Diagnostic polymerase chain reaction.

In this overview, the PCR sensitivities and specificities for diagnosis of B. pertussis in seven different pertussis vaccine studies are discussed. The performance sensitivity of the PCR methods ranged from < or = 1 to 10 cfu, and the diagnostic sensitivity from 73 to 100% when culture was used as a reference. The proportional increase in cases by positive PCR among culture-negatives ranged from 71 to 293% (four trials), whereas the gain was 6 to 11% among culture and serology-negatives (two trials). As the triggers for collecting nasopharyngeal samples, the selection of samples for PCR analysis, and the PCR protocols themselves differed between the trials, these figures must be interpreted with caution. However, the overall results indicate a considerable gain in sensitivity when PCR was added to culture, but a moderate gain in addition to serology.