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Also known as: '''''Blue-eye'''''—'''''BE'''''—'''''Blue eye syndrome'''''—'''''Porcine paramyxovirus blue eye disease'''''—'''''PPBED'''''.

Also known as: '''''Blue-eye''''' — '''''BE''''' — '''''Blue Eye Syndrome''''' — '''''Porcine Paramyxovirus Blue Eye Disease''''' — '''''PPBED''''' —

==Introduction==

==Introduction==

Blue eye disease is caused by the virus [[Blue-Eye Paramyxovirus|'''''Blue-eye paramyxovirus (BEP)''''']]. It causes '''nervous, reproductive''' and '''respiratory signs''' in its domestic host, the pig. The disease is not considered a zoonosis.

Blue eye disease is caused by the virus '''''Blue-eye paramyxovirus (BEPV)''''', which is a negative sense single stranded RNA (ssRNA) virus. It is closely related to the ''Mumps virus'' and ''Simian virus 5'' and is classified under the family [[:Category:Paramyxoviridae|'''''Paramyxoviridae''''']]. The virus is 135-148nm by 257-360nm, has a buoyant density in sucrose gradients of 1.21 g/ml and is considered to be '''polymorphic''' (but mainly spherical). BEPV envelope is covered in surface projections and the envelope nucleocapsid expresses hemagglutinin-neuraminidase and fusion and matrix proteins. The virus consists of six structural proteins  and is '''resistant''' to  '''actinomycin D''' and '''sensitive''' to '''chloroform, formalin''' and '''beta propiolactone'''.

 

It causes '''nervous, reproductive''' and '''respiratory signs''' in its domestic host, the pig. The disease is not considered a zoonosis.

==Signalment==

==Signalment==

The disease affects '''all age ranges of pigs''' and also causes '''reproductive disorder in the boar'''.

The disease affects '''all age ranges of pigs''' and also causes '''reproductive disorder in the boar'''.

'''Piglets and Weaners:'''

'''Piglets and Weaners:'''

Piglet and weaners suffer from prostration, hind limb '''stiffness''', generalised weakness, muscle fasciculation’s, retarded growth, depression, excitation, head pressing, circling, '''hyperaesthesia''', abnormal behaviour/'''aggression''' and '''coma'''. In piglets the disease also causes '''changes in hair coat''' (dull/rough), '''ocular erosions''', '''enlarged distended bladder''' and  '''constipation/reduction in faces or diarrhoea'''.

Piglet and weaners suffer from prostration, hind limb '''stiffness''', generalised weakness, muscle fasciculations, retarded growth, depression, excitation, head pressing, circling, '''hyperaesthesia''', abnormal behaviour/'''aggression''' and '''coma'''. In piglets the disease also causes '''changes in hair coat''' (dull/rough), '''ocular erosions''', '''enlarged distended bladder''' and  '''constipation/reduction in faeces or diarrhoea'''.

'''Sows:'''

'''Sows:'''

In sows the disease causes '''infertility''', reproductive failures, '''embryonic mortality''' and '''return to oestrus in the first third of gestation''' and '''stillbirths, small litters''' and '''mummification in late gestation'''.  

In sows the disease causes '''infertility''', reproductive failures, '''embryonic mortality''', '''return to oestrus in the first third of gestation''' and '''stillbirths, small litters''' and '''mummification in late gestation'''.  

'''Boars:'''

'''Boars:'''

In the boar it causes male '''infertility, lack of libido, haemospermia''', and '''orchitis with epidydimitis''' and swelling of the genitals.

In the boar it causes '''infertility, lack of libido, haemospermia''', and '''orchitis with epidydimitis''' and swelling of the genitals.

==Epidemiology==

==Epidemiology==

The virus can be found in the '''axon of neurons''' from its original site of replication, which is thought to be the '''nasal mucosa and tonsils'''.  It is also found   in tissues such as lung, liver, spleen, kidney, lymph node, heart and testis; suggesting that the virus is spread hematogenously.

BEPV is spread via direct contact, fomites and possibly birds. The virus can be found in the '''axon of neurons''' from its original site of replication, which is thought to be the '''nasal mucosa and tonsils'''.  It is also found in tissues such as lung, liver, spleen, kidney, lymph node, heart and testis; suggesting that the virus is spread haematogenously.

 

The virus has cytopathic effects on these tissues as causes individual rounded cells, cytoplasmic vacuoles, and syncytium formation, dead cells detachment, which leave small plaques. Viral inclusion bodies can be seen in some cells.

==Distribution==

==Distribution==

The disease is economically important to '''Central Mexico and its states'''.

The disease appears restricted to '''Central Mexico and its states'''.

==Diagnosis==

==Diagnosis==

''Blue-eyed disease'' can be diagnosed by a combination of history, above clinical signs, serology, lesions and virus isolation.

''Blue-eyed disease'' can be diagnosed by a combination of history, above clinical signs, serology, lesions and virus isolation.

A week after infection a serological response can be seen using a '''virus neutralization test''' and 2 weeks later with a '''haematoglutination inhibition test'''.  

A week after infection a serological response can be seen using a '''virus neutralization test''' and 2 weeks later with a [[Agglutination|'''haematoglutination inhibition test''']].  

The diagnosis can be '''confirmed''' using '''virus isolation''' on PK15 or primary pig kidney, using samples from infected tonsils, brain or lung.

The diagnosis can be '''confirmed''' using '''virus isolation''' on PK15 or primary pig kidney, using samples from infected tonsils, brain or lung.

During infection '''lymphocytosis''' and '''monocytosis''' may be observed.

During infection '''[[lymphocytosis]]''' and '''[[monocytosis]]''' may be observed.

On '''post mortem''' all age ranges have corneal opacity which is mainly unilateral. Piglets show evidence of mild pneumonia, distended bladder and stomach, fibrin strands in the peritoneal cavity and '''congestion in the brain'''. Growers show kidney and '''pericardial haemorrhages''' as well as brain congestion. '''Necrosis of the seminiferous tubules''' and rupture of the epidydimis walls and subsequent abscess and granuloma formation has been documented in boars.

On '''post mortem''' all age ranges have corneal opacity which is mainly unilateral. Piglets show evidence of mild pneumonia, distended bladder and stomach, fibrin strands in the peritoneal cavity and '''congestion in the brain'''. Growers show kidney and '''pericardial haemorrhages''' as well as brain congestion. '''Necrosis of the seminiferous tubules''' and rupture of the epidydimis walls and subsequent abscess and granuloma formation has been documented in boars.

'''Differential diagnosis''': [[Porcine Reproductive and Respiratory Syndrome| ''PRRS'']] and [[Suid Herpesvirus 1| ''Pseudorabies'']].

'''Differential diagnoses''': [[Porcine Reproductive and Respiratory Syndrome|''PRRS'']] and [[Suid Herpesvirus 1|''Pseudorabies'']].

==Treatment==

==Treatment==

There is '''no treatment''' for ''Blue eye disease''. '''Supportive medication''' for respiratory and inflammatory disease should be administered.

There is '''no treatment''' for ''Blue eye disease''. '''Supportive medication''' for respiratory and inflammatory disease should be administered.

==Control==

==Control==

The disease is '''self limiting''' and closed herds will have sporadic outbreaks of the disease once a herd is infected. There is '''no approved vaccine''' for the control of blue eye disease but killed-virus vaccine has been shown to be effective <ref name="Stephano et al., 1992"> Stephano, H.A., Olvera, M.J., Garcia, V.P., Ramirez, M.H., Cordoba, D.J. (1992). '''Eficacia de una vacuna inactivada para la prevencion de la infeccion por el paramyxovirus de ojo azul'''. ''Mem 27th Congr Assoc Mex Vet Esp Cerdos. Acapulco, Gro''., 24-28.</ref>.  Preventative health programmes to prevent the spread of the disease are the most effective methods of control. Eliminating blue eye disease from affected herds can be achieved by '''closing the herd, running an all-in/all-out systems''', and following good '''washing and disinfecting protocols'''.

The disease is '''self limiting''' and closed herds will have sporadic outbreaks of the disease once a herd is infected. There is '''no approved vaccine''' for the control of blue eye disease but killed-virus vaccine has been shown to be effective <ref name="Stephano et al., 1992"> Stephano, H.A., Olvera, M.J., Garcia, V.P., Ramirez, M.H., Cordoba, D.J. (1992). '''Eficacia de una vacuna inactivada para la prevencion de la infeccion por el paramyxovirus de ojo azul'''. ''Mem 27th Congr Assoc Mex Vet Esp Cerdos. Acapulco, Gro''., 24-28.</ref>.  Preventative health programmes to prevent the spread of the disease are the most effective methods of control. Eliminating blue eye disease from affected herds can be achieved by '''closing the herd, running an all-in/all-out systems''', and following good '''washing and disinfecting protocols'''.

 

 

 

==References==

==References==

<references/>

<references/>

{{Learning

{{CABI source

|flashcards = [[Blue Eye Disease Flashcard]]

|datasheet = [http://www.cabi.org/ahpc/?compid=3&dsid=91518&loadmodule=datasheet&page=2144&site=160 blue eye disease] and [http://www.cabi.org/ahpc/?compid=3&dsid=91519&loadmodule=datasheet&page=2144&site=160 blue eye paramyxovirus]

}}

}}

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