Parvoviruses and Circoviruses Flashcards
1
Q
Properties of parvoviruses
A
- Small Icosahedral virion (10 X smaller than poxes)
- Linear ssDNA genome
- Naked => Environmentally resistant
- Hardiest/smallest viruses
- Replicate in nucleus of rapidly dividing cells
- GI tract => Diarrhea and malabsorption
- WBC => Panleukopenia
- Pregnancy => S=stillbirth M=mummification
- ED = embryonic death I = infertility
- eosinophilic intranuclear inclusions
2
Q
Diseases of Parvoviruses
- Porcine parvovirus
- Feline panleukopenia virus
- Canine parvovirus
- Mink enteritis virus
- Aleutian mink dz virus
- Goose parvovirus
A
- Porcine parvovirus
- stillbirth, abortion, fetal death, mummification & infertility
- Feline panleukopenia virus
- Cerebellar hypoplasia, panleukopenia, enteritis
- Canine parvovirus
- Generalized neonatal disease, enteritis, myocarditis, panleukopenia
- Mink enteritis virus
- Panleukopenia, enteritis
- Aleutian mink dz virus
- Chronic immune complex disease, encephalopathy
- Goose parvovirus
- Hepatitis
3
Q
Parvovirus in pigs
(SMEDI syndrome)
Clinical Syndrome
A
- S=Stillbirth
- M=Mummification
- ED=Embryonic death
- I=infertility
S, M, ED
- occur because of intrauterine infection
Syndrome usually seen in gilts not immune and bred to new boar
No clinical dz in non-pregnant gilts/sows
4
Q
Parvovirus in Pigs
Clinical Findings
A
- reduced litter size
- fetuses dying after 30 days => mummies at birth
- after birth may contain macerated or mummified fetuses
- Sows immune after first infection
5
Q
Parvovirus in Pigs
Transmission
A
- infected boar bred to naive pig
- found in
- boar semen, testicles, feces
- can be shed continuously
- Virus resistent, persists up to 135 days in pens
6
Q
Parvovirus in Pigs
Diagnosis
Prevention
A
- Diagnosis
- mummified fetus best for DG
- IF
- PCR from viscera
- Serology if no fetus available
- virus neutralization, ELISA, Hemagglutination inhibition, immunodiffusion
- mummified fetus best for DG
- Prevention
- effective vaccines 3-4 weeks prior to breeding
- maternal antibodies can last 6 months and interfere with vaccination response
7
Q
Feline Panleukopenia
Disease characteristics
A
- Disease Characteristics
- highly contagious, often fatal dz in cats
- dz more severe in kittens
- virus not pathogenic to canids, can infect racoon & mink
- emerging canine parvovirus type-2 strains cause panleukopenia-like dz in felids
8
Q
Feline Panleukopenia
Transmission
A
- Widespread in nature
- most cats exposed in first year of life
- Direct transmission
- through feces, urine, saliva, vomit
- Indirect transmission
- fomites (humans, cates, catteries) fleas
- Transmitted vertically
- cerebellar hypoplasia
- Virus shed in urine and feces up to 6 weeks after recovery
9
Q
Feline Panleukopenia
Clinical signs (post parturition)
A
- Peracute dz: fever > 104F and death
- If cat survives
- lethargy, anorexia, vomiting of yellow fluid
- early fever, then hypothermia
- severe dehydration from malabsorption => death
- Diarrhea
- yellowish +/- blood
- GI tract
- palpably swollen, filled with gas/liquid
- +/- upper respiratory complications
- Substantial mortality in young animals
10
Q
Feline Panleukopenia
Clinical signs (in utero)
Test Question
A
-
Cerebellar hypoplasia
- loss of balance, broad based stance, ataxia, tremor, hypermetra, dysmetra, intention tremors
- stunted growth
11
Q
Feline Panleukopenia
Diagnosis
A
- Clinical signs
- CBC/Chem
- profound leukopemia
- Grave prognosis if blood WBC < 1000 cells
- hypoalbuminemia
- +/- fecal ELISA for CPV-2
- PCR
12
Q
Feline Panleukopenia
Treatment
A
- Supportive care is the only option
- fluids and electrolyte therapy
- plasma or hetastarch
- albumin often <2g/dL
- plasma or hetastarch
- fluids and electrolyte therapy
- Antibiotics
- threat of secondary infection (neutropenia & disrupted GI barrier lining)
- Cefazolin-nonfebrile
- Ampicillin + Enrofloxacin (big gun for G-)
- threat of secondary infection (neutropenia & disrupted GI barrier lining)
- +/- antiemetics
- metoclopramide
- ondansetron
- +/- H2 receptor antagonists
- Sulcralfate
13
Q
Feline Panleukopenia
Prevention
A
- Vaccination
- kittens 6-12 weeks
- ML (NOT IN PREGGOS or sicksies) or killed vaccine
- vaccinate every 3-4 weeks until 16 weeks old (3-4 doses)
- Kittens 12 + weeks/adults w/unknown vaccination hx
- ML or killed
- 2 doses 3-4 weeks apart
- Annual or 3 yr booster
- kittens 6-12 weeks
- Disinfection of environment
- exremely resistant virus
- bleach 6% or Quaternary ammonium effectve
14
Q
Canine Parvovirus-2
Disease Characteristics
A
- CPV-2 first described in 1978
- Spread rapidly worldwide in less than 6 months
- stable, efficient fecal-oral transmission, most dogs naive
- Panzootic of high morbidity and mortality
- Families susceptible to natural infection
- Canidae: dogs, wolves, foxes, coyotes
- Mustelidae: mink, ferrets
- Felidae: domestic cats and large cats
- Still imp cause of infectious diarrhea in wild and domestic canids
- Genetically distinct from CPV -1
- Continues to evolve, currently 3 novel strains
15
Q
Canine Parvovirus - 2
Signalments
A
- Puppies < 6 mo old
- Rottweilers, Dobermans, Labs, Staffordshire terriers, German Shepherds, Alaskan Sled Dogs
16
Q
Canine Parvovirus - 2
Clinical Signs
A
- Asymptomatic, subclinical dz very common
- Severe dz in rapidly growing puppies 6 wks-6 mos
- Enteritis syndrome
- Severe protracted vx/d first sign
- anorexia, lethargy/depression, severe dehydration
- hemorrhagic diarrhea, malodorous
- fever or hypothermia
- Septic shock due to intestinal vili destruction & translocation of bacteria
- Death
- MYOCARDITIS
17
Q
Canine Parvovirus - 2
Myocarditis
A
- Puppies infected in utero or during 1st week of life
- causes cardiomyopathy in 4-8 wk olds w/ acute heart failure and sudden death
- Syndrome rare due to vaccines and maternal immunity
18
Q
Canine Parvovirus - 2
Diagnosis
A
- Clinical signs, smell
- CBC/Chem
- hypoalbuminemia, neutropenia
- ELISA snap test
- CPV - 2 in feces
- Gross & microscopic pathology of intestine
19
Q
Canine Parvovirus - 2
Treatment
A
- Fluids
- balanced electrolytes
- KCL
- +/- hetastarch
- +/- dextrose
- balanced electrolytes
- Antibiotics
- Cefazolin: nonfebrile, neutropenic
- Ampicillin/enrofloxacin: febrile, neutropenic
- Antiemetis
- metoclopramide
- ondancetron
- Esophagitis therapy
- H2 receptor antagonists
- Sucralfate
20
Q
Canine Parvovirus - 2
Prevention
A
- Vaccination: DHPP
- start at 6-8 wks old
- 3-4 doses 3-4 weeks apart
- last dose between 16-20 weeks of age
- Booster at 1 year, update every 1-3 years
- unvaccinated adults: 2 doses, 4 weeks apart
- Disinfection
- extremely resistent: survives up to 5 months in environment
- Proper protective equiptment and quarantine procedures w/suspect cases
- Bleach (1 part bleach to 30 parts water)
- Reduce exposure
- don’t take unvaccinated pups around other dogs
- isolate unvaccinated pups in kennel or hospital
21
Q
Maternal antibodies don’t provide…
A
memory
22
Q
Canine Parvovirus - 2
Intereference by maternal antibodies
A
- wait until 8-10 weeks!
23
Q
Properties of Circoviruses
A
- Smallest known DNA viruses
- Naked, icosahedral shape-environmentally resistant
- Circular, ssDNA genomes
- Pathogens of birds and swine
- Replication in nucleus
- large basophilic intracytoplasmic, sometimes intranuclear inclusion bodies
- Replication occurs in rapidly dividing cells
- Persistent infection common
24
Q
Circoviruses and Diseases
- Porcine circovirus 2
- Psittacine beak and feather disease virus
- Chicken anemia virus
A
- Porcine circovirus 2
- postweaning polysytemic wasting syndrome
- Psittacine beak and feather disease virus
- Psittacine beak and feather disease
- Chicken anemia virus
- chicken anemia virus and disease
25
Q
Porcine CIrcovirus - 2 associated Disease Syndromes
A
- Post-weaning multisystemic wasting syndrome
- Porcine dermatitis & nephropathy syndrome
- Procine respiratory disease complex
- Reproductive failure
- Granulomatous enteritis
- Exudative epidermitis
- Necrotizing lymphadenitis
26
Q
Procine Circovirus - 2: Postweaning Multisystemic Wasting Syndrome
A
- Wasting and mortality of weanling piglets 7-15 weeks old, sometimes adults
- Multifactorial dz PCV-2 primary one
- porcine reproductive and resp syndrome
- porcine Parvovirus
- Swine influenzavirus
- torque teno viruses?
- Mycoplasma hyopneumoniae
- Overcrowding, poor air quality, comingling age groups, stressors
27
Q
Postweaning multisystemic wasting syndrome
A
- Affects mainly the immune system
- macrophages
- lymphocytes
- Granulomatous inflammation
- lymphoid tissues
- lungs
- liver
- kidney
- heart
- intestines
-
Botryoid basophilic intracytoplasmic inclusion bodies on Macs
- grape-like cluster
- Lymphocyte depletion & reticuloendothelial cell hyperplasia
28
Q
Porcine Circovirus-2 associated disease
A
- Emaciation
- marked dorsal spine & long bristle haircoat in wasting pig
- Hemorrhagic epidermitis associated with necrotic vasculitis & necrotic arteritis
- Respiratory disease
29
Q
Porcine Circovirus-2 Associated disease
Diagnosis
A
- Pigs show clinical signs that can be mistaken with other dz
- coinfections are common
- Examine pigs in environment
- necropsy sick pigs
- Virus ubiquitous, causes subclinical infections
- Careful interpretation from tissue samples
- Quantitation of viral load by qPCR in lymphoid cells important
- Immunohistochemistry and immunofluorescence of affected tissues
30
Q
Prcine Circovirus-2 associated disease
Management
A
- Full partition pens
- Use semen from uninfected boars
- practice all in/all out
- ensure consumptio of plenty of colostrum
- limic cross-fostering
- consider inc weaning age
- change blades, needles, disinfect
31
Q
Porcine Circovirus-2 Associated disease
Environment and health
A
- Keep rooms at correct temp (higher for young pigs)
- Keep humidity comfortable
- consider other vaccinations
32
Q
Porcine Circovirus-2 associated disease
Control
A
- Inactivated (subunit) vaccines effective
- 3-4 days, and again 3-4 weeks if high exposure
- normal exposure start at 3-4 weeks
- Allegedly reduces viremia and shedding
- Overcomes maternal antibody barrier
- Protection up to 22 weeks from high antigen content
- Significantly reduces morbidity/mortality
- May reduce lymphoid depletion & pneumonia from
- Mycoplasma hyopneumoniae
33
Q
Psittacine Beak and Feather disease
A
- Debilitating progressive dz of cockatoos, parrots, budgerigars
- Most are subclinical
- Natral infection in young birds < 5 yrs during feather formation
- Targets feather follicles, beak, claws
- growing cells cause necrosis & feather malformation
34
Q
Psittacine Beak and feather disease
Clinical Signs
A
- After each molt, greater number of feather affected
- Progressive feather dystrophy continues for months to years
- club-shaped sheaths
- deformed beak easily fractures
- Affected birds highly infectious
- horizontal/vertical transmission
- virus persists in environoment
35
Q
A
Psittacine Beak and Feather disease
36
Q
Psittacine Beak and Feather Disease
Pathogenesis and Pathology
A
- Viral replication in basal epithelia layer of feather follicles, beak and claw
- Development of botryoid basophilic intracytoplasmic inclusions in follicular epithelium
- EM shown to contain masses of virions
- Also occurs in macrophages, bursa epithelium
- Progressive dz and immunosuppresion
37
Q
Psittacine Beak and Feather Disease
Diagnosis
A
- Clinical signs
- Basophilic intracytoplasmic inclusions in bx of affected feather foliicles
- PCR of DNA from feather tips, biopsy, swabs
- EM
- Immunohistochemistry/fluorescence
- PCR
38
Q
Psittacine Beak and Feather Dz
Prevention and control
A
- High prevalence resulting from subclinical infection
- Eradication is difficult once in a colony
- Strict hygiene, continuous testing, lengthy quarantine in breeding colonies
- Neutralizing antibodies are protective
- No vaccine
39
Q
Chicken Anemia Virus Disease
A
- Ubiquitous worldwide
- Only chickens affected (broilers, layers)
- resistant to disifectants
- use bleach
- Vertical/horizontal fomite/direct transmission
- dz in first 2-3 weeks of life
- Chicks resistant to dz by 3 weeks of age
40
Q
Chicken anemia virus disease
Clinical Signs
A
- Anemia only specific sign
- severity of anemia peaks at 2 weeks after infection
- Birds pale and depressed
- Low PCV
- 6-27% (normal 30-40)
- blood pale and slow to clot
- loss hemocytocytoblasts
- dec erythrocyts, thrombocytes, granulocytes
- prone to bleeding => hemorrhagic dermatitis
- Generalized lymphoid depletion
- Immunosuppression
- Secondary infection
- mycotoxicosis, clostridium, staph, mareck’s dz
- can lead to high mortality
- mortality 5-10 percent, may reach 60%
41
Q
Chicken Anemia virus dz
Diagnosis
A
- Presumptive
- CBC: anemia
- Gross lesions: bleeding wounds
- Histopath:
- necrotic enteritis
- pale yellow & fatty bone marrow
- hypoplasia of erythroid and myeloid cell progenitors
- severely atrophied thymus
- Lab
- PCR
- Immunofluorescence
- Immunohistochem
- ELISA to detect antibodies
42
Q
Chicken Anemia virus dz
Prevention and Control
A
- Live modified virus vaccine
- vaccinate pullets 6 weeks prior to laying (12-5 wks)
- vaccinate all birds to avoid spreading to younger birds
