Paediatric active enhanced disease surveillance: a new surveillance system for Australia.

AIM: The Paediatric Active Enhanced Disease Surveillance (PAEDS) is described. PAEDS is active in four tertiary children's hospitals in four states of Australia and aims to address gaps in surveillance for severe vaccine-preventable diseases and adverse events following immunisation.
METHODS: From August 2007 to December 2010, surveillance nurses actively identified and recruited children admitted with: acute flaccid paralysis, varicella infection, intussusception, seizures in infants and pandemic influenza (June-October 2009). Details of presentation, medical and immunisation history, outcome and laboratory results were collected. Completeness of ascertainment was estimated through audits of International Classification of Diseases 10th edition-coded medical records where possible.
RESULTS: Seven hundred thirty-three cases matching case definition criteria for the four conditions were recruited. In addition, 601 cases of influenza were recruited during the 2009 pandemic. PAEDS enhanced acute flaccid paralysis surveillance by the Australian Paediatric Surveillance Unit; the World Health Organization surveillance target was met when Australian Paediatric Surveillance Unit and PAEDS cases were combined. Among 133 children hospitalised for varicella, only 16 were vaccinated; samples of vesicle scrapings were collected in 57% for genotyping. Of 122 infants presenting with seizures, only six (12%) had received a vaccine in the last 7 days. Intussusception was more frequent among infants receiving their first dose of either of the rotavirus vaccines. Results informed policy and education for parents and health professionals. Preliminary audits of medical records suggest excellent ascertainment through PAEDS.
CONCLUSIONS: PAEDS provides important, previously unavailable data to inform public health policy, clinical practice and community confidence. It has potential to respond quickly during outbreaks and epidemics.