Zusammenfassung der Ressource
Arboviruses
Anmerkungen:
- Arthropod borne, RNA.
Dist. on temperature.
Enzootic and Epizootic cycles.
Epizootic comes from changes in climate, ecology and from long distance movement.
DIAGNOSE:Serology
Exotic to NZ
- Reoviridae
Anmerkungen:
- Orbiviruses
Anmerkungen:
- Replicate in LN and then to blood.
They like the endothelial cells which causes vascular permeability, occlusion and oedema.
Many serotypes each (makes vaccination hard).
- Blue tongue
- Culicoides midge in AUS. Confined to North
AUS. Could come to NZ by importing
ruminants into zoos
- Signs=Swollen mouth, droopy ears,
coronary band swelling, lameness.
- African Horse Sickness
- Highly fatal disease of horses and mules.
Serotypes 1-8 (out of 9) are pathogenic.
- Control=Vaccination (poly or
monovalent), vector control, killing
infected horses,.
- Rotaviruses
Anmerkungen:
- Common cause of diarrhoea in infants - Disease seen in young animals 1-8 weeks old.
Acid stable virus, hardy in environment.
Factors contributing=chilling, overcrowding, poor hygiene, no colostrum.
Diagnose with agglutination test.
Control with vaccine.
- Bunyaviridae
Anmerkungen:
- Can cause disease in humans.
Can be transmitted via arthropod eggs too.
- Rift valley fever
- Not a huge threat to coming
into NZ
- Culex and aedes mosquitos
- Akabane
- Exotic to NZ- we don't have Culicoides
- Causes reproductive issues in
when it switched to epizootic
cycle, no clinical signs in enzootic
cycle.
- Nairobi sheep disease
- Not in NZ
- Causes fever, haemorrhagic
enteritis, abortion and mortality.
- Diagnose by virus isolation,
control by vaccine or tick
control
- Togaviridae
- Alphaviruses
Anmerkungen:
- Encephalitis
Anmerkungen:
- Primary and secondary viraemia occurs, primary in LN and secondary in organs. It is infective to the arthropod at the level of secondary viraemia, and it then invades the CNS.
Depression, incoordination, droopy face, impaired vision, circling, paralysis.
You can vaccinate (also works to control human infection)
- Eastern equine encephalitis
- Western equine encephalitis
- Venezuelan equine encephalitis
Anmerkungen:
- Flaviviridae
Anmerkungen:
- Easy to kill, Nucleic acid itself is infectious.
- Dengue
Anmerkungen:
- Immunity for life for a single serotype only (no cross protection)
- West Nile Virus
Anmerkungen:
- Uses humans and some mammals as secondary hosts
- Of Veterinary Importance
- Louping ill
Anmerkungen:
- Exotic to NZ
Neurological signs.
Control by vaccines and acaricides
- Wellesbron disease
- Japanese Encephalitis
Anmerkungen:
- Exotic to NZ
Pigs are amplifier host (can get sick too though).
Vaccine available.
- BVD and MD
- Outcome dependent on age,
immunity, dose, strain and
pregnancy status
- BVD: Clinical infection is common in
animals 6-18 months old, fever
diarrhoea etc. High morbidity, low
mortality.
- If pregnant: Under 40days=Failure to
conceive, 40-120 days=Persistently
infected calf, 120-150
days=congenital defects.
- Can vaccinate to control
more persistently infected
animals being born.
- MD: Low morbidity, high
mortality. Acute=Fever, erosions
etc leading to death.
Chronic=Erosions on muzzle,
death in 2-6 months.
- The BVD strain is either inherited
or becomes cytopathic in
persistently infected animals. They then shed the disease.
- Diagnosis is by normal
means, but PI animals are not
antibody positive.
- Prevention by vaccination.
- Classical swine fever
Anmerkungen:
- Exotic to NZ
Haemorrhage, ulcers, petechiae.
- Equine infectious Anaemia
- Of the lentivirus family but is an arbovirus too.
- 1-3 week incubation followed by either acute or
subacute forms of disease. Acute has serious effects
followed by 80% mortality. Subacute has lifelong
infection and shedding with recurrent episodes.
- Exotic to NZ