Background: The surveillance case definition for confirmed pertussis requires that an individual with a positive polymerase chain reaction (PCR) result for Bordetella pertussis have 2 weeks or more of cough and at least one of the following: paroxysmal coughing, inspiratory “whoop,” or posttussive vomiting.
Objectives: Determine (1) proportion of individuals with a positive PCR result who met additional criteria for surveillance confirmed pertussis, (2) whether the likelihood of PCR-positive individuals meeting additional elements of surveillance case definition varied by age or vaccination status, and (3) whether elements of the current case definition influence the likelihood of pertussis confirmation in PCR-positive individuals.
Methods: Pertussis PCR results were compared with case investigation data.
Results: Eighty-eight percent (165/188) of PCR-positive individuals met requirements for confirmed pertussis. Sixty-one percent (14/23) of PCR-positive individuals who had less than 2 weeks but more than 1 week of cough had at least one other reported sign or symptom. Fourteen (100%) reported paroxysmal coughing, 7 (50%) “whoop,” and 7 (50%) posttussive vomiting. Infants who met case definition were more likely to have reported apnea than were older individuals (15/17 vs 45/86, OR = 6.8, 95% CI = 1.4–64.2).
Conclusions: Decreasing cough duration from 2 weeks or more to more than 1 week would result in 95 percent of those with positive PCR results meeting confirmation criteria for pertussis. Apnea should be considered an additional sign for pertussis confirmation in infants.
This article discusses the existing case definition for pertussis and suggests that some other conditions, such as apnea, should also be accounted for while reporting public health.
Julie H. Shakib, DO, MPH, is a pediatrician in the Department of Pediatrics, General Pediatric Division, University of Utah, Salt Lake City.
Lisa Wyman, MPH, is with the Utah Department of Health, Salt Lake City.
Per H. Gesteland, MS, MD, is with the Department of Pediatrics, University of Utah, Salt Lake City.
Catherine J. Staes, PhD, MPH, is with the Department of Biomedical Informatics, University of Utah, Salt Lake City.
D. W. Bennion, MS, is with the Intermountain Healthcare Central Laboratory, Salt Lake City, Utah.
Carrie L. Byington, MD, is with the Department of Pediatrics, University of Utah, Salt Lake City.
Corresponding Author: Julie H. Shakib, DO, MPH, PO Box 581289, Salt Lake City, UT 84158 (firstname.lastname@example.org).
The University of Utah Children's Health Research Center provided funding for administrative, technical, and material support. This study was also supported by award CDC 1 PO1 CD000284 from the Utah Center of Excellence in Public Health Informatics (Drs. Shakib and Byington) and by grant K24-HD047249 from the NIH/Eunice Kennedy Shriver, NICHD (Dr Byington).