Table 4.
Manifestations of influenza index cases and occurrence of suspected influenza among contacts in large families
| Serotype | Manifestations of index case | Disease status | RR (95% CI) | |
|---|---|---|---|---|
| Sick | Healthy | |||
| H1N1 | Runny nose | |||
| Present | 49 (67·1) | 177 (49·3) | 1·86 (1·19–2·92) | |
| Absent | 24 (32·9) | 182 (50·7) | ||
| Cough | ||||
| Present | 69 (94·5) | 294 (81·9) | 3·28 (1·24–8·69) | |
| Absent | 4 (5·5) | 65 (18·1) | ||
| Seasonal | Runny nose | |||
| Present | 48 (80·0) | 277 (77·6) | 1·13 (0·63–2·04) | |
| Absent | 12 (20·0) | 80 (22·4) | ||
| Cough | ||||
| Present | 45 (75·0) | 300 (84·0) | 0·63 (0·37–1·06) | |
| Absent | 15 (25·0) | 57 (16·0) | ||
RR, relative risk.