title: Causal analysis of H1N1pdm09 influenza infection risk in a household cohort.
abstract: BACKGROUND
  Obtaining a comprehensive quantitative figure of the determinants of influenza infection will help identify priority targets for future influenza mitigation interventions. We developed an original causal model integrating highly diverse factors and their dependencies, to identify the most critical determinants of pandemic influenza infection (H1N1pdm09) during the 2010-2011 influenza season.
  
  
  METHODS
  We used data from 601 households (1450 participants) included in a dedicated cohort. Structural equations were used to model direct and indirect relationships between infection and risk perception, compliance with preventive behaviours, social contacts, indoor and outdoor environment, sociodemographic factors and pre-epidemic host susceptibility. Standardised estimates (βstd) were used to assess the strength of associations (ranging from -1 for a completely negative association to 1 for a completely positive association).
  
  
  RESULTS
  Host susceptibility to H1N1pdm09 and compliance with preventive behaviours were the only two factors directly associated with the infection risk (βstd=0.31 and βstd=-0.21). Compliance with preventive behaviours was influenced by risk perception and preventive measures perception (βstd=0.14 and βstd=0.27). The number and duration of social contacts were not associated with H1N1pdm09 infection.
  
  
  CONCLUSIONS
  Our findings suggest that influenza vaccination in addition to public health communication campaigns focusing on personal preventive measures should be prioritised as potentially efficient interventions to mitigate influenza epidemics.
authors.affiliation: INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, Paris, France.
authors.forename: Yohann
authors.initials: Y
authors.lastname: Mansiaux
authors.affiliation: IRD French Institute of Research for Development, EHESP French School of Public Health, UMR_D 190 "Emergence des Pathologies Virales", Aix Marseille Univ, Marseille, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Salez
authors.affiliation: INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, Paris, France Public Health Unit, Saint-Antoine Hospital, Paris, France.
authors.forename: Nathanael
authors.initials: N
authors.lastname: Lapidus
authors.affiliation: IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", CNRS-Aix Marseille Université, Marseille, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Setbon
authors.affiliation: Laboratoire de Virologie médicale et moléculaire Hôpital Robert Debré, CHU Reims, Reims, France Faculté de Médecine, EA 4684, Reims, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Andreoletti
authors.affiliation: Laboratory of Virology, Hospital Necker-.Enfants-malades, Assistance Publique-Hôpitaux de Paris APHP-University Paris Descartes, Sorbonne Paris Cité, Paris, France.
authors.forename: Marianne
authors.initials: M
authors.lastname: Leruez-Ville
authors.affiliation: Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Cauchemez
authors.affiliation: Antiviral Immunity, Biotherapy and Vaccine Unit, Institut Pasteur, Paris, France.
authors.forename: Marie-Lise
authors.initials: ML
authors.lastname: Gougeon
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, INSERM, U1104, Marseille, France CNRS, UMR7280, Marseille, France Aix Marseille Université, UM2, Marseille, France Service d'Immunologie, Assistance Publique-Hôpitaux de Marseille, Hôpital de la Conception, Marseille, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Vély
authors.affiliation: IAME, UMR 1137, INSERM, Paris, France IAME, UMR 1137, Sorbonne Paris Cité, Univ Paris Diderot, Paris, France Translational Health Economics Network, Paris, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Schwarzinger
authors.affiliation: Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale U1163, Paris, France Imagine Institute, Paris Descartes University, Sorbonne Paris Cité, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Abel
authors.affiliation: INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, Paris, France.
authors.forename: Rosemary Markovic
authors.initials: RM
authors.lastname: Delabre
authors.affiliation: Centre Virchow-Villermé, Descartes, Université Sorbonne Paris Cité, Paris, France Global Health Institute, University of Geneva, Geneva, Switzerland.
authors.forename: Antoine
authors.initials: A
authors.lastname: Flahault
authors.affiliation: IRD French Institute of Research for Development, EHESP French School of Public Health, UMR_D 190 "Emergence des Pathologies Virales", Aix Marseille Univ, Marseille, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: de Lamballerie
authors.affiliation: INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France UPMC Univ Paris 06, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Universités, Paris, France Public Health Unit, Saint-Antoine Hospital, Paris, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Carrat
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004198:Disease Susceptibility; D004777:Environment; D005191:Family Characteristics; D005260:Female; D005602:France / Q000453:epidemiology; D015438:Health Behavior; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission / Q000821:virology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D058873:Pandemics / Q000517:prevention & control; D012111:Residence Characteristics; D012307:Risk Factors; D012923:Social Class; D012931:Social Environment; D055815:Young Adult
keywords: BIOSTATISTICS; EPIDEMIOLOGY; INFLUENZA