 20% of individuals became infected by the turtle and fish isolate, respectively. Similarly, 5% of Mississippi map turtles Graptemys pseudogeographica kohni were subclinically infected with the turtle isolate at the end of the experiment. Channel Catfish Ictalurus punctatus experienced 5% mortality when exposed to the turtle isolate, while Western Mosquitofish Gambusia affinis experienced 10% mortality when exposed to the turtle and amphibian isolates and 5% mortality when exposed to the fish isolate. Our results demonstrated that interclass transmission of FV3-like ranaviruses is possible. Although substantial mortality did not occur in our experiments, the occurrence of low mortality and subclinical infections suggest that fish and aquatic turtles may function as reservoirs for FV3-like ranaviruses. Additionally, our study is the first to report transmission of FV3-like ranaviruses between fish and chelonians.
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Affiliation(s)
- Roberto Brenes
- a Department of Biology , Carroll University , 100 North East Avenue, Waukesha , Wisconsin 53186 , USA
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Evidence of Ranavirus Infections among Sympatric Larval Amphibians and Box Turtles. J HERPETOL 2014. [DOI: 10.1670/12-235] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Allender M, Mitchell M, Torres T, Sekowska J, Driskell E. Pathogenicity of Frog Virus 3-like Virus in Red-eared Slider Turtles (Trachemys scripta elegans) at Two Environmental Temperatures. J Comp Pathol 2013; 149:356-67. [DOI: 10.1016/j.jcpa.2013.01.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/18/2012] [Accepted: 01/25/2013] [Indexed: 11/17/2022]
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Abstract
Various new diseases have emerged in captive and wild populations of turtles and tortoises. Several of these seem to be on the rise and have the potential to cause widespread disease. This article reviews the current literature and authors' experience with intranuclear coccidiosis, cryptosporidium, iridovirus, and adenovirus. The biology, epidemiology, clinical signs, diagnosis, treatment, and pathologic changes are described for each disease.
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Affiliation(s)
- Paul M Gibbons
- Turtle Conservancy Behler Chelonian Center, Ojai, CA 93023, USA.
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Dong W, Zhang X, Yang C, An J, Qin J, Song F, Zeng W. Iridovirus infection in Chinese giant salamanders, China, 2010. Emerg Infect Dis 2012; 17:2388-9. [PMID: 22172343 PMCID: PMC3311219 DOI: 10.3201/eid1712.101758] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3.9.2. Togaviridae 3.10. Caliciviridae 3.11. Picornaviridae 3.12. Paramyxoviridae 4. Summary 5. Acknowledgements 6. Competing interests 7. References
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Affiliation(s)
- Ellen Ariel
- Microbiology and Immunology, School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Queensland 4810, Australia.
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