Lecture 5 10/15/24

Question 1

What is caused by bovine herpesvirus 1.1?

Answer 1

-infectious bovine rhinotracheitis
-conjunctivitis
-abortion
-immune suppression

Question 2

What is caused by bovine herpesvirus 1.2?

Answer 2

-infectious pustular vulvovaginitis
-infectious balanoposthitis
-abortion

Question 3

What is caused by bovine herpesvirus 1.3/BHV-5?

Answer 3

-encephalomyelitis
-abortion

Question 4

What is the pathophysiology of BHV-1?

Answer 4

causes:
-nasal and oral mucosal erosions
-severe tracheitis
-conjunctivitis
-abortions
-immunosuppression

Question 5

When do abortions occur with BHV-1?

Answer 5

during resp. outbreaks and up to 100 days after

Question 6

What are the characteristics of BHV-1 latency?

Answer 6

-maintained and spread by latently infected carriers
-latency occurs in trigeminal ganglion cells
-stress causes recrudescence and shedding of the virus

Question 7

Which tests can be done to detect an active viral infection?

Answer 7

-virus isolation
-PCR
-antigen capture ELISA
-immunofluorescence
-histopathology

Question 8

Which samples are used to detect an active viral infection?

Answer 8

-serum/plasma
-whole blood
-nasal swabs
-transtracheal wash/bronchoalveolar lavage
-tissue
-fetus/placenta
-semen

Question 9

Which tests can be done to detect a previous viral infection?

Answer 9

-serology
-antibody ELISA
-complement fixation
-card agglutination
-intradermal allergen test
-caudal fold test

Question 10

Which samples are used to detect a previous viral infection?

Answer 10

-serum/plasma
-whole blood
-intradermal antigen deposition

Question 11

Which diagnostic methods are most commonly used for diagnosis of BHV-1?

Answer 11

-PCR
-serology
-virus isolation
-immunofluorescent antibody staining
-histopathology

Question 12

What is the hallmark finding of herpes infections on histopath?

Answer 12

inclusion bodies

Question 13

What result on paired antibody ELISA titers indicates infection?

Answer 13

4 fold or greater increase in titers

Question 14

What is the typical treatment for viral infection?

Answer 14

-fluids
-antibiotics for secondary bacterial infections
-NSAIDs
-avoiding further stress
-maybe steroids; but they induce immunosuppression

Question 15

How is infectious bovine rhinotracheitis/BHV prevented?

Answer 15

vaccination and biosecurity

Question 16

What are the characteristics of the BHV MLV?

Answer 16

-best cell mediated immunity
-may cause abortions in cows not previously vaccinated
-cannot be used in neonates
-can cause latent “vaccine infections”

Question 17

What is the main characteristic of the BHV killed vx?

Answer 17

safe for pregnant cows

Question 18

What are the characteristics of the BHV intranasal MLV?

Answer 18

-fastest means of protection
-mucosal immunity through IgA prod.
-good cell mediated immunity
-no interference with maternal antibodies
-circulates between animals after vx
-short lived; 6 week duration

Question 19

What are the potential BVDV genotype and biotype combinations?

Answer 19

-genotype 1, non-cytopathic
-genotype 1, cytopathic
-genotype 2, non-cytopathic
-genotype 2, cytopathic

Question 20

How does cytopathic BVDV differ from non-cytopathic BVDV?

Answer 20

cytopathic kills cells in culture while non-cytopathic does not

Question 21

What is the most important manifestation of BVDV?

Answer 21

immunosuppression

Question 22

What are the manifestations of BVDV?

Answer 22

-immunosuppression
-diarrhea
-abortion
-upper resp. infection
-persistent infections
-persistent testicular infections
-mucosal disease
-congenital malformation

Question 23

Which lymphoid cells are effected by BVDV?

Answer 23

-Th cells
-B cells
-neutrophils
-monocytes
-cytotoxic T cells
-NK cells
-dendritic cells
-pulmonary alveolar macrophages

Question 24

How does BVDV impact lymphoid cells?

Answer 24

-reduces lymphoid cell number
-impairs interferon production, phagocytosis, chemotaxis, and microbial killing
-reduces MHC I and II expression and Th cell response

Question 25

What is a persistent BVDV infection?

Answer 25

-NCP virus infects the calf at 40-125 days of gestation
-calf’s immune system is developing at this time and recognizes the virus as self, allowing for immunotolerance

Question 26

Why are BVDV PIs important?

Answer 26

serve as a reservoir for BVDV transmission to the rest of the population

Question 27

What are the diagnostic methods for BVDV?

Answer 27

-virus isolation: 2 samples 3 weeks apart
-immunohistochemistry
-antigen capture ELISA

Question 28

Which samples are used for each BVDV diagnostic method?

Answer 28

-virus isolation: nasal swab, ear notch, whole blood buffy coat
-immunohistochemistry: ear notch
-antigen capture ELISA: ear notch, whole blood

Question 29

How long does it take for BVDV to transmit from a PI to another individual?

Answer 29

1 hour of fence line contact (very contagious)

Question 30

What are the characteristics of the BVDV vaccine?

Answer 30

-prevents clinical disease
-limits viral shedding
-protects fetus from abortion and PI
-used in the cows