Herpesviridae Part-1 Flashcards
Family Herpesviridae Viral Genome
Monopartite, linear, double stranded DNA
Terminal and internal reiterated repeated sequences
Have 3 types of genes, immediate early and early, late, and optional
Family Herpesviridae Viral Replication
DNA replication in nucleus
Viral envelope obtained via budding
Mature virions burst from cytoplasm released by exocytosis/cytolysis
What sort of inclusion bodies are characteristic of Herpesvirus
Type A Cowdry bodies
Eosinophilic intranuclear
T/F Syncitium is caused by Herpesviruses
True
What Dzs does Bovine Herpes Virus 1 Cause?
Infectious Bovine Rhinotracheitis (IBR) Infectious pustular vulvovaginitis Ocular form of IBR Abortion Systemic Dz of Newborn Calves
Bovine Herpes Virus-1 Etiology Serotype Subtypes Distribution Transmission
BHV-1 Single Serotype, 3 subtypes 1.1- respiratory 1.2 genital 1.3 encephalic Worldwide Droplet or Coitus/AI
What are the sites of latency of BHV-1?
Respiratory- trigeminal
Genital- Sciatic
Clinical Signs in BHV-1 Respiratory Form. Also what is the other name for this Dz?
Red Nose
Rhinitis, laryngitis, tracheitits
Genital Diseases associated with Bovine Herpesvirus-1
Infectious Pustular Vaginitis
Balanoposthitis
Vx for Bovine Herpesvirus-1safety in prego cows
Parenteral vx causes abortion in cows, intranasal does not
Bovine Ulcerative mammillitis Etiology Distribution Host Transmission
BHV-2
Worldwide
Cattle, heifer 2 wks after calving
direct contact via fomite or skin trauma, arthropods
Pseudo-Lumpy Skin Dz
Etiology
Distribution
Clinical signs
BHV-2
Southern Africa
Fever, nodules with depressed center, superficial dermis becomes necrotic
Pseudorabies/Aujesky Dz/Mad Itch
Etiology
Host
Porcine herpesvirus1
Primary Host- swine
Diverse range of secondary hosts
Pseudorabies transmission in Primary Host
Recovered pigs and rats act as resivours
Virus shed in saliva, nasal discharge, and milk of infected pigs
Biting,licking,aerosol, ingestion of contaminated carcass, water/feed
Pseduorabies transmission in Seconday Host
Dogs and cats- ingestion of infected pig/rat
Cattle- direct contact with infected pigs, oral/nasal routes
Pseudorabies in Pigs Pathogenesis
primary site of infection is URT
Spreads via lymph nodes
Spreads to CNS via cranial nerve axons w/preference for pons and medulla
CNS lesions associtated with Pseudorabies in pigs
gangioneuritis
nonsuppurative meningioencephalitis
perivascular cuffing
Family Herpesviridae Morphology
enveloped, spherical to pleomorphic 150-200nm Icosohedral 162 capsomers, has tegument Glycoproteins embedded in lipid envelope
Clinical Signs Pseudorabies in Pigs
Nonimmune piglets die
nonimmune pregnant sows 50% abortion
Older piglets, growers, and adult pigs- mild dz
Clinical signs in Pseudorabies in secondary hosts
Pruritis
High mortality
Do cats generally have pruritis with Pseudorabies?
No, the dz progresses too rapidly
Pseudorabies Dx
History and clinical finding Intranuclear inclusion bodies Perivascular cuffing Serology PCR
Do Pseudorabies vx prevent infection?
No they reduce clinical signs
Equine Herpes Virus-1
Distribtion
Transmission
endemic worldwide
aerosol
direct/indirect contact with nasal discharge, aborted fetuses, placenta/placental fluids
Where does latent EHV-1 live?
Trigeminal ganglia
Lymph system- lymphocytes
Central lesion associated with EHV-1
infection of endothelial lining
How does EHV-1 cause Immunosuppression?
EHV-1 codes for a protein that inhibits TAP, blocking antigen delivery of antigen to class I MHC molecules.
Respiratory EHV-1
Younger horses
Rhinopneumonitis
Fever
Secondary bacterial infections
Encephalomyelopathy of EHV-1
immune mediated vasculitis leading to infarction and hemorrhage within brain and spinal cord
can lead to lameness, quadraplegia and recombancy resulting in death
Reproductive Form of EHV-1
Mostly occur in last trimester, sporadic, natural immunity lasts up to 3 years hence “abortion storms”
Equine Viral Rhinopnemonitis Etiology Distribution Transmission Clinical signs
EHV-4
Worldwide
Droplet infection
rare and sporadic, upper resp tract dz
