The confirmed cases are children born after 01 October 2006, at least 14 weeks of age, hospitalized for SGE during the designated study period and whose stool samples have been tested positive for RV by polymerase chain reaction (PCR). The controls are those children hospitalised or visiting the hospital outpatient clinic for non-GE causes at the study hospitals during the same time-period as the case and will be included after matching by age.