This study aims to estimate the effectiveness of Rotarix™ vaccine which is used nationwide as a part of the expanded program on immunization (EPI), in preventing RV SGE among hospitalised children born after 1 March 2006, which corresponds to the date of introduction of Rotarix™ in the national immunization program.

Inclusion Criteria for enrolled subjects and cases :

• A male or female child born after 1 March 2006 (which corresponds to the date of introduction of Rotarix™ in the EPI) and at least 12 weeks of age.
• Subject admitted to the study hospital for SGE (refer to the glossary) during the study period.
• Onset of SGE ≤ 14 days prior to admission.
• Laboratory confirmed (i.e. by ELISA at the hospital laboratory) RV positive stool sample at hospital admission or during the first 48 hours of hospitalisation. Note: This criterion is applicable only for cases.
• Written informed consent obtained from the parent or guardian of the subject.

Inclusion criteria for controls:

• Admitted for non-GE causes at the same hospital as the case. Note: This criterion is applicable to hospital controls only.
• Living in the same neighbourhood as the case for at least three consecutive months. Note: This criterion is applicable to neighbourhood controls only.
• At least 12 weeks of age and being born within ± 2 weeks from the date of birth of the case. If the list of children born within ± 2 weeks is exhausted, then the range would be extended to ± 4 weeks.
• Written informed consent obtained from the parent or guardian of the child.

Exclusion Criteria for enrolled subjects and cases:

• Subject has previously participated as case or control in this study.
• Hospitalisation is unrelated to GE.
• Onset of SGE > 48 hours after admission to the hospital (nosocomial infections).

Exclusion criteria for controls:

• For hospital controls: Child who has symptoms of GE during current hospitalisation or on the day of interview of his/her parent or guardian.

OR

• For neighbourhood controls: Child who has symptoms of GE on the day of interview of his/her parent or guardian.
• Exclude children with the following vaccine preventable diseases: measles, mumps, rubella, diphtheria, pertussis, tetanus, tuberculosis, invasive Haemophilus Influenzae Type B (Hib) infections (meningitis, bacteraemia, septic arthritis, cellulitis, and epiglottitis) and hepatitis B.
• Child has participated in the past as a case or control in this study.
• Child living in the same house as the case. Note: This criterion is applicable to neighbourhood controls only