Parasitology
Immunological approaches to the control of sheep scab
Smith, D and Huntley, JF
Sheep scab is an allergic dermatitis caused by the mite, Psoroptes ovis. Non-chemical approaches to the control of arthropod ectoparasites are being sought as alternative strategies to insecticidal and acaracidal chemicals which are perceived to be harmful to operator personnel and to the environment, and which will eventually select for resistant strains. Immunopathogenesis studies have demonstrated that sheep develop strong protective immunity to P. ovis following infection. Furthermore, considerable protection to challenge can be induced by injecting sheep with certain fractions of the mite, the best to date reducing lesion areas and mite numbers by more than four and fifteen-fold, respectively. The objective of this study is to identify the precise antigens responsible for providing protection against the sheep scab mite and to synthesise these as recombinant proteins so that they can be produced sufficiently and cost-effectively for use in a commercial vaccine.