Table 3.

Sample size calculations for the serological surveys to estimate age-specific rates of high titres of serum IgG anti-H(d) antibodies

	Anticipated seroincidence (%)	Initial samples (n)	Anticipated number of events	Follow-up samples (n)*	Events detected (n)	Binomial exact (95% CI)	Probability of observing 0 events
0–4 years	0.2	2500	5	2000	4	0.0005 to 0.0051	0.0182
5–9 years	0.4	1300	5.2	1040	4	0.0010 to 0.0098	0.0155
10–14 years	0.8	800	6.4	640	5	0.0025 to 0.0181	0.0059
>14 years	0.2	3900	7.8	3120	6	0.0007 to 0.0042	0.0019
Total		8500	24.2	6800	19

Assumes age-stratified individual sampling; also accounts for detection of 1% chronic carriage rate in those aged ≥10 years.

*Assuming 5% migration and 15% refusal.