Herpesvirus Flashcards
How does the reproductive version of infectious bovine rhinotracheitis manifest?
- Infectious pustular vulvovaginitis in cows and heifers
- infectious pustular balanoposthitis in bulls
Where does BOHV-1 replicate?
It replicates in the mucous membranes of the genital tract
Where does BOHV-1 establish latency?
It establishes latency in the sacral ganglia
What two things cause the BOHV-1 virus to re-activate
- Stress such as transportation
- Corticosteroids
How is BOHV-1 transmissed?
- Via Aerosols
- Via direct Contact
How would you diagnose BOHV-1 ?
- Samples- nasal swabs, serum, tissue,
- Take antibodies from a serum (latent infection)
- Virus isolation (PCR)
What are the main control strategies for BOHV-1?
- Detection and slaughter
- Vaccination and slaughter
- Strict biosecurity measures
- detection of antibody positive herds and segregation from the seronegative
What are the three main BoHV-1 Vaccines?
- Modified Live-Marker vaccine (DIVA)
- Inert (inactivated and subunit) vaccines
- Attenuated live vaccine
What three things do both BOHV-1 and BOHV-5 have in common?
- Infect the epithelial cells at the portal of entry
- Establish a latent infection in the sensory nerve ganglia
- Have different neurovirulence capacities- BOHV-5 invades all areas of the CNS
What is BOHV-5?
Bovine Herpes Encephalitis
Where is the distribution of BOHV-5 restricted to?
It is restricted to South America
What are the three respiratory clinical signs of BOHV-5?
- Serous nasal discharge
- Severe depression with anorexia
- Hypersalivation
What are the five neurological clinical signs of BOHV-5?
- Jaw champing
- Muscle trembling
- Circling to the side
- Pushing their head against a wall
- Ataxia, followed by seizures
Vulvovaginitis and abortion have also been seen
Where is the BOHV-5 virus excreted?
It is excreted in semen-> differential diagnosis from BOHV-1
What is BOHV-2?
- Ulcerative disease of the teats and udders of cattle
Bovine Herpes Mammilitis
Which virus has the most severe presentation in cattle?
BOHV-2
What season does BOHV-2 usually present?
It usually presents in the autumn and early winter and often affects first time heifers
What is the recovery for BOHV-2 like?
It is usually a full recovery with completely ormal udders
* even if the presentation is severe
* only providing any secondary infections/ mastitis can be controlled
What is found on the muzzles of calves whos heifers have BOHV-2?
presence of ulcers
What is the incubation period of BOHV-2?
2-4 days with a seroconversion of 7-14 days
Name 4 clinical signs of BOHV-2
- High fever for 4-5 days
- Red appearance of the nasal mucosa/ nasal discharge
- Heavy breathing and Cough
- Abortion 4-8 months
Where are the viral lesions of BOHV-2 usually found?
Foetal liver and placenta
What does severe BOHV-2 infection lead to?
orchitis (swollen testes) and endometritis in the cow
usually recover within 2 weeks
What are the three main symptoms of EHV-1/ 4?
- Respiratory disease
- Abortion
- Neurological form= equine myelencephalopathy
What is the treatment for EHV-1/EHV-4?
- Antibiotics to prevent a secondary bacterial infection
- Vaccination is also available
Name 3 neurological symptoms of EHV-1 infection
- Hindlimb incoordinaton
- Urinary and faecal retention
- Loss of sensation in the perineum and tail
What is the main pathogenesis of EHV-1?
they replicate in several cells including…
- Leukocytes, such as myeloid cells CD8 T cells
- Trigeminal ganglia
- Endothelial cells (only EHV-1 replication site)
What causes the endothelial cell damage from EHV-1?
- Viral replication
- Immune responses
- Immune-Complex association
What is the in-utero consequence of EHV-1?
Vasculitis, Abortion
What is the in-brain consequence of endothelial cell damage in EHV-1?
Vasculitis, endothelial damage, ganglio and neuropathy- paresis/ paralysis
What charcterises Aujeskys disease?
overall central nervous system signs
- hind-leg paralyis
- meningo-encephalitis
- high mortality in young animals
- respiratory illness in older pigs
- 50% abortion in a susceptible herd
How is AUJESZKY’S DISEASE
transmissed between pigs?
- Nose to nose
- Feed
- Aerosols
- Iatrogenic
How is AUJESZKY’S DISEASE transmissed to other animals?
- Consumption of pig meat
- rats can also transmit between farms
What are the symptoms of canin herpesvirus in sexually mature dogs?
- Genital disease
- abortion/ stillbirth
- Vaginal/preputial discharge
- Focal nodular lesion of the vaginal, preputial and penile epithelium
How is CHV in puppies usually transmissed?
- By the infected mother during birth
- Contact with infected saliva/ nasal secretion
- sometimess aerosols
What are the clinical signs of CHV in puppies?
- Haemorrhage of blood vessels
- General weakness/crying
- abdominal pain
- nasal and ocular discharges
- excessive drooling
- yellow faeces/ diarrhoea
When does CHV cause death in puppies?
When they become hypothermic
* Virus is adapted to 33 degrees
* viral replication in the vascular endothelial cells of blood vessels
* keeping puppies warm improves the prognosis
How would you prevent CHV infection from the mother to the puppies?
- Vaccinate mother whilst she is in heat, during early pregnancy and then 14 days before giving birth
doesnt eliminate the risk to unborn pups but it does minimise it
What is the most common type of anti-herpesvirus drug?
nucloeside analogues (anti-herpesviral agents)
Name two antivirals that can be used for the helicase
- Pritelivir
- Amenamivir
Name 5 anti-virals that can be used for the polymerase
- Famiciclovir
- Acyclovir
- Ciclofovir
- Foscarnet
- Ganciclovir
How does acyclovir work?
- Acyclovir incorporate itself into the chain
- it has no 3’ hydroxyl so the chain cannot continue
called chain termination
How often is acyclovir given?
3/4 times a day over a short period of time
