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We report the first outbreak of nosocomial orf infection in a hospital burn unit in Gaziantep, Turkey. The outbreak lasted from October to December 2012 and involved a total of thirteen cases. It demonstrates the risk of introduction of orf virus to a burn unit, and the potential for extensive transmission among patients with compromised skin integrity. The importance of hygiene measures and infection control are highlighted and possible transmission routes of the virus discussed.

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Erysipeloid is a rarely reported zoonotic infection caused by Erysipelothrix rhusiopathiae. We report a case of coexisting erysipeloid and orf infections in a sheep farmer, an association not previously recorded to our knowledge.

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A captured gazelle kid (Gazella gazella) held in a mixed herd of sheep and goats in Israel developed the characteristic lesions of contagious ecthyma. Clinical diagnosis was confirmed by electron microscopy and histopathology examinations of infected tissue.

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Twelve goats about 3 months of age were divided into 4 equal groups. Goats in Groups 1 and 2 were infected with orf virus followed by Corynebacterium pyogenes infection of Groups 1 and 3, 3 days after the first appearance of orf lesions. Goats in Group 4 were uninfected controls. Complicated orf lesions which consisted of wet suppurative scabs around the entire lips were observed in goats in Group 1. The lesions persisted for 24 days but were most severe from days 8 to 13. Goats in Group 2 developed lesions typical of orf virus infection that lasted 10 days, while goats in Group 3 developed small nodules of about 1 cm diameter, 48 hours following the introduction of C. pyogenes, which persisted for only 6 days. No lesion was observed in goats in Group 4. Two goats in Group 1 with complicated orf died after 16 and 22 days respectively.

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Orf virus, derived from contagious pustular dermatitis (scabby mouth) lesions in sheep, was adapted to cell culture and subsequently evaluated as a potential vaccine for sheep. The traditional vaccine virus, prepared from the infected scabs of orf virus lesions in sheep, was used to vaccinate sheep by scratching with an applicator (mounted pins) dipped in virus. Less than 10 TCID50 (50% tissue culture infectious doses) of virus was required to produce large lesions (greater than 5 mm diameter) which developed during a period of 10 to 14 d prior to onset of healing which was complete by 28 to 30 d. A serum neutralising antibody response was also detected and protection against challenge by application of virulent virus to abraded skin was demonstrated in that challenge lesions developed and healed more quickly (14 d against 30 d). However, cell culture-adapted virus required more than 10(5) TCID50 to induce even small lesions (less than 2 mm diameter). An antibody response could not be detected and no evidence of protection against challenge with virulent virus was demonstrated. In contrast, a recent field isolate has yielded a cell culture-adapted virus preparation that readily infects sheep, produces large lesions, detectable antibody and protects against challenge. This isolate is distinct from the traditional vaccine strain on the basis of restriction enzyme analysis but provides cross-protection in sheep inmmunisation and challenge studies. These results demonstrate that a cell culture produced scabby mouth vaccine is feasible.

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Three Vero cell culture-adapted contagious ecthyma virus (CEV) isolates were compared by plaque morphology, ability to induce vesicles in skin and in vivo growth curve characteristics by sampling sequentially experimental skin lesions produced in four sheep and one goat. Two of the isolates (CEV-29A and CEV-378) were from outbreaks of ecthyma in sheep and one (CEV-102) from a human case of orf. When replicating in Vero cells, the viruses exhibited similar growth parameters, but were distinguishable from each other on the basis of plaque morphology. In vivo latent periods for these isolates were 48 h (CEV-29A), 96 h (CEV-102), and 120 h (CEV-378). When isolates CEV-102 and CEV-29A were passaged into another sheep, they produced similar patterns of growth. Isolate CEV-102 produced the highest infectivity titer [1.4 X 10(9) plaque forming units (PFU) g-1], followed by CEV-29A (6.8 X 10(7) PFU g-1) and CEV-378 (2.5 X 10(7) PFU g-1). In addition, these viruses varied in their ability to induce vesicle formation. Virus was no longer detectable at the inoculation sites at 288 h post-infection (PI). We conclude that plaque morphology, ability to induce vesicle formation in the skin and growth curves in the skin can be considered as important criteria to differentiate CEV isolates. A comparison of the growth curves of CEV-378 in the skin of sheep and goats suggested differences in virus-host interaction between the two animal species. Since intravenous injection of 1 X 10(9) PFU of CEV failed to produce lesions in the sham-scarified skin of sheep, virus spread via the hematogenous route from one site to another appears unlikely. No virus-neutralizing antibody or interferons were found in serum samples or in skin homogenates collected between 0 and 24 days PI. Virus-neutralizing antibody was present in the circulation as late as 24 days PI. Lymphocytes collected from CEV-exposed sheep as early as 12 days PI responded specifically to stimulation with CEV antigen. As this was about the time when infectious virus disappeared from the sites, we assume that cell-associated immune mechanisms may play a larger role in virus clearance from skin lesions than virus-neutralizing antibody.

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Damage to the skin is essential for the establishment of orf virus infection and the development of typical lesions. However, analysis of the pathogenesis of experimental lesions induced by viral challenge of mildly abraded skin, indicated that the virus does not establish in the damaged epidermis, but replicates in the cells of an underlying replacement epidermal layer derived from the walls of the wool follicles. The skin reaction consists of a cellular response with necrosis and sloughing of the affected epidermis and underlying stratum papillare of the dermis. Healing is then completed by the formation of a third epidermis derived from the deeper portions of the wool follicles. Previous cutaneous infection did not prevent reintroduction of the disease, even on the same area of skin although the lesions were less severe and persisted for a shorter period.

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Frequent in France among domesticated sheep and goats, contagious pustular dermatitis of the sheep is called Orf when it occurs in man. The authors present a case of recontamination in a woman farmer of the Cher department (Central France), who had been bottle-feeding lambs affected with the zoonosis. This 71-year old woman developed papules, then papulopustules on the ulnar aspect of her hands and wrists (fig. 1). Within a few days, these lesions were 1.5 to 2 cm in diameter and surrounded with a severe inflammatory reaction. Two weeks later, the pustules became encrusted. Electron microscopy of a fragment of lesion demonstrated the virus. Cure was observed after 3 weeks. Eight months later, however, lesions identical with the previous ones appeared on the 4th finger and on the median aspect of the right wrist, corresponding to excoriations caused by nibbling from the lambs. The eruption was accompanied with fever which persisted for one month. In this patient's farm, the disease was present for the first time and affected only 2-month old lambs in the form of numerous papulo-pustules located on the lips and later covered by hard and thick scabs. These lesions were also found on the tongue and palate of some animals (fig. 5), preventing them from taking any food. Vaccination resulted in rapid and dramatic regression of the enzootie. From a more general point of view, the clinical features and epidemiology of the disease are described comparatively in animals and man. The differential diagnosis is dealt with at the end of the article. The literature on the subject is reviewed (151 references).

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Dexamethasone was administered to 2 Dall ewes that had clinically recovered from contagious ecthyma in an attempt to reactivate contagious ecthyma in the sheep. Clinical signs of disease were not detected within 24 days after corticosteroid injection, and virus was not detected in tissues collected at necropsy.

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Orf is an occupational skin disease acquired through contact with infected animals. In humans, orf is usually a self-limited disease that resolves spontaneously within four to 24 weeks. We report a case with multiple lesions of orf, acquired by contact with a wild sheep. The patient was temporarily immunosuppressed by a concomitant viral hepatitis. We reviewed the histologic and electron microscopic findings. Also, we attempted to stain the Parapoxvirus in the skin of the patient, using the immunoperoxidase technique. The antiserum was obtained from sheep immunized against orf. We used lesional skin from sheep infected with orf as a positive control. The negative results of this technique in the patient's skin indicated that Parapoxvirus infecting wild sheep is antigenically different from that causing the disease in domestic animals.

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Restriction enzyme analysis with KpnI revealed heterogeneity among 10 different strains of contagious ecthyma virus from sheep, musk ox, Dall sheep and humans. Hybridization of electroblots indicated deletion of DNA segments and changes in nucleotide sequences.

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