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Bovine Viral Diarrhea Virus: Bovine reproductive tract infections - Coggle…
Bovine Viral Diarrhea Virus: Bovine reproductive tract infections
flavivirus
West Nile
pestivirus
not transmitted by insects
border disease
hog cholera
characteristics
capable of establishing persistent infection following in utero infection
persistent infected animals transmit disease
unstable in environment
enveloped
susceptible to common disinfectants
direct and indirect transmission
contaminated fomites
no arthropods
ssRNA
types
genotypes
type I
type 2
biotypes
cytopathic
cytopathology
cell death
"cp"
arise spontaneously
mutation
recombo of ncp isolates
non-cytopathic
non=pathogenic i tissue culture
"ncp"
acute infections
persistently infected animals are best source
transmission
acute infections
horizontal
all body secretions and fluids
in utero
MDAbs critical
disappear in 3-8mo
persistently infected (PI) animals
most important source for virus
persists in semen
develop when the fetus is immunologcally imamture and develop tolerance to the virus
do not amount an immune response
virus spread all over body
shed virus through all excretions
shed large #s
40-80% prevalence in the US
10-14d viremia in transiently infected animals
pathogenesis
5-7d incubation period
clinical signs
in immunocompetent, non-PI, no pregnant
:female-doctor:
biphasic fever
bovine respiratory disease
hemorrhagic syndrome
:microscope:
leukopenia
immunosuppression
:eye:
ulcers on muzzle on lips
immunocompetent, non-PI, pregnant
fetal infection
dependent on age
early infection
-9 to 45 d
direct effect on developing embryo
uterine enviornment not conducive for implantation
infection following embryo
45-175d
abortion
congenital defects
CNS
cerebellar hypoplasia
hypomyelination
PI animals results
Ab neg
virus +
asymptomatic, may be unthrifty
develop mucosal disease
6-24mo after birth
appearance of cp strain or coinfection w/ cpBVDV
mutation or recombo event
localizes in N
activate immune cells
unknown mechanism
severe clinical BVD signs
necrosis of keatinocytes in
stratum spinosum
ulcers
fatal
hemorrhagic diarrhea
late gestation infection
150 - 285d
fetus is immunocompetent
diagnosis
viral detection
isolation
blood
lymphoid organs
spleen
serum
DFA
lymphoid organs
lung
spleen
IHC staining
post-mortem
skin biopsy/ear notch
ACE
skin biopsy
serum
PCR
serum
post-mortum tissue
mostly detect Ag
serology
serum neutralization
paired serology
single titers
per-colostral SN titer
herd screening (pooled sample)
viral isolation
PCR
IHC/ACE
prevention
immunity
natural exposure
passive immunity
colstrum
lasts 3-8mo
vaccination
MLV
IM
IN
killed
prevents acute disease
may not protect fetus
screnning and elimination PI animals
biosecurity
BVD Zero video
