L21: Poxviruses (Waltzek) Flashcards
Poxvirus Virion Architecture
- large dsDNA viruses
- enveloped
- parapoxviruses are “brick shaped”
- very well dx with EM isnce they are so large and complex***
papule vs. macule vs. pustule
papule: pigmented area (precursor to macule)
macule: small raised lesion
pustule: larger raised lesion
when any of the above ruptures, forms crust
Poxvirus Dz general chars.***
- epitheliotropic, inducing proliferative lesions (hyperplasia, neoplasia, macule, papule, vesicle, pustule, crust)
- eosinophilic INTRACYTOPLASMIC inclusions (Bollinger bodies)***
DNA viruses typically induce intracytoplasmic/intranuclear inclusions**
intranuclear
Poxvirus host specificity and pathogenesis***
- broad host range
- ortho and parapoxviruses zoonotic***
- serious in immunocompromised
- contains genes for intracytoplasmic existence and immune evasion genes
most important pox viruses in vet med. Why?**
capripoxviruses: sheeppox, goatpox, lumpyskin disease viruses
- high mortality, economic loss in young
- morbidity in adults causes loss of milk and/or meat
- expanding in geo. distr.
- notifiable foreign animal diseases
Name 6 genuses of poxviruses in domestic animals. Which are zoonotic?***
Orthopoxvirus (zoonotic) - BROAD Parapoxvirus (zoonotic) - narrow Capripoxvirus - narrow Suipoxvirus - narrow Leporipoxvirus - narrow Avipoxvirus - narrow
Genus orthopoxvirus contains which virus(es)? Range?
cowpox virus; Europe
Genus parapoxvirus contains which virus(es)? Range?
Pseudocowpox virus
Bovine papular stomatitis virus
Orf virus
WORLDWIDE
Genus capripoxvirus contains which virus(es)? Range?
Sheeppox virus (Africa, Asia) Goatpox virus (Africa, Asia) Lumpyskin disease virus (Africa)
genus suipoxvirus contains which virus(es)? Range?
swinepox (worldwide)
genus leporipoxvirus contains which virus(es)? Range?
myxoma virus; Americas, Australia, Europe
genus avipoxvirus contains which virus(es)? Range?
fowlpox; Worldwide
reservoir for cowpox
rodents
is cowpox zoonotic?
Y
what other animal can be infected with cowpox?*** CS?
cats. (Cowpox rare in cows, NOT rare in cats since they prey on reservoir rodents!)***
CS: fever, skin lesions
Dx of cowpox
EM
isolation of virus from cell culture
isolation on chorioallantoic membrane of the chick egg
pseudocowpox virus belongs to which genus? Zoonotic?
Parapoxvirus. Zoonotic (causes milker’s nodule)
pseudocowpox virus chars.
- mild dz in dairy cattle
- assoc. with poor hygiene
- can spread to calves during nursing
- dx by EM
pseudocowpox CS
- causes proliferative teat lesions w/ characteristic horseshoe shape*
- 2ary bacterial mastitis
Bovine papular stomatitis virus belongs to which genus? Zoonotic?
Parapoxvirus. Y
Bovine papular stomatitis chars.
- common incidental infection in beef cattle worldwide
- effects suckling calves
- no tx
- dx by EM
Orf belongs to which genus? Zoo?***
Parapoxvirus. Y (localized lesions with occasionl lymphadenopathy)
Orf general chars.
- occurs in sheep/goat worldwide
- cause of contagious ecthyma, pustular dermatitis, and sore mouth
- most common in young lambs; restricts suckling
- lamb can spread to udder of ewes
- rapid spread w/n flock
- resistant in environment
- recovered animals only immune for few months
CS of orf
- lesions at oral mucocutaneous junctions, muzzle/nostrils
- rare systemic spread
Dx of Orf
- rapid spread in young animals
- typical scabs around mouth
- high morbidity, low mortality
- EM
transmission of capripoxviruses
- respiratory route, direct contact, biting fly vector
- African Buffalo wild reservoir
2 forms of sheeppox and goatpox virus
1) Malignant
- more common
- depression, fever, nasal d/c, skin lesions on mucosa
2) Benign
- skin lesions only
pathogenesis, Dx, Tx, and control of sheeppox/goatpox virus
Path: replication in resp. lymph nodes, viremia, 2ary skin lesions
Dx: CS, virus isolation, EM
Tx: supportive
Control: cull, quarantine. Vax not effective.
sheeppox, goatpox, lumpyskin disease belong to which genus? Zoo?
Capripoxvirus. NO
lumpy skin disease vs. sheep/goatpox
- causes similar resp. and skin lesions, lymphadenopathy, edema
- has higher morbidity (100%) and lower mortality (1-2%)
- distinguish from pseudolumpy disease, which is a herpesvirus**
swinepox CS
- red papules –> raised hard elevations –> crusts
- usually benign with mild fever
swinepox transmission/Dx/control
- swine louse vector
- direct contact uncommon
- Dx: EM
- Control: eliminate lice
Avipoxvirus chars.
- affects poultry/wild birds
- fowlpox affects chickens
- transmitted by arthropods, scabs
- can persist in environment
Fowlpox (type of Avipoxvirus) lesions
eosinophilic intracytoplasmic inclusion bodies (Bollinger bodies)
