Rabies and the Lyssaviruses Flashcards
1
Q
Describe the structure of the rabies virus
A
Single stranded RNA
Highly susceptible to detergents and UV
2
Q
Describe the pathogenesis and transmission of the rabies virus
A
- Fatal encephalitis affecting warm blooded animals
- Transmitted in saliva by bites or scratches
- long and variable incubation period: site of exposure, severity, virus, host
3
Q
What are the 6 steps of infection?
A
- Bite site - slow multiplication of virus in muscle cells
- Rapid transport of virus genomes in the nerve axons
- Rapid virus spread in the CNS
- Massive virus replication in nerve cells
- Transport in nerve axons to salivary glands and other peripheral organs
- Massive virus replication in salivary glands
4
Q
What is the prodromal phase?
A
Possible symptoms
- Behavioural changes
- Temperature rises
- Pupils dilated
- Excess salivation
5
Q
What are signs of the furious form of rabies?
A
Aggressive Phonation Swallowing difficulty Seizures Paralysis, coma, death
6
Q
What are the signs of the dumb form of rabies?
A
Dropped jaw
Bone in throat
Incoordination
Paralysis and death
7
Q
How is rabies diagnosed?
A
- Immunofluorescent staining of brain sections detects rabies virus antigens: gold standard post mortem test
- Rabies tissue culture test detects virus
- Histological staining
- RT-PCR detects viral RNA
- Virus neutralisation assays
8
Q
What are the control options for rabies?
A
Post exposure prophylaxis/treatment - immediate washing of wound
Pre and post exposure vaccination
Controlling disease in dogs = main reservoir
