Human Orf virus infection from household exposures - United States, 2009-2011.

Orf, also known as contagious ecthyma, is a zoonotic infection caused by a dermatotropic parapoxvirus that commonly infects sheep and goats; it is transmitted to humans through contact with an infected animal or fomites. In humans, orf manifests as an ulcerative skin lesion sometimes resembling bacterial infection or neoplasm. Human infection typically is associated with occupational animal contact and has been reported in children after visiting petting zoos and livestock fairs. Cases lacking these exposure histories might be misdiagnosed, leading to unnecessary treatment of orf lesions, which do not usually require any specific treatment. This report describes four cases of human orf associated with household meat processing or animal slaughter, highlighting the importance of nontraditional risk factors. Orf should be included in the differential diagnosis of patients with clinically compatible skin lesions and a history of household meat processing or animal slaughter. Persons and communities with these exposure risks also should receive counseling regarding the use of nonpermeable gloves and hand hygiene to prevent infection.