Southeastern United States: The geographic area of the southeastern region of the United States in general or when the specific state or states are not included. The states usually included in this region are Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, West Virginia, and Virginia.GeorgiaSouth CarolinaClimatic Processes: Characteristic events occurring in the ATMOSPHERE during the interactions and transformation of various atmospheric components and conditions.Encephalomyelitis, Eastern Equine: A form of arboviral encephalitis (primarily affecting equines) endemic to eastern regions of North America. The causative organism (ENCEPHALOMYELITIS VIRUS, EASTERN EQUINE) may be transmitted to humans via the bite of AEDES mosquitoes. Clinical manifestations include the acute onset of fever, HEADACHE, altered mentation, and SEIZURES followed by coma. The condition is fatal in up to 50% of cases. Recovery may be marked by residual neurologic deficits and EPILEPSY. (From Joynt, Clinical Neurology, 1996, Ch26, pp9-10)North CarolinaMississippiAfrican Americans: Persons living in the United States having origins in any of the black groups of Africa.Borrelia burgdorferi: A specific species of bacteria, part of the BORRELIA BURGDORFERI GROUP, whose common name is Lyme disease spirochete.European Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Europe.United StatesGeography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Demography: Statistical interpretation and description of a population with reference to distribution, composition, or structure.Genetic Variation: Genotypic differences observed among individuals in a population.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.