Rotavirus epidemiology in Queensland during the pre-vaccine era.

Rotavirus, the most common cause of severe gastroenteritis in early childhood, is now a vaccine preventable disease with immunisation added to the Australian publicly funded schedule in July 2007. To better understand rotavirus epidemiology in Queensland prior to vaccine introduction, we used 3 routinely-collected data sources. We analysed hospital records of all children less than 5 years of age admitted to Queensland hospitals between July 2001 and June 2006 with any rotavirus-specific code or with an acute gastroenteritis (AGE) code in the principal field. We linked a sample of public hospital admission records to laboratory test requests to determine the extent of diagnostic testing for causes of AGE. Finally, we analysed rotavirus notifications for the same age group between December 2005 and December 2006. Hospitalisation and notification data both identified Indigenous children as having a higher burden of rotavirus illness than non-Indigenous children. Hospitalisations occurred disproportionately in Indigenous children, at a younger age, and resulted in a longer duration of stay. AGE hospitalisations occurred more commonly than rotavirus admissions, but the seasonal trend mirrored rotavirus data. Linking a sample of hospitalisations with laboratory testing data showed that, for admissions having a rotavirus-specific discharge code, 89% had laboratory-confirmed rotavirus infection. In the pre-vaccine era, rotavirus had the greatest impact in the young and Indigenous. Using routinely collected data, it should be possible to monitor the impact of vaccine introduction in Queensland.