title: Guillain-Barre syndrome, influenzalike illnesses, and influenza vaccination during seasons with and without circulating A/H1N1 viruses.
abstract: The role of influenzalike illnesses and influenza vaccination in the development of Guillain-Barré syndrome (GBS), particularly the role of A/H1N1 epidemics and A/H1N1 vaccination, is debated. Data on all incident GBS cases meeting the Brighton Collaboration criteria that were diagnosed at 25 neurology centers in France were prospectively collected between March 2007 and June 2010, covering 3 influenzavirus seasons, including the 2009-2010 A/H1N1 outbreak. A total of 457 general practitioners provided a registry of patients from which 1,080 controls were matched by age, gender, index date (calendar month), and region to 145 cases. Causal relations were assessed by multivariate case-control analysis with adjustment for risk factors (personal and family history of autoimmune disorders, among others), while matching on age, gender, and calendar time. Influenza (seasonal or A/H1N1) or influenzalike symptoms in the 2 months preceding the index date was associated with GBS, with a matched odds ratio of 2.3 (95% confidence interval (CI): 0.7, 8.2). The difference in the rates of GBS occurring between influenza virus circulation periods and noncirculation periods was highly statistically significant (P = 0.004). Adjusted odds ratios for GBS occurrence within 6 weeks after seasonal and A/H1N1 vaccination were 1.3 (95% CI: 0.4, 4.1) and 0.9 (95% CI: 0.1, 7.6), respectively. Study results confirm that influenza virus is a likely risk factor for GBS. Conversely, no new concerns have arisen regarding influenza vaccination.
authors.affiliation: LA-SER, Paris, France. lgrimaldi@pgrx.net
authors.forename: Lamiae
authors.initials: L
authors.lastname: Grimaldi-Bensouda
authors.forename: Annick
authors.initials: A
authors.lastname: Alpérovitch
authors.forename: Gérard
authors.initials: G
authors.lastname: Besson
authors.forename: Christophe
authors.initials: C
authors.lastname: Vial
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Cuisset
authors.forename: Caroline
authors.initials: C
authors.lastname: Papeix
authors.forename: Olivier
authors.initials: O
authors.lastname: Lyon-Caen
authors.forename: Jacques
authors.initials: J
authors.lastname: Benichou
authors.forename: Michel
authors.initials: M
authors.lastname: Rossignol
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D004196:Disease Outbreaks / Q000706:statistics & numerical data; D005260:Female; D005602:France / Q000453:epidemiology; D020275:Guillain-Barre Syndrome / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines / Q000009:adverse effects / Q000627:therapeutic use*; D007251:Influenza, Human / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines