Orthomyxo Flashcards
influenza C viruses
host?
disease?
humans, swine
respiratory dz, least severe
influenza B viruses
host?
disease?
humans, seals
respiratory disease, moderately severe
influenza A viruses e.g. avian influenza
enveloped or non-enveloped
RNA or DNA
virulence factors
diagnostics
enveloped
-ssRNA
hemagglutinin & neuraminidase
hemagglutination inhibtion (HI)
Avian Influenza
host
reservoir host
transmissions
shedding
diseases
hosts: wide range of avian & mammalian species
reservoirs: waterfowl & shorebirds
transmissions: ingestion/fecal-oral, inhalation, fomites, human tracking
shed: feces, resp secretions
diseases: high path or low path
difference between HPAI and LPAI
HPAI - “fowl plague”, generalized infections associated with H5 and H7 subtypes, sporadic outbreaks
LPAI - infections of GI, resp, repro, occurs worldwide
Describe the pathogenesis for Avian Influenza
1.enveloped assembly by budding taking outer lipid layer
2. reassortment
3. antigenic shift creating new subtype with highly transmittable strains (sudden change) or antigenic drift (point mutations in RNA genome - gradual change)
what does PCR detect for Avian Influenza
matrix 1 and 2
Swine Influenza
influenza ___
enzootic subtypes _____
sporadic subtypes ______
host
disease
influenza A
enzootic = H1 & 3
sporadic = H2,4,5,7,9
host: swine, primarily commercial growers
disease: reduced rate of gain, upper resp infection, broncho/interstitial pneumonia
Equine Influenza
influenza ____
etiologic agents
host
transmission
shed
disease
influenza A
H3N8 or A2 (curent) H7N7 or A1 (30 yrs)
equine - esp. stressed/congregation
highly contag, inhalation, fomites, hands, clothing, instruments
aerosolized resp secretions
upper resp infection, pneumonia
some ways to prevent equine influenza
quaratine/isolation
sanitation
inactivated vx - decrease disease, not prevent shed or infection
ML vx intranasally - decrease shedding
Canine Influenza
influenza _____
etiologic agent
host
transmission
shed
disease
influenza A
H3N8, H3N2
canine
inhalation, fomites
aerosolized resp secretion
“kennel cough” (upper resp infection) and hemorrhagic pneumonia
prevention and control for canine influenza
isolation
sanitation
inactivated vx - decrease severity
bivalent vx