Infectious Causes of Stroke

Dinesh V. Jillella; Dolora R. Wisco


Curr Opin Infect Dis. 2019;32(3):285-292. 

In This Article

Abstract and Introduction


Purpose of review: Stroke continues to be a leading cause of debility in the world. Infections have been associated with stroke, but are not considered as directly causal, and so they are not often included in the traditional stroke workup and management. They are especially important in patients with stroke of undetermined etiology, and in certain patient populations, such as young patients without traditional risk factors and immunocompromised patients.

Recent findings: There has been strong evidence for infectious conditions, such as endocarditis, and pathogens, such as varicella zoster in stroke causation, and more supportive evidence is surfacing in recent years of several organisms increasing the stroke risk or being directly causal in stroke. The evidence also seems to be pointing to the role of inflammation in increasing the risk of stroke via accelerated atherosclerosis, vasculitis and vasculopathy.

Summary: Infectious causes should be considered in the differential and work up of stroke in certain patient populations and appropriate treatments need to be initiated to minimize adverse stroke-related outcomes.


Stroke is one of the leading causes of all-cause mortality and morbidity in the United States and worldwide. Although improved vascular risk factor management, stroke systems of care, and expansion of acute treatment time windows helped to downgrade stroke from number three cause of mortality to five, it is still a leading cause of significant morbidity in the United States.[1]

Association of stroke with infectious entities like infectious endocarditis (IE) has been well described,[2] but direct infectious causes outside the realm of IE continues to be an area of debate. This becomes more relevant in strokes deemed as cryptogenic or of undetermined cause, which constitute about a third of all strokes.[3] A significant proportion of recent strokes are also being reported from low-income to middle-income countries, where infectious causes might play an important role in the causation.[4]