There is increasing evidence that, in addition to conventional risk factors, 
acute and chronic infectious diseases increase the risk of stroke. Acute 
infection, mainly respiratory, and both bacterial and viral infection, represent 
temporarily active trigger factors for cerebral ischemia. Chronic infectious 
diseases that may increase the risk of stroke include periodontitis, chronic 
bronchitis and infections with microbial antigens, such as Helicobacter pylori 
and Chlamydia pneumoniae. From observational studies, there is evidence that 
vaccination against influenza is associated with a reduced risk of stroke, 
myocardial infarction and all-cause mortality. This report provides an overview 
on the influence of infection on stroke risk and potential anti-infective 
strategies that may play a future role in stroke prevention.