Herpesviruses of Domestic species

Question 1

Herpes virus hallmarks

Virion architecture

Answer 1

• Core: contains dsDNA genome
• Icosahedral nucleo Capsid
• Tegument
• Outer Envelope (lipid bilayer)
  
  • ​lock and key to let virus into next cell
  • makes them less resistant disinfection
    
    • sunlight
    • disinfectant

Question 2

Herpes virus dz characteristics

Answer 2

• Typical microscopic lesions
  
  • intranuclear inclusions
  • karyomegaly
• Host specific
  
  • typically self-limiting
  • serious in immunocompromised
  • when they cross species very serious
• Latency for life after initial infection
• Recrudescence under stress => life-long shedding

Question 3

All DNA virus cause

Answer 3

intranuclear inclusions

Question 4

All RNA viruses cause

Answer 4

Inclusions in the cytoplasm

Question 5

To be infectious all viruses have to pass

Answer 5

The epithelium

Question 6

Monkey-bite encephalomyelitis

Answer 6

• When macaques have a herpesvirus that gets transmitted to a human
  
  • high mortality
• Human herpes virus 1 can cause lethal disease in small pet primates

Question 7

Herpes viruses a problem…

Answer 7

• When it crosses species
• Or in an immunocompromised patient
  
  • young
  • old
  • chemo
  • immunosuppressants

Question 8

Alpha herpesviruses that cause dz in comestic animals

Answer 8

• Human herpesvirus 1: oral herpes
• Human herpesvirus 2: genital herpes
• Human herpesvirus 3: chickenpox and shingles
• Bovine herpesvirus 1: IBR, IPV, IPB
• Bovine herpesvirus 2:
• Pseudorabies virus: Mad Itch, Aujeszky’s dz
• Equine herpesvirus 1: Abortion/neuro dz
• Equine herpesvirus 4: Rhinopneumonitis
• Equine herpesvirus 3: coital exanthema
• Canine herpesvirus 1: Hemorrhagic dz of pups
• Feline herpesvirus 1: Feline viral rhinotracheitis
• Avian herpesvirus 1: infectious laryngotracheitis
• Avian herpesvirus 2: Mark’s disease virus
• B virus: inapparent in monkeys, paralysis in humans

Question 9

Bovine herpesvirus 1

Answer 9

• Can do it all
• Infectious Bovine Rhinotracheitis (IBR)
  
  • one agent implicated in shipping fever complex
• Infectious pustular Vulvovaginitis (IPV)
• Infectious Pustular Balanoposthitis (IPB)
  
  • inflammation of glans penis
• Abortion
• mastitis

*can be lethal

Question 10

BHV1

Infectious bovine rhinotracheitis

Answer 10

• Upper respiratory dz
• Lesions on mucosa
• abortion

Question 11

Shipping fever complex

Viral etiology

Bact component

Answer 11

• Viral etiologies
  
  • Bovine Viral Diarrhea (BVD)
  • Infectious Bovine Rhinotracheitis (IBR)
  • Bovine respiratory Syncytial Virus (BRSV)
  • Parainfluenza Type-3 virus (PIV-3)
  • Bovine Coronavirus (BCoV)
• Bacterial components
  
  • Mannheimia hemolytica
  • Pasturella multocida
  • Mycoplasma bovis

Question 12

Shipping fever complex

Clinical signs

Diagnosis

Treatment

Answer 12

• Clinical signs
  
  • depression, anorexia, resp distress, death
• DX
  
  • history and clinical signs
• TX/Prevention
  
  • vaccination
  • supportive care
  • antibiotics
  • antiinflammatories to reduce lung pathology

Question 13

BHV1 Associated Ocular Lesions

Answer 13

• Conjuctivitis
• Corneal keratitis and ulceration
• Possible associate with cancer eye

Question 14

BHV1

Infectious Pustular Vulvovaginitis

Infectious pustular Balanoposthitis

Answer 14

• Does not lead to abortion
• May be historical form of BHV1 infection

Question 15

BHV1 infection of young calf

Answer 15

• Infection acquired shortly after birth
  
  • may lead to systemic infection and death
  • microscopic lesions throughout body
  • respiratory signs
• why we should vaccinate!

Question 16

BHV1 Abortion

Answer 16

• follows respiratory infection, not genital
• Not a distinct virus
• Liver is best source of virus for dx
• Live vaccines for IBR can be used on feedlots as abortigen (synchronizing)
  
  • attenuated vaccine can have inc virulence for fetus

Question 17

Epidemiology/diagnosis of BHV1

Answer 17

• Emergence in feedlogs in 1960s in US
• Spreads by aerosol and coitus (IPV/IPB)
  
  • village bull
• Enveloped (fragile)
• Causes latent infection
• Easily reactivated with corticosteroids
  
  • lymphpenia
• Easy virus to isolate in cell culture and characterize

Question 18

Cytopathic effect

Answer 18

• Unhappy cells….
• What’s done to isolate the virus
• Need host specific cells

Question 19

Control and Prevention of BHV1

Answer 19

• WIde range
• vaccinate 3 weeks ahead of shipping

Question 20

Bovine Herpesvirus 2

Answer 20

• Dermopathic bovine herpesvirus
• Bovine mammallitis
• Pseudo-lumpy skin disease

Question 21

BHV2 about

Answer 21

• localized to udder and teat
  
  • can’t milk these
• raised lesions on skin (differentiate from true lumpy skin dz pox dz in Africa)
  
  • BHV2 lesions have central depression
• Springing heifers affected
  
  • immunosuppressed
• Related to human herpes simplex

Question 22

BHV2

Transmission

Dx

Tx

Answer 22

• Transmission
  
  • direct contact (milking machines)
  • Insect vector
• DX
  
  • clinical signs
  • virus recovery
• Tx
  
  • Supportive care

*Not lethal

Question 23

Pseudorabies virus

Answer 23

• Pseudorabies
• Mad Itch
• Aujeszky’s dz

Question 24

Pseudorabies

(Aujeszky’s dz)

Pathogenesis pigs

Answer 24

• Typically acute infection first as upper respiratory tract, then latency
• Portal of entry
  
  • nasal, oral epithelium
• Early replication in upper respiratory tract
• may be short, poorly defined viremia
• Spread to brain (likes neurons b/c no immunosurveillance)
  
  • gives rise to pruritis
• Latency in trigenminal ganglia
• VIrus shed primarily from nose and mouth for 17 days post infection

Question 25

Pseudorabies

Epidemiology

M:46:14

Answer 25

• Pigs main reservoir
• primary spread is airborne
• virus excreted in milk
• transmitted by boars at service
• transplacental infection possible
• carrier occur
• may be activated by stress
  
  • transport
  • dietary change
  • farrowing

Question 26

Pseudorabies (Aujesky’s disease)

Clinical Signs

Pigs < 2 weeks old

Answer 26

• Incubation 1 week
• sigsn related to species/age
• Pigs
  
  • less than 2 weeks old
    
    • very susceptible
    • indistinct syndrome
    • fever, convulsive episodes, prostration
    • 100% mortality w/in a few hours of onset of clinical signs

Question 27

Pseudorabies (Aujeszky’s Dz)

Clinical Signs

Piglets > 2 weeks old

Answer 27

• Protracted course for up to a week
• fever, anorexia
• CNS signs
  
  • hindlimb incoordination
  • walk with sideways progression or circle
  • fine to coarse muscle tremors
  • lateral deviation of head
• Respiratory signs: replicates in upper respiratory mucosa
  
  • Dyspnea, nasal d/c
• 5-25% mortality

Question 28

Pseudorabies (Aujeszky’s dz)

Clinical signs

Adults

Answer 28

• Signs vary with strain of virus
• evidence for increasing virulence
• if mild
  
  • anorexia, dullness, constipation
  • may abort/mummification/stillbirths
• virulent straints
  
  • mild incoordination/fever/vomit
  • resp sympt
  • sneezing/nasal d/c
  • coughing/severe dyspnea
• development of incoordination, paralysis

Question 29

Pseudorabies control and eradication

Answer 29

• Marker vaccines: delete part of genome
• DIVA principle
  
  • differentiation of infected from vaccinated animals
• Vaccination alone doesn’t usually prevent infection, but prevents disease
• US eradicated pseudorabies with gene deleted vaccines

Question 30

Pseudorabies in other species

Answer 30

• Swine disease that jumps hosts: mad itch
• Cattle, sheep, cats, dogs
  
  • sudden death
  • intense local pruritis is cardinal sign
  • nibbling, biting, self mutilation
  • excitement, convulsions
  • dead end host
• dDx: rabies

Question 31

Pseudorabies in Dogs

Answer 31

• Associated with hunting of feral pigs or feeding infected meat to dogs
• mad itch
• relatively common in FL

Question 32

Equine Herpesvirus 4

(Equine Rhinopneumonitis)

Answer 32

• Incidence and Occurrence
  
  • infection of horses worldwide
• Clinical Signs
  
  • Fever (102-107 F)
  • Serous nasal d/c
  • Depression
  • Anorexia
  • Pharyngitis
  • Cough
  • Submandibular/retropharyngeal lymphadenopathy
  • Secondary bacterial infection
    
    • pneumonia
    • mucopurulent nasal d/c

*EHV1 will also do all of above things

Question 33

EHV1

Equine Abortion/Myeloencephalitis

Answer 33

• associate this with abortion!
• Incidence worldwide
• Etiology
  
  • abortion and neurological dz
• Pathogenesis
  
  • droplet infection => virus replication in upper resp tract
  • Leukocyte-associated viremic spread to other tissues (CNS/uterus/fetus)
    
    • fetus fresh when expelled
    • generalized infection of fetus
    • virus can be isolated from liver

Question 34

EHV1

three primary manifestations

Answer 34

• Neurologic dz
• Upper respiratory dz
• Abortion (late term)

Question 35

EHV1

Equine abortion/myeloencephalitis

Answer 35

• Clinical Signs
  
  • non-specific
  • Respiratory
  • Abortion
    
    • late term
    • foals born alive will have viral pneumonia
  • neurological disease
    
    • mild incoordination
    • posterior paresis
      
      • mild
      • sitting dog
      • recumbant
      • loss of bladder and tail function
    • quadraplegia
  • death

Question 36

Herpes viruses love…

Answer 36

Neurons

Upper respiratory tract

Eyes

Question 37

EHV1

Neuro dz

Answer 37

• ascending infection of nerve tissues seeded by viremia
• Most horses exhibit progressive ataxia and die/are euthanized

Question 38

EHV1 and EHV4

DX

Answer 38

• Clinical Signs
  
  • Rhinopneumonitis (EHV1 and EHV4)
  • Abortion (EHV1 and EHV4)
  • Neurologic disease (EHV1)
• Virus isolation
  
  • respiratory tract
  • blood
  • fetal and placental samples
• serology
• histopath: intranuclear inclusions
• PCR: can diff EHV1 and EHV4
• Immunofluorescence (IFA)

Question 39

EHV1 and EHV4

Prevention

Answer 39

• Vaccination
  
  • multiple vaccines
    
    • prevent abortion
    • reduce CS
    • doesn’t prevent neuro dz
• Quarantine and hygiene
  
  • confirmed cases iso for 28 days
  • avoid preg mares for 56 days (and immunocompromised animals)

Question 40

Virus detection by virus isolation

Answer 40

• Grind up infected cells
• Put this on happy cells
• Cytopathic effect means test is positive for virus

Question 41

Equine herpesvirus 3

Coital exanthema

Incidence, Etiology, CS

Answer 41

• Incidence and occurence
  
  • worldwide distr
  • often subclinical
  • persistence and recurrence in mares and stallions observed
• Etiology
  
  • single antigenic type
• Clinical Signs
  
  • Vesicles on skin of vulva or penis
    
    • heal in 2 weeks
  • secondary bact infection common
  • may leave pigmented areas

*Less severe disease

Question 42

Equine Coital Exanthema

(EHV3)

Transmission, Pathogenesis, Dx, Tx, Control

Answer 42

• Transmission
  
  • venereal
• Pathogenesis
  
  • local superficial infection
• Diagnosis
  
  • virus isolation (swabs/scrapings)
  • serological dx by SN test
• TX
  
  • sexual rest
  • topical antibiotics
• Control
  
  • no vaccine
  • Horses w/o active lesions may not be infectious

Question 43

Canine herpesvirus 1

Epidemiology

Answer 43

• Epidemiology
  
  • present worldwide in domestic and wild dogs in US and Europe
• Seropositive rates > 30% in feral dogs
• Kennels can have rates of infection near 100%
  
  • pups can be born w/o dz (maternal immunity)

Question 44

Canine Herpesvirus

Transmission/Risk Factors

Answer 44

• Unstable in environment
  
  • transmission through direct contact with infectious body fluids
• Latent after primary infection
• Puppies 1-3 weeks old most at risk
  
  • influenced by degree of passive transfer
    
    • 2-4wks old: mild-asymptomatic
    • 4+ wks old: occasional dz
    • 6+ wks old: rare dz
• Mortality rate high in puppies exposed during 1st week of life
  
  • rapid dz progression
  • most puppies die w/in 24-48 hours after onset clinical signs

Question 45

Canine Herpesvirus

CS

Answer 45

• Puppies
  
  • many non-specific
  • painful abdomen
  • rash
  • hepatomegaly (or enlarged other organs)
  • CNS
• Adult
  
  • asymptomatic
  • respiratory infection
  • reproductive infection
  • abortion/stillbirth of puppies

Question 46

Canine Herpesvirus

Dx

Answer 46

• Clinical signs
• viral culture
• Histopath
  
  • intranuclear inclusions
• necropsy
• PCR
• Serology +clinical signs

Question 47

Canine Herpesvirus

Necropsy

Answer 47

• Lesions found at necropsy
  
  • disseminated focal necrosis and hemorrhage of organs
• Splenomegaly
• Diffuse LN enlargement
• CNS lesions

Question 48

Canine Herpesvirus

TX, Prognosis

Answer 48

• Treatment
  
  • Supportive care
    
    • heat lamp or pad
    • Tube feeding
• Prognosis
  
  • poor for puppies < 3 weeks old
  • survival is rare, permanet organ damage common in survivors

Question 49

Canine Herpesvirus

Prevention

Answer 49

• Vaccination
  
  • No vaccine in US
  • Killed vaccine in Europe
• Antiserum (passive immunity)
  
  • must be given before exposure
  • academic exercises
• C-section and isolation
  
  • mixed results
• Sanitation, hygiene, disinfection
• Isolation of pregnant bitches and litters

Question 50

Feline herpesvirus1

(feline viral rhinotracheitis)

Agents involved

Answer 50

• Herpes virus (Feline Viral Rhinotracheitis)
• Calicivirus
• Chlamydophila
• Bordetella
• Myxoplasma

*compares to shipping fever, because it’s a complex

Question 51

Feline URI

Transmission, Epidemiology/Etiology

Answer 51

• Transmission
  
  • direct contact with infected cats
  • Indirect contact with infected cats through fomites
  • aerosolization
• Epidemiology/Etiology
  
  • latent component
    
    • recurrence
    • glucocorticoids/stress
  • multi-cat households
  • Syndromes
    
    • Chronic abortions in queens
    • fading kitten 2-4 weeks
    • URI anyone

Question 52

Feline URI (FHV)

Clinical Signs

Answer 52

• Corneal ulceration
• abortion
• neonatal death
• Non specific signs

Question 53

Calisi virus

Answer 53

• ulcerative stomatitis (lesions in mouth)
  
  • then to lungs and joints

Question 54

Differentiation of Feline URI

Answer 54

• Chlamydophila and mycoplasma: conjunctivitis
• Herpesvirus: rhinitis, pharyngitis, corneal ulcers
• Calicivirus: oral ulcers only or pneumonia

Question 55

Feline URI

Dx

Answer 55

• History, physical exam, CS
• Fluorescent antibody tests
  
  • conjuctival scrapings
  • pharyngeal swabs
  • tonsillar swabs
  • impression smears from bxs
• Virus isolation tests (Takes too long)
  
  • pharyngeal
  • nasal
  • conjuctival swabs
  • tissue bxs
• Serological assays
  
  • 4 fold inc in antibody titers
• Viral nucleic acid testing
  
  • multiplex PCR

Question 56

Feline URI Tx

Acute

Answer 56

• Supportive => hydration/nutrition
• Steam/vapor
• Corneal ulcer and conjuctivitis care
  
  • topical antivirals
    
    • Cidofovir => chain terminating nucleosides for virus
  • routine ulcer tx
• Abx therapy
• no glucocorticoids => we don’t want a lymphopenia

Question 57

Feline URI Tx

Chronic

Answer 57

• Facilitate drainage of d/c
  
  • nasal flushes, topical decongestants, moist rooms, nasal saline
• Chronic antibiotic therapy
  
  • Amoxicillin
  • Trimethoprim-sulfadiazine
  • Chloramphenicol, doxycycline
  • continue 4-6 weeks if benefits seen after 1 week
• Lysine
• +/- Glucocorticoids => risky
• +/- Turbinectomy and frontal sinus ablation => last resort

Question 58

Feline URI

vaccination

Answer 58

• vaccination (lessens severity of dz)
  
  • kittens 6-12 weeks until 16 weeks old (ML/killed every 3-4 weeks)
  • annual booster after initial 3 doses
• ML vaccines should be avoided in sick or pregnant animals
• Use more aggressive protocols in multi-cat households w/ chronic problems

Question 59

Feline URI

Prevention

Answer 59

• Quarantine for 3 weeks
• Keep queens with litters separate until 1-2 weeks after final vaccination dose
• Disinfect and sanitize
• Adequate ventilation => aerosolization big route of infection

Question 60

Avian Herpesvirus 1 (Gallid):

Infectious Laryngotracheitis (ILT) virus

Answer 60

• Occurs worldwide in chickens and pheasants
• All ages susceptible, most common in 4-18 month old

Question 61

AHV 1

Clinical Signs

Answer 61

• mild coughing, sneezing, nasal and ocular d/c, dyspnea, lough gasping, depression
• Pump handle respiration => raised head and neck during inspiration
• Head shaking during coughing causes
  
  • bloody mucous, frank blood on beak, face, feathers
• Low virulent straints cause
  
  • conjunctivitis
  • ocular discharge
  • swollen sinuses
  • low egg production

Question 62

AHV 1

Morbility/mortality

Tx/Dx

Answer 62

• Morbidity => almost 100%
• Mortality
  
  • 50-70% for virulent strains
  • 20% for low virulent strains
• Mild enzootic form most common in production
• Dx
  
  • CS
  • Confirmatory tests: PCR, ELISA

Question 63

AHV 2

Marek’s Dz virus

Answer 63

• CS associated with lymphoproliferative syndromes
  
  • lymphoma w/in visceral organs and nervous system
• Asymmetric paralysis of one/both legs/wings
  
  • fowl paralysis
  • incoordination an early signs
• 3 dz manifestations

Question 64

AHV 2

3 manifestations

NAVLE

Answer 64

• Acute Marek’s dz (Fowl paralysis)
  
  • extensive outbreaks in young birds
  • depression followed by ataxia and paralysis
  • significant mortality
• Ocular lymphomatosis
  
  • rare
  • causes graying of iris and blindness
• Cutaneous Marek’s dz (redleg syndrome)
  
  • round, nodular lesions along feathered skin
  • red coloration down legs

Question 65

Answer 65

AHV 2

Question 66

AHV 2

Mortality

Dx

Answer 66

• W/O vaccination mortality up to 80% in birds 2-5 months old
• Dx
  
  • PE
  • Signalment
  • CS
  • gross necropsy
• Confirm Dx by histopath
• Viral antigen detected by
  
  • immunofluorescence

Question 67

AHV 2

Vaccination

Answer 67

• In ovo vaccination at 18 days is standard
  
  • Parenteral vaccination in 1 day old chicks also possible
• Vaccination dec
  
  • lymphoproliferative syndromes
  • neoplastic lesions in visceral organs
• vaccination doesn’t dec
  
  • peripheral neuro dz
• viral strains developing resistance => requires updated vaccines

Question 68

Alpha herpes virus recap

Answer 68

• love neurons
• URIs

Question 69

Beta and Gammaherpesviruses like…

Answer 69

• WBCs

Question 70

Betaherpesvirinae

Answer 70

• Human herpesvirus 5
• Human herpesvirus 6
• Human herpesvirus 7
• Bovine herpesvirus 3
• Porcien (Suid) herpesvirus 2
• Murid Herpesviruses 1 and 2
• Elephantid Herpesvirus

Question 71

Porcine (Suid) Herpesvirus 2:

Porcine Cytomegalovirus Virus/

Inclusion body rhinitis

Answer 71

• Enzoonotic in swine herds worldwide
  
  • 90% of swine in enzootic herds may carry virus
• CS generally occur with intro of stress/conc dz
• Rhinitis occurs up to 10 weeks of age, then become subclinical
• Most severe in pigs < 2 weeks old

Question 72

SHV 2

CS

TX

DX

Answer 72

• CS
  
  • sneezing, coughing, serous nasal d/c, ocular d/c, depression
  • d/c becomes mucopurulent (when concurrent with bacteria) and interferes with suckling
  • piglets undergo rapid weightloss, die w/in days; survivors stunted
• Tx
  
  • generally horizontal
  • can be transplacental
    
    • hysterotomy possible, not usually done
• Dx
  
  • histologically see large basophiic intranuclear inclusions in turbinate mucosa
    
    • inclusion body rhinitis

Question 73

Elephantid Herpesvirus

Answer 73

• big problem, very virulent

Question 74

Gammaherpesvirinae

Answer 74

• Alcelaphine herpesvirus 1: Bovine Malignant catarrhal fever
• Ovine herpesvirus 2: Bovine Malignant Catarrhal fever

Question 75

Remeber Monkey Virus B

Answer 75

Found in Macaques, if jumps to Humans very very nasty

Question 76

Remember Human Herpes virus 1

Answer 76

• if jumps to marmosets very nasty and lethal

Question 77

Bovine Malignant Catarrhal Fever

About

Answer 77

• Wildebeest and sheep asymptomatic shedders
• Sheep assoc OvHV-2 passed to cattle, bison, deer (USA)
• Wildebeast assoc AlcHV-1 passed to cattle and other ungulates (Africa/Zoos) (USA)

Question 78

Bovine Malignant Catarrhal Fever

Dx indicators

Answer 78

• snotsiekte (Afrikans)
• Bilateral corneal opacity
• 100% mortality but morbidity is low

Question 79

Answer 79

Bovine Malignant Catarrhal Fever

Question 80

Bovine Malignant Catarrhal Fever

Manifestations

Answer 80

• Acute
  
  • highly fatal lymphoproliferative dz
  • catarrhal inflammation of URT and GI mucosa
  • keratoconjunctivitis
  • encephalitis
  • Lymph Node enlargement
• Peracute forms
  
  • high fever
  • dyspnea
  • acute gastroenteritis
  • death in 1-3 days
• Head and eye
  
  • high persistent fever (up to 107F)
  • listlessness
  • rapid pulse
  • profuse mucopurulent nasal d/c
  • dyspnea
  • CNS signs
  • lymphadenopathy
  • corneal opacity
  • death in 3-4 days

Question 81

Bovine Malignant Catarrhal Fever

Transmission

Diagnosis

Control

Answer 81

• African-type tx assoc with calving
• N. American-type associated with sheep at lambing
• Dx presumptive
  
  • hx, CS
  • PCR available
• Tx
  
  • none
• Control
  
  • separate wildebeest, sheep, cattle

Question 82

Herpes virus conclusion

test questions

Answer 82

• Ancient, successful viruses: vertebrates and invertebrates
• Conserved Virion Morphology
  
  • enveloped, icosahedral capsid
• Induce typical microscopic lesions
  
  • nuclear inclusions
• Host specific
  
  • usually self-limiting infections
  • serious dz in immunocompromised or novel hosts
• Latency => persist in host
• Recrudesce => times of stress/life-long shedding
• Dz caused by alpha, beta, gamma herpesviruses