Dr. Detwiler said that because of this possibility, importation of sheep and goats into the United States has been prohibited except from Canada, Mexico, Australia and New Zealand. Dr. Katherine O'Rourke with USDA's Agricultural Research Service told the committee that a live animal test for scrapie, described last spring, has been revised twice to improve sensitivity and specificity. She anticipates a two-year validation test involving U.S. sheep. OPP can be eradicated from a flock by testing and eliminating positive animals or by separating newborm lambs from seroopositive ewes and raising them in isolation. Several diagnostic tests have been used to identify OPP-infected sheep.
Basic research is needed in the areas of transmission and in developing an effective vaccine.
Identification of subclinically infected animals remains the greatest challenge to prevention and control.