Poxviridae - Parapoxviruses Flashcards
What are the three parapoxviruses?
1) Pseudocowpox (humans, cattle)
2) Contagious Ecthyma/Orf Virus (sheep, goats, humans)
3) Bovine Papular Stomatitis Virus (cattle, humans)
What type of clinical signs do you see with pseudocowpox in cows?
Mild sores on the udders of cattle.
What is the common name of pseudocowpox in humans?
Milker’s nodule
Where is pseudocowpox epidemic?
Reported in most countries
What is the source of transmission of pseudocowpox?
Infected cattle
How can pseudocowpox be transmitted?
- Contaminated milker’s hands/teat cups
- Biting insects
- Calves can get infected transmammary
- Semen of bulls
What is the pathogenesis of pseudocowpox?
Lesions are characterized by hyperplasia of squamous epithelium.
What are the clinical signs of pseudocowpox?
Infections are generally mild.
Up to 10 lesions on one teat.
What do acute lesions of pseudocowpox look like?
Thick scab .5 to 25cm in diameter becomes elevated due to accumulation of granulation tissue.
After 7-10 days, the scab drops off, leaving a horseshoe-shaped ring of small scabs surrounding a small wart-like granuloma.
What do chronic lesions of pseudocowpox look like?
Yellow-gray, soft scabs that are rubbed off during milking.
Skin is corrugated.
No pain.
Lesions for months.
How is pseudocowpox diagnoses?
Horseshoe-shaped ring like lesion are pathognomic for the disease.
Can also isolate from vesicular fluid or teat skin.
What are the DDXes vs. pseudocowpox?
How do you treat pseudocowpox?
Removal of scabs
Burn the scabs to prevent environmental contamination
Application of an emollient ointment before or astringent after milking.
How do you prevent pseudocowpox?
Disinfection with an iodophor teat dip.
Isolation and treatment of affected cows
Reduce teat trauma
What are the synonyms for Contagious Ecthyma?
ORF
Scabby Mouth
Sore Mouth
Contagious Pustular Dermatitis
What are the hosts for Contagious Ecthymavirus?
Sheep and goats. Primarily lambs and kids.
What are the morbidity/mortality rates for Contagious Ecthyma?
Morbidity - 100%
Fatality - 5-15%
What are the modes of transmission for Contagious Ecthyma?
- Scabs that fall off from healing lesions containing the virus.
- Contaminated instruments– docking or ear-tagging
How does Contagious Ecthyma infect healthy animals?
Primarily through damaged skin or oral lesions in lambs/kids nursing from dams with teat lesions.
What is the evolution of lesions in Contagious Ecthyma?
Macule –> papule –> vesicle –> pustule –> ulcers –> scab
What are the clinical signs of Contagious Ecthyma?
- Lesions develop in the mucocutaneous junction, which are accompanied by swelling of the lips.
- Lesions spread to muzzle and nostrils.
- Anorexia and weight loss due to painful oral lesions.
How can Contagious Ecthyma result in mastitis in goats or sheep?
Infected babies cause lesions on teats.
Predispose to a secondary bacterial infection.
Where will you see lesions in severe cases of Contagious Ecthyma?
Genitals (infertility)
Coronets (feet)(lameness)
Ears
What will you seen clinically with Contagious Ecthyma?
Weeks 1-4, scabs drop off and underlying tissues heal with scarring.
What can cause a complication in the healing of Contagious Ecthyma?
Bacterial infections
Myiasis
How should vaccinations of Contagious Ecthyma be administered?
Painted onto a small area of scarified skin on the inside of the thigh.
DO NOT USE IN FARMS THAT DO NOT HAVE AN ISSUE
How long do Contagious Ecthyma vaccinations last?
1-2 years (they are not long-lasting)
In problem flocks, when should lambs/kids be vaccinated for Contagious Ecthyma?
6-8 weeks
In SEVERE problem flocks, when should lambs/kids be vaccinated for Contagious Ecthyma?
2-3 days old
When should pregnant ewes be vaccinated for Contagious Ecthyma?
7-8 weeks before lambing
Describe Contagious Ecthyma in humans.
Macro-papular lesions in the finger, hand, arm, face, and penis.
Lasts 4-9 weeks
Healing occurs without scarring
Secondary bacterial infections may cause complications.
