Journal Article

An outbreak of serotype-1 sequence type 306 invasive pneumococcal disease in an Australian Indigenous population

Abstract:
Between 2010 and 2013, an outbreak of serotype-1 sequence type 306 (ST306) invasive pneumococcal disease (IPD) occurred primarily in remote locations of Northern and Central Australia. This is a descriptive study of the epidemiology of the outbreak using nationwide IPD surveillance data, sup-plemented with more detailed data held by affected jurisdictions, and of the response to the outbreak, including vaccination strategies. In the year the outbreak peaked (2011), serotype-1 IPD incidence was over 30-fold higher in the affected regions than in the rest of Australia (incidence rate ratio: 30.7 [95% CI 20.1–48.9]). The study includes 245 cases of serotype-1 IPD from the outbreak regions, with 75.5% identified as Indigenous.No reported cases of serotype-1 IPD occurred in young children who had completed either a 10- or 13-valent pneumococcal conjugate vaccine schedule. However serotype-1 IPD did occur in older chil-dren who had previously received 23-valent pneumococcal polysaccharide vaccine.Development of public-health-focused national IPD management guidelines, including suitable vac-cine strategies for consistent use nationwide, could potentially decrease the duration and intensity of similar outbreaks in the future.