Effectiveness of RotarixTM Vaccine in Children Aged Between 12 Weeks to < 5 Years, Hospitalised for Severe Gastroenteritis

Inclusion Criteria: For SGE subjects: * A male or female child aged 12 weeks to \< 5 years at the time of hospital admission/ ED stay. The subject becomes ineligible on the fifth birthday. * Subject admitted to (or who will have an ED stay at) the study hospital(s) for SGE during the study period. * Onset of SGE ≤ 14 days prior to admission/ ED stay. * Written/thumb printed informed consent obtained from the parent(s)/legally acceptable representative(s) (LAR (s)) of the subject. For Cases: • Laboratory confirmed (i.e. by ELISA) RV-positive stool sample collected at hospital admission/ ED stay or during the first 48 hours of hospitalisation. For Controls: * Subject admitted to (or who will have an ED stay at) the same study hospital(s) for SGE as that of the case during the study period. * Laboratory confirmed (i.e. by ELISA) RV-negative stool sample collected at hospital admission/ ED stay or during the first 48 hours of hospitalisation. * Subjects born within ± 2 weeks from the date of birth of the case. Exclusion Criteria: For SGE subjects: * Child in care. * Hospitalisation is unrelated to GE. * Onset of SGE \> 48 hours after admission to (or ED stay at) the hospital. * Subject has digestive tube anomalies, chronic gastrointestinal disease or uncorrected congenital abnormalities. * Subject with immunodeficiency. * Subjects who live out of the federative entity where hospital(s) are located. For Controls: • Subject has previously participated as case in this study.