Study Finds Predictors of ICU Admission in Pneumococcal Bloodstream Infections

Smoking, recent substance use, and the presence of metastatic complications are significantly associated with severe disease and intensive care unit (ICU) admission in patients with pneumococcal bloodstream infections, according to new data presented at IDWeek. The data were presented on October 20, 2025, in Atlanta, Georgia.¹

What Are Pneumococcal Bloodstream Infections?

Streptococcus pneumoniae (S pneumoniae) bacteremia is a condition in which the bacteria causing pneumococcal disease enters the bloodstream. The condition can be serious, especially in individuals with weakened immune systems. Symptoms may not appear immediately, but if bacteremia progresses, it can induce chills, tachycardia, hypotension, abdominal pain, or nausea.²

Bacteremia can occur in 10% to 20% of patients with pneumococcal pneumonia and can significantly increase mortality beyond that observed in pneumonia alone. Investigators have parsed well-known correlates to this condition, especially advanced age and underlying disease. Despite targeted interventions in the form of pneumococcal vaccines being widely available to target burdensome S pneumoniae serotypes, non-vaccine serotypes can emerge and become novel causes of disease.^3,4

As such, mortality due to pneumococcal bloodstream infections remains as high as 20%. In patients with existing comorbidities—such as hematologic diseases, splenectomy, or having received an organ transplant—the risk of bacteremia, invasive infection, and poor outcomes is especially high. Patients may also exhibit resistance to commonly used antibiotics, complicating treatment and management. Oftentimes, ICU admission is required for prompt and comprehensive treatment.¹

Which Factors Influence ICU Admission in Pneumococcal Bloodstream Infections?

Although ICU admission can correlate with poor outcomes, specific predictors of severe disease remain underexplored. Therefore, the current investigators conducted a retrospective review of hospitalized adults with S pneumoniae bacteremia between 2013 and 2023. Researchers collected and examined laboratory values, clinical comorbidities, vaccination status, microbiologic data, and treatment strategies for each patient. Univariate logistic regression and descriptive statistics were utilized to assess predictors of ICU admission.¹

In total, 185 patients were included. Most patients were male (60%), with a median age of 65 years. There were immunocompromising conditions present in 60%, and only 43% were up to date with pneumococcal vaccination. In 28% of cases, metastatic infection was identified; these were often meningoencephalitis, musculoskeletal involvement, and endocarditis. Notably, ICU admission within 24 hours of presentation was required in 55% of patients.¹

A series of predictors of ICU admission were identified. Active smoking (OR: 2.20), substance use within the past 5 years (OR: 3.45), presence of metastatic foci (OR: 2.39), and neurological complications (OR: 6.10). Predictors of 30-day mortality included a history of smoking, a higher Charlson comorbidity index, hemodynamic shock at admission, and lab abnormalities, including hypoalbuminemia and elevated liver enzymes.¹

Being up to date on pneumococcal vaccination elicited a protective effect against pneumococcal bloodstream infections, according to the investigators. Thirty-day mortality was 18.9%, and 90-day mortality was 25.4%.¹

This investigation affirms the significant mortality associated with pneumococcal bloodstream infections, especially among patients admitted to the ICU. It simultaneously highlighted the immense benefits of pneumococcal vaccination in protecting against such infections. In this vein, pharmacists can play a pivotal role, using their counseling skills to encourage at-risk patients to receive a pneumococcal vaccine.¹

Pharmacists can also play a proactive role in discouraging at-risk behaviors that may put patients at a heightened risk of contracting a pneumococcal bloodstream infection and subsequently severe outcomes. Through consistent follow-up visits, risky behaviors like a lack of exercise and smoking can be curbed, while other complications that arise can be noted on a patient’s health record and monitored over the long term. With collaboration and care, pharmacists can help prevent the most severe outcomes of pneumococcal disease.¹

REFERENCES

1. Samreen A, Igwilo-Alaneme R, Ranganath N, Saleh OMA. (P-59) Clinical predictors of ICU admission in patients with invasive Pneumococcal blood stream infection: a review of 10-year single-center experience. Presented: IDWeek; October 20, 2025; Atlanta, GA. Accessed via IDWeek’s Virtual Platform on November 13, 2025.

2. Bacteremia. Cleveland Clinic. Updated July 21, 2023. Accessed November 13, 2025. https://my.clevelandclinic.org/health/diseases/25151-bacteremia

3. Cobo F, Cabezas-Fernandez MT, Cabeza-Barrera MI. Streptococcus pneumoniae bacteremia: clinical and microbiological epidemiology in a health area of Southern Spain. Infect Dis Rep. 2012;4(2):e29. doi:10.4081/idr.2012.e29

4. Maki DG. Pneumococcal bacteremia: Lessons learned, yet more to learn. Mayo Clinic Proceedings. 2004;79(5):599-603. doi:10.4065/79.5.599