title: Timing and number of minor infections as risk factors for childhood arterial ischemic stroke.
abstract: OBJECTIVE
  In a population-based case-control study, we examined whether the timing and number of minor infections increased risk of childhood arterial ischemic stroke (AIS).
  
  
  METHODS
  Among 102 children with AIS and 306 age-matched controls identified from a cohort of 2.5 million children in a large integrated health care plan (1993-2007), we abstracted data on all medical visits for minor infection within the 2 years prior to AIS or index date for pairwise age-matched controls. We excluded cases of AIS with severe infection (e.g., sepsis, meningitis). Using conditional logistic regression, we examined the effect of timing and total number of minor infections on stroke risk.
  
  
  RESULTS
  After adjusting for known pediatric stroke risk factors, the strongest association between infection and AIS was observed for infectious visits ≤3 days prior to stroke (odds ratio [OR] 12.1, 95% confidence interval [CI] 2.5, 57, p = 0.002). Respiratory infections represented 80% of case infections in that time period. Cases had more infectious visits, but not significantly so, for all time periods ≥4 days prior to the stroke. A greater cumulative number of infectious visits over 2 years did not increase risk of AIS.
  
  
  CONCLUSIONS
  Minor infections appear to have a strong but short-lived effect on pediatric stroke risk, while cumulative burden of infection had no effect. Proposed mechanisms for the link between minor infection and stroke in adults include an inflammatory-mediated prothrombotic state and chronic endothelial injury. The transient effect of infection in children may suggest a greater role for a prothrombotic mechanism.
authors.affiliation: From the Departments of Neurology (N.K.H., H.J.F.), Epidemiology and Biostatistics (N.K.H.), and Pediatrics (H.J.F.), University of California, San Francisco; and the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland.
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Hills
authors.affiliation: From the Departments of Neurology (N.K.H., H.J.F.), Epidemiology and Biostatistics (N.K.H.), and Pediatrics (H.J.F.), University of California, San Francisco; and the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sidney
authors.affiliation: From the Departments of Neurology (N.K.H., H.J.F.), Epidemiology and Biostatistics (N.K.H.), and Pediatrics (H.J.F.), University of California, San Francisco; and the Division of Research (S.S.), Kaiser Permanente Northern California, Oakland. FullertonH@neuropeds.ucsf.edu.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Fullerton
mesh_terms: D000293:Adolescent; D002545:Brain Ischemia / Q000150:complications* / Q000453:epidemiology; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007239:Infections / Q000150:complications* / Q000453:epidemiology; D020765:Intracranial Arterial Diseases / Q000150:complications* / Q000453:epidemiology; D008297:Male; D012141:Respiratory Tract Infections / Q000150:complications / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*; D013997:Time Factors