The Potential Role of Fish in Spreading Ranaviruses

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The Potential Role of Fish in Spreading
Ranaviruses

• Leigh Owens
• Bradford Cullen
• James Cook University

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Viral Pandemics in Aquatic Animals

• Nodaviruses in marine fish
• Ranavirus in fish
• Ranavirus in amphibians ?
• Are these linked

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Visualisation of Systemic Iridovirus in Hobby and
Related Fish
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Visualisation of Systemic Iridovirus in Hobby and
Related Fish continued
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Iridoviruses in Hobby Fish in Australia
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Experimental Ranavirosis
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Experimental Ranavirosis continued
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Normal
removal of senescent RBC from circulation by the
spleen
Red Blood Cells age
haemosideran removed for new RBC
production of RBC
Chronic
destruction of haematopoietic tissue
macromolecule synthesis shutdown
no production of red blood cells
widespread haemosiderosis lowered PCV
anaemia immunosuppression
haemosideran stored for production of RBC
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Conclusions

• Some fish are acutely susceptible some are
  chronically susceptible to ranavirus
• Surviving fish are carriers for the rest of their
  lives
• The pathogenesis of ranavirus in fish and
  amphibians appears identical
• Most currently used diagnostic tests are not
  sensitive enough to give an accurate picture
• Hobby fish appear to be a major conduit for
  diseases in fish, amphibians and reptiles