title: Spatiotemporal circulation of influenza viruses in 5 African countries during 2008-2009: a collaborative study of the Institut Pasteur International Network.
abstract: BACKGROUND
  Although recent work has described the spatiotemporal diffusion of influenza viruses worldwide, comprehensive data on spatiotemporal patterns of influenza from the African continent and Madagascar are still lacking.
  
  
  METHODS
  National Influenza Centers from 5 countries-Cameroon, Côte d'Ivoire, Madagascar, Niger, and Senegal--collected specimens from patients presenting with influenza-like illness who visited sentinel surveillance clinics during a 2-year period (2008-2009). Isolates were genetically and antigenically characterized.
  
  
  RESULTS
  Overall, 8312 specimens were tested. Seasonal influenza A virus subtypes H1N1 and H3N2 and influenza B viruses were detected in 329, 689, and 148 specimens, respectively. In 2009, pandemic influenza A virus subtype H1N1 was detected in Madagascar most commonly (98.5% of cases). Influenza activity was either significant year-round or occurred during a specific period of the year in the African countries we evaluated.
  
  
  CONCLUSIONS
  Our results demonstrate that, from Madagascar to Senegal, the epidemiologic and virologic characteristics of influenza viruses are diverse in terms of spatiotemporal circulation of the different virus types, subtypes, and strains. Our data highlight the importance of country-specific surveillance and of data and virus sharing, and they provide a rational basis to aid policy makers to develop strategies, such as vaccination at the right moment and with the right formulation, aimed at reducing the disease burden in Africa and Madagascar.
authors.affiliation: National Influenza Center, Institut Pasteur de Madagascar, Antananarivo, Madagascar. jmheraud@pasteur.mg
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Heraud
authors.forename: Richard
authors.initials: R
authors.lastname: Njouom
authors.forename: Dominique
authors.initials: D
authors.lastname: Rousset
authors.forename: Herve
authors.initials: H
authors.lastname: Kadjo
authors.forename: Valerie
authors.initials: V
authors.lastname: Caro
authors.forename: Mbayame Niang
authors.initials: MN
authors.lastname: Ndiaye
authors.forename: Kathleen
authors.initials: K
authors.lastname: Victoir
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Collard
authors.forename: Arnaud
authors.initials: A
authors.lastname: Orelle
authors.forename: Elsie Laban
authors.initials: EL
authors.lastname: Yekwa
authors.forename: Euloge
authors.initials: E
authors.lastname: Ekaza
authors.forename: Norosoa Harline
authors.initials: NH
authors.lastname: Razanajatovo
authors.forename: Lagare
authors.initials: L
authors.lastname: Adamou
authors.forename: Leon
authors.initials: L
authors.lastname: Biscornet
authors.forename: Vincent
authors.initials: V
authors.lastname: Enouf
authors.forename: Sylvie
authors.initials: S
authors.lastname: van der Werf
authors.forename: Ousmane Madiagne
authors.initials: OM
authors.lastname: Diop
mesh_terms: D000349:Africa / Q000453:epidemiology; D000956:Antigens, Viral / Q000032:analysis; D014644:Genetic Variation; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D007391:International Cooperation; D008270:Madagascar / Q000453:epidemiology; D009975:Orthomyxoviridae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D012367:RNA, Viral / Q000235:genetics; D018571:Sentinel Surveillance; D013997:Time Factors; D019371:Topography, Medical
chemical_list: D000956:Antigens, Viral; D012367:RNA, Viral