Pankreassykdom PD pancreas disease

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Pankreassykdom (PD) (pancreas disease)

• Dr.med.vet. Torunn Taksdal
• Veterinarian/researcher
• Section of Fish Health
• National Veterinary Institute

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Pancreas disease (PD)

• is a viral disease that ruins the pancreas and
  injure heart and skeletal muscle (fillet). The
  disease progress is longer and more complicated
  than Infectious pancreatic necrosis (IPN)
• is caused by infection with PD-virus Salmonid
  alphavirus (SAV)

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Salmonid alphavirus (SAV) causes

• Pancreas disease (PD) in Atlantic salmon in sea
  water fish farms in Scotland and Ireland (SAV 1)
• Sleeping disease (SD) in rainbow trout in fresh
  water fish farms in Europe (SAV 2)
• Pancreas disease (PD) in Atlantic salmon and
  rainbow trout in sea water fish farms in Norway
  (SAV 3)
• Atlantic salmon in fresh water is susceptible to
  SAV 1 and SAV 3 by experimental infection

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PD outbreaks i Norge 1995 November 2008
NO of cases
Kilder Anne Berit Olsen og Ruth Torill Kongtorp,
Veterinærinstituttet Bergen og Oslo
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Pancreas disease (PD)

• has a significant economic impact for the fish
  farming industry and is spreading
• is a notifiable disease in Norway (since December
  2007)
• Combat PD outside the endemic zone
• Prevent, control and limit the spread of PD
  inside the endemic zone

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Industry initiatives against PD

• Northern Norway
• Mid Norway (the counties north of the endemic
  zone)
• West Norway within PD endemic zone that has near
  100 support from the local farmers www.pdfri.no

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How do we discover PD?
Tid
Reduced appetite
Disease outbreak
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Autopsy

• Yellow mucoid gut contents, typical for fish that
  does not eat
• Circulatory disturbance ascites, exopthalmus,
  scale pocket oedema similar to ISA, CMS
• Pale heart similar to HSMI
• Heart rupture similar to CMS and HSMI
• Petechiae in the pyloric region similar to IPN
• Discoloured muscle/fillet
• No autopsy findings
• Runts from one to several months later
• The selection of fish for sampling for further
  laboratory examinations is vital for the final
  result

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Sampling if serious diseases are suspected

• Blood (for antibody examinations)
• Tissues for virus examination
• on transportation medium for cell culture
• on RNAlater for real time RT-PCR
• Bacteriological examinations, usually done
  locally
• Tissues for histological examinations, at least
  gill, heart, liver, pancreas, mid-kidney, spleen,
  muscle
• All samples from the same individuals from 5-10
  fish

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PD acute phase
Normal exocrine pancreas
Red colour indicates SAV in necrotic pancreas by
immunohistochistry, using antibodies to SAV
Acute pancreatic necrosis
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PD chronic phase,loss of pancreatic tissue
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Normal heart
Heart inflammation
Dead cells in heart
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Skeletal muscle
Normal red/aerob muscle
N
Dead, white/anaerobe muscle fibres /filet
(arrow), chronic PD N
normal muskel fibres
Inflammation in red/ aerob muscle, chronic PD
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Diagnostic criteria for PD National Veterinary
Institute, Norway

• Histopathology
• Detection of characteristic tissue lesions in
  samples from clinical diseased fish
• Detection of SAV from same individuals as above,
  by
• real time RT-PCR (heart and kidney)
• cell culture (heart and kidney)
• immunohistochemistry in necrotic pancreas

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2003
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2004
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2005
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2006
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2007
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2008
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• Combat PD outside the endemic zone
• If enhanced mortality diseases diagnostics aimed
  at finding the cause(s)
• Screening for SAV
• Prevent, control and limit the impact of PD
  inside the endemic zone
• If enhanced mortality diseases diagnostics aimed
  at finding the cause(s)
• Screening for SAV

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• horizontal spread is dominating
• vertical spread is uncertain i.e. not documented
• sleeping disease (SD) has been transferred
  vertically experimentally, but whether this
  happens under field conditions is uncertain.
• PD appears through the whole sea water production
  from sea water transfer to slaughter
• Most PD-affected fish groups remain infected with
  SAV until slaughter (will be published)
• some cases with SAV infection without registered
  disease outbreak

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Thank you for listening!
Foto Anne Berit Olsen, Veterinærinstituttet
Bergen