Can leptospirosis cause stroke in patients with underlying medical conditions, such as hypertension, diabetes, or cardiovascular disease?

Can Leptospirosis Cause Stroke?

Yes, leptospirosis can cause stroke, particularly hemorrhagic stroke, with the highest risk occurring in younger patients (ages 18-39) and within the first 2 years after infection. 1

Evidence for Leptospirosis-Associated Stroke

Hemorrhagic Stroke Risk

• A nationwide population-based cohort study of 3,699 patients with newly diagnosed leptospirosis demonstrated a 58% increased risk of hemorrhagic stroke (adjusted HR 1.58,95% CI 1.12-2.23) compared to matched controls 1

• The risk was particularly elevated in specific subgroups:

  • Young adults (18-39 years): 3.67-fold increased risk of hemorrhagic stroke (95% CI 1.33-10.14) 1
  • Males: 1.62-fold increased risk (95% CI 1.08-2.44) 1
  • First 2 years post-diagnosis: 1.97-fold increased risk (95% CI 1.15-3.38) 1

• Among patients younger than 39 years, leptospirosis conferred a 2.49-fold overall stroke risk, with age acting as an effect modifier 1

Ischemic Stroke Risk

• The same cohort study found no statistically significant increase in ischemic stroke risk (adjusted HR 1.01,95% CI 0.80-1.29) 1

• However, case reports document cerebral infarction from leptospirosis-induced cerebral arteritis, though this remains rare 2

Mechanisms of Stroke in Leptospirosis

Direct Vascular Injury

• Leptospira can directly invade cerebral arteries, causing inflammation, endothelial activation, and thrombosis—mechanisms similar to other infectious vasculitides like varicella zoster virus 3

• Cerebral arteritis induced by leptospirosis has been documented, leading to arterial occlusion and infarction 2

Systemic Complications

• Severe leptospirosis causes multi-organ dysfunction with dysregulated immune responses triggering cytokine storms and immunoparesis, which may contribute to vascular injury 4

• The disease can cause hemorrhagic complications through multiple mechanisms, including coagulopathy and direct vascular damage 5

Clinical Implications for Patients with Underlying Conditions

Risk Stratification

• Patients with hypertension, diabetes, or cardiovascular disease who develop leptospirosis face compounded stroke risk from both their baseline vascular disease and the acute infection 1

• The presence of hypotension, oliguria, and abnormal chest auscultation at initial presentation are key risk factors for severe outcomes in leptospirosis 6

Management Approach

• Early antibiotic therapy is critical: Leptospira are susceptible to benzyl penicillin, doxycycline, cephalosporins, and macrolides when used in the early phase of infection 4

• Prompt antibiotic treatment significantly reduces embolic complications in infectious vasculitis, a principle that applies to leptospirosis-associated cerebral involvement 3

• Patients presenting with neurologic symptoms during leptospirosis should undergo urgent neuroimaging (non-contrast CT initially to exclude hemorrhage, followed by MRI for better detection of infarcts) 7

Important Clinical Caveats

• Hemorrhagic stroke predominates over ischemic stroke in leptospirosis, contrasting with most other infectious causes of stroke 1

• The risk is time-dependent and highest in younger patients, requiring heightened vigilance in this demographic during and after acute leptospirosis 1

• Severe leptospirosis can progress rapidly to multi-organ failure and death within days despite intensive support, making early recognition and treatment essential 2, 4

• Atypical manifestations of leptospirosis, including neurologic complications, can be easily missed by clinicians unfamiliar with the disease 5

• The fatality rate for severe leptospirosis exceeds 50% even with ICU support, underscoring the importance of early diagnosis and aggressive management 2