title: Mapping transmission risk of Lassa fever in West Africa: the importance of quality control, sampling bias, and error weighting.
abstract: Lassa fever is a disease that has been reported from sites across West Africa; it is caused by an arenavirus that is hosted by the rodent M. natalensis. Although it is confined to West Africa, and has been documented in detail in some well-studied areas, the details of the distribution of risk of Lassa virus infection remain poorly known at the level of the broader region. In this paper, we explored the effects of certainty of diagnosis, oversampling in well-studied region, and error balance on results of mapping exercises. Each of the three factors assessed in this study had clear and consistent influences on model results, overestimating risk in southern, humid zones in West Africa, and underestimating risk in drier and more northern areas. The final, adjusted risk map indicates broad risk areas across much of West Africa. Although risk maps are increasingly easy to develop from disease occurrence data and raster data sets summarizing aspects of environments and landscapes, this process is highly sensitive to issues of data quality, sampling design, and design of analysis, with macrogeographic implications of each of these issues and the potential for misrepresenting real patterns of risk.
authors.affiliation: Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America.
authors.forename: A Townsend
authors.initials: AT
authors.lastname: Peterson
authors.affiliation: Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Lina M
authors.initials: LM
authors.lastname: Moses
authors.affiliation: Department of Tropical Medicine, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Bausch
mesh_terms: D000354:Africa, Western / Q000453:epidemiology; D062305:Geographic Mapping; D005843:Geography; D006801:Humans; D007835:Lassa Fever / Q000453:epidemiology* / Q000635:transmission*; D008954:Models, Biological; D011786:Quality Control; D018570:Risk Assessment / Q000379:methods; D015983:Selection Bias; D019371:Topography, Medical / Q000379:methods*
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