Table 3. Confirmed SAR of pandemic (H1N1) 2009 virus infection, according to time antiviral drug prophylaxis began after onset of illness in primary case-patient, plus timing of secondary cases after onset of primary case, United Kingdom, 2009*.
| Timing |
No. contacts |
No. secondary case-patients at 14 d |
SAR, % (95% CI) |
No. (%) secondary case-patients | |||
|---|---|---|---|---|---|---|---|
| 2 d |
3–4 d |
5–7 d |
>7 d |
||||
| No prophylaxis |
143 |
45 |
31.5 (24.0–39.8) |
15 |
12 |
10 |
8 |
| Day 0 | 57 | 1 | 1.8 (0.0–9.4) | 0 | 0 | 1 | 0 |
| Days 1–2 (<48 h) | 81 | 4 | 4.9 (1.4–12.2) | 0 | 3 | 1 | 0 |
| Day 3–7 (inclusive) | 214 | 3 | 1.4 (0.3–4.0) | NA | 0 | 3 | 0 |
| >7 d |
92 |
0 |
0.0 (0.0-3.9) |
NA |
NA |
NA |
0 |
| Total case-patients | 587 | 53 | 9.0 (6.8–11.7) | 15 (2.6) | 15 (2.6) | 15 (2.6) | 8 (1.4) |
*SAR, secondary attack rate; CI, confidence interval; NA, not applicable.