This study aims to monitor the incidence rates and duration of hospitalisations for rotavirus gastroenteritis (RV GE) and all cause GE, compared to bronchiolitis from 1998 to 2009, in children < 5 years of age after the introduction of Rotarix in 2006 by year, both inside and outside rotavirus season in Australia. It further aims to compare the two dose regimen of Rotarix with the three dose regimen of RotaTeq from 2007 to 2009.

Inclusion Criteria:

• Children <5 years of age;
• Children with a diagnosis of all-cause gastroenteritis, rotavirus gastroenteritis or bronchiolitis in the Australian Institute of Health and Welfare (AIHW) database in New South Wales, Australian Capital Territory, Tasmania and Northern Territory, from 1998 to 2009;
• Children who were vaccinated with Rotarix or RotaTeq in New South Wales and Queensland, registered in the Australian Childhood Immunisation Register (ACIR) database in Queensland and New South Wales, from 2007 to 2009.

Exclusion Criteria:

No exclusion criteria will be applied.

Australian children aged < 5 years who have been vaccinated with RotaTeq (in Queensland) and Rotarix (in New South Wales) from 2007 to 2009 as well as all children aged < 5 years hospitalised for all-cause gastroenteritis, rotavirus gastroenteritis or bronchiolitis, before and after introduction of Rotarix vaccination in New South Wales, Australian Capital Territory, Tasmania and Northern Territory, from 1998 to 2009.