Table 3.
Seroprevalence to influenza A/H1N1/2009 virus by gender and age grouped into decades
| Characteristic | Sample proportion, n (%) | Age, mean ± SD | Seropositive subjects | Seropositivity prevalence, % (95% CI)a |
|---|---|---|---|---|
| Genderb | ||||
| Male | 870 (39%) | 28.4 (19.8) | 364 | 41.8% (38.6–45.1) |
| Female | 1352 (61%) | 35.2 (22.0) | 495 | 36.6% (34.1–39.2) |
| Age grouped into decadesc | ||||
| 6–10 | 229 (11%) | 8.2 (1.5) | 117 | 51.1% (44.7–57.5) |
| 11–20 | 623 (29%) | 15.8 (2.8) | 305 | 49.0% (45.0–52.9) |
| 21–30 | 321 (15%) | 24.6 (3.0) | 119 | 37.1% (32.0–42.5) |
| 31–40 | 311 (14%) | 35.7 (2.9) | 84 | 27.0% (22.4–32.2) |
| 41–50 | 313 (14%) | 45.3 (2.9) | 91 | 29.1% (24.3–34.3) |
| 51–60 | 143 (7%) | 54.8 (2.9) | 36 | 25.2% (18.8–32.9) |
| 61–70 | 45 (2%) | 64.5 (2.7) | 16 | 35.6% (23.2–50.2) |
| 71–80 | 61 (3%) | 76.2 (2.8) | 25 | 41.0% (29.5–53.5) |
| 81–90 | 80 (4%) | 85.5 (2.5) | 30 | 37.5% (27.7–48.5) |
| 91+ | 34 (2%) | 94.5 (3.4) | 13 | 38.2% (23.9–55.0) |
SD, standard deviation; CI, confidence interval.
a
Seropositivity prevalence data represent percentage and 95% CI of individuals with positive antibodies in that group.
b
Gender: p-value = 0.259.
c
Age cohort: p-value < 0.000; 62 missing values for decade of birth.
p-Values were obtained from a logistic model adjusted for gender and age.