Lecture 3 - pox viruses

Question 0

what type of lesions does poxvirus cause?

Answer 0

epitheliotropic inducing proliferative lesions
eosinophilic intracytoplasmic inclusions
this is unique bc most DNA viruses cause intranuclear inclusions

Question 1

what is the architecture of a poxvirus?

Answer 1

dsDNA

enveloped ovoid-pleomorphin complex virion

Question 2

poxvirus pathogenesis

Answer 2

• broad host range
• great potential for zoonosis - ortho and parapoxviruses
• large viral genome contains genes for intracytoplasmic existence and immune evasion genes

Question 3

what does orthopox virus cause?

Answer 3

cowpox virus

Question 4

cowpox virus general characteristics

Answer 4

caused by orthopox virus
foreign animal disease
ZOONOTIC!!
reservoir: rodent

Question 5

cowpox virus: clinical signs

Answer 5

cattle: nasty lesions on cow teats
cats: fever, skin lesions - fatal in cheetahs

Question 6

what is a funky fact about cowpox virus

Answer 6

the name is a misnomer - the disease is rare in cattle and common and severe in animals that hunt the main reservoir - rodents.

for instance, cats commonly get cowpox and is a severe disease

Question 7

how do you diagnose cowpox virus?

Answer 7

• electron microscopy of clinical material should look like a BRICK
• isolation of virus in culture
• isolation on the chorioallantoic membrane of a chick egg

Question 8

milker’s nodule

Answer 8

human infection caused by cowpox virus so wear gloves!!

bc cowpox is ZOONOTIC!

Question 9

what does parapox virus cause?

Answer 9

pseudocowpox virus
bovine papular stomatitis virus
orf virus

Question 10

general characteristics of pseudocowpox virus?

Answer 10

ZOONOTIC!

• associated with poor hygiene
• pathopneumonic teat lesion –> horseshoe lesion
• secondary bacterial mastitis occurs
• human infection= milker’s nodule

Question 11

dx of pseudocowpox virus

Answer 11

electron microscopy –> oval shape (NOT BRICK)

Question 12

bovin papular stomatitis virus general characteristics

Answer 12

parapox virus

common infection in beef cattle worldwide

Question 13

clinical signs of bovine papular stomatitis virus

Answer 13

papules on lips and lesions in mouth in suckling calves

Question 14

dx and tx of bovine papular stomatitis virus

Answer 14

dx: EM
tx: none

Question 15

what is orf virus also known as?

Answer 15

contagious ecthyma, contagious pustular dermatitis, sore mouth

Question 16

what animals does orf virus occur in?

Answer 16

sheep/goats and humans

Question 17

clinical findings of orf virus

Answer 17

most common in 3 - 6 month old lambs

• lesions develop as papules –> pustules –> thick scabs
• start at oral mucocutaneous junctions then spread to muzzle and nostrils
• results in restricted suckling and grazing

Question 18

transmission of orf virus

Answer 18

• rapid spread within flock via contact with infected animals or scabs
• environmental contamination
• recovered animals are immune for several months but immunity wanes

Question 19

is orf virus zoonotic?

Answer 19

yes!

lesion is persistent and becomes an itchy nodule. typically localized with occasional lymphadenopathy

Question 20

dx of orf virus

Answer 20

scabs around commissures great sample sites for diagnostics

EM!

up to 90% morbidity with low mortality

Question 21

what diseases does capripox virus cause?

Answer 21

sheeppox, goatpox and lumpyskin disease

Question 22

general characteristics of capripox virus

Answer 22

most important of all poxviruses!
NOTIFIABLE foreign animal diseases
high mortality
NOT zoonotic

Question 23

transmission of capripox virus

Answer 23

respiratory route
direct contact with infected lesions/scabs
biting flies may serve as vectors
wildlife reservoir may be the buffalo

Question 24

sheepox and goatpox: clinical findings

Answer 24

incubation period: 2 - 14 days
malignant form is more common
benign form is common in adults

Question 25

what are the clinical signs of the malignant form of sheepox and goatpox?

Answer 25

depression, prostration, high fever, ocular and nasal discharge
lesions occur on unwooled skin
50% mortality - affected lambs may die before lesions develop

Question 26

pathogenesis of sheepox and goatpox virus

Answer 26

replication in respiratory LN, viremia, secondary lesions in skin

Question 27

dx and tx of sheepox and goatpox virus

Answer 27

dx: clinical signs, virus isolation, EM
tx: supportive

Question 28

control of sheepox and goatpox virus

Answer 28

prohibition of importation from infected area
destruction of infected flocks
quarantine of infected premises

Question 29

lumpy skin disease of cattle: characteristics and clinical signs

Answer 29

FOREIGN! (unlike pseudo lumpyskin disease)

• high morbidity and low mortality compared to sheepox and goatpox
• clinical signs: respriatory and skin lesions, generalized lymphadenopathy, edema

Question 30

suispoxvirus causes what disease?

Answer 30

swinepox virus

Question 31

swinepox virus clinical findings

Answer 31

red papules appear in 4 -5 days and develop into raised, hard elevation

• hard crusts develop and drop off over 10 - 14 days
• benign disease with slight fever and mild reaction
• if swine louse is involved in transmission, lesions develop on lower parts of body and inside thighs

Question 32

transmision of swinepox virus

Answer 32

vector - swine louse

pig to pig is uncommon

Question 33

dx and control of swinepox

Answer 33

dx: virus isolation or EM
control: elimination of lice

Question 34

what disease does avipoxvirus cause?

Answer 34

fowlpox virus

Question 35

transmission of avipox virus

Answer 35

arthropods and scabs

Question 36

clinical findings of avipox virus

Answer 36

gross lesions on comb, wattles, and face

Question 37

what microscopic lesions are found with avipox virus

Answer 37

eosinophilic intracytoplasm inclusion bodies called Bollinger bodies