Herpesvirus Flashcards
Herpesviridae morphology
Enveloped, spherical to pleomorphic
icosahedral capsid, T=16
Herpesvirus capsid contains a globular material called ___
Tegument
Herpesvirus genome
monopartite, linear, double-stranded DNA genome
Herpes virus replication occurs in ___
the nucleus
T or F
some herpesviruses are oncogenic
True
Herpesvirus inclusion bodies
Type A Cowdry bodies, eosinophilic intranuclear , composed of nucleic acid and protein
herpesvirus facilitates cell-to-cell fusion that spread the infection and avoids the immune system
Syncytium
Herpesvirus capsid contains a globular material called ___
Tegument
Bovine Herpesvirus belongs to subfamily ____
Alpha herpesvirus
3 subtypes of bovine herpesvirus
Respiratory
Genital
Encephalitic
Bovine herpesvirus: transmission
Respiratory disease and conjunctivitis from droplets
Genital disease from coitus
Bovine herpesvirus: Pathogenesis
1st- cell-asso. viremia
focal epithelial cell necrosis, inclusions may be in nuclei
intense inflammatory response
life long latency in Trigeminal n. (resp.) and Sciatic n. (genital)
Bovine herpesvirus: Clinical signs - Respiratory
red nose, necrotic rhinitis, dust pneumonia
mucopurulent nasal discharge, death maybe by 2nd infection
conjunctivits, abortion, systemic infected calves
Bovine herpesvirus: Clinical signs - genital
Infectious pustular vaginitis (IPV)
swollen vulva, mild discharge, inflamed pustules on penis
Bovine herpesvirus: control
modified live vaccines
combination or multivalent vaccines
Bovine herpesvirus 2 causes ___
Bovine ulcerative mammillitis
Pseudo-lumpy skin disease
BUM: hosts
cows, usually in 2 weeks of calving
BUM: transmission
direct contact and fomites by damage to skin
Mechanical by arthropods
BUM: Clinical signs
swollen, painful teats, bluish skin and exudates serum to ulcers
reduce milk yield, mastitis
Pseudo-lumpy skin disease: transmission
Mechanically by arthropods
Pseudo-lumpy skin disease: Clinical signs
mild fever, skin nodules with flat surface and depressed center
Porcine herpesvirus 1 causes ___
Pseudorabies (Aujeszky disease, Mad itch)
Pseudorabies: transmission
recovered pigs are primary reservoir (also rats)
shed in saliva, nasal discharge, and milk
Pseudorabies: Pathogenesis
primary- upper respiratory tract, spreads by lymphatics
to CNS (pons and medulla)
-ganglioneuritis, nonsuppurative meningoencephalitis, perivascular cuffing
Pseudorabies: Clinical signs
Varies per age
sows- poor fertility, abortions, weak piglets
piglets- CNS signs, death, stunted growth and resp. distress
Pseudorabies: 2nd hosts - Mad itch
intense pruritus, self harm
drooling, paralysis of jaws
Pseudorabies: Diagnosis
history and CS
Histopathology, Serology, nucleic acid by PCR
T or F
Pseudorabies vaccine protects from infection
False
But it may alleviate clinical signs
Equine Herpesvirus-1: transmission
Inhalation
Direct or indirect contact with nasal discharge, aborted fetuses, placenta, or fluids
EHV-1 can reside latently in the ____ ganglia and in ___cytes
Trigeminal ganglia of CNS
Lymphocytes
EHV-1: Pathogenesis
cell-asso. viremia, spreads into endothelial ling of blood vessels in CNS and uterus
EHV-1 immunosuppressed the host by inhibiting the ___ protein
TAP protein
blocks delivery of antigen to MHC I molecules
EHV-1 causes
Respiratory disease- rhinopneumonitis, younger
Encephalomyelopathy
Reproductive form - abortions
Equine Herpesvirus 4 causes _____ disease
Equine viral rhinopneumonitis
EVR: transmission
sporadic infections,
EVR: clinical signs
upper respiratory tract disease
nasal discharge- mucoid or mucopurulent discharge, mild coughing, fever, rarely abortion
T or F
Vaccine immunity of Equine Herpesvirus is short-lived
True
Canine herpesvirus is known for ___
Hemorrhagic disease of puppies (Fading puppy syndrome)
HDP: transmission
contact of infected secretions from dam
In-utero transmission
passage through birth canal
older- direct contact, vernerally
HDP: pathogenesis
fetus- leukocyte-asso. viremia = CNS signs, abortion
other- localized infection= latency
2 main factors in managing HDP
Body temperature of puppies
Maternal immunity
HDP: clinical signs of puppies
painful crying, abdominal pain, anorexia, dyspnea, soft greenish stools
*Hemorrhagic, necrotic foci in kidneys
HDP: clinical signs of adults
vaginal hyperemia, discharge and vesicular lesions, abortions
mild respiratory infection
conjunctivitis
HDP: diagnosis
focal necrosis on organs
intranuclear inclusion bodies, culture, PCR, serology
HDP: control
keep puppies warm, isolation
no vaccine
Feline herpesvirus-1 causes ___
Feline rhinotracheitis
FHV-1: transmission
Direct contact with infected cat secretions
Recovered cats become latent carriers
FHV-1: pathogenesis
upper respiratory infection
multifocal epithelial necrosis, inflammation and fibrinous exudation
FHV-1: clinical signs
Kittens (
FHV-1: eye ulcer diagnosis
Fluroescein ophthalmic strips
florescien stain
FHV-1: Diagnosis
CS, histopathology, virus isolation, serology, PCR
3 types of FHV-1 vaccine
modified live virus parenterally
MLV intranasally
inactivated vaccine parenterally
Gallid Herpesvirus 1 causes ____
Infectious Laryngotracheitis
Gallid herpesvirus 2 causes ____
Marek’s disease
(ILT) Infectious Laryngotracheitis: transmission
mostly inhalation
droplets to conjunctiva, ingestion
recovered chickens are carriers
ILT: Pathogenesis
severe laryngotracheitis = necrosis, hemorrhage, ulceration, and diphtheritic membranes
membranes can cause asphyxia
ILT latency persists in ____ ganglia
Trigeminal ganglion
ILT: clinical signs
mild coughing, sneezing, nasal discharge, depression
low morbidity for conjunctivis
Severe form of respiratory distress has a distinctive raised neck with extended head during inspiration called ___
Pump handle respiration
ILT: diagnosis
CS, tracheal plug, histopathology, virus growth in embryonated eggs, PCR
ILT: control
Complete culling of infected population and disinfection of environment
3 types of ILT vaccine
Chick embryo origin
Tissue culture origin
Pox-vectored recombinant vaccine
Marek’s disease is caused by ___
Gallid herpesvirus 2
4 forms of gallid herpesvirus 2
Mild
Virulent
Very virulent
very virulent plus
Marek’s disease: virus is detectable in ____ organs
spleen, thymus, bursa of Fabricius
Marek’s disease is normally cell-asso. Cell free infections can only be detected in ___
Dander of feather follicles
Marek’s disease: Clinical lesions
Neuro, virceral, ocular, cutaneous lymphomatosis
Marek’s disease: diagnosis
Clinical signs, necropsy, histopathology, PCR, cell culture, CAM inoculation
T or F
Marek’s disease is a reportable disease
True
Betaherpesvirus Characteristics
slow replicating viruses, chronic infections. Enlarged cells (cytomegaly), latent form in secretory glands and macrophages and lymphocytes
Porcine herpesvirus 2 causes ___
Inclusion body Rhinitis a.k.a Procine cytomegalovirus (PCMV)
PCMV: hosts
pigs, 2-10 weeks
severe seen in
PCMV: Transmission
Inhalation
Transplacental
PCMV: Pathogenesis
Widespread petechiae and edema
commonly in thoracic cavity and SQ tissues
Placental- abortion, mummies
PCMV: Clinical signs
Gammaherpesvirus characterisitics
Lymphotropic, slow cytopathic for epithelial and fibroblastic cells (death w/o virion prod.)
continous shedding, latency in lymphoid tissue, can cause lymphoid tumors
Gammaherpesvirus causes ___
Malignant Catarrhal Fever (MCF)
Two most important MCF viruses are ____
Alcephaline herpesvirus-1 (AHV-1)
- wildebeest asso.
Ovine herpesvirus-2 (OvHV-2)
- sheep asso.
Wildebeests are also called
Gnus
T or F
AHV-1 does not cause disease in wildebeest
True
AHV-1: transmission to cattle
direct contact with nasal and ocular secretions, aerosol of young wildebeest
OvHV-2: transmission
respiratory, transplacental, contact with nasal secretions
Unknown transmission to cattle
T or F
MCF can be transmitted from cattle to cattle
False
Cattle are dead-end hosts
MCF: pathogenesis
cell-asso. viremia. necrotizing vasculitis
epithelial erosions and keratoconjunctivitis
MCF: 4 forms of clinical signs
Peracute-sudden death
Head and Eye- most common
Intestinal form- death by diarrhea
mild form- recovery expected
MCF: Head and eye signs
reddened eyelids, nasal discharge, salivation, erosions of oral mucosa
lymph node swells, horn and hoof slough, CNS signs
Necropsy sign of MCF is severe linear congestion of colon mucosa called ___
Zebra striping
MCF: control
Separation from wildebeest and sheep
No vaccine
