SECTION I - INFECTIOUS AGENT


Name: Orf

SYNONYM OR CROSS REFERENCE: Contagious ecthyma, contagious pustular dermatitis, scabby mouth.

CHARACTERISTICS: Poxviridae, parapoxvirus, dsDNA (130 kb), ovoid virion, 260 x 160nm, cytoplasmic replication.

SECTION II - HEALTH HAZARD

PATHOGENICITY: Single maculopapular rash or pustular lesion at site of inoculation. Papule is painful and gradually hardens. Human infections are generally self limiting and resolve after 2 to 4 weeks. Some cases may progress to regional lymphadenitis, severe cutaneous eruptions or ocular lesions.

EPIDEMIOLOGY: Occupational hazard associated with handling sheep or goats.

HOST RANGE: Humans, sheep, goats, domestic camelids and wild ungulates. Human cases resolve without treatment.

INFECTIOUS DOSE: Unknown

MODE OF TRANSMISSION: Cutaneous contact with infected animal.


INCUBATION PERIOD: Humans, 3 - 7 days; sheep or goats, 2-3 days.

COMMUNICABILITY: Transfer of infectious agent high when exposed to infected sheep, some accounts of human to human spread.

SECTION III - DISSEMINATION

RESERVOIR: Sheep, goats, domestic camelids and wild ungulates

ZOONOSIS: Yes

VECTORS: None

SECTION IV - VIABILITY

DRUG SUSCEPTIBILITY: Not applicable

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to disinfectants - 1% sodium hypochlorite (20% commercial bleach), 2% glutaraldehyde, formaldehyde.

PHYSICAL INACTIVATION: Viral antigens destroyed at 100o C.

SURVIVAL OUTSIDE HOST: Virus remains potent outside host and is resistant to desiccation, can be infective when dried onto inanimate surface (fomite).

SECTION V - MEDICAL

SURVEILLANCE: Monitor for symptoms, confirmation by fiistopatholog'cal identification of maculopapular lesion, isolation of vinis.

FIRST AID/TREATMENT: None; antibiotics utilized only in case of secondary infection.


IMMUNIZATION: None


PROPHYLAXIS: None

SECTION VI - LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: Laboratory infections are rare. Numerous cases acquired during the vaccination of sheep with live attenuated animal vaccine.

SOURCES/SPECIMENS: Lesion fluid, crust or tissue of infected host.

PRIMARY HAZARDS: Ingestion, parenteral inoculation, droplet or aerosol exposure to mucus membranes or broken skin with infectious fluids or tissues.

SPECIAL HAZARDS: Virus extremely resistant to desiccation; commercial live attenuated animal vaccine infective to humans.

SECTION VII - RECOMMENDED PRECAUTIONS

CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities involving the manipulation of this virus; primary containment devices and biological safety cabinets are recommended.

PROTECTIVE CLOTHING: Laboratory coat; gloves and gown when working with agent.


OTHER PRECAUTIONS: None

SECTION VIII - HANDLING INFORMATION

SPILLS: Allow aerosols to settle; wearing protective clothing (respirator), gently cover spill with paper towel and apply 1% sodium hypochlorite (20% commercial bleach), starting at perimeter and working towards the center; allow sufficient contact time before clean up (30 min).

DISPOSAL: Decontaminate before disposal; incineration, steam sterilization.

STORAGE: In sealed containers that are appropriately labeled (in locked level 2 facility).


Information prepared by the Colorado State University Office of Biosafety; June 16, 1998.

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