Table 3.
Clinical Features of Patients With Parapertussis and Patients With Pertussis, by Age—Wood County, Wisconsin, 1 October 2011–31 May 2012
| All Ages | Aged <5 y | Aged 5–10 y | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Clinical Feature | Parapertussis No. (%)a (n = 28) | Pertussis No. (%)a (n = 103) | P Valueb | Parapertussis No. (%)a (n = 13) | Pertussis No. (%)a (n = 10) | P Valueb | Parapertussis No. (%)a (n = 13) | Pertussis No. (%)a (n = 32) | P Valueb |
| Cough duration (days), median (IQR) | 14 (11–28) | 28 (17–40) | .004 | 14 (7–25) | 31 (20–41) | .045 | 14 (12–37) | 30 (17–35) | .265 |
| Paroxysmal cough | 21 (75) | 78 (76) | .937 | 10 (77) | 8 (80) | 1.000 | 10 (77) | 21 (66) | .724 |
| Paroxysmal cough duration (days), median (IQR) | 6 (4–7) | 16 (8–30) | <.001 | 7 (5–7) | 12 (7–18) | .254 | 5 (3–7) | 14 (8–18) | .022 |
| Posttussive vomiting | 8 (29) | 36 (35) | .603 | 5 (38) | 7 (70) | .231 | 3 (23) | 9 (28) | 1.000 |
| Whoop | 8 (29) | 15 (15) | .078 | 3 (23) | 2 (20) | 1.000 | 4 (31) | 3 (9) | .075 |
| Apnea | 2 (7) | 12 (12) | .512 | 2 (15) | 5 (50) | .074 | 0 (0) | 1 (3) | 1.000 |
| Sleep disturbance in patientc | 21 (78) | 78 (77) | .952 | 9 (75) | 8 (80) | 1.000 | 11 (85) | 25 (78) | 1.000 |
| Sleep disturbance in any household memberc | 14 (54) | 22 (56) | .839 | 5 (45) | 2 (100) | .462 | 8 (62) | 9 (69) | 1.000 |
| Hospitalized | 0 (0) | 2 (2) | 1.000 | 0 (0) | 2 (20) | .178 | 0 (0) | 0 (0) | … |
| Met pertussis clinical case definitiond | 17 (61) | 76 (74) | .177 | 8 (62) | 8 (80) | .405 | 8 (62) | 23 (72) | .502 |
| Up-to-date for age with pertussis vaccinations, patients aged 3 mo-10 yc,e | 24 (96) | 34 (89) | .640 | 11 (92) | 4 (67) | .245 | 13 (100) | 30 (94) | 1.000 |
Abbreviation: IQR, interquartile range.
All data are presented as number and percentage except for the cough and paroxysmal cough durations which are presented as median and IQR.
P-value of χ2 or Fisher exact test for difference in presence of symptoms by type of infection or Mann–Whitney U test for difference in symptom duration by type of infection.
Percentages exclude patients with missing information.
Illnesses were classified by whether they met the Council of State and Territorial Epidemiologists clinical case definition of pertussis (cough illness ≥14 days with ≥1 of the following: whoop, paroxysms, or posttussive vomiting) used during 2011–2012 [25].
Patients aged 3 months–10 years were categorized as up-to-date for age with pertussis vaccinations on the basis of the Advisory Committee on Immunization Practices recommended vaccination schedule [26].