In order to evaluate a new commercial enzyme immunoassay (ProspecT Campylobacter Microplate Assay; Alexon-Trend, USA) for the detection of Campylobacter jejuni and Campylobacter coli in stool samples, 30 faecal specimens known to be culture-positive for Campylobacter jejuni were tested with the new assay. The detection limit was approximately 3 x 10(6)/ml in faecal suspensions. The sensitivity relative to culture was 80% (24/30). All of the 24 positive samples, except for one, remained positive after being stored at -20 degrees C for 60 days. The specificity of the test was 100%. Interestingly, 6 of 11 additional Campylobacter jejuni culture-positive samples that had been obtained from patients with Guillain-Barré syndrome and stored at -20 degrees C for periods of up to 5 years tested positive in the assay. The performance of the assay indicates that it has potential value for use in future early intervention studies.