Infants hospitalised with pertussis: estimating the true disease burden

Aim: New Zealand (NZ) has a large pertussis disease burden compared with other developed countries. Accurate ascertainment of disease burden is fundamental to controlling pertussis and informing immunisation policy. Disease burden estimates are primarily from passive surveillance, which underestimates disease incidence. The aim of this study is to use active surveillance to determine pertussis disease burden in infants hospitalised in NZ. Methods: Using the NZ Paediatric Surveillance Unit, active surveillance from 08/2004 to 07/2005 for infants