Diagnosis of bovine venereal campylobacteriosis by ELISA. 
An enzyme-linked immunosorbent assay (ELISA) measuring IgA antibodies in the vaginal mucus was used to diagnose bovine venereal campylobacteriosis in 241 herds with infertility and abortions.  The presence of the disease was confirmed on 84 farms (34.8%) and it was suspected on a further 27 farms (11.2%).  The specificity of the ELISA was found to be 98.5% but in the absence of a reliable comparative test sensitivity can not be estimated.  Vaccination against campylobacteriosis will not interfere with the IgA ELISA because only IgG is present in the vaginal mucus of vaccinates.  Because of the possibility of false reactions caused by antibody fluctuations in individual cattle, the ELISA is best used as a herd test.  It appears that at present the vaginal mucus IgA ELISA is the test of choice for the diagnosis of bovine venereal campylobacteriosis.