National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases University of Sydney, Westmead

Although invasive pneumococcal disease (IPD) accounts for only a minority of the infections caused by Streptococcus pneumoniae (such as pneumonia and otitis media), it is associated with the most severe disease and is readily measured, as it is by definition associated with a sterile site isolate. The Metropolitan NSW Pneumococcal Study Group was formed in 1997 to generate data describing the age-specific incidence, serotype distribution and antimicrobial resistance patterns of invasive pneumococcal disease in a large population that is believed to be representative of urban Australia. Results from the first two years of active surveillance for invasive pneumococcal disease in metropolitan NSW have been previously reported. This article presents data from a 4.5-year period, with a greater focus on differences between the regions covered by the area health services within metropolitan NSW. These data provide an expanded picture of the profile of IPD in a representative Australian urban region—the metropolitan area health services within Sydney, the Hunter and the Illawarra.