Table 1. Demographic characteristics and pandemic (H1N1) 2009 infection rates among 223 household contacts of 87 index case-patients, by contact type, Taiwan, August–November 2009*.
| Study participants | No. participants | Mean age, y (SD) | Sex, F/M | Positive for pandemic (H1N1) 2009 |
No. positive/no. tested (%) | |
|---|---|---|---|---|---|---|
| By PCR, no. | By HI, no./no. tested (%) | |||||
| Index case-patients |
87 |
10.6 (7.2) |
42/45 |
71 |
81/84 (96) |
87/87 (100) |
| Household members | 223 | 33.8 (17.9) | 122/101 | 21 | 59/222 (27)† | 60/223 (27) |
| Children | 57 | 8.0 (3.6) | 28/29 | 21 | 34/56 (61)† | 35/57 (61) |
| Siblings | 56 | 7.9 (3.6) | 28/28 | 21 | 34/55 (62)† | 35/56 (63) |
| Cousin | 1 | 11.5 | 0/1 | 0 | 0/1 (0) | 0/1 (0) |
| Adults | 166 | 43.2 (10.5) | 94/72 | 0 | 25/166 (15) | 25/166 (15) |
| Siblings | 5 | 20.3 (1.7) | 3/2 | 0 | 0/5 (0) | 0/5 (0) |
| Parents | 138 | 41.0 (5.6) | 76/62 | 0 | 20/138 (14) | 20/138 (14) |
| Grandparents | 18 | 66.6 (5.9) | 11/7 | 0 | 4/18 (22) | 4/18 (22) |
| Uncles/aunts |
5 |
41.5 (1.7) |
4/1 |
0 |
1/5 (20) |
1/5 (20) |
| Total | 310 | 27.5 (18.9) | 169/141 | 92 | 140/310 (45) | 147/310 (47) |
*HI, hemagglutination inhibition. †One person was confirmed to be infected with pandemic (H1N1) 2009 virus by PCR of a throat swab specimen without testing of a blood sample.