Abstract Background Streptococcus pneumoniae is a major global cause of invasive pneumococcal disease (IPD) and death. Introduction of the pneumococcal conjugate vaccine (PCV) has led to substantial declines in IPD incidence in many countries. Long-term, population-based studies on mortality trends among survivors of acute IPD are scarce. Methods Data encompassing all individuals diagnosed with IPD in Iceland from 1975 to 2020 were analyzed. Diagnosis required a positive blood or cerebrospinal fluid culture. 30-day and 5-year mortality rates were assessed across three decades (1985–2014), adjusting for multiple covariates. Additionally, age-standardized all-cause mortality rates (ASRs) were compared between IPD patients and the general population. Results The cohort included 1,463 patients of all ages. IPD incidence peaked in 1995–2004 and declined significantly thereafter (p.001). Serotype 7F was the most prevalent. No improvement in short-term mortality at 30 days was detected over time (p=.98). A modest improvement in 5-year mortality was observed, although this did not reach statistical significance (p=.076). Even when early deaths were excluded, the ASR for all-cause mortality in IPD patients was 2.6 times higher than in the general population (0.021 vs. 0.008 per person-year). Conclusion IPD incidence declined substantially over time, particularly following the introduction of the 10-valent pneumococcal conjugate vaccine in 2011, yet short-term mortality remained unchanged. A modest improvement in long-term mortality was observed, possibly reflecting advances in chronic disease management. IPD survivors face significantly elevated long-term mortality compared to the general population. Targeted interventions are needed to reduce short-term mortality associated with IPD.
Bragason et al. (2025) studied this question.