Table 1.
Characteristics of enterotoxigenic Escherichia coli (ETEC) O169 enteritis outbreaks in seven schools, Republic of Korea in 2012 (n = 1642), according to site of outbreak occurrence
| Characteristics | Outbreak sites | ||||||
|---|---|---|---|---|---|---|---|
| School A | School B | School C | School D | School E | School F | School G | |
| No. of cases | 135 | 550 | 39 | 17 | 755 | 128 | 18 |
| Total exposure* | 920 | 1150 | 582 | 575 | 1,213 | 854 | 250 |
| Attack rate (%) | 14·7 | 47·8 | 6·7 | 3·0 | 62·2 | 15·0 | 7·2 |
| Symptom onset (date) | 3 Sept. | 4 Sept. | 4 Sept. | 5 Sept. | 4 Sept. | 6 Sept. | 7 Sept. |
| Symptoms, n (%) | |||||||
| Diarrhoea, ⩾3/day | 30 (22·2) | 316 (57·5) | 11 (28·2) | 7 (41·2) | 443 (58·7) | 66 (51·6) | 17 (94·4) |
| Mucoid diarrhoea | 9 (6·7) | 38 (6·9) | 1 (2·6) | 0 | 38 (5·0) | 12 (9·4) | 2 (11·1) |
| Bloody diarrhoea | 2 (1·5) | 9 (1·6) | 0 | 0 | 9 (1·2) | 2 (1·6) | 0 |
| Fever | 22 (16·4) | 126 (22·9) | 5 (12·8) | 10 (58·8) | 206 (27·3) | 19 (14·8) | 6 (33·8) |
| Vomiting | 10 (7·4) | 22 (4·0) | 1 (2·6) | 7 (41·2) | 68 (9·0) | 15 (11·7) | 0 |
| Abdominal pain | 79 (58·5) | 342 (62·2) | 26 (66·7) | 10 (58·8) | 582 (77·1) | 114 (89·1) | 16 (88·9) |
| Incubation time | |||||||
| Mean (days) | 2 | 3 | 2 | 2 | 2 | 3 | 2 |
| Range (h) | 17 | 20 | 13 | 5 | 14 | 20 | 10 |
| Food samples (n) | 24 | 42 | 30 | 25 | 26 | 29 | 72 |
| Isolated ETEC† | 69 | 60 | 35 | 11 | 20 | 27 | 8 |
*
Total exposure: number of individuals who ate at the school cafeteria.
†
Isolation from affected individuals.