Difference between revisions of "Avian Infectious Bronchitis"
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| − | + | Also Known As: '''''Infectious Coryza''''' — '''''Infectious Bronchitis''''' — '''''Infectious Proventriculitis''''' — '''''Avian Infectious Nephrosis''''' | |
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| − | Also Known As: '''''Infectious Bronchitis''''' | ||
| − | Caused By: '''''Avian Infectious Bronchitis Virus'' '''also know as:''' ''AIBV'' — ''IBV'' — ''AIB'' — ''IB''''' | + | Caused By: '''''Avian Infectious Bronchitis Virus'' '''also know as:''' ''AIBV'' — ''ICTV'' — ''IBV'' — ''AIB'' — ''IB''''' |
==Introduction== | ==Introduction== | ||
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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 ''' | + | It can become '''latent''' in a bird and recrudesce with '''stress''', e.g. at point of lay. |
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| + | This disease is notifiable to the World Organisation for Animal Health [http://www.oie.int/ (OIE)]. | ||
==Signalment== | ==Signalment== | ||
| − | Chickens | + | Chickens, pigeons and pheasants are affected. |
Disease is most severe in chicks. | Disease is most severe in chicks. | ||
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'''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''' 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. |
Respiratory Signs: | Respiratory Signs: | ||
| − | :'''Sneezing, | + | :'''Sneezing, Coughing, Dyspnoea''', Ingesta present in respiratory passages, Nasal discharge, Abnormal lung sounds on auscultation |
Alimentary and Urinary Signs: | Alimentary and Urinary Signs: | ||
| − | :''' | + | :'''Diarrhoea, dehydration''', polydipsia |
:'''Polyuria, Pollakiuria''' | :'''Polyuria, Pollakiuria''' | ||
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: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 tracheal swabs or tracheal/lung biopsies. | + | In the acute phase, '''viral isolation''' can be attempted from eggs, 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. | + | '''RT-PCR''' can be performed on buccal or oropharyngeal swabs but will not differentiate live from dead virus isolate. |
'''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. | ||
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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 | + | 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)]]. |
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. | ||
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==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 | + | '''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. |
| − | 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'''. | + | 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'''. |
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==References== | ==References== | ||
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Animal Health & Production Compendium, '''Avian Infectious Bronchitis datasheet''', accessed 04/06/2011 @ http://www.cabi.org/ahpc/ | Animal Health & Production Compendium, '''Avian Infectious Bronchitis datasheet''', accessed 04/06/2011 @ http://www.cabi.org/ahpc/ | ||
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| + | {{review}} | ||
[[Category:Respiratory Diseases - Birds]] | [[Category:Respiratory Diseases - Birds]] | ||
[[Category:Avian Viruses]] | [[Category:Avian Viruses]] | ||
[[Category:Coronaviridae]] | [[Category:Coronaviridae]] | ||
| − | [[Category:CABI Expert Review | + | [[Category:CABI Expert Review]] |
Revision as of 12:57, 15 June 2011
Also Known As: Infectious Coryza — Infectious Bronchitis — Infectious Proventriculitis — Avian Infectious Nephrosis
Caused By: Avian Infectious Bronchitis Virus also know as: AIBV — ICTV — IBV — AIB — IB
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 latent in a bird and recrudesce with stress, e.g. at point of lay.
This disease is notifiable to the World Organisation for Animal Health (OIE).
Signalment
Chickens, pigeons and pheasants are affected.
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. Mortality is highest in intensively reared broiler flocks.
Respiratory Signs:
- Sneezing, Coughing, Dyspnoea, Ingesta present in respiratory passages, Nasal discharge, Abnormal lung sounds on auscultation
Alimentary and Urinary Signs:
- Diarrhoea, 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
- Neurological signs
Diagnosis
In the acute phase, viral isolation can be attempted from eggs, 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 but will not differentiate live from dead virus isolate.
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, monitoring of vaccination and identification of latently infected birds. 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 or sprays. 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.
| Avian Infectious Bronchitis Learning Resources | |
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 Test your knowledge using flashcard type questions |
Avian Infectious Bronchitis Flashcards |
 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/
 |
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