title: Influenza-attributable deaths in south-eastern France (1999 to 2010): mortality predictions were undependable.
abstract: BACKGROUND
  Following the 2009 influenza pandemic, several studies showed that the mortality pattern associated with the A(H1N1)2009 virus primarily affected children and young adults. In this study, we aimed to estimate the influenza-attributable deaths during the periods from 1999 to 2010, in the Provence-Alpes-Côte-d'Azur (PACA) region of south-eastern France in order to corroborate the hypothesis that (i) influenza-attributable deaths caused by A(H1N1)2009 strain were much lower than initially expected.
  
  
  METHODS
  In order to compare our results with published data, we used the same statistical model of an Austrian team, using a Poisson model adjusted on co-circulating respiratory syncytial virus to explain the weekly mortality.
  
  
  RESULTS
  We assessed that 5.7% of the respiratory deaths were attributable to influenza virus during the 2009-2010 pandemic season. This mortality was lower than that observed during the ten preceding epidemic periods (13.8% on average). Age group-based analysis revealed that during the pandemic period, the groups under 65 had a systematically higher excess of respiratory mortality while the age group over 65 had a much lower mortality than during the seasonal epidemic seasons. Similarly, among the less specific outcome (non violent and cardiovascular mortality) the age groups over 45 had higher excess of mortality during the seasonal epidemics than during the pandemic period.
  
  
  CONCLUSIONS
  Since most of the influenza mortality is commonly observed in the elderly group (>65 year-old), the moderate elderly mortality during the 2009 pandemic period has impacted the total mortality, and has resulted in a reduced total mortality despite an increased mortality in the young age group. Despite using identical parameters and the same approach as in a previously published study using an Austrian population sample, we observed a lower excess respiratory mortality in the south-eastern France than in Vienna. Thus, the pandemic virus caused less death than the epidemic viruses that circulated during the preceding years. In contrast with catastrophic predictions made in the early phase of the pandemic, human lives were saved during the circulation period of A(H1N1)2009 virus, resulting in a lower overall mortality.
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", 13385, Marseille, France. djamt@yahoo.fr.|IHU Méditerranée Infection, APHM Public Hospitals of Marseille 13385, Marseille, France. djamt@yahoo.fr.
authors.forename: Simon-Djamel
authors.initials: SD
authors.lastname: Thiberville
authors.affiliation: Aix-Marseille Univ, UMR912, SESSTIM (AMU, IRD, INSERM), Marseille, France. jean.gaudart@univ-amu.fr.
authors.forename: Jean
authors.initials: J
authors.lastname: Gaudart
authors.affiliation: IHU Méditerranée Infection, APHM Public Hospitals of Marseille 13385, Marseille, France. didier.raoult@univ-amu.fr.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", 13385, Marseille, France. remi.charrel@univ-amu.fr.|IHU Méditerranée Infection, APHM Public Hospitals of Marseille 13385, Marseille, France. remi.charrel@univ-amu.fr.
authors.forename: Remi N
authors.initials: RN
authors.lastname: Charrel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001399:Azure Stains; D002648:Child; D002675:Child, Preschool; D058872:Epidemics; D005006:Ethnicity; D005602:France / Q000453:epidemiology; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009026:Mortality / Q000639:trends*; D012141:Respiratory Tract Infections / Q000401:mortality; D012938:Social Perception; D055815:Young Adult
chemical_list: D001399:Azure Stains; C025818:Azure A