Rotavirus Disease and Genotype Diversity in Older Children and Adults in Australia.

BACKGROUND: Rotavirus is a major cause of gastroenteritis in children†<5 years of age. The disease burden in older children, adults, and the elderly is underappreciated. This study describes rotavirus disease and genotypic diversity in the Australian population comprising children†≥5 years of age and adults. METHODS: Rotavirus positive fecal samples were collected from laboratories Australia-wide participating in the Australian Rotavirus Surveillance Program between 2010 and 2018. Rotavirus samples were genotyped using a heminested multiplex reverse-transcription polymerase chain reaction. Notification data from the National Notifiable Diseases Surveillance System were also analyzed. RESULTS: Rotavirus disease was highest in children aged 5-9 years and adults†≥85 years. G2P[4] was the dominant genotype in the population†≥5 years of age. Genotype distribution fluctuated annually and genotypic diversity varied among different age groups. Geographical differences in genotype distribution were observed based on the rotavirus vaccine administered to infants†<1 year of age. CONCLUSIONS: This study revealed a substantial burden of rotavirus disease in the population†≥5 years of age, particularly in children 5-9 years and the elderly. This study highlights the continued need for rotavirus surveillance across the population, despite the implementation of efficacious vaccines.