Paramyxovirus Flashcards
Name three properties of paramyxoviridae
- Enveloped
- Spherical
- 150 to 300nm in diameter
How many proteins does the paramyxoviridae genome encode for?
Around eight proteins
How are paramyxoviridae usually transmissed?
- Droplet transmission e.g aerosols/ fomites
- Close contact is usually required
- they do not persist for a long time in the environment
What is the pathogenesis of paramyxoviridae?
- Replicates in ciliated airway epithelial cells
- airway inflammation is usually the result of an inflammatory response
- secondary infection contributes to morbidity and mortality
What is the pathogenesis of bovine respiratory synctial virus?
- Predisposed by stress
- Inflammation of the respiratory epithelium
- Epithelial cells slough into the bronchi and alveoli
How would you control bovine respiratory synctial virus?
- Do not use vaccines they offer poor protection and can enhance disease
How may you diagnose Bovine Respiratory Synctial Virus?
- Raise in antibodies in the blood
- Nasal aspirates
What are the clinical signs of Bovine Respiratory Synctial Virus?
- Pyrexia
- Coughing
- Nasolacrimal discharge
What are the clinical signs of avian metapneumovirus?
- Respiratory signs, egg drop
- Swollen head syndrome in chickens
How can you diagnose avian metapneumovirus
- Swab from the respiratory tract
- early in infection
What are the clinical signs of bovine parainfluenza type 3?
- Pyrexia, Coughing, Nasolacrimal discharge
What are the clinical signs of canine paramyxovirus?
- Characteristic coughing (hard dry + retching)
What are the clinical signs of canine distemper?
- Acute respiratory and GI signs
- Acute and Chronic Progressive neuro signs
- hyperkeratosis
How is canine distemper transmissed?
- Highly contagious
- Usually via aerosol droplets
What are the G-glycoprotein surface proteins responsible for?
Attachment and entry into the host cell
Fusion protein and Hemagglutinin
What is the function of the M-matrix protein?
acts as a linke between virus membranes and the RNP core
What is formed when the L protein complexes with the P protein?
A viral Polymerase
What is the function of the N-nucleocapsid?
Encapsidates viral RNA, essential for replication
What does the paramyxoviridae genome look like?
Negative-stranded RNA linear genome around 15kb in size
How does the transcription gradient work?
Different proteins are produced by the Polymerase recognising specific signals between each gene
* Approximately 20-30% of polymerase molecules dissociate at each start/ stop junction
How do you control avian metapneumovirus?
- Live control given by spraying
- Inactivated vaccines are given 4-6 weeks later
How many antigenic groups of avian metapneumovirus are there?
A,B,C,D (4)
How do you control bovine parainfluenza virus?
- Correct ventilation and stocking density
- Intranasal vaccines are available
How would you diagnose bovine parainfluenza virus type 3?
- Blood (rise in antibody titre)
- Nasal aspirates (virus isolation, immunofluorescence)
What is the pathogenesis of bovine parainfluenza virus?
- Stress predisposes
- Inflammation in the respiratory epithelium
- Mild in the absence of secondary infection
What are the clinical signs of rinderpest?
has been eradicated
- Mucopurulent odour
- Nasal discharge
- Excoriation of the perineum and tail
How is PPRV mainly transmissed?
Aerosols/ Direct contact
* Fomites
* Bedding
* Feed
* Water troughs
No carrier state
What are the seasonal variations of PPRV?
- During the rainy season
- During the dry cold season
- Increased local trade in goats
What are the main hosts of PPR?
Sheep and Goats are the main susceptibel hosts
What is the PPRV vaccine based on?
Vero cell-based live-attenuated PPR vaccine
What is the immunity duration of the PPRV vaccine?
3-6 years tested so far
What is the definition of canine distemper?
Canine distemper is a highly contagious, systemic, viral disease of dogs seen worldwide
What is the pathogenesis of canine distemper?
- For 3-6 days it replicates in the lymphatic tissue of the respiratory tract
- Cell-associated Viraemia
What is the pathogenesis of Newcastle Disease?
- Lentogenic – low virulent
- Mesogenic – moderately
virulent, respiratory disease &
mortality in very young birds - Velogenic – highly virulent,
severe disease & high
mortality - Viscerotropic – mortality
with intestinal
haemorrhagic lesions - Neurotropic –
neurological disease w/o
intestinal haemorrhage
What are the clinical signs of Newcastle Disease?
- Resp+ oedema of the face
- GI: greenish diarrhoea
- Neuro: trembling, paralysis of legs &
wings, depression, twisting of the neck,
How would you diagnise Newcastle disease?
- Trachea and GIT
- Grown in eggs
- Haemagglutination
- RT-PCR
How is newcastle disease transmissed?
- Occurs worldwide
- Ingestion/inhalation/fo
mites - Wild birds could be a
source
How is Newcastle Disease controlled?
Notifiable disease
* Live import restrictions
* Vaccines- live,
inactivated,
recombinant
