2011 International Ranavirus
Symposium
Minneapolis,
Minnesota, USA
Overview
The scientific community is increasingly aware that emerging
infectious diseases pose a significant threat to global biodiversity. A group of viruses in the genus Ranavirus (Family Iridoviridae)
cause disease in amphibians, reptiles and fish, and appear to be emerging in
some populations. Ranavirus-associated die-offs in larval and
adult amphibians have been documented in the Americas, Europe, and Asia, with
death rates often exceeding 90% during an outbreak. Ranavirus infections also have been reported
in wild and cultured fish populations worldwide. While research on reptiles has been slower to
accumulate, recent evidence suggests that ranaviruses are capable of causing morbidity
and mortality in free-ranging populations.
Together, these widespread die-offs have sparked a diversity
of research programs addressing the ecology and evolution of ranavirus-host
interactions, potential reservoirs and transmission dynamics, molecular
techniques for identifying and characterizing ranaviruses, immunological and
histopathological responses to infection, hypothesized causes for emergence,
and potential conservation strategies to control emergence.
In an attempt to bring scientists together from across the
globe to learn and share information about ranaviruses, the organizers began
planning in 2009 for the First
International Symposium on Ranaviruses.
In total, 23 scientists from 9 countries are participating with
expertise in herpetology, ichthyology, ecology, veterinary medicine,
immunology, genetics and molecular biology.
We thank these individuals for participating. We also thank our 12 sponsors that provided
>$22,000 to help offset travel costs for our presenters.
Below are resources that were generated from the
symposium. We thank everyone who
contributed!
Programs
Short Program: http://fwf.ag.utk.edu/mgray/ranavirus/RanavirusProgramFinalDraft.pdf
Expanded Program: http://fwf.ag.utk.edu/mgray/ranavirus/RanavirusProgram_LongVersion_FinalDraft.pdf
Research Directions
·
Future
Research Directions identified by Speakers related to their talks.
·
Urgent Research Directions identified
during Roundtable Discussions
Pathology,
Immunology, and Genetics
·
Ranavirus
Persistence: Occurrence and
mechanisms of ranavirus persistence in the host (i.e., covert infections) need
to be identified.
·
Immune
Responses: Better characterization of
immune responses against ranaviruses is needed among different host species and
amphibian developmental stages.
·
Tissues
Targeted: More information is needed
on what tissues are targeted initially and over time, and if these patterns
differ among amphibian species.
·
Reservoirs: Virus reservoirs need to be identified.
·
Historical
Occurrence: Archival specimens may be
useful at examining the historical occurrence of ranaviruses and approximate
times of introduction/emergence.
·
Captive
Facilities, Pathogen Pollution, and Virulence: Role of bullfrogs and ranaculture
facilities in the introduction of ranaviruses into naïve amphibian populations
needs to be determined. There is some evidence that highly virulent
strains may be associated with bullfrog farms and fish bait stores.
·
Vaccine
Development: For captive populations
and repatriation projects, there is a need to develop a vaccine for treatment
of individuals.
Ecology
and Conservation
·
Global
Ranavirus Mapping Project:
Jesse Brunner asked to contact him or Amanda Duffus if you are interested in
helping with launching a future website that will be used for reporting
occurrences of ranavirus infection and die-offs. Once launched, it will
be a great resource for sharing surveillance data.
·
Diagnostic
Testing: There is a need to
test the sensitivity and specificity of diagnostic tests and to test the
reliability of tissue (tail, toe, organ type) versus swab samples. The
group should consider aggressively seeking funds for a well-designed study,
particularly considering OIE’s listing of ranaviral disease.
·
Model Species: Jesse Brunner proposed that we consider
establishing one or more model species for ranavirus experiments so that
results from different experiments are more comparable. Two species were
suggested: wood frogs (Lithobates sylvaticus;
highly susceptible species) and American bullfrog (Lithobates catesbeianus; low susceptible species).
·
Sequencing: The group agreed there is a strong need to
sequence the entire genome of a variety of isolates and identify regions that
are important for differentiating strains and species of ranavirus.
Identifying portions of the genome that consistently contribute to virulence
also could lead to developing markers for identifying highly pathogenic
strains.
Moderator: Jason Hoverman
8:15: Ranaviruses: Past, Present, and Future (keynote address)
Greg Chinchar (University of Mississippi, USA)
8:45: Are Ranaviruses Capable of Causing Population Extirpations and Contributing to Species Declines?
Matt Gray (University of Tennessee, USA)
9:00: Amphibian
Ranavirus Transmission and Persistence
Jesse Brunner (Washington State University, USA)
9:15: Amphibian Susceptibilities to the Emerging
Amphibian Pathogen Ranavirus
Jason Hoverman (University of Colorado, USA)
9:30: Ranaviruses
and Amphibians: Outside the Box of Host-Parasite Relationships
David Lesbarrères (Laurentian University, Canada):
Jacob Kerby (University of South Dakota, USA)
Moderator: Andrew Storfer
10:15: Evidence
for Multiple Recent Host Species Shifts among the Ranaviruses (Family Iridoviridae)
James Jancovich (Cal State San Marcos, USA)
10:30: Host-Pathogen Coevolution:
From Genes to Landscapes
Andrew Storfer (Washington State University, USA)
10:45: Weakness
of innate immunity also contributes to susceptibility of Xenopus
tadpoles to FV3 infection
Jacques Robert (University of
Rochester, USA)
11:00: Complex
Role of Macrophages in Xenopus
Immune Defenses and Persistence of the Ranavirus FV3
Jacques Robert (University of Rochester, USA)
11:15: Comparative Pathology of Ranavirus Infections in Wild Amphibians
D. Earl Green (U. S. Geological Survey, USA)
11:30: Pathological Changes Observed in European Amphibians with Ranaviral Diseases
Ana Balseiro (SERIDA, Spain)
11:45: Comparative Pathology of Ranaviral Disease among Amphibians, Reptiles, and Fish
Debra Miller (University of Tennessee, USA)
Moderator: Jesse Brunner
1:30: Amphibian
Ranaviruses in Canada – Historical, Current, and Future Research Directions
Danna Schock (Keyano College, Canada)
1:45: Ranaviruses
in European Amphibians
Amada Duffus (Gordon College, USA)
2:00: Current
Understanding of Ranaviruses in South America
Rolando Mazzoni (Universidade Federal de Goiás, Brazil)
2:15: Emergence of
Ranaviruses in Japan
Yumi Une (Azabu University, Japan)
2:30: Ranaviruses in Frogs and Fish in Southeast Asia
Somkiat Kanchanakhan (Aquatic Animal Health Research Institute, Thailand)
2:45: Isolation
of Frog Virus 3 from Pallid Sturgeon Suggests an Interclass Host Shift
Tom Waltzek (University of Florida, USA)
Moderator: Debra Miller
3:15: Ranaviruses in European Reptiles
Rachel Marschang (Hohenheim University, Germany)
3:30: Ranaviral
Disease in Chelonians of North America
Matt Allender (University of Illinois, USA)
3:45: Challenge
Studies of Australian Native Reptiles with a Ranavirus Isolated from a Native
Amphibian
Ellen Ariel (James Cook University, Australia): (Matt Allender presenting)
Britt Bang Jensen (Norwegian Vet Institute, Norway)
4:15: Amphibian Commerce and the Threat of Pathogen Pollution
Angela Picco (U.S. Fish and Wildlife Service, USA)
Presentation Videos and Photos
Symposium Video (new!)
Instructions: (1) Download iTunes (if needed),
(2) Link to iTunes U site for the symposium,
(3) Click on any of the blue “View In iTunes” links,
(4) View by clicking on the desired “Video Number” on the left of list,
(5) Videos also can be downloaded by clicking on “Free”.
Gold Level of Support ($5,000)
·
University of
Tennessee Institute of Agriculture
Silver Level of Support ($2,500)
·
Association of
Reptilian and Amphibian Veterinarians
·
Australian Commonwealth Scientific and
Industrial Research Organisation
·
Environment
Canada, National Wildlife Research Centre
·
Morris Animal
Foundation
·
Tennessee Wildlife
Resources Agency
·
U.S. Forest
Service, Pacific Northwest Research Station
Bronze Level of Support (<$2,500)
·
American Society
of Ichthyologists and Herpetologists
·
Missouri
Department of Conservation
·
Partners in
Amphibian and Reptile Conservation
·
Tennessee
Herpetological Society
·
USGS Amphibian
Research and Monitoring Initiative
UT Department of
Forestry, Wildlife and Fisheries
