Changes

==Introduction==

==Introduction==

Infectious Pancreatic Necrosis (IPN) is a '''fish disease caused by an unenveloped icosahedral birnavirus'''. It is '''highly contagious''' and mainly affects '''intensively reared salmonid species of fish''' although it has a wide host range.  

Infectious Pancreatic Necrosis (IPN) is a '''fish disease caused by an unenveloped icosahedral birnavirus'''. The IPN virus is the type species of the genus Aquabirnavirus. It is '''highly contagious''' and mainly affects '''intensively reared salmonid species''' although it has a wide host range.  

The '''virulence of IPNV isolates varies massively'''; while most are isolated from subclinical cases, some can produce very high mortality.

The '''virulence of IPNV isolates varies widely'''; while most are isolated from subclinical cases, some isolates can produce very high fish mortality.

This disease is not zoonotic.

This disease is not zoonotic.

Due to increased awareness, regulations on movement of fish eggs and hygiene policies, '''many US states and provinces have successfully reduced or eradicated the disease from their fisheries.''' Unfortunately the situation in Europe is not so positive and disease is widespread. Iceland has no IPN infection in salmonids despite their large scale production probably and extensive fish inspection procedures. This may be due to their very strict importation policy for fin fish and may be an example to follow.

Due to increased awareness, regulations on movement of fish eggs and hygiene policies, '''many US states and provinces have successfully reduced or eradicated the disease from their fisheries.''' Unfortunately the situation in Europe is not so positive and disease is widespread. Iceland has no IPN infection in salmonids despite their large scale production probably and extensive fish inspection procedures. This may be due to their very strict importation policy for fin fish and may be an example to follow.

The disease is '''transmitted horizontally via shared water'''. The virus is shed in both '''faeces and urine'''. Brook and rainbow trout can also transmit disease '''vertically''' and this may be a feature in other species too. '''Homeothermic vertebrates and invertebrates''' are thought to be a source of disease early in an outbreak. '''Fomites and personnel''' can also act as mechanical vectors for transmission.

The virus is '''transmitted horizontally via shared water'''. It is shed in both '''faeces and urine'''. Brook and rainbow trout can also transmit disease '''vertically''' and this may be a feature in other species too. '''Homeothermic vertebrates and invertebrates''' are thought to be a source of the virus early in some outbreaks. The virus can also be transmitted mechanically by '''fomites and personnel'''.

==Signalment==

==Signalment==

Although salmonid species are by far the most common and economically important, a huge range of fish can be infected by IPN including Japanese eels, milkfish, pike, menhaden, wrasse, halibut, scallops and clams. The true scope of the virus is difficult to monitor due to the isolation of many other widespread birnaviruses that are difficult to differentiate from IPNV.  

Although salmonid species are by far the most common and economically important, a huge range of fish can be infected by IPN including Japanese eels, milkfish, pike, menhaden, wrasse, halibut, scallops and clams. The host range of the virus is difficult to monitor due to the isolation of many other widespread birnaviruses that are difficult to differentiate from IPNV.  

The disease most characteristically presents in '''rainbow trout, brook trout, brown trout, atlantic salmon and several pacific salmon species. '''

The disease most characteristically presents in '''rainbow trout, brook trout, brown trout, atlantic salmon and several pacific salmon species. '''

==Clinical Signs==

==Clinical Signs==

The first sign of an outbreak in salmonid fry is a '''sudden increase in daily mortality''' which progressively increases. Faster growing fish will usually be affected first, increasing the economic impact of the disease. '''Cumulative mortality varies from 10% to >90%.'''

The first sign of an outbreak in salmonid fry is a '''sudden increase in daily mortality''' which progressively increases. Faster growing fish will usually be affected first, increasing the economic impact of the disease. '''Cumulative mortality varies from 10% to >90%.'''

Disease course is usually only '''1-2 weeks in individual fish''', after which surviving fish recover.

Disease course is usually only '''1-2 weeks in individual fish''', after which surviving fish recover.

==Diagnosis==

==Diagnosis==

Virus can be consistently detected using '''cell cultures from teleost cell lines'''. It can then be confirmed by '''serum neutralisation or [[ELISA testing|ELISA]] '''. Antigen can be detected in tissues by [[FAT|'''indirect fluorescent antibody testing.''']]

Virus can be consistently detected using '''cell cultures from teleost cell lines'''. It can then be confirmed by '''serum neutralisation or [[ELISA testing|ELISA]] '''. IPNV antigens can be detected in tissues by [[FAT|'''indirect fluorescent antibody testing.''']]

On post-mortem, the '''pancreas has white-grey necrotic patches''' throughout and '''petechiation''' is evident throughout the viscera.  

On post-mortem, the '''pancreas has white-grey necrotic patches''' throughout and '''petechiation''' is evident throughout the viscera.  

Control is difficult due to the ubiquitous nature of the virus and thus control policies must be strictly adhered to and hygiene practices followed exclusively. Unfortunately, the '''economic losses from slaughter policies and movement restrictions''' are often larger than those caused directly by the disease itself.

Control is difficult due to the ubiquitous nature of the virus and thus control policies must be strictly adhered to and hygiene practices followed exclusively. Unfortunately, the '''economic losses from slaughter policies and movement restrictions''' are often larger than those caused directly by the disease itself.

'''Fertilised eggs should not be introduced if from broodstock of questionable IPN status. A protected water supply''' such as a spring or borehole pond where no fish ingress is possible should be used. Broodstock in which the virus is isolated should be destroyed.

'''Fertilised eggs should not be introduced if from broodstock of questionable IPN status. If possible, a protected water supply''' such as a spring or borehole pond where no fish ingress is possible should be used. Infected broodstock in which the virus is isolated should be destroyed.

Disinfection of eggs is unfortunately not always successful but may have some value.

Disinfection of eggs is unfortunately not always successful but may have some value.

==References==

==References==

<references/>

<references/>

{{CABI source

{{CABI source

|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=79273&loadmodule=datasheet&page=2144&site=160 infectious pancreatic necrosis] and [http://www.cabi.org/ahpc/?compid=3&dsid=96359&loadmodule=datasheet&page=2144&site=160  infectious pancreatic necrosis virus]

|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=79273&loadmodule=datasheet&page=2144&site=160 infectious pancreatic necrosis] and [http://www.cabi.org/ahpc/?compid=3&dsid=96359&loadmodule=datasheet&page=2144&site=160  infectious pancreatic necrosis virus]

|date =31 July 2011

|date =31 July 2011

}}

}}

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[[Category:Fish Diseases]]

[[Category:Fish Diseases]]

[[Category:CABI Expert Review]]

[[Category:CABI Expert Review]]