Viral Infections of the CNS

seraclues's version from 2015-09-06 00:50

Easter, Western and Venezuelan encephalomyelitis

Question Answer
The alphaviruses Estern, Western and Venezuelan ecnecphalomyelitis, belong to which Family?Togaviridae
Describe the pathology of E/W/Ven encephalomyelitis, in horses?Mosquito bite. It replicates in the vesselsan lymph nodes, viraemia develops. Then secondary replication in lymph nodes and muscles. Then brain invasion, where it replicates in h neurons,glial cells and blood vessels.
What are the gross lesions expected with E/W/Ven encephalomyelitis in horses?Cerebral hyperemia, edema, petechiation and focal necrosis in the gray matter
E/W/Ven encephalomyelitis causes neuronl necrosis, but what else, less commonly?Vasculitis and thrombosis

West Nile Virus

Question Answer
West Nile Virus encephalomyelitis belongs to which family?Flaviviridae
How is west nile virus maintained in the environment?bird-mosquito cycle
What role do wild birds play in West nile virus?Wild birds are amplifier hosts of west nile virus
What are the gross lesions of west nile virus?Hyperermia and petechiation/haemorrhage of lower brain stem and spinal cord.
What are the microscopic lesions of west nile virus?Polioencephalomyelitis, gliosis and glial nodule formation
which species can the mosquito pass West Nile Virus to?bird, human and horses

Louping ill Virus

Question Answer
Which Family doe Louping Ill Virus belong to?Flaviviridae
Where in the world is LIV enzootic?England, Scotland, and Northern Ireland
How is LIV transmitted?My ticks
What are the clinical signs of LIV?Mildly febrile systemic infecion, and signs of encephalitis when it progresses to the CNS

Japanese Encephalitis Virus

Question Answer
What family does Japanese Encephalitis Virus belong to?Flaviviridae
How is JEV transmitted?By mosquitos
Which species are susceptible to JEV?vertebrates, mainly pigs and wading birds
Which animals are of concern for us here in Australasia?It infects domestic pis and horses
Describe the effusive form of FIVserositis, fluid accumulation in the abdominal cavity and varyign degrees of pyogranulomatous inflammation
Describe the non-effusive form of FIVCan result in leptomeningitis, chorioependymitis, focal encephalomyelitis and ophthalmitis

Herpes viruses

Question Answer
How do herpesviruses cause cell injury?Necrosis of infected neurons, glial cells and endothelial cells, induced apoptosis, and secodnary to the effects of inflammation
How do herpesviruses enter the CNS?retrograde axonal transport, hematogenously, and via leukocyte traffickign
In what class of catle woudl you see BHV5+1 encephalitis?outbreaks may occur in young cattle
Which class of dog does CHV encephalitis (CHV1) affect?Acute, highly fatal disease of neonates
What are the clinical signs of EHV (EHV1) myeloencephalopathy?Ataxia, paresis and paralysis

Pseudorabies / Aujesky's disease

Question Answer
Which herpesvirus causes Pseudorabies or Aujesky's diease?Suid Herpesvirus 1
Which species are possible hosts of Aujeskys disease?Pigs are the only natural host, but common domestic species are susceptible
How does Aujeskys/Pseudorabies affect different aged pigs differently?There is a high morality n nursin pis and weaners, but mature pigs are usually just latent carriers
What are the clinical signs of Aujeskys/Pseudorabies in PIGS?Mildly febrile, NO pruritis or nerouvs signs. Recover n 1 week. May get mumified litters
What are the clinical signs of Aujeskys/Pseudorabies in OTHER SPECIES?inense cutaneous irritation and fatal encephalitis
What are the clinical signs of Aujeskys/Pseudorabies in DOGS?Facial pruritis, dyspnea, vomiting and diarrhoea, ataxia, muscle stiffness and death.


Question Answer
Which species are susceptible to Rhabdoiridae (rabies)?All mammals are susceptible
How do rhabdoviridae enter the CNS?They replicate in myocytes in the wound, then invade the neuromuscular junction into the CNS, ascending via axoplasmic flow.
How is rhabdoviridae spread?They spread to the exit portansl; the adrenal gland, nasal mucosa and salivay glands
What are the histopathological signs of rabies?nonsuppurative encephalomyelitis. Neuronal degeneration and the preence of inclusion bodies of Negri
How does the extent of neuronal degeneration differ between species, in rabies?Neuronal degeneration is extensive in carnivores, but little in pigs and herbivores

Visna/Maedi and CAEV

Question Answer
Which family does Visna/Maedi of sheep, belong to?Lentivirus
Which family does Caprine arthritis encephalitis virus (CAEV), belong to?Lentivirus
How does Visna and Maedi cause damage to the CNS?Demyelinating
What are the clinical signs of Visna and Maedi in sheep?Caudal ataxia and fine trembling of the lips
What age of goats are most susceptible o CAEV?2-6mo
How does CAEV damage the CNS?Necrotising, demyelinating leukoencephalomyelitis. May or may not have interstitial pneumonia

Canine distemper

Question Answer
Which family does Canine distemper belong to?Paramyxoviridae
How does CDV move in to the CNS?After primary viraemia, a secondary viraemia occurs with systemic epithelial colonization and viral shedding. Then spreads haemotogenously to the brain and choroid plexus, to infect astrocytes and microgli
How long before a dog recovers from CDV?Within 14 days if good immunity; if poor or intermediate then may develop severe disease
What would you look for intracytoplasmic inclusion bodies of CDV?in the respiratory epithelium
When would CNS signs develop?about 1-3 weeks after systemic signs. Or they may occur after a subclinical infection
What gross lesions would you see in the CNS, with CDV?White matter vacuolation, due to the direct effect of the virus on oligodendrocytes.
What are the three syndromes (age-related) of CDV?Distemper encephalomyelitis in mature dogs (progressive, when infects dogs at 4-8yo), Post-vaccinal canine distemper encephalitis (Live vaccines occasionally fatal encephalitis in young dogs and exotic carnivores), "old dog" encephalitis (usually past middle age, due to long-term sublincnial persistent infection)


Question Answer
What aniamals are susceptible to borna disease?horse, sheep, cattle, cats, dogs and ostriches
Derscribe the histologic lesions of Borna diseaselymphocytic and plasmacytic encephalomyelitis
Where is Borna disease found?world wide distribution