Primary Objectives: a) to estimate the proportin of RV GE among all acute GE emergency room visits among children <5 years of age, b) to estimate the proportion of RV GE among all acute GE hospitalisations among children <5 years of age, c)to estimate the incidence of nosocomial RV GE among all hospitalised children <5 years of age.

All children <5 yeas of age presenting at the selected sites with acute GE will be asked to provide their stool sample to be tested for RV, only if their parents/guardians give their consent. All RV positive stool samples will be genotyped. Paretns/Guardians of enrolled subjects will be interviewed regarding their child´s diarrhoea. In addition, a subset of the hospitalised subjects´parents/guardians will be asked to complete a health economic questionnaire.