Table 1.

 Demographic characteristics in all children with rotavirus confirmed by polymerase chain reaction and having at least one valid control (according to protocol, confirmed cohort) and matched controls. Figures are numbers (percentage) unless stated otherwise

Characteristic	Children with rotavirus (n=215)	Controls (n=276)
Age at onset* (months):
Mean	13.0	12.6
Median (range)	11 (2-31)	12 (2-31)
Age at onset* (months):
0-2†	1 (0.5)	1 (0.4)
3-5	16 (7)	20 (7)
6-11	87 (41)	118 (43)
12-23	93 (43)	117 (42)
≥24	18 (8)	20 (7)
Boys	109 (51)	148 (54)

*For controls, age is computed at date of onset of disease in matched case.

†Age at onset could be lower than 3 months given that inclusion criteria were “at least 14 weeks of age at time of hospital admission” and “onset of severe gastroenteritis ≤14 days before admission.” Two children <3 months were exactly 89 days old (for case) and 81 days old (for control).