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)
