title: Climatic drivers of seasonal influenza epidemics in French Guiana, 2006-2010.
abstract: OBJECTIVE
  Influenza seasonality remains poorly studied in Equatorial regions. Here we assessed the seasonal characteristics and environmental drivers of influenza epidemics in French Guiana, where influenza surveillance was established in 2006.
  
  
  METHODS
  Sentinel GPs monitored weekly incidence of Influenza-like illnesses (ILI) from January 2006 through December 2010 and collected nasopharyngeal specimens from patients for virological confirmation. Times series analysis was used to investigate relationship between ILI and climatic parameters (rainfall and specific humidity).
  
  
  RESULTS
  Based on 1533 viruses identified during the study period, we observed marked seasonality in the circulation of influenza virus in the pre-pandemic period, followed by year-round activity in the post-pandemic period, with a peak in the rainy season. ILI incidence showed seasonal autoregressive variation based on ARIMA analysis. Multivariate dynamic regression revealed that a 1 mm increase of rainfall resulted in an increase of 0.33% in ILI incidence one week later, adjusting for specific humidity (SH). Conversely, an increase of 1 g/kg of SH resulted in a decrease of 11% in ILI incidence 3 weeks later, adjusting for rainfall.
  
  
  CONCLUSIONS
  Increased rainfall and low levels of specific humidity favour influenza transmission in French Guiana.
authors.affiliation: Fogarty International Centre, National Institutes of Health, Bethesda, USA. mahamataba@gmail.com
authors.forename: A
authors.initials: A
authors.lastname: Mahamat
authors.forename: P
authors.initials: P
authors.lastname: Dussart
authors.forename: A
authors.initials: A
authors.lastname: Bouix
authors.forename: L
authors.initials: L
authors.lastname: Carvalho
authors.forename: F
authors.initials: F
authors.lastname: Eltges
authors.forename: S
authors.initials: S
authors.lastname: Matheus
authors.forename: M A
authors.initials: MA
authors.lastname: Miller
authors.forename: P
authors.initials: P
authors.lastname: Quenel
authors.forename: C
authors.initials: C
authors.lastname: Viboud
mesh_terms: D002980:Climate; D005616:French Guiana / Q000453:epidemiology; D006801:Humans; D006813:Humidity; D015994:Incidence; D007251:Influenza, Human / Q000453:epidemiology*; D009305:Nasopharynx / Q000821:virology; D009975:Orthomyxoviridae / Q000302:isolation & purification; D011891:Rain; D012621:Seasons