Stroke-Associated Infections and Complications

Infections following stroke represent a major contributor to poor outcomes, prolonged hospital stays and increased mortality. Stroke-induced immunodepression, characterised by a transient suppression of cellular immunity, combines with factors such as dysphagia, impaired consciousness and the need for invasive devices to heighten susceptibility. The most frequent complications are pneumonia and urinary tract infections, each affecting around one in ten patients, and both linked to reduced functional recovery and higher early mortality. Aspiration due to impaired swallowing and reduced cough reflex underpins much of the pneumonia burden, while catheterisation, immobility and age predispose to urinary infections. Fever, sepsis and systemic inflammatory responses further worsen neurological injury and compromise rehabilitation. Prevention and early detection are therefore pivotal. Strategies range from strict swallowing assessments, oral hygiene and cautious use of feeding tubes to immunomodulatory approaches and biomarker-guided surveillance. Despite multiple candidate interventions, durable reductions in infection rates and improvements in long-term functional status remain elusive, underscoring the need for precision in risk stratification and personalised prophylaxis. Globally, the burden of post-stroke infections emphasises the importance of integrated stroke care pathways that combine neurology, critical care, infectious diseases and allied health professions to mitigate these common and preventable complications.

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Stroke-Associated Infections and Complications publication trend

The graph below shows the total number of articles in stroke-associated infections and complications across all publications each year (not limited to Nature Index journals).

Technical terms

Stroke-associated pneumonia (SAP): Pneumonia developing within the first week after stroke, often linked to aspiration and immune suppression.

Dysphagia: Difficulty or discomfort in swallowing, common after stroke and a key risk factor for aspiration pneumonia.

National Institutes of Health Stroke Scale (NIHSS): A clinical tool to quantify neurological deficit after stroke, used to stratify severity and predict complications.

Modified Rankin Scale (mRS): An ordinal scale measuring the degree of disability or dependence in daily activities following stroke, used to assess functional outcome.

Neutrophil-to-lymphocyte ratio (NLR): A biomarker derived from routine blood counts that reflects systemic inflammation and correlates with infection risk.

Biomarker: A measurable indicator of a biological state or condition, used for risk stratification, diagnosis or monitoring of disease processes.

References

1. Prevention of infections and fever to improve outcome in older patients with acute stroke (PRECIOUS): a randomised, open, phase III, multifactorial, clinical trial with blinded outcome assessment. The Lancet Regional Health - Europe (2023).
2. Does stroke-associated pneumonia play an important role on risk of in-hospital mortality associated with severe stroke? A four-way decomposition analysis of a national cohort of stroke patients. International Journal of Stroke (2023).
3. The clinical value of neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR) and systemic inflammation response index (SIRI) for predicting the occurrence and severity of pneumonia in patients with intracerebral hemorrhage. Frontiers in Immunology (2023).