Orf viruses, also known as contagious ecthyma or contagious pustular dermatitis, are a group of highly contagious viruses that primarily affect sheep and goats. They belong to the Parapoxvirus genus of the family Poxviridae.
These viruses cause a specific and characteristic skin disease in their host animals, characterized by the formation of pustules or blisters on the lips, mouth, muzzle, and sometimes on the feet of affected animals. Orf viruses typically enter the body through breaks in the skin, such as cuts or abrasions, and can also be transmitted through direct contact with infected animals, contaminated objects, or via aerosol droplets.
The incubation period for orf infection is relatively short, usually ranging from 3 to 7 days, after which small red papules appear, eventually developing into painful, raised pustules or blisters filled with clear or yellowish fluid. These lesions can be itchy, causing the animals to scratch and further spread the virus.
While orf infections are usually self-limiting and resolve within a few weeks, severe cases can occur, especially in young animals or those with weakened immune systems. Secondary bacterial infections may also develop in conjunction with orf lesions. Humans can also contract orf through direct contact with infected animals, resulting in similar skin lesions, although the disease is generally milder compared to animals.
Prevention and control of orf viruses are crucial in livestock settings, and strategies such as quarantine, hygienic measures, and vaccination are commonly employed to manage outbreaks and minimize transmission among animals and humans.
