Difference between revisions of "Avian Infectious Bronchitis"

From WikiVet English
Jump to navigation Jump to search
Line 1: Line 1:
Also Known As: '''''Infectious Coryza''''' — '''''Infectious Bronchitis''''' — '''''Infectious Proventriculitis''''' — '''''Avian Infectious Nephrosis'''''
+
Also Known As: '''''Infectious Bronchitis'''''
  
Caused By: '''''Avian Infectious Bronchitis Virus'' '''also know as:''' ''AIBV'' — ''ICTV'' — ''IBV'' — ''AIB'' — ''IB'''''
+
Caused By: '''''Avian Infectious Bronchitis Virus'' '''also know as:''' ''AIBV'' — ''IBV'' — ''AIB'' — ''IB'''''
  
 
==Introduction==
 
==Introduction==
Line 9: Line 9:
 
IBV is transmitted mainly by '''aerosols''' and also by contaminated people/vehicles/equipment.
 
IBV is transmitted mainly by '''aerosols''' and also by contaminated people/vehicles/equipment.
 
   
 
   
It can become '''latent''' in a bird and recrudesce with '''stress''', e.g. at point of lay.
+
It can become '''persistent''' in a bird and recrudesce with '''stress''', e.g. at point of lay.
 
 
This disease is notifiable to the World Organisation for Animal Health [http://www.oie.int/ (OIE)].
 
  
 
==Signalment==
 
==Signalment==
Chickens, pigeons and pheasants are affected.
+
Chickens are the only known natural host of IBV. Other birds are affected by genetically similar yet distinct avian coronaviruses.
  
 
Disease is most severe in chicks.
 
Disease is most severe in chicks.
Line 24: Line 22:
 
'''Reduced weight gain''' or '''egg production''' and reluctance to move is often the first indicator of disease.
 
'''Reduced weight gain''' or '''egg production''' and reluctance to move is often the first indicator of disease.
  
'''Mortality''' often occurs due to secondary infection, particularly due to [[Escherichia coli|''E. coli'']] and [[:Category:Mycoplasmas|''Mycoplasma'']] infections. Mortality is highest in intensively reared broiler flocks.
+
'''Mortality''' often occurs due to secondary infection, particularly due to [[Escherichia coli|''E. coli'']] and [[:Category:Mycoplasmas|''Mycoplasma'']] infections.
  
 
Respiratory Signs:
 
Respiratory Signs:
:'''Sneezing, Coughing, Dyspnoea''', Ingesta present in respiratory passages, Nasal discharge, Abnormal lung sounds on auscultation
+
:'''Sneezing, coughing, dyspnoea, tracheal rales''', ingesta present in respiratory passages, nasal discharge, abnormal lung sounds on auscultation
  
 
Alimentary and Urinary Signs:
 
Alimentary and Urinary Signs:
:'''Diarrhoea, dehydration''', polydipsia
+
:'''Wet droppings, dehydration''', polydipsia
 
:'''Polyuria, Pollakiuria'''
 
:'''Polyuria, Pollakiuria'''
  
Line 38: Line 36:
 
:Conjunctival congestion and increased lacrimation or ocular discharge
 
:Conjunctival congestion and increased lacrimation or ocular discharge
 
:'''Soft egg shells''', thin albumin and watery yolks
 
:'''Soft egg shells''', thin albumin and watery yolks
:Neurological signs
 
  
 
==Diagnosis==
 
==Diagnosis==
In the acute phase, '''viral isolation''' can be attempted from eggs, tracheal swabs or tracheal/lung biopsies.  
+
In the acute phase, '''viral isolation''' can be attempted from tracheal swabs or tracheal/lung biopsies.  
  
 
If more than one week after initial infection, caecal tonsils or cloacal swabs are more reliable.
 
If more than one week after initial infection, caecal tonsils or cloacal swabs are more reliable.
  
'''RT-PCR''' can be performed on buccal or oropharyngeal swabs but will not differentiate live from dead virus isolate.
+
'''RT-PCR''' can be performed on buccal or oropharyngeal swabs.
  
 
'''Agar Gel Precipitation''' and '''Immunofluorescent Antibody''' (IFAT) tests can also be used to detect the virus.
 
'''Agar Gel Precipitation''' and '''Immunofluorescent Antibody''' (IFAT) tests can also be used to detect the virus.
Line 55: Line 52:
 
The kidneys are '''pale and swollen''' and tubules distended with '''urates''' if nephritis is also present. Heterophilic inflammation and degeneration may be evident.  
 
The kidneys are '''pale and swollen''' and tubules distended with '''urates''' if nephritis is also present. Heterophilic inflammation and degeneration may be evident.  
  
Detection of '''viral antibodies''' is also valuable in surveillance, monitoring of vaccination and identification of latently infected birds. This can be performed using [[Immunodiffusion|'''Agar Gel Immunodiffusion''' (AGID)]] , [[ELISA testing |ELISA]], Virus Neutralisation (VN) and [[Agglutination|Haemagglutination-Inhibition (HI)]].
+
Detection of '''viral antibodies''' is also valuable in surveillance and monitoring of vaccination. This can be performed using [[Immunodiffusion|'''Agar Gel Immunodiffusion''' (AGID)]] , [[ELISA testing |ELISA]], Virus Neutralisation (VN) and [[Agglutination|Haemagglutination-Inhibition (HI)]].
  
 
RT-PCR, VN and HI can also be used to type IBV isolates.
 
RT-PCR, VN and HI can also be used to type IBV isolates.
Line 65: Line 62:
  
 
==Control==
 
==Control==
'''Live and Killed IBV vaccines''' are available and widely used but cross-protection is poor and numerous serotypes exist so disease is not always prevented. Vaccinations can be administered as intra-muscular injections or sprays. Killed vaccines used alone do not induce immunity and therefore live vaccines are required to prime immunity first.
+
'''Live and Killed IBV vaccines''' are available and widely used but cross-protection is poor and numerous serotypes exist so disease is not always prevented. Vaccinations can be administered as intra-muscular injections (killed vaccines) or sprays/drinking water (live vaccines). Killed vaccines used alone do not induce immunity and therefore live vaccines are required to prime immunity first.
  
Good '''biosecurity''' and '''hygiene''' protocols are imperative to control of this highly contagious disease. Particular efforts should be made with respect to '''ventilation''' and '''air quality'''.
+
Good '''biosecurity''' and '''hygiene''' protocols are imperative to control this highly contagious disease. Particular efforts should be made with respect to '''ventilation''' and '''air quality'''.
  
  

Revision as of 06:37, 24 August 2011

Also Known As: Infectious Bronchitis

Caused By: Avian Infectious Bronchitis Virus also know as: AIBVIBVAIBIB

Introduction

Avian Infectious Bronchitis is a highly contagious viral disease primarily of the respiratory system of birds, caused by a coronavirus. The virus can also cause damage to the kidneys and oviducts.

IBV is transmitted mainly by aerosols and also by contaminated people/vehicles/equipment.

It can become persistent in a bird and recrudesce with stress, e.g. at point of lay.

Signalment

Chickens are the only known natural host of IBV. Other birds are affected by genetically similar yet distinct avian coronaviruses.

Disease is most severe in chicks.

Distribution

Worldwide

Clinical Signs

Reduced weight gain or egg production and reluctance to move is often the first indicator of disease.

Mortality often occurs due to secondary infection, particularly due to E. coli and Mycoplasma infections.

Respiratory Signs:

Sneezing, coughing, dyspnoea, tracheal rales, ingesta present in respiratory passages, nasal discharge, abnormal lung sounds on auscultation

Alimentary and Urinary Signs:

Wet droppings, dehydration, polydipsia
Polyuria, Pollakiuria

Other Signs:

Reluctance to move
Swelling of the head and face
Conjunctival congestion and increased lacrimation or ocular discharge
Soft egg shells, thin albumin and watery yolks

Diagnosis

In the acute phase, viral isolation can be attempted from tracheal swabs or tracheal/lung biopsies.

If more than one week after initial infection, caecal tonsils or cloacal swabs are more reliable.

RT-PCR can be performed on buccal or oropharyngeal swabs.

Agar Gel Precipitation and Immunofluorescent Antibody (IFAT) tests can also be used to detect the virus.

On post-mortem examination, yellow catarrhal or caseous exudates are present in the trachea, nasal passages, sinuses and air sacs.

On histopathology of the trachea, loss of cilia and sloughing with heterophilic infiltration is evident.

The kidneys are pale and swollen and tubules distended with urates if nephritis is also present. Heterophilic inflammation and degeneration may be evident.

Detection of viral antibodies is also valuable in surveillance and monitoring of vaccination. This can be performed using Agar Gel Immunodiffusion (AGID) , ELISA, Virus Neutralisation (VN) and Haemagglutination-Inhibition (HI).

RT-PCR, VN and HI can also be used to type IBV isolates.

Treatment

No treatment is available for the viral infection.

Use of antibiotics in drinking water to treat and prevent secondary infection may reduce mortality and losses.

Control

Live and Killed IBV vaccines are available and widely used but cross-protection is poor and numerous serotypes exist so disease is not always prevented. Vaccinations can be administered as intra-muscular injections (killed vaccines) or sprays/drinking water (live vaccines). Killed vaccines used alone do not induce immunity and therefore live vaccines are required to prime immunity first.

Good biosecurity and hygiene protocols are imperative to control this highly contagious disease. Particular efforts should be made with respect to ventilation and air quality.



Avian Infectious Bronchitis Learning Resources
FlashcardsFlashcards logo.png
Flashcards
Test your knowledge using flashcard type questions
Avian Infectious Bronchitis Flashcards
CABICABI logo.jpg
Literature Search
Search for recent publications via CAB Abstract
(CABI log in required)
Avian Infectious Bronchitis Publications



References

Animal Health & Production Compendium, Avian Infectious Bronchitis datasheet, accessed 04/06/2011 @ http://www.cabi.org/ahpc/


CABIlogo

This article was originally sourced from The Animal Health & Production Compendium (AHPC) published online by CABI during the OVAL Project.

The datasheet was accessed on 25/06/2011.