Orf is a disease primarily of sheep and goats, but can also affect humans. It is caused by a parapoxvirus known as orf virus (ORFV) which has a worldwide distribution. Although it can affect animals of any age it is most prevalent around lambing time, affecting both lambs and ewes. Farmers, shepherds, veterinarians, abattoir workers and fleece handlers are at greatest occupational risk of contracting the disease, but others have been exposed through recreational use of the countryside.
The disease is characterised by scabby lesions that are often bloody, that form around the mouth and nares of the affected animals and in the ewe can often be found on the teats. In humans lesions are most commonly seen on the hands. If the disease affects nursing ewes they are often reluctant to allow lambs to suckle and equally, affected lambs often find normal feeding difficult. Together this can result in weakened lambs that do not thrive as well as others and can also be more susceptible to other infections. In extreme cases lamb finishing times can be prolonged.
Current interests and future aims:
Moredun is conducting research on Orf virus within the Scottish Government Strategic Research Programme (2016-2021) looking at the development of combination vaccines that would protect against orf and other diseases of sheep.