Contagious Pustular Dermatitis (Orf Disease) - Epidemiology, Diagnosis, Control and Public Health Concerns

Abstract

| Contagious pustular dermatitis (CPD), also known as Orf or contagious ecthyma is an important viral disease of sheep and goats. It is mainly seen as a benign disease but malignant form has also been reported from few parts of the world. The rates of morbidity and mortality are higher, particularly in lambs and kids experiencing the disease for the first time. The causative agent of disease is Orf virus, type species of the genus Parapoxvirus belonging to family Poxviridae. The virus produces localized persistent proliferative skin lesions and affected hosts are infected repeatedly owing to its host immune evasive strategy. These viruses have been found uniformly labile to chloroform but resistant to ether and also exhibit antigenic variations among them. Clinically, the disease is enzootic and occurs in three forms viz. labial, genital / mammary and generalized forms. The incubation period in natural cases is 2-3 weeks. The disease outbreaks mostly occur between autumn and spring but its severity is more in autumn and winter than spring. The virus grows well in cell cultures of caprine, ovine and bovine origin. Confounding symptoms impose laboratory affirmation by serological assays or molecular techniques. The disease can be diagnosed by electron microscopy, serological tests and PCR/ quantitative real-time PCR. Virus specific antibody response to structural proteins of capripox and orf viruses in western-blot analysis readily differentiates these two infections. The antibody response to the 32 kDa and 26 kDa proteins of capripox viruses provides a firm basis for differentiation. Although, the role of humoral immunity is well established but probably cell mediated immunity plays a major role in recovery from natural infections. A number of inactivated and live or live modified vaccines have been tried with variable success. The duration of immunity after vaccination is controversial; outbreaks have occurred in vaccinated animals. The disease is also of public health significance as it causes infection in human beings. Keywords

Ecthyma Contagiosa’lı Koyunlarda Paraoksonaz Aktivitesi, Total Sialik Asit ve Oksidatif Stresin Değerlendirilmesi

“…In addition, typical lesions can be seen in mouth, nose, oral mucosa, tongue, gingiva and palate. Similar lesions are observed in the lambs as small erythematous and ulcerated papules on the gums, tongue and palate [2,3,5,8,9] . Skin lesions of the disease are frequently seen in the head, face, ears, neck, chest, legs and inguinal region [10] .…”

“…It has also known that the rate of spread of the disease and the size of the lesions are related to the labor exposure which causes injuries on the mouths of animals during grazing [3] . It has been reported by different researchers that the disease affects all age groups equally, without racial and gender discrimination between animals [5][6][7] .…”

“…Skin lesions of the disease are frequently seen in the head, face, ears, neck, chest, legs and inguinal region [10] . The lesions can usually be cauliflower-like papillomatosis, proliferative, granulomatous, dry crusted, embossed and erosive [5] . The average incubation period in ecthyma contagiosum disease is 2-3 weeks [11,12] .…”

Clinical and Diagnostic Studies of Contagious Ecthyma (ORF) In Sheep

“…In general contagious ecthyma will commonly affects animal lips, However mouth and surrounding skin were also harmed, Furthermore the disease can also affect the face, feet and even the udder skin of lactating ewes, As the causative virus will causes superficial sores, which then will crusted and finally scabbing over and then falling down, Moreover, the underlying skin heals without scarring, where, this cycle takes approximately 4-5weeks or maybe less, Thereby lambs lose condition as they are reluctant to eat and it is too painful for ewes to feed suckling lambs, However, those with foot lesions will be lame, Furthermore, these sores may become infected by opportunistic bacteria, causing further infection (Kumar et al, 2015).…”

“…Infection occurs via direct contact with the virus which is highly resistant and can survive in the environment for more than one year (Constable et al ,2017). The disease occurs most commonly in young lambs, but occasionally in older sheep, Grazing of coarse pastures or stubbles may predispose to infection with scabby mouth as oral abrasions increase the potential for the virus to gain entry (Kumar et al ,2015 ). In Basrah governorate, there was no real document clarify the disease and little information had been provided in sheep, therefore, the main aims of the current study were to study and explore the main clinical manifestations of the disease showed by diseased sheep, and confirmed the diagnosis of the causative virus using molecular method, PCR technique, Moreover to study the hematological changes in diseased animals, Evaluation of acute phase response of diseased animals via evaluation of haptoglobin and Fibrinogen.…”