EVALUATION OF PCR FOR DIAGNOSIS OF BORDETELLA-PERTUSSIS AND BORDETELLA-PARAPERTUSSIS INFECTIONS

PCR, using primers PIp1 and PIp2, was evaluated for the detection of D NA from Bordetella pertussis in bacterial strains and in nasopharyngea l samples from patients with a cough lasting at least 7 days. The assa y could detect DNA from 6 CFU of B., pertussis/10 mu l of sample, Resu lts of the PCR assay were compared with those of cultures, a determina tion of serum antibodies against pertussis toxin and filamentous hemag glutinin, and a clinical evaluation of 2,442 coughing episodes, The ov erall sensitivity of PCR was 65% (623 of 956), which was higher than t he sensitivity of cultures (58%) (P < 0.001), Factors influencing the sensitivity of PCR were the interval between the onset of symptoms and sampling and the vaccination status of the patient, The specificity o f PCR was 98% (1,451 of 1,486), The positive and negative predictive v alues were 95 and 81%, respectively, Parapertussis PCR, using primers BPPA and BPPZ, was positive in 11 of 18 culture-positive cases and was confirmed by serology in another 4 cases, In conclusion, PCR is a val uable complement to cultures and can probably replace cultures for dia gnosis of B., pertussis and Bordetella parapertussis infections.