Changing epidemiology of invasive pneumococcal disease in central Australia prior to conjugate vaccine: A 16-year study

This study reports a 16-year prospective surveillance of invasive disease isolates in central Australian Aborigines. There were 621 (89.6% of total) isolates recovered from Aborigines. The mortality in children less than 5 years of age was 4% but rose to 34.5% in those over 49 years of age. The study documented continuing high rates of disease overall, but with significant reductions in incidence rates for children. In children under 2 years of age, the incidence fell by 32% from 2053 per 100,000 in the period 1985–1990 to 1184 per 100,000 in the period 1996–2000. Rates of disease in adults showed no reduction despite an adult immunisation programme with 23 valent vaccine which occurred in the 1990s. Epidemics of serotypes 1, 5 and 12F were documented during the study period.