Abstract Background Streptococcus pneumoniae is a leading cause of invasive bacterial infections, including bacteremia and sepsis, particularly in immunocompromised and high-risk populations. Prior studies have identified COPD, HIV, and corticosteroid exposure as risk factors while pneumococcal vaccination remains underutilized despite its proven benefits and updated recommendations for PCV15/20 and PPSV23. Admission lactate is a potential biomarker of disease severity, yet its prognostic value remains underexplored in minority communities. We proposed to describe a cohort of patients with S. pneumoniae bacteremia at a safety-net hospital in Brooklyn, New York, and evaluate the association of admission lactate with sepsis, septic shock, acute respiratory failure, and mortality. We also complete a secondary analysis examined pneumococcal vaccination and chronic pulmonary disease as protective and risk factors, respectively. Methods A retrospective cohort analysis included all adult patients with confirmed S. pneumoniae bacteremia from January 2023 to December 2024. Demographic, clinical, and laboratory data were abstracted, including lactate levels categorized as 2 mmol/L, 2-4 mmol/L, and 4 mmol/L. Associations with sepsis, septic shock, and mortality were tested using chi-square and Cochran-Armitage trend analyses. Relative risks (RR) and 95% confidence intervals (CI) were computed for vaccination, chronic lung disease, and other demographic predictors. Results Among 28 patients, with the majority between 60 and 80 years (46%), 60 years (43%), and 80 years (11%), 57% were male, 76% identified as African American, and 18% were HIV positive. COPD/Asthma was present in 25%, while 15% were vaccinated against pneumococcus. Overall mortality was 20%.A significant upward trend in mortality was observed across lactate categories (Cochran-Armitage Z = 2.74, p = 0.006), with rates of 8%, 19%, and 50% for 2, 2-4, and 4 mmol/L, respectively. Higher lactate also correlated with septic shock (p = 0.03) and prolonged hospitalization (p = 0.04). Pneumococcal vaccination was associated with a lower mortality risk (RR = 0.45, 95% CI 0.22-0.93), while chronic pulmonary disease conferred higher mortality (RR = 2.10, 95% CI 1.03-4.29). Intubation was strongly associated with mortality (RR = 3.7). No significant associations were found with HIV or IVDU status. Conclusion Admission lactate serves as a strong prognostic marker for mortality and severe disease among patients with pneumococcal bacteremia in older adult minority populations. Pneumococcal vaccination appears protective, while chronic pulmonary disease increases risk for poor outcome. These findings underscore the importance of early lactate measurement, targeted vaccination efforts specially in vulnerable populations, and proactive management of patients with chronic respiratory conditions. This abstract is funded by: none
Martinez et al. (Fri,) studied this question.