1,433
edits
Changes
Jump to navigation
Jump to search
no edit summary
[[Category:To Do - Steph]]
Also Known As –''''' BEF – Dengue Fever – Lazy Man’s Disease – Stiff Sickness – 3 day Sickness – Dragon Boat Disease – Vil – Bovine Epizootic Fever – Stiffsiekte (South Africa)'''''
Caused By – ''Bovine Ephemeral Fever Virus - BEFV''
==Introduction==
Bovine Ephemeral Fever is a '''[[Viruses|viral]] disease''' causing fever, dehydration, gastrointestinal, reproductive and neurological disease in '''cattle'''. The pathogen involved is a [[Rhabdoviridae|rhabdovirus]].
Due to its geographical distribution and association with heavy precipitation, BEF often occurs simultaneously with '''epizootics of [[Rift Valley Fever]].'''
BEF is not zoonotic.
This disease is '''notifiable''' to the World Organisation for Animal Health [http://www.oie.int/ (OIE)]
==Distribution==
'''Asia, Africa, Australia and Pacific islands'''
BEF is transmitted by a range of '''insect vectors''' including [[Culicidae|mosquitoes]] and [[Ceratopogonidae|midges]]. This is the '''ONLY route of disease transmission.'''
==Signalment==
Cattle and buffalo appear to be the only natural host of BEF.
Disease is more severe in '''fat, lactating and heavily pregnant cows and bulls/steers.'''
In tropical regions, disease occurs in the wet season, while in temperate countries, it tends to present throughout Spring, Summer and Autumn.
When outbreaks occur annually or semi-annually, younger animals tend to be infected and so the economic impact is often less. Hence, the '''less frequent epidemics are, the more severe''' they tend to be.
==Clinical Signs==
'''Very high fever, dehydration, animals often refuse to drink.'''
Many signs are attributable to the '''[[Hypocalcaemia|hypocalcaemia]]''' caused by BEF.
Lymphadenopathy
'''Stiffness and lameness''' in the limbs with tremors/spasms and recumbency
Gastrointestinal '''hypomotility''' and constipation or [[Diarrhoea|diarrhoea]].
Pregnant cattle may '''abort and infertility''' can occur in either sex. Cows may develop agalactia.
Dullness, depression, lethargy and coma in severe cases
'''Respiratory''' disease
'''Subcutaneous emphysema, oedema and crepitation'''
Hot weather increases mortality in epidemics.
'''''Mild cases''''' - <18mo old, ocular and nasal discharge, lameness, inappetance, fever, recovery in 1-2days.
'''''Moderate''''' – Severe depression, recumbency, respiratory signs, salivation and dehydration, Rumenal atony, milk reduction.
'''''Severe''''' – lateral recumbency, paralysis, reflex loss, subcutaneous emphysema, tachycardia and tachypnoea, mortalities. Residual paralysis may remain after resolution of fever.
Viraemia usually lasts '''3-5 days''' after which recovery and natural immunity are life-long.
==Diagnosis==
Diagnosis is often based on '''clinical observations''' of various stages of disease present simultaneously and '''history''' of sudden onset outbreaks on the farm or neighbouring units.
'''Isolation of virus from blood''' taken during '''pyrexic phase''' is most efficient laboratory method of diagnosis. The virus can be identified by '''Immunofluorescence or immunostaining.'''
A '''rising antibody titre''' when sampled during fever and 2 weeks later is also confirmatory.
On post-mortem, only generalised inflammatory changes are evident with neutrophilic infiltration of tissues and muscle necrosis. Straw coloured fibrinous fluid is often present in several cavities.
==Treatment==
'''Calcium borogluconate'''
'''NSAIDs''' will resolve many clinical signs and reduce pyrexia.
All should be '''injected''' as swallowing reflex may be dysfunctional.
Draught cattle need '''rest for at least one week''' after recovery or further mortalities may occur.
==Control==
'''Vaccines''' are available in Japan, Australia and South Africa. Annual boosters are essential to maintain immunity. All are too '''expensive''' for use in developing countries.
Vector control is theoretical and almost impossible.
Quarantine also has no impact upon local spread due to vector transmission.
'''Movement regulations''' vary with country and time and should be adhered to.
{{Learning
|flashcards = [[Bovine Ephemeral Fever Flashcards]]
}}
==References==
<references/>
Animal Health & Production Compendium, '''Bovine Ephemeral Fever datasheet''', accessed 16/06/2011 @ http://www.cabi.org/ahpc/
Animal Health & Production Compendium, '''Bovine Ephemeral Fever Virus datasheet''', accessed 16/06/2011 @ http://www.cabi.org/ahpc/
[[Category:To Do - CABI review]]