Systemic Viral Disease Flashcards
are RNA or DNA viruses more error prone?
RNA
what is bluetongue virus?
reoviridae
dsRNA
non-enveloped
who does bluetongue virus affect?
primarily sheep
rarely goat, cattle, deer, antelope
what does bluetongue virus do?
damages vascular endothelium: permeability of capillaries and intravascular coagulation
what are the clinical signs associated with bluetongue virus?
high fever
lameness
salivation
nasal discharge
tongue may be cyanotic
swollen face and tongue
+/- reproductive failure
how is bluetongue virus transmitted?
biting midges: culicoides spp
in utero transmission (often fatal)
no direct animal-animal transmission
what cells does bluetongue virus infect?
epithelial
macrophages
dendritic cells
vascular endothelium
is there treatment for bluetongue virus?
no curative
which vaccine for bluetongue virus is approved in the US?
monovalent attenuated modified live vaccine to serotype 10
what is infectious bursal disease?
birnaviridae
dsRNA
non-enveloped
how many serotypes are there with infectious bursal disease?
two
serotype 1: pathogenic in chickens
serotype 2: asymptomatic carriage
what does infectious bursal disease cause clinically?
highly contagious
young chickens and turkeys primarily
depression, ruffled feather, dehydration
watery diarrhea
immunosuppression
20-30% mortality
what cells does infectious bursal disease impact?
B cells devoid of Ig or that have surface IgM only
cloacal bursa: viral bursectomy
what does the viral bursectomy by infectious bursal disease lead to?
decreased antibodies
poor response to vaccines
secondary infections
how is infectious bursal disease transmitted?
fecal-oral
what is malignant catarrhal fever (MCF)?
herpesviridae
dsDNA
enveloped
who does alcelaphine herpesvirus-1 impact?
wildebeest
malignant catarrhal fever
who does ovine herpesvirus-2 impact and what is it?
sheep
malignant catarrhal fever
accidental hosts: bison, deer, antelope
what does malignant catarrhal fever cause?
multisystemic
lymphoid proliferation
widespread vascular epithelial and mesothelial lesions
what does malignant catarrhal fever do to lymphocytes?
widespread lymphoblastic vasculitis with fibrinoid vascular necrosis and thrombosis associated with macroscopic lesions
what are the four forms of malignant catarrhal fever?
peracute
head and eye
intestinal
mild
what happens in the peracute form of malignant catarrhal fever?
severe oral and nasal mucosal inflammation
hemorrhagic gastroenteritis
sudden death
what is the most common form of malignant catarrhal fever?
head and eye
what is marek’s disease?
herpesviridae
marek’s disease virus
enveloped
dsDNA
what major things can be seen in marek’s disease?
chicken T cell lymphomas
peripheral nerve enlargement
neurologic disorders
how is marek’s disease transmitted?
inhalation of dander
what is feline infectious peritonitis (FIP)?
feline infectious peritonitis virus
+ssRNA
enveloped
how does feline infectious peritonitis develop?
from mutations in S-proteins of ubiquitous feline enteric coronavirus
what are the typical sites of disease of feline infectious peritonitis?
peritoneal and thoracic cavities
ocular and central nervous system
kidneys
what are the two forms of feline infectious peritonitis?
wet form
dry form
what happens in the inflammatory process of FIP?
chronic, progressive, fatal, systemic inflammation due to within-the-host viral mutation and atypical host responses
cytokines produced by FIPV-infected cells drive positive feedback loops
some anti-S antibodies enhance FIPV entry into monocytes and macrophages
how is feline infectious peritonitis transmitted?
not contagious itself: mutations develop in each cat
parent virus feline enteric coronavirus transmitted from queens to kittens
what is border disease?
Flaviviridae
border disease virus
+ssRNA
what are the clinical features and epidemiology of border disease?
congenital disease of lambs
rare in goats: abortion
what can be seen in congenital disease of lambs in border disease?
abortions
low birth weight
poor viability
musculoskeletal defects
abnormal myelination
excessively hairy coat
what are the cell targets of infection with border disease?
oligodendrocytes
thyroid epithelial cells
epithelium of secondary hair follicles (?)
what is infectious salmon anemia?
Orthomyxoviridae
-ssRNA
enveloped
what does infectious salmon anemia do?
infects red blood cells
what are the clinical signs with salmon infectious anemia?
abnormal swimming/close to surface
swollen abdomen
skin lesions/petecchia
pale gills, raised scales, bulging eyes
swollen kidney, spleen, liver
in what species is salmon infectious anemia subclinical?
herring
cod
pollock
what is equine viral arteritis?
arteriviridae
+ssRNA
enveloped
what virus causes equine viral arteritis?
equine arteritis virus
what are the clinical features of equine viral arteritis?
fever, URI, leukopenia
edema, effusion, hemorrhages
abortion: autolytic fetuses
urticaria
most subclinical
many clinical signs: periorbital edema and conjunctivitis are classic
what are the cell targets of infection of equine viral arteritis?
initial: cytoplasm of pulmonary macrophages
then lymph nodes and endothelial cells
also: epithelial, mesothelial, vascular smooth muscle
from the stallion carrier state, where is equine viral arteritis shed from?
reproductive tract
how is equine viral arteritis transmitted?
horizontal: aerosol, biting, venereal, urine, feces
breeding/semen is major route
what is feline immunodeficiency virus?
retroviridae
+ssRNA
enveloped
what is important about the feline immunodeficiency virus ssRNA genome?
has DNA intermediates that can integrate into the hose genome
reverse transcriptase
what signs are associated with feline immunodeficiency virus?
fever
lymphadenopathy
leukopenia
what are the signs of feline immunodeficiency virus due to?
viral infection of lymphocytes and initial immune stimulation
what are the typical feline immunodeficiency virus mechanisms of disease?
targets and kills immune cells, especially CD4 T helper cells
humoral and cell mediated immunity rare
rapid mutation rate
what is feline leukemia virus?
retroviridae
+ssRNA
enveloped
how many subtypes of feline leukemia virus are associated with particular disease manifestations?
4
what is feline leukemia virus A associated with?
low pathogenicity
what is feline leukemia virus T associated with?
wasting and immune suppression due to tropism for T cells
how can feline leukemia virus impact bone marrow?
dysplasias
leukemias
fibrosis
what cats typically get feline leukemia virus-associated lymphomas?
younger to middle-aged
where are feline leukemia virus-associated lymphomas located?
thymus
eyes
central nervous system
multicentric
how is feline leukemia transmitted?
horizontal: oronasal through saliva
vertical: transplacental
what is equine infectious anemia?
retroviridae
+ssRNA
enveloped
what are the 5 forms of equine infectious anemia?
acute
subacute
chronic
latent
neurotropic
what are the cell targets of equine infectious anemia?
monocytes first
then viral replication associated with tissue macrophages
what drives disease manifestation of equine infectious anemia in susceptible horses?
cyclical viral replication and host responses
what are some bad immune responses to equine infectious anemia?
complement-mediated lysis of red blood cells and platelets
antigen-antibody complexes deposited in kidneys lead to glomerulonephritis and possibly vasculitis
what are the ways that equine infectious anemia can be transmitted?
horseflies and stable flies are mechanical vectors
reusing needles or inadequate sterilization
transplacental
is bluetongue virus enveloped and what is the genome?
no
dsRNA
what is serotype 2 of infectious bursal disease?
asymptomatic carriage
what is serotype 1 of infectious bursal disease?
pathogenic in chickens
does infectious bursal disease affect stem cells or peripheral B cells?
no
what is the reservoir of infectious bursal disease?
chicken feces
how does malignant catarrhal fever often present?
no overt signs
what happens in the head and eye form of malignant catarrhal fever?
early: fever, reddened mucosa, conjunctivitis, corneal opacity
late: necrosis and hyperemia in oral cavity
what happens in the intestinal form of malignant catarrhal fever?
early: pyrexia, hyperemic oral and nasal mucosa with profuse catarrhal and mucopurulent discharge, generalized lymphadenopathy, death from severe diarrhea prior to necrotic lesions
is there a vaccine for malignant catarrhal fever?
no
what is mareks disease taken up by?
macrophages
where does mareks disease replicate?
respiratory tract and feather follicle
what do the mutations in feline infectious peritonitis permit?
infection of monocytes and macrophages that cannot eliminate the virus
how is feline infectious peritonitis driven by inflammation?
chronic, progressive, fatal, systemic inflammation due to within-the-host viral mutation and atypical host responses
cytokines produced by FIPV-infected cells drive positive feedback loops
some anti-S antibodies enhance FIPV entry into monocytes and macrophages
what might the wet form of feline infectious peritonitis reflect?
TH2 immune response bias
what might the dry form of feline infectious peritonitis reflect?
TH1 immune response bias
does border disease affect goats?
rarely abortion
what is the major route of equine viral arteritis transmission?
breeding/semen
why is it important that feline immunodeficiency virus has a rapid mutation rate?
antiviral antibodies and antigen-specific T cells produced too slow and late
what is the unusual feline immunodeficiency virus mechanism of disease?
neurotropic FIV strains infect CNS cells
microglia and astrocytes
in how many infected cats does progressive/persistent infection of feline leukemia develop?
1/3
is feline leukemia virus associated with gastrointestinal tract lymphomas?
no
what can progressive feline leukemia virus lead to?
cell growth disturbances: bone marrow, FeLV-associated lymphomas
immunopathologic diseases: immune suppression, immunocomplex deposition
what is the most common form of equine infectious anemia?
latent
what are the two immune response options with equine infectious anemia?
good: clear with humoral and cell-mediated
bad: complement-mediated lysis of red blood cells and platelets
what are the signs of bovine leukosis?
none
