Viral Injury of the Respiratory Tract Flashcards
where are particles over 10 microns, 3-10 microns, and smaller deposited in the respiratory tract?
over 10 microns: mucosa of nasal cavity and upper airways
3-10 microns: trachea and bronchi
smaller: terminal airways and alveoli
what viruses have a predisposition to the upper respiratory tract?
rhinoviruses and herpesviruses
what two mechanisms will viruses follow?
either enter a specific cell type directly and cause cell death or gets taken up by alveolar macrophages and transported to regional lymph nodes, leading to viremia and secondarily invading respiratory epithelial cells
what is the innate immune response to respiratory viruses?
toll-like receptors recognize, release cytokines and chemokines
natural killer cells and neutrophils
viruses that cause respiratory disease are ______________ for the cells in which they replicate
cytocidal
what leads to cell death by a virus?
severe biochemical alterations occur in cells
early: stop host cell protein and RNA synthesis
later: large viral macromolecules accumulate and can be toxic
inclusion bodies
multinucleated giant cells
what do inclusion bodies show?
some viruses have virions and proteins accumulate in crystalline aggregates in the nucleus or cytoplasm
what is the most important factor in determining if an animal will develop signs and what they will be?
amount and location of tissue destruction and inflammation
what characterizes the inflammatory response in a viral infection?
hyperemia
vascular leakage of plasma proteins
extravasation of leukocytes
what area of inflammation does coughing indicate?
trachea and bronchi
if the inflammatory reaction primarily involves the terminal airways and alveoli, what will the signs be?
if small amount of damage: pneumonitis with impaired gas exchage: hyperpnea and increased respiratory effort
severe: dyspnea and cyanosis (alveoli full of plasma proteins and inflammatory cells)
what are examples of canine viruses that predispose them to secondary bacterial infections?
canine parainfluenza virus
canine adenovirus type-2
canine distemper virus
what are examples of feline viruses that predispose them to secondary bacterial infections?
feline herpesvirus (FVR)
calicivirus
what are examples of bovine viruses that predispose them to secondary bacterial infections?
parainfluenza-3
IBR
bovine respiratory syncytial virus
what are examples of equine viruses that predispose them to secondary bacterial infections?
equine herpesvirus I (equine rhinopneumonitis)
equine type A influenzavirus
what are examples of porcine viruses that predispose them to secondary bacterial infections?
porcine circovirus type 2
porcine respiratory corona virus
swine influenzavirus (H1N1 and H3N2)
what are examples of avian viruses that predispose them to secondary bacterial infections?
avian influenza virus
avian herpesvirus
newcastle disease virus
what are the two subfamilies of herpetoviridae?
alpha-herpesviruses
beta-herpesviruses
where do herpetoviridae have predisposition to infect?
nasal passages
trachea
bronchi
what viruses can establish latency? what cells?
herpesviruses
certain ones, especially neurons
what diseases is equine herpesvirus I responsible for?
equine rhinopneumonitis
equine viral abortion
what virus is responsible for infectious bovine rhinotracheitis (IBR) and infectious pustular vulvovaginitis (IPV)?
bovine herpesvirus I
what causes feline viral rhinotracheitis (FVR) and what is it?
herpesvirus felis, feline herpes virus-1
highly contagious disease of upper respiratory tract
what does herpesvirus suis (SuHv-1) cause?
usually mild in adult swine, can be severe in young piglets
pseudorabies/Aujeszky’s disease in cattle, swine, sheep, dogs, cats, and rats- often fatal in non-swine
what is herpesvirus canis associated with?
kennel cough
cause of neonatal death in puppies less than 2 weeks
what does avian laryngotracheitis cause?
upper respiratory infection in chickens: nasal discharge, gasping, dyspnea
what is the beta-herpetovirinae important in veterinary medicine?
porcine cytomegalovirus
what does porcine cytomegalovirus cause?
inclusion body rhinitis
what is canine adenovirus II associated with?
kennel cough
what is feline calicivirus associated with?
feline respiratory disease: rhinitis, conjunctivitis, palatine and glossal ulcerations and bronchopneumonia
what genus belongs to the orthomyxoviridae family?
influenzavirus
influenza viruses change ______________, to evade previously acquired immunity
antigenically
antigenic shift
antigenic drift
what is antigenic shift?
a new combination of HA or NA proteins arise on the virion surface
what is antigenic drift?
mutations in the antigenic portions of surface glycoproteins occur
what does equine type A influenzavirus do?
highly contagious but rarely fatal disease
nasal discharge, cough, dyspnea, fever, depression
what does swine type A influenzavirus do?
swine influenza
can be caused by Metastrongylus sp- lungworm
what do paramyxoviridae cause?
frequently multinucleate, syncytial giant cells and eosinophilc intracytplasmic or intranuclear inclusion bodies
what genera are in the paramyxoviridae family?
morbillivirus
paramyxovirus
pneumovirus
what are the important morbilloviruses important in veterinary medicine?
canine distemper virus (morbillivirus canis)
measles virus
rinderpest virus
what does canine distemper virus/morbillivirus canis cause?
severe/fatal disease of dogs, wolves, ferrets, mink, otter, raccoons
penumonia, encephalomyelitis, severe lymphocyte depletion and immunosuppression
what are some paramyxoviruses important in veterinary medicine?
parainfluenza (paramyxovirus)-1 (sendai virus)
parainfluenza (paramyxovirus)-2
parainfluenza (paramyxovirus)-3
newcastle disease virus
what does infectious bronchitis virus do?
severe tracheobronchitis of chickens
what viruses belong to the family retroviridae?
maedi/visna virus
viral induced neoplasia of the lungs
what does maedi/visna virus do?
ovine progressive pneumonia (maedi) and a neurological disorder known as visna: sheep
which viral family is characterized by a high mutation rate during virus division?
influenzavirus
which viral family is characterized by formation of multinucleated giant cells during division of infected cells?
paramyxovirus
where specifically can viral particles deposit in the respiratory system?
smaller bronchioles: watery protein layer rich in lysozymes and immunoglobulins
alveoli: immediate contact with type I epithelium and macrophages
what is pneumonitis?
leakage of plasma proteins into interstitial space
how can swine get swine type A influenzavirus?
infected aerosols or Metastrongylus sp
which strain of newcastle disease virus causes a rapidly fatal systemic disease characterized by severe respiratory disease and widespread necrosis of visceral organs and encephalitis?
velogenic strain
does canine influenzavirus cause kennel cough?
no
cough, nasal discharge, +/- pneumonia
what virus is equine type A influenzavirus similar to?
equine herpesvirus
equine rhinopneumonitis is disease it is similar to
what do paramyxoviridae cause?
syncytial giant cells
eosinophilic intracytoplasmic or intranuclear inclusion bodies
what nonhuman primates does measles virus infect?
M. mulatta
M. fascicularis
M. arctoides
marmosets (Saguinus spp)