Virology Final Flashcards
Tricias Equine, Swine, and Avian plus the 4 bovine
What family is equine infectious anemia?
retroviridae
How is equine infectious anemia transmitted? 3 ways
blood feeding insects (stable fly and horse fly) - mechanical
iatrogenic
placenta and milk
Where does EIA persist in the horse for life?
leukocytes
What happens during the subacute form of EIA?
moderate fever, recovery from neutralizing Ab
What are the CS of chronic EIA?
mild, episodic fever, cachexia anemia, and ventral edema
What are the cells infected by EIA?
macrophages and lymphocytes
What can immune complexes cause in EIA?
vasculitis, glomerulonephritis
What can cause the reoccurant infection during EIA?
significant genomic variations
How is EIA diagnosed?
Serology - coggins, ELISA
What are characteristics of Arteriviridae?
RNA, enveloped
What diagnostic can be used to detect proviral DNA of EIA in foals and seropositive animals?
PCR
What are the 2 main CS of EVA?
respiratory dz and abortions
What kind of morbidity and mortality does EVA have?
high morbidity, low mortality
What is the rate of abortion in EVA and at what time of pregnancy do they occur?
50%, 5-10 months
What is atypical about the transmission of EVA?
can remain viable in the environment for long periods (but is enveloped)
What role do stallions play in transmitting EVA?
long term shedders, result in venereal spread
How else is EVA spread besides venereal?
fomites
fetal fluids of aborted fetus
transplacental
How does EVA become viremic?
alveolar macrophages –> lymph nodes –> viremia
Where does EVA replicate in the horse?
endothelial cells
What are some ddX for EVA?
equine herpesvirus, influenza, EIA
What is the diagnostic test of choice for EVA?
RT-PCR
Where are samples collected for diagnosing EVA?
nasopharyngeal swabs, blood, urine, aborted fetus
When should vaccines be given to mares before mating with a EVA stallion? Wen should mares NOT be vaccinated?
mating - at least 3 weeks in advance
dont vax during last 2 months of pregnancy
When should foals be vaccinated for EVA?
6-8 months
What family causes equine encephalitides?
togaviridae
What are the characteristics of togaviridae viruses?
RNA, enveloped, zoonotic, bird resevoirs
What are the CS associated with encephalitides?
neurologic signs, encephalitis, neurologic sequelae
What part of encephalitides pathogenesis is important for transmission and CNS invasion?
2nd viremia - high titer
What are the differential diagnosis for equine encephalitides?
rabies, equine herpes 1, west nile
What diagnostic tests are used for equine encephalitides?
IgM capture ELISA
confirmation - neutralization
postmortem RT-PCR from brain
What are the 2 control measures for equine encephalitides?
inactivated vax
mosquito control
What family is west nile encephalitis?
flavivirdae (RNA, enveloped, arbovirus, zoonotic)
What are the CS associated with west nile?
asymptomatic, neurologic, small proportion die
What are the diagnostic tests for west nile virus?
anything (sero or antigen)
What kind of vaccine is available for west nile?
recombinant vax
What is the agent that causes equine influenza?
orthomyxoviridae - influenza A
What clinical signs are present in equine influenza?
bronchopneumonia
prolonged fever –> abortion
What is the pathogenesis of equine infuenza? What are some of the secondary infections?
epithelial cells in respiratory –>inflammation –> nasal serous discharge
secondary infections –> conjuctivitis, bronchopneumonia, guttural pouch infections
What are the differential diagnosis for equine influenza virus?
herpes 1 and 4, adenovirus, rhinovirus
What samples can be used for equine influenza diagnosis?
nasal mucus (early on) lung material (necropsy)
What diagnostic tests are used for equine infuenza?
virus isolation in culture
hemagluttination inhibition –> strain
retrospective serologic testing
What is the agent that causes equine rhinopneumonitis?
EHV-4
What can be used to diagnose EHV-4 (equine rhinopneumonitis)?
almost anything - virus isolation
What are control measures for EHV-4?
vaccines
What are characteristics of the adenovirus family?
DNA, naked, intranuclear inclusion bodies
What are clinical signs of adenovirus pneumonia in horses?
most –>asymptomatic
mild upper and lower respiratory infection
What are the problems in arabian foals with SCID and have adenovirus pneumonia?
virus destroys cells in pancreas salivary glands, renal, bladder, intestinal epithelium
What can be used to diagnose adenovirus pneumonia? How is it controlled?
almost any test
nothing is done to control
What are the characteristics of coronaviridae?
RNA, enveloped
What are the clinical signs of coronavirus?
self limiting diarrhea in foals (not as common as rotavirus)
What is the agent that causes equine abortion virus?
EHV-1
When does abortion occur in horses when they have EHV-1?
last 4 months of pregnancy
What type of EHV-1 infection can result in fatal generalized disease in horses?
perinatal infection
What leads to ataxia, recumbency, limb paralysis and death in EHV-1 in horses?
encephalitis
What is the most common sign of EHV-1 in horses for virus myelopathy?
urinary incontinence
What is the pathogenesis of EHV-1?
antigen-antibody complexes –> vasculitis, ischemia, infarcts –> neurologic disease and abortion
What type of EHV-1 causes respiratory distress and high mortality?
pulmonary vasculotropic EHV1
What other clinical signs are present during EHV1 besides neurologic, respiratory, and abortion?
ocular disease
What tests are used to diagnose EHV-1?
anything - intranuclear bodies, virus isolation, PCR, immunoflourescence, paired serum
What is the causative agent of equine coital exanthema?
EHV-3
What are the general clinical signs of EHV-3?
acute, mild, pustules in genital area, on lips of foals, respiratory mucosa, NO ABORTION, decreased libido
How is EHV-3 diagnosed?
pigment loss on black skin in genital region
PCR, serology
What virus is suspected in causing equine sarcoid?
bovine papillomavrus
What equine sarcoid type are hairless areas of slightly thickened skin?
occult sarcoids
What type of equine sarcoid appears on head, neck, and groin and grows slowly?
verrucous sarcoids
What is the transmission of EHV-3?
direct, sexual, fomites
What lesions does equine papillomatosis cause??
small papillomas around lips, nose, regress in 1-9 months
How is vesicular stomatitis transmitted?
breaks in mucosa and skin
also by arthropods and fomites
What are some of the clinical signs of vesicular stomatitis?
profuse salivation, lameness, vesciles and ulcers on tongue
What allows for the rapid healing of vesicular stomatitis?
no viremic phase, only vesiculation and interstitial edema
What causes reinfections for vesicular stomatitis?
antibodies short lived, different serotypes
What virus family causes classical swine fever?
flaviviridae (rna, enveloped)
What is another name for classical swine fever?
hog cholera
What are some of the clinical signs associated with hog cholera?
conjuctivitis, GI signs, pneuomonia neurologic
What blood clinical sign indicates hog cholera?
leukopenia
What can happen in pregnant sows infected with hog cholera?
reabsorption, abortion, fetal mummification, still births, newborns die soon after birth
What causes the extended or intermittent clinical disease associated with classical swine fever?
strains of moderate virulence
Where does 2ry replication occur in the pathogenesis of hog cholera? What clinical signs does this lead to?
endothelial, lymphoid, BM
–>hemorrhages, leukopenia, thrombocytopenia
What cases of hog cholera may show no gross changes at necropsy?
peracute
What is the most prominent lesion at necropsy of acute hog cholera cases?
general exhaustion of the lymphoid system
What is the problem with live-born piglets infected in utero with hog cholera?
persistently infected, immunologically tolerant
What are the 2 most common diagnostic tests for hog cholera?
IF, antigen ELISA
How is classical swine fever transmitted?
direct/indirect
How is hog cholera controlled in US?
test and slaughter (vaccine available in endemic areas)
What virus family causes african swine fever?
asfaviridae
What are the characteristics of the asfaviridae family?
DNA, enveloped, paracrystalline arrays in the cytoplasm
What can transmit african swine fever and what is the resevoir species?
transmitted by soft ticks
asymptomatic in warthogs
What are the 2 distinct patterns of transmission in african swine fever?
sylvatic cycle and epidemic/endemic cycles of domestic swine
What are the clinical signs of african swine fever?
same as hog cholera
What lesions are present in acute cases of african swine fever?
lymphatic and vascular systems, petechia in cortex of kidney
What are the lesions associated with chronic cases of african swine fever?
cutaneous ulcers, pneumonia, pleuritis, arthritis
What diagnostic tests are used for african swine fever?
detect viral antigen, virus isolation
What are the big 5 problems in controlling african swine fever?
no vaccine, pork products, persistantly infected pigs, ticks, similar to CSF
What is the main source of virus to infect pigs with african swine fever?
direct contact, aerosols
Why is there a problem for developing an african swine fever vaccine?
pigs can’t make functional neutralizing antibodies
What viral family is pseudorabies?
herpesviridae
What is different about pseudorabies and the intranuclear inclusion bodies?
not always observed