Influenza surveillance and immunisation in New Zealand, 1997-2006

Abstract

Background: The national influenza surveillance in New Zealand is an essential public health component for assessing and implementing strategies to control influenza. Objective: The aim of this study is to report the national influenza surveillance data collected during 1997-2006 in terms of the community disease burden, circulating viral strains, hospitalisations, mortality, and immunisation coverage. Methods: The national influenza surveillance system includes sentinel general practice surveillance, laboratory-based surveillance, and hospital admission and mortality surveillance and immunisation coverage. The results obtained during 1997-2006 were analysed. Results: When the last 10 years were compared to the previous years, sentinel general practice surveillance recorded a decreasing trend of influenza-like illness rates in the community. Sentinel surveillance also showed that children aged 0-4 years were the most affected. Influenza-related hospitalisation surveillance reported an increasing trend of hospital admissions particularly in children aged 0-19 years. Introduction of routine influenza vaccination among the New Zealand elderly was associated with a significant decrease of influenza-related mortality. Conclusions: This report demonstrates that an integrated virological and epidemiological surveillance system for influenza is essential for monitoring the disease burden, identifying circulating strains, guiding effective vaccination and planning for a potential pandemic. © 2008 The Authors Journal Compilation © 2008 Blackwell Publishing Ltd.