Table 1.
Comparison of Pertussis Episodes to Nonpertussis Episodes
| Nonpertussis Episodes | Pertussis Episodes | ||||
|---|---|---|---|---|---|
| (n = 3913) | (n = 17) | P Valuea | |||
| Characteristic | Proportion | Mean | Proportion | Mean | |
| Symptomsb | |||||
| Cough | 62% | 71% | .62 | ||
| Difficulty breathing | 40% | 65% | .05 | ||
| Cough with vomit | 12% | 50% | .00 | ||
| Wheeze | 45% | 47% | .99 | ||
| Fever | 53% | 47% | .64 | ||
| Whoop | 6% | 33% | .01 | ||
| Apnea | 4% | 17% | .08 | ||
| Cyanosis | 1% | 8% | .09 | ||
| Ear Infection | 5% | 6% | .59 | ||
| Episode duration (days) | 5 | 8 | .07 | ||
| Age at episode start (days) | 91 | 83 | .54 | ||
| Coinfections | |||||
| RV | 50% | 53% | .99 | ||
| BoV | 5% | 24% | .01 | ||
| PIV3 | 4% | 12% | .17 | ||
| RSV | 9% | 6% | .99 | ||
| Influenza | 5% | 6% | .55 | ||
| MPV | 5% | 6% | .57 | ||
| CoV | 8% | 6% | .99 | ||
| PIV1 | 2% | 0% | .99 | ||
| PIV2 | 1% | 0% | .99 | ||
| PIV4 | 2% | 0% | .99 | ||
| AdV | 2% | 0% | .99 | ||
| Vaccination | |||||
| Received 1st pertussis vaccination | 38% | 35% | 0.99 | ||
| Days since vaccination | 49 | 18 | 0.03 | ||
Abbreviations: AdV, adenovirus; BoV, bocavirus; CoV, coronavirus; MPV, human metapneumovirus; PIV, parainfluenza; RSV, respiratory syncytial virus; RV, rhinovirus.
a t tests were used for continuous predictors and Fisher’s exact tests were used for categorical predictors; statistical significance of P < .05 indicated in bold.
bCough with vomit, apnea, whoop, and cyanosis were only captured in year 2; denominator for these symptoms was 2034 episodes.