Virology 4: DNA Viruses Flashcards
What are the 3 main types of herpesviridae
alphaherpesvirinae, beta, gamma
What is the approximate size range of herpes viruses
200-250 nm in diameter
Is herpes virus DNA or RNA? Double or single stranded?
Double stranded DNA
How does herpes virus enter cells?
by fusing with cell membrane
Where does herpes virus replicate?
In nucleus of host cells
What is herpes virus seen histologically as?
intranuclear inclusion bodies
Herpes virus becomes latent in _______
What does this mean?
sensory ganglia
animals will be subclinically infected and clinical disease manifests in times of stress
In latent infection when does disease manifest?
During times of stress
What is meant by herpes virus being labile in environment?
needs close contact for transmission
For labile viruses such as herpes what is an effective control method?
quarantine
What type of cells do alpha herpesvirus infect?
epithelial or endothelial cells such as skin, mm, tracheal mucosa, liver, brain
What does active infection of alpha herpes virus lead to?
Cell death such as ulcers, erosions, hepatocellular necrosis, vasculitis
Bovine Herpesvirus 1 is a type of _________
alphaherpesvirinae
What are the 3 subtypes of Bovine Herpesvirus 1
BHV 1.1, 1.2 (1.2a, 1.2b)
What does BHV1.1 affect?
respiratory (IBR) and reproductive (abortion)
What is BHV 1.2 affect?
Genital (infectious pustular valvovaginitis)
Which causes abortions, BHV 1.2a or 1.2b
1.2a
How is BHV-1 subtype 1.1 transmitted and why?
Aerosol transmission (nose-to-nose) as the virus replicates in the mm of the upper respiratory tract and large amounts of virus are shed in nasal secretions
Is BHV-1 subtype 1.1 ever latent? Where? When/does it become reactivated?
latent in the trigeminal ganglia and reactivated during times of stress
In BHV-1, 1.1 ___________ develops but _________ can result in severe disease
strong immunity
secondary bacterial infections
What is IBR
Infectious Bovine Rhinotracheitis
What is reproductive disease pertaining to IBR?
viremia in preg cows and infection of fetus resulting in abortion
multifocal hepatic necrosis in fetus with intranuclear inclusions
IBR respiratory disease can predispose bovine to
secondary bacterial pneumonia - bovine respiratory disease complex
Equine Herpes virus 1 is part of
alphaherpesvirusvirinae
What are the 2 strains of EHV1?
D752
N752
What can a single nucleotide change in EHV1 result in?
more severe disease
What is EHV1 D752?
Respiratory (rhinopneumonitis)/reproductive (abortion)/neurologic
What is EHV1 N752?
respiratory/reproductive/non-neurologic
EHV-1 and EHV-4 is
equine rhinopneumonitis
Where does equine rhinopneumonitis replicate?
mm of upper respiratory tract and regional lymph nodes
Where does equine rhinopneumonitis become latent? When is it reactivated?
trigeminal ganglia
time of stress
In what ways does equine rhinopneumonitis cause respiratory disease?
Rhinitis
tracheitis
may extend into lungs especially in small animals
In what ways does equine rhinopneumonitis cause reproductive disease?
viremia in preg mares results in abortion
EHV-1 has predilection for vascular endothelium resulting in placental vasculitis and thrombosis
multifocal hepatic necrosis in fetus with intranuclear inclusions
What is equine herpes myeloencephalopathy typically associated with?
D752
What does equine herpes myeloencephalopathy follow
outbreak of respiratory disease or abortion on the farm
What does equine herpes myeloencephalopathy lead to?
vasculitis, necrosis, and hemorrhage in spinal cord and brain
How is canine herpesvirus 1 transmitted?
aerosol or in utero (thru placenta)
Where does canine herpesvirus 1 replicate?
mm of upper respiratory tract, pharynx, and tonsils
Where does canine herpesvirus 1 become latent and when does it reactivate?
trigeminal ganglia
during times of stress
Where are large amounts of canine herpesvirus 1 shed?
nasal and vaginal secretions
In canine herpesvirus 1, what temperatures is replication most efficient?
below body temp
What age are dogs most susceptible to canine herpesvirus
neonatal pups in first 3 weeks of life
What happens if dam is infected with canine herpesvirus within 3 weeks of whelping?
puppies will be infected through placenta
Canine herpesvirus can infect _______ of the litter
the entirety
True or False: Canine herpesvirus causes high morbidity and mortality
True
Once a dam develops immunity to Canine herpesvirus what will happen to subsequent litters?
unaffected
What post mortem changes will occur in dead puppies whose cause of death was Canine Herpesvirus?
multifocal necrosis in multiple organs and hemorrhage in kidneys with intranuclear inclusions
How is Feline herpesvirus 1/Feline Viral Rhinotracheitis transmitted?
aerosol transmission - nose to nose contact since large amounts of virus are shed in nasal secretions
Where does Feline Herpesvirus 1 replicate?
in mm of upper respiratory tract and conjunctiva
Where does Feline Herpesvirus 1 become latent and when does is it reactivated?
trigeminal ganglia
times of stress
Feline Viral Rhinotracheitis account for __% of respiratory disease in cats
40%
Feline viral rhinotracheitis is a(n) _______ upper respiratory tract infection causing what 3 common symptoms?
Acute
sneezing, hypersalivation, and conjunctivitis
What can feline viral rhinotracheitis lead to?
ulcerative keratitis
Secondary bacterial infections caused by feline viral rhinotracheitis can result in
pneumonia
What is porcine herpesvirus-1 called in pigs?
Aujeszky’s disease
Porcine Herpesvirus 1 or Aujeszky’s disease in pigs is called ______ in other species
pseudorabies
True or False: PHV-1 is the only alphaherpesviruses that can infect other species but is not zoonotic
TRUE
How is Aujeszky’s disease transmitted?
aerosol - nose-to-nose transmission
Where does Aujeszky’s disease replicate?
epithelium of oropharynx and tonsils
Where does Aujeszky’s disease spread?
regional lymph nodes and brain via cranial nerves
Where is Aujeszky’s disease shed?
nasal secretions, milk, and semen
Where does Aujeszky’s disease become latent and when is it reactivated?
trigeminal ganglia
times of stress
Mortality rate of Aujeszky’s disease can reach almost _____% in suckling pigs
100%
What age does neurologic signs of Aujeszky’s disease predominate in?
young pigs
What can infection of Aujeszky’s disease in sows result in?
abortion with hepatic necrosis and intranuclear inclusions in fetus
What does pseudorabies in other species manifest as
severe neurologic disease and pruritis and death within a few days
Compare and contrast herpesvirus in cats, dogs, pigs, and horses
cats - not usually associated with abortion
dogs - neonatal death
pigs - can be transmitted to other species
horses - neurologic form infects endothelial cells
In which species is herpesvirus NOT associated with abortion?
cats
In which species is herpesvirus associated with neonatal death?
dogs
In which species can herpesvirus be transmitted to other species?
pig
In which species does the neurologic form of herpesvirus infect endothelial cells?
horses
What do gammaherpesviruses infect?
lymphocytes
What can gammherpesvirus cause?
neoplastic transformation
________ produces latent infection in lymphocytes
gammaherpesvirus
Malignant Catarrhal Fever is associated with which 3 gammaherpesviruses?
Ovine gammaherpesvirus 2, alcelaphine gammaherpesvirus 1, and caprine gammaherpesvirus 2
Which species are affected by malignant catarrhal fever?
cattle, deer, giraffes, pigs, bison
True or False: In Malignant Catarrhal Fever, there is no clinical disease in natural reservoir hosts but severe disease can occur in susceptible hosts
TRUE
When do sheep shed Malignant Catarrhal Fever?
during lambing
What are some examples of clinical signs in susceptible hosts of Malignant Catarrhal Fever
vasculitis (hemorrhage)
primary necrosis of epithelium
corneal edema
mucopurulent nasal discharge
GI and bladder hemorrhage
neurologic dx
cutaneous dx
fatal lymphoproliferative dx
