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Sample size required for the target populations in the three sites to estimate annual, blood culture-confirmed typhoid incidence in passive clinical surveillance
| Age groups (years) | Anticipated typhoid incidence per 1000 persons* | Precision or half-width | Sample size required |
| 0–4 | 1.5 | 0.75 | 10 125 |
| 5–14 | 1.0 | 0.5 | 15 119 |
| >14 | 0.5 | 0.25 | 29 801 |
*Assumed age-specific incidence rates (based on data from Dhaka, Bangladesh, Delhi, India, and Dong Thap, Vietnam).
