Bordetella parapertussis is a cause of pertussis-like illness that is often milder than B. pertussis infection but can still be clinically significant. U.S. PCR surveillance has shown that about 14% of Bordetella-positive respiratory specimens were B. parapertussis, and recent data indicate a resurgence of B. parapertussis cases. Detecting B. parapertussis via PCR prevents misclassification of whooping cough and explains some cases that might otherwise be labeled vaccine failures. (Noble et al. 2024, Cherry & Seaton 2012).
Noble, B. A., Jiudice, S. S., Jones, J. D., & Timbrook, T. T. (2024). Reemergence of Bordetella parapertussis, United States, 2019-2023. Emerging infectious diseases, 30(5), 1058–1060.
Cherry, J. D., & Seaton, B. L. (2012). Patterns of Bordetella parapertussis respiratory illnesses: 2008-2010. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 54(4), 534–537.