Pertussis Seasonality Evident in Polymerase Chain Reaction and Serological Testing Data, Queensland, Australia.

We investigated the seasonality of pertussis in Queensland, Australia, between 2008 and 2011 using notification and laboratory data. Polymerase chain reaction and serology testing data demonstrate that in the vaccine era, pertussis remains a seasonal illness, with annual peaks in summer months, and that the seasonality of notification data is masked by testing trends.