Table 1.
Prevalence of Hepatitis B Surface Antigen Stratified by Birth Date and Vaccination Status
| Population | Crude HBsAg Prevalence | Population Standardized HBsAg Prevalence, % (95% CI)a | Risk Ratio (95% CI) | P Value | |
|---|---|---|---|---|---|
| Frequency | % (95% CI) | ||||
| All individuals | 160/6073 | 2.6 (2.3–3.1) | 3.2 (2.7–3.7) | ||
| Birth date relative to vaccine introductionb | |||||
| 5 y before vaccine | 15/500 | 3.0 (1.8–4.9) | 2.9 (1.8–4.7) | Reference | |
| 5 y after vaccine | 1/758 | 0.1 (.02–.7) | 0.1 (.02–.8) | 0.04 (.06–.29) | .001 |
| 10 y before vaccine | 30/884 | 3.4 (2.4–4.8) | 3.6 (2.5–5.1) | Reference | |
| 10 y after vaccine | 5/1932 | 0.3 (.1–.6) | 0.2 (.1–.6) | 0.07 (.03–.17) | <.0001 |
| All before vaccine | 152/3280 | 4.6 (4.0–5.4) | 5.1 (4.3–6.0) | Reference | |
| All after vaccine | 9/2793 | 0.3 (.2–.6) | 0.3 (.2–.6) | 0.06 (.03–.12) | <.0001 |
| Vaccination status for age ≤10 y | |||||
| Completed 3 doses | 3/1141 | 0.3 (.1–.8) | 0.2 (.1–.8) | Reference | |
| Unknown statusc | 5/913 | 0.5 (.2–1.3) | 0.6 (.2–1.4) | 2.3 (.5–10.2) | .26 |
| Incompleted | 0/31 | 0.0 (.0–11.0) | … | … | |
Abbreviations: CI, confidence interval; HBsAg, hepatitis B surface antigen.
Standardized to census age and sex distribution.
Hepatitis B vaccination was introduced on 1 January 2002.
Participants born after vaccine introduction for whom vaccination status could not be ascertained from parent, guardian, or documentation; vaccine status was ascertained for 1172/2085 (56.2%) children aged ≤10 years.
Received 0, 1, or 2 doses.