Table 1.

Serological marker prevalence by volunteer age group.

Age group, years	N	HBsAg			Anti-HBc			Anti-HBs
		n	%	95% CI	n	%	95% CI	n	%	95% CI
1–17	118	0	0.0	0.0–3.1	10	8.5	4.7–14.9	42	35.6*	27.5–44.6
1–5	13	0	0.0	0.0–24.7	1	7.7	1.4–33.3	10	76.9*	49.7–91.8
6–11	43	0	0.0	0.0–8.2	5	11.6	5.1–24.5	17	39.5*	26.4–54.4
12–17	62	0	0.0	0.0–5.8	4	6.5	2.5–15.4	15	24.2	15.2–36.2
18–29	249	1	0.4	0.1–2.2	13	5.2	3.1–8.7	145	58.2*	52.0–64.2
30–39	501	2	0.4	0.1–1.4	27	5.4	3.7–7.7	102	20.4	17.1–24.1
40–49	688	5	0.7	0.3–1.7	43	6.3	4.7–8.3	103	15.0#	12.5–17.8
50–59	468	7	1.5	0.7–3.1	45	9.6	7.3–12.6	76	16.2#	13.2–19.9
60–69	320	8	2.5	1.3–4.9	40	12.5	9.3–16.6	42	13.1#	9.9–17.3
70+	189	2	1.1	0.3–3.8	42	22.2*	16.9–28.7	37	19.6	14.5–25.8
Total	2,533	25	1.0	0.7–1.5	220	8.7	7.7–9.8	547	21.6	20.0–23.2

^*Significantly higher than the total value. ^#Significantly lower than the total value; p < 0.05 for all comparisons.