Table 1. Baseline characteristics of NoV-positive and NoV-negative case-patients and control participants, Vietnam, 2009–2010*.
| Characteristic |
Case-patients |
|
Controls |
| NoV positive, n = 241 | NoV negative, n = 1,126 | NoV positive, n = 15 | NoV negative, n = 592 | ||
|---|---|---|---|---|---|
| Male sex |
147 (61.0) |
724 (64.3) |
|
8 (53.3) |
314 (53.0) |
| Mean age, mo (range) |
13.3 (2–45) |
15.8 (1–59) |
|
15.8 (2.3–52) |
16.8 (0–60) |
| Age groups, mo | |||||
| <6 | 24 (10.0) | 165 (14.7) | 3 (20.0) | 98 (16.6) | |
| 7–12 | 102 (42.3) | 375 (33.3) | 4 (26.7) | 208 (35.1) | |
| 13–18 | 76 (31.5) | 245 (21.8) | 3 (20.0) | 113 (19.1) | |
| 19–24 | 25 (10.4) | 147 (13.1) | 3 (20.0) | 56 (9.5) | |
| 24–60 |
14 (5.8) |
194 (17.2) |
|
2 (13.4) |
117 (19.8) |
| Poor Z score† |
18 (7.5) |
73 (6.5) |
|
1 (6.7) |
75 (12.7) |
| Breastfed |
187 (77.6) |
790 (70.2) |
|
11 (73.3) |
452 (76.4) |
| Daily activity | |||||
| Day care/nursery school | 30 (12.5) | 194 (16.4) | 4 (26.7) | 89 (15.2) | |
| Home | 211 (87.6) | 938 (83.6) | 11 (73.3) | 498 (84.8) |
*Values are no. case (%) unless otherwise specified. Case-patients indicate patients who had diarrhea; controls indicate asymptomatic (diarrhea-free) children. Study dates span May 2009–December 2010. NoV, norovirus; WHO, World Health Organization. †Weight-for-age Z score calculated based on WHO Child Growth Standards guidelines (www.who.int/childgrowth/standards/technical_report/en/); Z score below −2 was considered to indicate that a child was malnourished.