Lymphocyte stimulation in swine dysentery.

In lymphocyte stimulation studies of pigs affected with swine dysentery (SD) all of the pigs gave significant response (P less than 0.05) to soluble antigen from Treponema hyodysenteriae. Swine infected with virulent or attenuated T. hyodysenteriae gave significant lymphocytic response 3 or 6 weeks after infection; uninfected pigs did not give a similar lymphocytic response. The delayed hypersensitivity (DH) skin test, in which soluble T. hyodysenteriae antigen preparation was used, detected only 3 out of 14 SD-affected swine. The lymphocyte stimulation assay by detection of protein synthesis may offer a rapid, reliable test for the diagnosis of SD within herds suspected of being affected.