Duration of Bordetella pertussis Polymerase Chain Reaction Positivity in Confirmed Pertussis Illness.

Pertussis cases have been increasing in the United States for the past 40 years. Polymerase chain reaction (PCR) testing is now the preferred method of diagnosis, but little is known about duration of PCR positivity. We conducted a pilot study using serial B pertussis PCR testing to determine duration of PCR positivity. Kaplan-Meier survival analysis suggested a median duration of 58 days (interquartile range, 40-110 days).