The Prevalence, Predictors, and In-Hospital Outcomes of Stroke-Associated Infection in Acute Ischemic Stroke: A Malaysian Prospective Cohort Study

Background: Stroke-associated infection (SAI) is a common complication of acute ischemic stroke and is associated with adverse clinical outcomes. Contemporary prospective data from Southeast Asia remain limited. The primary objective was to determine the prevalence of SAI in patients with acute ischemic stroke. Secondary objectives were to identify associated clinical predictors and evaluate its relationship with in-hospital outcomes. Methods: This prospective observational cohort study included 390 adults with acute ischemic stroke admitted to a tertiary center between August 2024 and November 2025. SAI was defined as clinically diagnosed infection occurring within seven days of stroke onset using standardized criteria. Demographic, clinical, and treatment variables were collected. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). Functional outcome at discharge was evaluated using the modified Rankin Scale (mRS). Multivariable logistic regression was performed to identify independent predictors of SAI. Results: SAI occurred in 75 patients, giving a prevalence of 19.2% (95% CI 15.3–23.1). Pneumonia was the predominant subtype (14.4%). On multivariable analysis, higher NIHSS score (adjusted OR 1.10 per point; 95% CI 1.05–1.14; p < 0.001) and mechanical thrombectomy (adjusted OR 3.02; 95% CI 1.11–8.26; p = 0.031) were independently associated with SAI. Patients with SAI had longer hospital stays (median 8 vs. 4 days, p < 0.001), poorer functional outcomes (81.3% vs. 24.8% with mRS 3–6, p < 0.001), and higher in-hospital mortality (17.3% vs. 1.0%, p < 0.001). Conclusions: Stroke-associated infection affected approximately one-fifth of patients with acute ischemic stroke and was strongly associated with stroke severity and adverse clinical outcomes. These findings support early risk stratification and targeted preventive strategies in acute stroke care.