Gastrointestinal Tract Viral Disease Flashcards
what are the forms of feline panleukopenia?
subclinical
peracute
acute
chronic does not exist
what is the most common form of panleukopenia?
subclinical
what is seen in peracute panleukopenia?
sudden onset fever
leukopenia
death within 24 hours
may look like sudden death (“fading kitten syndrome”)
who is seen with acute panleukopenia?
fetus to neonate
more than 4 weeks old to adult
what happens if a fetus in early to mid gestation is infected with panleukopenia?
death
in cats more than 4 weeks old, what cells does panleukopenia target?
small intestine epithelial cells
lymphocytes
bone marrow precursor cells
how does feline panleukopenia virus enter cells?
clathrin-mediated endocytosis
where does feline panleukopenia virus first replicate?
oropharyngeal lymphoid tissues
which cells does feline panleukopenia virus target?
rapidly dividing cells
why are there gastrointestinal signs with feline panleukopenia virus?
intestinal crypt epithelial cells have a high rate of replication
why does feline panleukopenia virus cause leukopenia?
bone marrow progenitors have a high rate of replication
which patients show cerebellar hypoplasia due to infection with feline panleukopenia virus?
kittens infected in utero
how does feline panleukopenia virus cause cell death?
apoptosis
necrosis
lysis by cytotoxic T cells
why does recovery from panleukopenia occur relatively quickly?
neutralizing antibodies develop in 3-5 days
acute disease can be devastating
how does feline panleukopenia virus spread?
direct contact with bodily fluids from cats with acute and subclinical infections
can be shed from recovered cats for >6 weeks
what are the clinical signs of canine parvovirus?
fever
vomiting
diarrhea
dehydration
lethargy
anorexia
what virus causes canine parvovirus?
canine parvovirus 2 (CPV-2)
what is the genome of canine parvovirus 2?
ssDNA
5Kb genome
is there cerebellar hypoplasia with in utero canine parvovirus 2?
no known
what cells are impacted if a fetus to a week old puppy is infected with canine parvovirus 2?
cardiac myocytes
what cells are impacted by canine parvovirus 2 in dogs more than 4 weeks old?
intestinal crypt epithelial cells
bone marrow hematopoietic progenitors
in dogs more than 4 weeks old, what happens with canine parvovirus?
bone marrow precursor cells impacted
neutropenia pronounced: short half-life
neutropenia predisposes to secondary bacterial infections (esp. pneumonia)
neutropenia transient
how long does canine parvovirus 2 survive in the environment?
months
what are the disease syndromes of infectious canine hepatitis (ICH)?
peracute
acute
chronic
what are the reservoirs of canine parvovirus?
canids primarily
what do you see in the chronic form of infectious canine hepatitis?
chronic active hepatitis
hepatic fibrosis
cirrhosis
survival up to 8 months
what is the most common form of infectious canine hepatitis?
acute
what virus causes infectious canine hepatitis?
canine adenovirus-1 (CAV-1)
how does initial infection of infectious canine hepatitis occur?
nasopharyngeal, conjunctival, or oropharyngeal routes
then replication in tonsils
then systemic infection
how is infectious canine hepatitis shed?
saliva
feces
urine
how is infectious canine hepatitis spread?
direct contact
fomites
who does white scours affect?
bovine
swine
who is affected in bovine by white scours?
5-14 days old
what is the most common diarrheal disease in calves?
white scours
who is affected in swine by white scours?
7-10 days old
why does white scours have a high mortality rate?
dehydration
secondary infections in calves as well
what are the direct mechanisms of pathogenesis of white scours?
infection targets mature villus tip enterocytes
secretory diarrhea
what are the indirect mechanisms of pathogenesis of white scours?
osmotic dysregulation
malabsorption due to villus blunting
how is white scours transmitted?
fecal-oral: direct, fomites
environmentally stable
what are the clinical syndromes of calf diarrhea or winter dysentery?
calf diarrhea
winter dysentery
respiratory disease
what does calf diarrhea cause?
usually in <3 weeks old, can be up to 3 months
profuse watery diarrhea
high morbidity/mortality
what does winter dysentery cause?
adults affected
explosive bloody diarrhea
low mortality
concurrent mild respiratory disease
what are the cell targets of calf diarrhea or winter dysentery?
epithelial cells of gastrointestinal tract
epithelial cells of respiratory tract
does recovery from calf diarrhea or winter dysentery protect against disease and infection?
only disease, not infection
what are some porcine enteric coronaviruses?
transmissible gastroenteritis (TGE)
porcine epidemic diarrhea syndrome (PEDS)
porcine delta coronavirus (PDCoV)
swine acute diarrhea syndrome (SADS)
how does transmissible gastroenteritis (TGE) affect swine less than 7 days old?
near 100% mortality
how does transmissible gastroenteritis (TGE) affect growers?
moderate diarrhea
how does transmissible gastroenteritis (TGE) affect 2-3 week old swine?
severe disease
survive
what does transmissible gastroenteritis do?
targets jejunum, ileum
destroys apical enterocytes
villous atrophy
what can confer immunity for transmissible gastroenteritis (TGE)?
porcine respiratory coronavirus (deletion mutant of TGE)
oral modified-live vaccines protective
infection results in long-term immunity
when is transmissible gastroenteritis more common?
winter
how is transmissible gastroenteritis transmitted?
fecal-oral
how can you prevent transmissible gastroenteritis?
closed herd
all-in all-out production
sanitation
what has largely stifled porcine epidemic diarrhea syndrome (PEDS)?
enhanced biosecurity in response to
what ages are affected by porcine epidemic diarrhea syndrome (PEDS)?
all in naive herd
how is porcine epidemic diarrhea syndrome (PEDS) transmitted?
fecal-oral
is there a vaccine for porcine epidemic diarrhea syndrome (PEDS)?
no
how is porcine epidemic diarrhea syndrome (PEDS) prevented?
closed herd
all-in all-out production
sanitation
how is it suspected that swine got swine acute diarrhea syndrome (SADS)?
bat to pig transmission
what signs does swine acute diarrhea syndrome (SADS) cause?
diarrhea
weight loss
death
90% mortality in piglets <6 days
what are the two distinct viral forms of bovine viral diarrhea (BVD)?
cytopathic: transient infection
non-cytopathic: can cause persistent infection
what can you see in non-pregnant cattle with bovine viral diarrhea (BVD)?
biphasic fever
mild to explosive diarrhea
may see oculonasal discharge and oral erosions, thrombocytopenia
immune suppression
in whom does mucosal disease from bovine viral diarrhea develop?
infection with non-cytopathic biotype in utero
then infected with cytopathic biotype post-natal
what can persistent infection of bovine viral diarrhea lead to?
stunting
vague and non-specific signs related to immune suppression and opportunistic infections
what virus causes bovine viral diarrhea?
bovine viral diarrhea virus (BVDV)
what does cytopathic bovine viral diarrhea do?
induces cell death likely via viral proteases, unrestrained genome replication
emerge from non-cytopathic due to mutation
cannot induce persistent infection
what does non-cytopathic bovine viral diarrhea do?
does not induce cell death
can induce persistent infection
what lesions can be seen with bovine viral diarrhea in prenatal or persistent infection?
abortion of autolyzed fetuses
congenital defects of: CNS and eye, skeletal defects, hair follicles
what cells does cytopathic bovine viral diarrhea impact?
lymphocytes
macrophages
dendritic cells
epithelial cells
what clinical signs are associated with bovine viral diarrhea in the chronic form?
not gastrointestinal
skin ulcers/hypeerkeratosis
how does bovine viral diarrhea impact herds?
with immunity: sporadic losses
no immunity: major losses upon exposure
what cell types does rinderpest impact?
immune cells
epithelial cells
endothelial cells
what does rinderpest cause?
gastrointestinal tract ulcerations from mouth to anus
necrosis and hemorrhage of peyer’s patches
severe but transient lymphopenia
diarrhea, dehydration, shock, death
why do parvoviruses target primarily replicating cell populations?
cellular DNA replication machinery is required for viral genome replication
atrophy of the intestinal villi tips due to scours leads to ________________
malabsorptive diarrhea
true/false: persistently BVD infected calves cease to shed virus after re-infection with a non-cytopathic BVD strain
false: tolerant to a virus
never going to develop the antibody response needed
was feline panleukopenia derived from canine parvovirus?
no
in what species other than canines have cases of canine parvovirus been reported?
ferrets
mink
cats
what do you see in the peracute form of infectious canine hepatitis?
circulatory collapse in 24-48 hours
coma
death
what do you see in the acute form of infectious canine hepatitis?
fever
diarrhea
leukopenia
tonsilitis, conjunctivitis
corneal edema
signs of liver disease
what signs of liver disease do you see in the acute form of infectious canine hepatitis?
abdominal swelling
jaundice
vomiting
hepatic encephalopathy
what cells does infectious canine hepatitis primarily target?
vascular endothelial cells (kidney especially) and hepatocytes
replication in corneal epithelial cells
what can you see in the respiratory disease of calf diarrhea or winter dysentery?
mild but can see severe pneumonia
is the bovine coronavirus (calf diarrhea or winter dysentery) enveloped?
yes
what can confer immunity to transmissible gastroenteritis?
porcine respiratory coronavirus
deletion mutant of TGE
what is thought to have largely stifled porcine epidemic diarrhea syndrome in the US?
enhanced biosecurity
is there a vaccine for porcine epidemic diarrhea syndrome?
no
what can lead to death with bovine viral diarrhea?
immune suppression can lead to death via respiratory and gastrointestinal tract secondary infections
what is targeted in cats >4 weeks old with acute panleukopenia?
small intestine epithelial clls
lymphocytes
bone marrow precursor cells
what is the genome of feline panleukopenia virus?
-ssDNA
is feline panleukopenia virus enveloped?
no
feline panleukopenia virus enters s-phase cells by ________________________, then enters the nucleus by ______________________
clathrin-mediated endocytosis
transferrin receptors
are there non-cat reservoirs of feline panleukopenia virus?
no
what is the genome of canine parvovirus?
-ssDNA
is canine parvovirus enveloped?
no
what do the intestines of dogs more than 4 weeks old look like with canine parvovirus?
petechiae and “ground glass”
fibronecrotizing and hemorrhagic enteritis if severe
who is infectious canine hepatitis most common in now?
dogs less than a year old
what is the genome of canine adenovirus-1 and is it enveloped?
dsDNA
no
what can lead to clouding/edema/blue eye with infectious canine hepatitis?
replication of virus in corneal epithelial cells
can infectious canine hepatitis survive well in the environment?
yes
months
what is the genome of white scours?
dsRNA
is white scours enveloped?
no
what signs of white scours can be seen in swine 7-10 days of age?
diarrhea
high mortality: dehydration
endemic in most swine herds
recovery 3-4 days
what does white scours do directly to cause secretory diarrhea and villus tip blunting?
viral enterotoxin
stimulates neurotransmitters to activate secretion from crypts
loss digestive enzymes
reduced glucose coupled Na transport
what does calf diarrhea cause?
profuse watery diarrhea
high morbidity and mortality
what genome does bovine coronavirus have?
+ssRNA
is bovine coronavirus enveloped?
yes
what virus causes calf diarrhea or winter dysentery?
bovine coronavirus
what are the cell targets of bovine coronavirus?
epithelial cells of gastrointestinal tract
epithelial cells of respiratory tract
what does transmissible gastroenteritis cause?
decreased absorptive area
decreased digestive enzymes
accumulation of nutrients and electrolytes
osmotic/malabsorptive diarrhea
when were the first cases of porcine epidemic diarrhea syndrome identified in the US?
2013
is porcine epidemic diarrhea syndrome or transmissible gastroenteritis milder clinically?
porcine epidemic diarrhea syndrome
also less contagious
when is porcine epidemic diarrhea syndrome more common?
in winter
what are the different outcomes with different gestation stages of cows with bovine viral diarrhea?
early: death
100-125 days: fetal death, malformations, persistent infection
after 125 days: fetal death, +/- malformations, +/- appear healthy, no persistent infection
what is the genome of bovine viral diarrhea virus?
+ssRNA
is bovine viral diarrhea virus enveloped?
yes
what form of bovine viral diarrhea is most common?
subclinical
what are the two forms of mucosal disease with bovine viral diarrhea?
acute
chronic: no gastrointestinal impacts
who does rinderpest infect?
all cloven-hooved
cattle main
what genome does rinderpest have?
-ssRNA
is rinderpest enveloped?
yes
