title: Bayesian spatio-temporal analysis and geospatial risk factors of human monocytic ehrlichiosis.
abstract: Variations in spatio-temporal patterns of Human Monocytic Ehrlichiosis (HME) infection in the state of Kansas, USA were examined and the relationship between HME relative risk and various environmental, climatic and socio-economic variables were evaluated. HME data used in the study was reported to the Kansas Department of Health and Environment between years 2005-2012, and geospatial variables representing the physical environment [National Land cover/Land use, NASA Moderate Resolution Imaging Spectroradiometer (MODIS)], climate [NASA MODIS, Prediction of Worldwide Renewable Energy (POWER)], and socio-economic conditions (US Census Bureau) were derived from publicly available sources. Following univariate screening of candidate variables using logistic regressions, two Bayesian hierarchical models were fit; a partial spatio-temporal model with random effects and a spatio-temporal interaction term, and a second model that included additional covariate terms. The best fitting model revealed that spatio-temporal autocorrelation in Kansas increased steadily from 2005-2012, and identified poverty status, relative humidity, and an interactive factor, 'diurnal temperature range x mixed forest area' as significant county-level risk factors for HME. The identification of significant spatio-temporal pattern and new risk factors are important in the context of HME prevention, for future research in the areas of ecology and evolution of HME, and as well as climate change impacts on tick-borne diseases.
authors.affiliation: Kansas State Veterinary Diagnostic Laboratory/Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America.
authors.forename: Ram K
authors.initials: RK
authors.lastname: Raghavan
authors.affiliation: Bureau of Epidemiology and Public Health Informatics, Kansas Department of Health and Environment, Topeka, Kansas, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Neises
authors.affiliation: Department of Geography, College of Arts and Sciences, Kansas State University, Manhattan, Kansas, United States of America.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Goodin
authors.affiliation: Department of Computing and Information Sciences, College of Engineering, Kansas State University, Manhattan, Kansas, United States of America.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Andresen
authors.affiliation: Department of Diagnostic Medicine/Pathobiology, Kansas State University, College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Roman R
authors.initials: RR
authors.lastname: Ganta
mesh_terms: D001499:Bayes Theorem; D057231:Climate Change; D016873:Ehrlichiosis / Q000453:epidemiology*; D006801:Humans; D007615:Kansas / Q000453:epidemiology; D012307:Risk Factors; D012959:Socioeconomic Factors; D062211:Spatio-Temporal Analysis