Table 1.
Characteristics of the study population, overall and by seropositivity for anti-PT IgG
| Total (n = 1999) | Seropositivea (n = 295) | Seronegativeb (n = 1704) | |
|---|---|---|---|
| Demographics | |||
| Age (years) | 47.4 ± 17.7 | 48.8 ± 19.4 | 47.1 ± 17.4 |
| Female | 1212/1999 (60.6) | 160/295 (54.2) | 1052/1704 (61.7) |
| Pertussis-related history | |||
| Pertussis vaccination | 882/1163 (75.8) | 127/165 (77.0) | 755/998 (75.7) |
| Prior pertussis | 88/1566 (5.6) | 15/227 (6.6) | 73/1339 (5.5) |
| Infant | 3/87 (3.4) | 0 | 3/73 (4.1) |
| Child | 75/87 (86.2) | 13/14 (92.9) | 62/73 (84.9) |
| Adolescent | 3/87 (3.4) | 1/14 (7.1) | 2/73 (2.7) |
| Adult | 6/87 (6.9) | 0 | 6/73 (8.2) |
| Long-lasting coughc | 164/1971 (8.3) | 20/290 (6.9) | 144/1681 (8.6) |
| Recent contact with a person with pertussis/long-lasting coughc | 227/1795 (12.6) | 30/270 (11.1) | 197/1525 (12.9) |
| Regular contact with children | 919/1999 (46.0) | 122/295 (41.4) | 797/1704 (46.8) |
| Relevant medicationsd | 241/1962 (12.3) | 39/287 (13.6) | 202/1675 (12.1) |
| Relevant hospitalizationse | 10/1994 (0.5) | 4/294 (1.4) | 6/1700 (0.4) |
Data are mean ± SD or n/N (%), where N is the number of subjects with known data
Abbreviations: Anti-PT IgG anti-pertussis toxin immunoglobulin G, OD optical density, SD standard deviation
a>0.3 OD units
b≤0.3 OD units
cLasting ≥3 weeks in the previous 12 months
dAny antibiotics and/or other medication (i.e., any cough medicines) for lower respiratory tract infections or (suspected) pertussis infections in the previous 12 months
eHospitalized due to respiratory infections in the previous 12 months