Epidemiology of invasive pneumococcal disease in Southwest Sweden during the first eleven years after the introduction of general childhood pneumococcal vaccination

BACKGROUND: Invasive pneumococcal disease (IPD) still causes significant morbidity and mortality. In this study, we describe incidence, risk factors, manifestations, and outcome of IPD in Southwest Sweden during the first eleven years after the introduction of conjugate pneumococcal vaccines in the childhood vaccination program in 2009. METHODS: Clinical data from 2,288 consecutive episodes of IPD in Region Västra Götaland, Sweden during 2009-2019 were retrospectively collected from medical records. Incidence rates were calculated using population data from the same period. The results were compared to data from three previous studies from the same geographical area with a total follow-up of 56 years. RESULTS: The incidence of all IPD episodes in 2009-2019 was 12.8/100,000/year. A very high IPD incidence was seen in patients with multiple myeloma (1,497/100,000) and chronic lymphocytic leukemia (505/100,000). Meningitis occurred in 26% of the IPD episodes in children