Evaluation of a Multitarget Real-Time PCR Assay for Detection of Bordetella Species during a Pertussis Outbreak in New Hampshire in 2011

A multitarget real-time PCR assay with three targets, including insertion sequence 481 (IS481), IS1001, and an IS1001-like element, as well as pertussis toxin subunit S1 (ptxS1), for the detection of Bordetella species was evaluated during a pertussis outbreak. The sensitivity and specificity were 77 and 88% (PCR) and 66 and 100% (culture), respectively. All patients with an IS481 CT of <30 also tested positive by ptxS1 assay and were clinical pertussis cases. No patients with IS481 CT values of ≥40 tested positive by culture. Therefore, we recommend that culture be performed only for specimens with IS481 CT values of 30 ≤ CT <40.