ORIGINAL ARTICLE Decline in rotavirus hospitalisations following introduction of Australia’s national rotavirus immunisation programme Kristine K Macartney, 1,2,4 Mamta Porwal, 1 Dianne Dalton, 2 Terri Cripps, 3 Trish Maldigri, 2 David Isaacs 2,4 and Alison Kesson 2,4 1 National Centre for Immunisation Research and Surveillance, 2 Department of Infectious Diseases and Microbiology, The Children’s Hospital at Westmead, Westmead, 3 The Sydney Children’s Hospital, Randwick and 4 Discipline of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales, Australia Aim: To determine the impact of rotavirus immunisation on rotavirus hospitalisations in young children. Methods: Annual hospitalisations for rotavirus gastroenteritis to The Children’s Hospital at Westmead, a tertiary care paediatric hospital in Sydney, were recorded from 2001 for 6 years prior to and 2.5 years following the introduction of rotavirus vaccines to the National Immunisation Program. Data on hospital-acquired rotavirus gastroenteritis were collected prospectively. Results: Hospitalisations for rotavirus gastroenteritis declined in the two full rotavirus seasons (2008 and 2009) after vaccine introduction by 75% compared with mean annual hospitalisations from 2001 to 2006. The greatest decline was seen in those <12 months of age (93%), but the reduction occurred consistently across all age groups, even in children not eligible for immunisation, suggesting an effect on herd immunity. A substantial decline in nosocomial rotavirus gastroenteritis was seen from 2007 to 2009, suggesting a reduction in virus transmission in the hospital setting. Conclusion: This study demonstrates a substantial reduction in hospitalisations in children of all ages to a large paediatric hospital and reduced nosocomial infections since the introduction of a nationally funded rotavirus immunisation programme in Australia. Key words: gastro-enteritis; hospitalisation; immunisation; rotavirus; vaccine. Rotavirus is the most common cause of acute severe gastroen- teritis in young children. World-wide, nearly every child is infected with rotavirus by the age of 5 years, with approxi- mately 500 000 deaths occurring in this age group annually, predominantly in developing countries. 1 In Australia, prior to the introduction of rotavirus vaccines, rotavirus gastroenter- itis caused approximately 10 000 hospitalisations, 22 000 emergency department visits and 115 000 visits to general practitioners of children <5 years of age. 2 There was approxi- mately one rotavirus-related death each year. 3 The peak age of hospitalisation from rotavirus is 6–24 months, with an earlier age at hospitalisation in indigenous children. 3–5 In temperate parts of Australia, the disease occurs predominantly in winter and early spring, placing strain on paediatric hospital services. 2,6,7 The annual cost of emergency department and general prac- titioner visits, and hospitalisations for young children in Aus- tralia was estimated to be A$30 million, 2 and rotavirus vaccination was predicted to be cost-effective from both a soci- etal and health-care perspective. 8 Two oral live attenuated rotavirus vaccines were registered for use in Australia in 2006 and were added to the National Immunisation Program from 1 July 2007. Immunisation of infants in the Northern Territory Correspondence: A/Professor Kristine Macartney, National Centre for Immunisation Research and Surveillance (NCIRS), The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia. Fax: +02 9845 1418; email: kristinm@chw.edu.au Accepted for publication 30 May 2010. What Is already known on this topic 1 Rotavirus is the most common cause of severe gastroenteritis in young children. 2 Rotavirus vaccines provided 85–100% protection against severe disease in pre-licensure clinical studies. 3 Preliminary data suggests a decline in notifications and hospi- talisations of rotavirus in Queensland following introduction of rotavirus vaccines onto the Australian National Immunisation Program. What this paper adds 1 This study demonstrates a decline in hospitalisations for rotavi- rus gastroenteritis over 2.5 years following introduction of the vaccines on the National Immunisation Program. 2 A decline in rotavirus hospitalisations across all paediatric age groups, suggesting a herd immunity effect. 3 A decline in nosocomial infections because of rotavirus not demonstrated in recently published post-licensure studies from the USA. doi:10.1111/j.1440-1754.2010.01953.x Journal of Paediatrics and Child Health 47 (2011) 266–270 © 2011 The Authors Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians) 266