Evaluation of an enzyme immunoassay-based stool antigen test to detect Campylobacter jejuni and Campylobacter coli

An enzyme immunoassay-based antigen test (Ridascreen Campylobacter; R-Biopharm, Darmstadt, Germany) was evaluated for the detection of Campylobacter jejuni and Campylobacter coli in 1050 clinical stool samples as compared with culture on selective medium. After routine inoculation for Salmonella, Shigella, Yersinia, Aeromonas, Plesiomonas, and Campylobacter, the same swab specimens were used for the antigen test. The positivity rate for Campylobacter was 9.3% in culture, and the antigen test gave a sensitivity of 69%. Forty-six stool samples culture-negative for Campylobacter grew other enteropathogens; one (positive for Salmonella sp.) was positive in the antigen test. Of all the 952 Campylobacter culture-negative samples, 830 were negative in the antigen test, giving a specificity of 87%. Almost 5% of the samples showed equivocal antigen test results. If the moderate sensitivity of the antigen test was due to a low sensitivity of culture or receiving the stool samples in transportation tubes remains to be studied.