Comparison of real-time PCR and conventional hemi-nested PCR for the detection of Bordetella pertussis in nasopharyngeal samples

We directly compared a conventional hemi-nested PCR assay with a real-time (LightCycler) PCR assay for the detection of Bordetella pertussis in nasopharyngeal samples. Of the 152 samples tested, 49 (32%) were positive by first-round conventional PCR, 56 (37%) were positive by the hemi-nested PCR assay, and 39 (26%) were positive by the real-time assay. All samples testing positive with the real-time assay were also positive by the hemi-nested assay (both first- and second-round PCR), and all culture-positive samples tested positive by both PCR assays. These results suggest that the hemi-nested assay is more sensitive than the real-time assay for detecting B. pertussis .