title: Epidemiology and viral etiology of the influenza-like illness in corsica during the 2012-2013 Winter: an analysis of several sentinel surveillance systems.
abstract: Influenza-like illness (ILI) surveillance is important to identify circulating and emerging/reemerging strains and unusual epidemiological trends. The present study aimed to give an accurate picture of the 2012-2013 ILI outbreak in Corsica by combining data from several surveillance systems: general practice, emergency general practice, hospital emergency units, intensive care units, and nursing homes. Twenty-eight respiratory viruses were retrospectively investigated from patients in general practice with ILI. Sequence analysis of the genetic changes in the hemagglutinin gene of influenza viruses (A(H1N1)pdm2009, A(H3N2) and B) was performed. The trends in ILI/influenza consultation rates and the relative illness ratios (RIRs) of having an ILI consultation were estimated by age group for the different surveillance systems analyzed. Of the 182 ILI patients enrolled by general practitioners, 57.7% tested positive for influenza viruses. Phylogenetic analyses suggested a genetic drift for influenza B and A(H3N2) viruses. The ILI/influenza surveillance systems showed similar trends and were well correlated. In accordance with virological data, the RIRs of having an ILI consultation were highest among the young (<15 years old) and decreased with age. No clusters of acute respiratory illness were declared by the sentinel nursing homes. This study is noteworthy in that it is the first extensive description of the 2012-2013 ILI outbreak in Corsica as monitored through several surveillance systems. To improve ILI surveillance in Corsica, a consortium that links together the complementary regional surveillance ILI systems described here is being implemented.
authors: EA7310, Laboratoire de Virologie, Université de Corse, Institut national de la Santé et de la Recherche Médicale, Corte, France.
authors: Laëtitia
authors: L
authors: Minodier
authors: EA7310, Laboratoire de Virologie, Université de Corse, Institut national de la Santé et de la Recherche Médicale, Corte, France; Observatoire régional de la Santé de Corse, Ajaccio, France.
authors: Christophe
authors: C
authors: Arena
authors: Cellule de l'Institut national de Veille Sanitaire en région, Ajaccio, France.
authors: Guillaume
authors: G
authors: Heuze
authors: Sorbonne Universités, UPMC Univ Paris 06, UMR_S 1136, F-75013, Paris, France.
authors: Marc
authors: M
authors: Ruello
authors: INSERM, UMR_S 1136, F-75013, Paris, France.
authors: Jean Pierre
authors: JP
authors: Amoros
authors: Sorbonne Universités Pierre et Marie Curie, Paris 06, UMRS 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France; Institut national de la Santé et de la Recherche Médicale, UMRS 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France.
authors: Cécile
authors: C
authors: Souty
authors: EA7310, Laboratoire de Virologie, Université de Corse, Institut national de la Santé et de la Recherche Médicale, Corte, France.
authors: Laurent
authors: L
authors: Varesi
authors: EA7310, Laboratoire de Virologie, Université de Corse, Institut national de la Santé et de la Recherche Médicale, Corte, France.
authors: Alessandra
authors: A
authors: Falchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D060085:Coinfection; D004196:Disease Outbreaks; D005260:Female; D005602:France / Q000453:epidemiology; D062306:Geography, Medical; D049674:History, 21st Century; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000145:classification / Q000235:genetics; D009981:Influenza B virus / Q000145:classification / Q000235:genetics; D007251:Influenza, Human / Q000453:epidemiology* / Q000266:history / Q000821:virology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009735:Nursing Homes; D010802:Phylogeny; D012621:Seasons; D018571:Sentinel Surveillance; D014777:Virus Diseases / Q000453:epidemiology* / Q000266:history / Q000821:virology*; D055815:Young Adult