OBJECTIVE: To examine the epidemiology of invasive pneumococcal disease (IPD) in Western Australia (WA), and thereby to assess whether current Australian recommendations on vaccination are suitable for WA and whether vaccines cover the local IPD-causing serotypes. DESIGN AND SETTING: Prospective laboratory surveillance, with data gathered on all people in WA who had Streptococcus pneumoniae (pneumococcus) isolated from a normally sterile body site, 1 April 1996 to 1 April 1997. MAIN OUTCOME MEASURES: IPD incidence and mortality rates, risk factors, clinical presentation and disease-causing serotypes. RESULTS: IPD incidence and mortality were higher in the Indigenous than non-Indigenous population (relative risk [RR] for incidence, 11.9; 95% CI, 6.8-14.9, P < 0.001; RR for mortality, 22.7; 95% CI, 7.2-71.3, P < 0.001), but the case-fatality rate did not differ significantly. Incidence increased significantly from the ages of 25 years in Indigenous people and 60 years in non-Indigenous people. Most disease-causing isolates from adults (94% from non-Indigenous and 86% from Indigenous adults) belonged to serotypes included in the current 23-valent vaccine. Thirty-one isolates (92%) from non-Indigenous children (aged < 15 years) belonged to serotypes included in the new seven-valent conjugate vaccine, compared with only five (50%) from Indigenous children (chi 2 = 9.7; P < 0.001). CONCLUSIONS: Current Australian vaccination recommendations do not appear to match IPD epidemiology in WA; consideration should be given to lowering the age criterion for vaccination to 25 years for Indigenous and 60 years for non-Indigenous people. The new seven-valent conjugate vaccine may not adequately cover disease-causing serotypes in Indigenous children.
OBJECTIVE: To examine the epidemiology of invasive pneumococcal disease (IPD) in Western Australia (WA), and thereby to assess whether current Australian recommendations on vaccination are suitable for WA and whether vaccines cover the local IPD-causing serotypes. DESIGN AND SETTING: Prospective laboratory surveillance, with data gathered on all people in WA who had Streptococcus pneumoniae (pneumococcus) isolated from a normally sterile body site, 1 April 1996 to 1 April 1997. MAIN OUTCOME MEASURES: IPD incidence and mortality rates, risk factors, clinical presentation and disease-causing serotypes. RESULTS: IPD incidence and mortality were higher in the Indigenous than non-Indigenous population (relative risk [RR] for incidence, 11.9; 95% CI, 6.8-14.9, P < 0.001; RR for mortality, 22.7; 95% CI, 7.2-71.3, P < 0.001), but the case-fatality rate did not differ significantly. Incidence increased significantly from the ages of 25 years in Indigenous people and 60 years in non-Indigenous people. Most disease-causing isolates from adults (94% from non-Indigenous and 86% from Indigenous adults) belonged to serotypes included in the current 23-valent vaccine. Thirty-one isolates (92%) from non-Indigenous children (aged < 15 years) belonged to serotypes included in the new seven-valent conjugate vaccine, compared with only five (50%) from Indigenous children (chi 2 = 9.7; P < 0.001). CONCLUSIONS: Current Australian vaccination recommendations do not appear to match IPD epidemiology in WA; consideration should be given to lowering the age criterion for vaccination to 25 years for Indigenous and 60 years for non-Indigenous people. The new seven-valent conjugate vaccine may not adequately cover disease-causing serotypes in Indigenous children.