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=Influenza by Species=
 
=Influenza by Species=
==Equine Influenza==
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===[[Equine Influenza]]===
===Subtypes===
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*Two subtypes of Equine Influenza have been described:
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**H7N7 (Equine 1), which was prevalent in the UK between 1963-1977
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**H3N8 (Equine 2), or the European strains, have been circulating since 1965
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*Some drift has occurred, causing outbreaks of North-American-like strains of H3N8 in 1998 (EU) and 2003 (South America)
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===Pathogenesis===
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*Aerosol and fomite transmission infects the epithelium of the upper respiratory tract, resulting in cell necrosis
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*This manifests a bronchiolitis and serous exudation
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*1-3 day incubation period
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*Excretion of the virus in nasal secretions peaks at 3-4 days and finishes by 10 days
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*Clinical signs:
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**Harsh dry cough
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**Pyrexia (103-106F)
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**Depression
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**Loss of appetite
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**Enlarged submandibular lymph nodes
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*Secondary bacterial infection can follow defective muco-ciliary transport, eg ''Streptococcus zooepidemicus''
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*For more, see [[Respiratory Viral Infections - Pathology#Equine influenza|here]]
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===Diagnosis===
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*Virus isolation: Deep nasal swabs (12 inches) deposited into 10ml of transport medium and transported at 4C
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*Antigen detection via ELISA: tests for type A nucleoprotein
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*Serology provides a retrospective diagnosis by '''Haemagglutination Inhibition (HI)''':
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**Acute and Convalescent (2 weeks post-acute) samples are tested from the same animal
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**4-fold increase of HI must be shown to confirm diagnosis
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===Control===
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*Isolate coughing horses to minimize spread
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*Vaccination:
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**All vaccines include H7 and varieties of the current circulating strains of H3
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**'''Inactivated'''egg-grown vaccing is produced with alhydrogel as an adjuvant
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**'''Live''' vaccines using purified haemagglutinin do not require adjuvants
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**UK Jockey Club rules regarding timing:
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***Horses must be certified as completing a vaccination course of 3 injections at least 10 days prior to racing
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***The course consists of a primary inoculation followed by a second within 21-92 days and a third after a further 150-215 days
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***Boosters are given annually to maintain immunity, and in the event a year is missed the initial course of three jabs must be repeated
      
==Swine Influenza==
 
==Swine Influenza==
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