lecture 15- equine virology Flashcards
what strain of equine influenza still persists today? when did the other strain go away
today H3N8
H7N7 was last detected in 1977
how many types of influenza virus are there? which is of importance with horses?
4- A, B, C, D
A is of importance with horses
A1 is ___
H7N7
A2 is ___
H3N8
how is equine influenza transmitted?
true or false: shedding of infectious influenza virus from vaccinated horses is not possible
false - it is possible
what body system is infected by equine flu?
respiratory (ciliated epithelial cells and alveolar macrophages)
how are mares impacted by flu virus if they are pregnant?
can cause fetal loss due to fever/clinical signs (hypoxia) but NOT directly due to the virus itself
a group of horses presents with a fever, depression, inapp, conjunctivitis, serous discharge, dry/harsh cough
what are you concerned about
equine influenza
what sample type is best for confirming equine flu?
nasopharyngeal swabs, blood sampes
how does a hemagglutination inhibition test work to test for equine flu
how is PCR used in identifying the clade equine flu ? why is this important?
identify which strain of flu
different immune response
what is the modified live cold-adapted equine influenza vaccine? why is this significant? how is it administered?
vaccine strain is temperature sensitive and does not replicate at lower respiratory tract –> strong (and faster!) immunity at entrance of where virus would enter
can use at the face of an outbreak (unique!)
administered intranasal route
describe how marker / DIVA vaccines work in regards to equine flu
what is the main goal of DIVA vaccine strategy
differentiate between vaccinated and infected animals
if there is an inefficient buffer zone with regards to emergency vaccination, what happens if an individual is introduced that is not vaccinated
pathogen can escape the vaccination buffer
what is EVA
equine viral arteritis
EVA is a _____ notifiable disease
annually
the source of EVA is from…
the stallion
stallions are _____ carriers of EVA
long term
how is EVA transmitted
through breeding
true or false: mares can carry EVA
false!! stallions only
describe the pathogenesis of EVA
a mare aborts a fetus on a breeding farm…. what virus might you be concerned about
EVA
abortion is rare with EVA when transmitted by _____, but common with _____ transmission
rare with venereal transmission
common with aerosol transmission
horse presents with depression, edema*, nasal discharge, epiphora, and urticarial rash
what are you concerned about
EVA
how do viruses induce vasculitis (and thus edema)?
what is equine sarcoids caused by
bovine papilloma virus 1 and 2
how is equine sarcoids transmitted?
through fomites, but bovine must be present
true or false: equine to equine transmission of bovine papilloma virus is common
false- this is not possible
what are the gross forms of equine sarcoid?
nodular and verrucous form
fibroblastic form
what is seen histologically with equine sarcoid?
epidermal proliferation - long rete pegs into dermal fibroblastic tissue
you are a veterinarian in an equine practice in north america and presented with horses for vaccination against equine influenza. the subtype you chose to vaccinate is
E- H3N8