Orthomyxoviruses Flashcards
1
Q
Orthomyxovirus - genome, structure, special properties, another name for these viruses
A
- (-)ve sense ssRNA, segmented genome
- Envelope
- Spikes of HA and NA
- Reassorts a lot
- Replicate in nucleus!!! bud at plasma membrane
2
Q
Equine Influenza (Equine-2 H3N8) (Equine-1 (H7N7 is extinct))
- Clinical signs?
- When is it shed?
A
- Reddening of nasal mucosa
- conjunctivitis
- serous or mucopurulent discharge
- harsh paroxysmal cough
- fever
- inappetent
- depressed
- Secondary bac inf’s - bronchopneumonia and purulent exudates
- Disease self limiting - complete recovery in 2-3 weeks
Highly contagious during INCUBATION pd
3
Q
Canine Influenza
- Prevalence?
- Most prevalent in what type of housing environment?
- Clinical signs?
- 2 different strains, where did each come from?
A
Inf not common except in shelters or kennels
Mild resp dis, some have severe signs - high temp and pneumonia, possibly mixed inf’s
Two strains - H3N8 and H3N2
- H3N8 is a new disease derived from H3N8 equine influenza
- H3N2 in China and Korea, introduced to US in Feb 2015, Chicago region
4
Q
Porcine Influenza
- Clinical progression of disease
- Signs?
- Danger associated with it
A
Spreads rapidly, recover quickly - outbreaks mostly in fall and early winter
- Fever, nasal and ocular discharge, coughing, lethargic, and anoretic
- LRT - interstitial pneumonia, and hemorrhagic ln’s
Zoonotic - Respiratory disease; more human to swine spread - many reassortments with gene segments from human, swine, and avian viruses
5
Q
Avian Influenzas
- Clinical signs for highly virulent vs less virulent strains
- Reportable?
A
Highly virulent
- sudden death
- stop egg laying
- resp distress
- lacrimation
- sinusitis
- diarrhea
- edema (head and neck)
Less virulent
- dec egg prod
- resp dis
- visceral and lymphoid necrosis -> pancreatitis, myocarditis, myositis, and encephalitis
- petechial hemorrhages in resp, digestive, and cardiac tissues
Yes, reportable
