Comparison of throat and nasopharyngeal swab specimens for culture diagnosis of Bordetella pertussis infection.

During a 9-month period, we evaluated the relative sensitivity of throat and nasopharyngeal swab cultures for isolation of Bordetella pertussis. Of 38 pertussis cases, 36 (95%) had positive nasopharyngeal cultures, while only 16 of 36 (44%) had positive throat cultures. There were no cases of nasopharyngeal-negative, throat-positive cultures. The sensitivity of the direct fluorescent-antibody test was 70% when compared with culture.