Poxviridae Part 2 Flashcards
Pseudocowpox
Etiology
Epidemiology
Transmission
Member of the genus Parapoxvirus
Most countries
Infected cattle, milker’s hands/Teat cups, biting insects, suckling, semen of bulls
Pseudocowpox
Pathogenesis
Clinical Signs
Hyperplasia of squamous epithlemium
Acute lesions followed by scabs falling off leaving Horseshoe shaped ring of small scabs surrounding small wart like granuloma
Chronic lesions- erythema + yellow gray scabs that rub off during milking, may persist for months
Pseudocowpox dx
Horseshoe shaped ring lesion
Isolation of virus from vesicular fluid/teat skin
Tx of Pseudocowpox virus
removal of scabs, burn scabs, apply ointment before milking and astringent after milking
Prev- disinfection/iodophor teat dip. Isolate infected cows, reduce teat trauma.
Pseudocowpox in humans causes
Milker’s Nodule
Contagious Ecthyma
Etiology
Host
Distribution
Orf virus of genus Parapoxvirus
Sheep and goats, primarily lambs and kids
Worldwide
Transmission of Contagious Ecthyma
Virus survives in scabs
Infects healthy animals through infected skin
Oral lesions in lambs/kids result from nursing dams w/ teat lesions and vice versa
Pathogenesis of Contagious Ecthyma
macule-papule-vesicle-pustules-ulcers-scab formation
Clinical signs of Contagious Ecthyma
Lesions first develop in mucocutaneous junctions and there’s swelling of the lips
Lesions spread to mouth and nostrils, there may be anorexia and secondary bacterial infections. 1-4 wks scabs fall off, heal without scarring
T/F A malignant form of Orf/Contagious Ecthyma has been observed in sheep
T
Contagious Ecthyma vx preparation and how long do they last
Mix scab with saline and paint onto the inside thigh of a lamb. Check a week later for a local rxn to make sure it worked. Don’t use on a farm that doesn’t have a problem w/ Orf
Vx only last 1-2 years.
When should animals be vx for Contagious Ecthyma?
Problem herds
Lambs/Kids- 6-8 wks
Pregnant evew 7-8 wks before lambing
Can humans get Contagious Ecthyma
Yes, it causes macropapular lesions on the hands of people who handle sheep/goats, goes away after 4-9 wks
Sheeppox and Goatpox
Etiology
Distribution
member of Capripoxvirus
Endemic in Africa, Asia, parts of Europe
How is Sheeppox and Goatpox transmitted
Respiratory/Aerosol
Contaminated iatrogenic materials
Biting arthropods
Pathogenesis of Sheeppox
Incubation followed by leukocyte associated viremia
Virus localizes in skin and other internal organs.
Deposition of immune complexes results in severe necrotizing vasculitis in arterioles and postcapillary venules of the skin. Results in ishemic necrosis and of dermis and epidermis.
Malignant form of Sheeppox
Incubation period is 4-8 days
Initally depressed with fever, salivation, edema of eyelids and mucopurulent nasal discharge
1-2 after pox lesions extend to pharynx larynx lungs, vagina, abomasum and spleen.
Lesions leave a star shaped scar.
Mortality 50%
Case fatality in lambs 100%
What breeds is the Malignant form of Sheeppox seen in?
Lambs and nonnative breeds- Merino
The Benign form of Sheepox is more common in _______.
What are the clinical signs?
adults and resistant breeds
Only skin lesions or very mild systemic rxn
Sheeppox Prev and Control
Notifilable dz in most countries
Live attenuated and killed vx available, live at. works better
Clinical signs of Goatpox
Reportable
Young kids- systemic dz w/ lesions on skin, respiratory and alimentary mucosae. Mild in adults.
Flat hemorrhagic form of capripox seen in some European goats and has a high case fatality.
Lumpy Skin Dz Etiology Distribution Transmission Host
Member of genus Capripoxvirus
Enzootic in sub-saharan africa and Middle East
arthropod vector and direct contact
cattle, all ages and types
Lumpy Skin Dz
Clinical findings
Control
Fever, multiple nodular lesions on skin and mm, lymphadenopathy. Morbidity 80% during epzootics
Control- live att. vx. Slaughter affected/in contact animals.
Swinepox Etiology Distribution Host Transmission
genus Suipoxvirus
Worldwide
Pigs
Direct contact/skin injury, Haematopinus suis, flies/insects, transplacental
Clinical signs and Control of Swinepox
transient fever
typical pox lesions on abdomen and thigs
Control- eradicate lice
Fowlpox Etiology Hosts Distribution Transmission
Avipoxvirus
poultry and turkeys
worldwide
Lives in scabs for a long time, transmitted by minor wounds and abrasions, mosquitos/lice/ticks, possibly aerosol
What are the 3 forms of Fowlpox?
Cutaneous (Dry)
Diphtheric (wet)
Ocular
Cutaneous form of Fowlpox lesions
Most Common form
small papules on comb, wattles and around beak
sharp fall in egg production
recovery in 4 wks
Wet form of Fowlpox lesions
Droplet infection
lesions in oral mm eventually coalesce into a necrotic pseudomembrane which causes death by asphyxiation
Clinical signs in the Ocular form of Fowlpox
conjunctivitis
cheesy exdate under eyelids
What is a histopathologic finding of Avipoxvirus?
Borrel bodies inside Bollinger bodies
Fowlpox Control
Vx either by scarification or water
Control mosquito population and other biting insects
Ulcerative Dermatosis of Sheep
Etiology
Transmission
Clinical forms
Virus antigenically similar to Ecthyma virus
damaged skin or coitus
lip and leg ulceration or veneral
Dx of Poxviruses
clinical signs
scrapings from skin lesions
electron microscopy
Histopath of Poxviruses
Most poxviruses have slightly basophilic Type-B Guanierie inclusion bodies
Cowpox and Ectromeli have Type A/ATI inclusion bodies (eosinophilic)
t/f Parapoxviruses grow on CAM
False
What are the Parapoxviruses?
Pseudocowpox
Contagious Ecthyma/Orf Virus
Bovine Papular Stomatitis
