BSE might have found a way to infect goat and sheep populations. The magnitude of this spread is unknown since conventional tests cannot distinguish between BSE and scrapie in small ruminants. Intensified testing programs are now expected to yield a clearer picture of TSE in small ruminants.
Experimental transmission studies have shown that sheep and goats (small ruminants) can be infected with BSE. But since January 2005, when France confirmed the first natural case of BSE in a goat, it is now clear that the disease can spread beyond cattle outside of the laboratory. However, it is still not clear how many of the detected "scrapie" cases have in fact been BSE.
The goat had already been discovered in 2002 under the context of the French TSE surveillance program, as testing positive for scrapie, a disease similar to BSE. Tests triggered a suspicion that it could have been a BSE infection, and after a number of lengthy tests, such as mouse bioassays, the Veterinary Laboratories Agency (VLA) in Weybridge, U.K., could only recently confirm the case as positive for BSE.
Now the discrimination between BSE and scrapie can be performed much faster. The VLA has launched a diagnostic kit that distinguishes between the two TSEs. The kit that is a modification of the Prionics®-Check WESTERN has been compiled in a collaborative effort between Prionics, the VLA and R-Biopharm.
Based on clinical symptoms and current detection methods, BSE infections cannot be definitively determined in small ruminants. Therefore TSE fingerprinting tests i.e. the VLA Discriminatory Western Blot , based on the Prionics®-Check WESTERN will be invaluable.
Towards a clear picture of TSE in small ruminants
What are the consequences of BSE in small ruminants? While scrapie is thought not to be infectious to humans, it is unclear whether BSE in small ruminants could cause Creutzfeldt-Jakob disease. To determine whether the BSE goat was an isolated case, the European Commission announced that an additional 200'000 goats will be tested in all 25 EU member states in the first half of 2005 (compared to 140'000 goats tested between April 2002 and December 2004). In an attempt to determine the TSE status of the domestic small ruminant population, Switzerland has also carried out a monitoring program between July 2004 and June 2005. During the one-year period, samples of all slaughtered sheep and of sick slaughtered and fallen goats were tested with immunohistochemistry and rapid TSE tests, including the Prionics®-Check WESTERN SR. Almost 28'000 animals have been tested so far; six sheep with scrapie (1 typical case and 5 atypical cases) and 2 goats with atypical scrapie were found, but none with BSE.
