title: An association between sub-arachnoid haemorrhage and influenza A infection.
abstract: The sera of 25 patients with confirmed sub-arachnoid haemorrhage were assayed by complement fixation for 14 viruses. Twenty (80%) showed elevated titres to influenza A virus compared with 3 out of 25 (12%) of control subjects matched for age, sex and district and 3 out of 17 (17%) of a group of patients with other neurological disorders. A seasonal variation in the notification of sub-arachnoid haemorrhage appeared to be related to changes in the incidence of influenza A infection.
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D003168:Complement Fixation Tests; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D009980:Influenza A virus / Q000276:immunology; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D014852:Wales
chemical_list: D000914:Antibodies, Viral