Қойлардың жұқпалы дерматозы және адамға қаупі

Human disease

Orf is a farmyard pox, a type of zoonosis. A pale halo forms around a red centre. It may persist for several weeks before crusting and then either resolves or leaves a hard lump. It can occur in humans who handle infected animals or contaminated objects. One third of cases may develop erythema multiforme. It causes a purulent appearing papule locally and generally no systemic symptoms. Infected locations can include the finger, hand, arm, face and even the penis (caused by infection either from contact with the hand during urination or from bestiality). Consequently, it is important to observe good personal hygiene and to wear gloves when treating infected animals.

Orf is primarily a disease of sheep and goats although it has been reported as a natural disease in humans, steenbok and alpacas, chamois and tahrs, reindeer, musk oxen, dogs, cats, mountain goats, bighorn sheep, dall sheep, and red squirrels. Occasionally the infection can be extensive and persistent if the animal does not produce an immune response. The vaccine can cause disease in humans. In sheep and goats, the lesions mostly appear on or near the hairline and elsewhere on the lips and muzzle. In some cases the lesions appear on and in the nostrils, around the eyes, on the thigh, coronet, vulva, udder, and axilla. In rare cases, mostly involving young lambs, lesions are found on the tongue, gums, roof of the mouth and the oesophagus. It has also been reported a number of times to cause lesions in the rumen. In one case it was shown that a severe form of orf virus caused an outbreak involving the gastrointestinal tract, lungs, heart, as well as the buccal cavity, cheeks, tongue and lips. Another severe case was reported pharyngitis, genital lesions and infection of the hooves which led to lameness and, in some cases, sloughing of the hoof. More typically, sheep will become free of orf within a week or so as the disease runs its course. Sheep custodians can assist by ensuring infected lambs receive sufficient milk and separating out the infected stock to slow down cross transmission to healthy animals. It is advisable for those handling infected animals to wear disposable gloves to prevent cross infection and self infection. A veterinarian must be contacted if there is a risk of misdiagnosis with other, more serious conditions.