title: Seasonality of Plasmodium falciparum transmission: a systematic review.
abstract: BACKGROUND
  Although Plasmodium falciparum transmission frequently exhibits seasonal patterns, the drivers of malaria seasonality are often unclear. Given the massive variation in the landscape upon which transmission acts, intra-annual fluctuations are likely influenced by different factors in different settings. Further, the presence of potentially substantial inter-annual variation can mask seasonal patterns; it may be that a location has "strongly seasonal" transmission and yet no single season ever matches the mean, or synoptic, curve. Accurate accounting of seasonality can inform efficient malaria control and treatment strategies. In spite of the demonstrable importance of accurately capturing the seasonality of malaria, data required to describe these patterns is not universally accessible and as such localized and regional efforts at quantifying malaria seasonality are disjointed and not easily generalized.
  
  
  METHODS
  The purpose of this review was to audit the literature on seasonality of P. falciparum and quantitatively summarize the collective findings. Six search terms were selected to systematically compile a list of papers relevant to the seasonality of P. falciparum transmission, and a questionnaire was developed to catalogue the manuscripts.
  
  
  CONCLUSIONS
  152 manuscripts were identified as relating to the seasonality of malaria transmission, deaths due to malaria or the population dynamics of mosquito vectors of malaria. Among these, there were 126 statistical analyses and 31 mechanistic analyses (some manuscripts did both).
  
  
  CONCLUSIONS
  Identified relationships between temporal patterns in malaria and climatological drivers of malaria varied greatly across the globe, with different drivers appearing important in different locations. Although commonly studied drivers of malaria such as temperature and rainfall were often found to significantly influence transmission, the lags between a weather event and a resulting change in malaria transmission also varied greatly by location.
  
  
  CONCLUSIONS
  The contradicting results of studies using similar data and modelling approaches from similar locations as well as the confounding nature of climatological covariates underlines the importance of a multi-faceted modelling approach that attempts to capture seasonal patterns at both small and large spatial scales.
authors.affiliation: Fogarty International Center, National Institutes of Health, Bethesda, MD, USA. rcreiner@indiana.edu.|Department of Epidemiology and Biostatistics, Indiana University School of Public Health, Bloomington, IN, USA. rcreiner@indiana.edu.|Department of Entomology, University of California, Davis, CA, USA. rcreiner@indiana.edu.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Reiner
authors.affiliation: Department of Biological Sciences, University of Chester, Chester, UK. m.geary@chester.ac.uk.
authors.forename: Matthew
authors.initials: M
authors.lastname: Geary
authors.affiliation: Faculty of Science and Technology, Engineering Building, Lancaster University, Lancaster, LA1 4YR, UK. P.M.Atkinson@soton.ac.uk.|Faculty of Geosciences, University of Utrecht, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands. P.M.Atkinson@soton.ac.uk.|School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast, BT7 1NN, Northern Ireland, UK. P.M.Atkinson@soton.ac.uk.|Geography and Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, UK. P.M.Atkinson@soton.ac.uk.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Atkinson
authors.affiliation: Fogarty International Center, National Institutes of Health, Bethesda, MD, USA. dlsmith@jhsph.edu.|Center for Disease Dynamics, Economics and Policy, Washington, DC, USA. dlsmith@jhsph.edu.|Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK. dlsmith@jhsph.edu.
authors.forename: David L
authors.initials: DL
authors.lastname: Smith
authors.affiliation: Spatial Ecology and Epidemiology Group, Department of Zoology, University of Oxford, Oxford, UK. peter.gething@zoo.ox.ac.uk.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Gething
mesh_terms: D000818:Animals; D000852:Anopheles; D002980:Climate; D006801:Humans; D015994:Incidence; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000635:transmission*; D010963:Plasmodium falciparum; D012621:Seasons; D014887:Weather