Table 1.
Secondary household transmission rate and pathogens in each outbreak
| Daycare centre | No. of STEC-positive daycare centre children* | No. of family members | No. of infected cases | Secondary household transmission rate (%) | STEC O serogroup/Stx type |
|---|---|---|---|---|---|
| A | 17 | 43 | 0 | 0·0 | O26/Stx1 |
| B | 8 | 21 | 6 | 28·6 | O157/Stx1 and Stx2 |
| C | 8 | 35 | 0 | 0·0 | O26/Stx1 |
| D | 18 | 72 | 2 | 2·8 | O26/Stx1 |
| E | 23 | 94 | 6 | 6·4 | O26/Stx1 |
| F | 30 | 96 | 2 | 2·1 | O157/Stx1 and Stx2 |
| G | 17 | 47 | 12 | 25·5 | O26/Stx1 |
| H | 7 | 17 | 1 | 5·9 | O157/Stx1 and Stx2 |
| I | 5 | 36 | 1 | 2·8 | O26/Stx1 |
| J | 10 | 32 | 11 | 34·4 | O157/Stx1 and Stx2 |
| K | 6 | 20 | 0 | 0·0 | O157/Stx1 and Stx2 |
| L | 13 | 26 | 2 | 7·7 | O26/Stx1 |
| M | 12 | 48 | 0 | 0·0 | O26/Stx1 |
| N | 20 | 71 | 18 | 25·4 | O26/Stx1 |
| O | 8 | 36 | 8 | 22·2 | O26/Stx1 |
| P | 20 | 57 | 0 | 0·0 | O26/Stx1 |
| Total | 222 | 751 | 69 | 9·2 |
Stx, Shiga toxin.
* No. of STEC-positive daycare centre children whose families met the requirements for calculating the secondary household transmission rate.