A CLINICAL VALIDATION OF BORDETELLA-PERTUSSIS AND BORDETELLA-PARAPERTUSSIS POLYMERASE CHAIN-REACTION - COMPARISON WITH CULTURE AND SEROLOGYUSING SAMPLES FROM PATIENTS WITH SUSPECTED WHOOPING-COUGH FROM A HIGHLY IMMUNIZED POPULATION

The aim of this study was to validate the performance of the polymeras e chain reaction (PCR) assay for Bordetella pertussis and Bordetella p arapertussis in comparison with both culture and serology. The number of samples positive in PCR was 2.4-fold higher than the number of samp les positive in culture. In serologically confirmed cases, the sensiti vity of PCR and culture depended on the duration of disease and the ag e of the patient, being less sensitive in older age and later in disea se. The sensitivity of the PCR in patients with <10 days of symptoms w as 70%, 50%, and 10% in the age groups <1 year, 1-4 years, and greater than or equal to 5 years, respectively. Evidence suggested that the e ffect of age on sensitivity may be due to differences in immune respon ses. The low IgA response in the <1 year age group may be related to t he high number of samples positive in PCR and culture, even late in di sease.