Impact of rotavirus vaccines on gastroenteritis hospitalisations in Western Australia: a time-series analysis

BackgroundRotavirus vaccination was introduced into the Australian National Immunisation Program in mid-2007. We aimed to assess the impact of the rotavirus vaccination program on the burden of hospitalisations associated with all-cause acute gastroenteritis (including rotavirus gastroenteritis and non-rotavirus gastroenteritis) in the Aboriginal and non-Aboriginal population in Western Australia.MethodsWe identified all hospital records, between July 2004 and June 2012, with a discharge diagnosis code for all-cause gastroenteritis. Age-specific hospitalisation rates for rotavirus and non-rotavirus acute gastroenteritis before and after the introduction of the rotavirus vaccination program were compared. Interrupted time series models were used to examine differences in the annual trends of all-cause gastroenteritis hospitalisation between the two periods.ResultsBetween July 2004 and June 2012, there were a total of 106,974 all-cause gastroenteritis-coded hospitalisations (1381 rotavirus-coded [15% among Aboriginal] and 105,593 non-rotavirus gastroenteritis-coded [7% among Aboriginal]). Following rotavirus vaccination introduction, significant reductions in rotavirus-coded hospitalisation rates were observed in all children aged <5 years (up to 79% among non-Aboriginal and up to 66% among Aboriginal). Among adults aged ≥65 years, rotavirus-coded hospitalisations were 89% (95% CI:16-187%) higher in the rotavirus vaccination program period. The time series analysis suggested reductions in all-cause gastroenteritis hospitalisations in the post-vaccination period among both vaccinated and unvaccinated (age-ineligible) children, with increases observed in adults aged ≥45 years.ConclusionsRotavirus vaccination has been associated with a significant decline in gastroenteritis hospitalisations among children. The increase in the elderly requires further evaluation, including assessment of the cost-benefits of rotavirus vaccination in this population.