Human and Canine Tick-Borne Disease Surveillance in Oklahoma: One Health Ecological Triangulation Study

BACKGROUND Tick-borne diseases (TBDs) in the United States are increasing due to ecological and climate changes. However, national surveillance data are principally available only at aggregate state and federal levels, limiting granular analysis and constraining TBD diagnosis, prevention, and public health communication. From a One Health perspective, recognizing the shared environments of people and animals and integrating canine serological data with human surveillance can improve geographic risk assessment and reduce reporting bias. Oklahoma offers a useful case in point: several TBDs are endemic, the state contains significant vulnerable populations, and public health records date to 1928, providing a longitudinal record examinable at the county level. OBJECTIVE With Oklahoma as a use case, we (1) identify geographic patterns and disparities in county-level human TBD reporting, (2) compare human TBD distribution with canine disease data to assess underreporting and geographic risk gaps, and (3) examine long-term disease trends and data inconsistencies across reporting periods. METHODS A descriptive analytical ecological study using a One Health triangulation approach was conducted in which the units of analysis were counties (n=77) in the US state of Oklahoma. Data were summarized using 1990-forward human reporting histories, human county tables (2004-2007), and Companion Animal Parasite Council (CAPC) canine testing summaries (2012-2026). National Oceanic and Atmospheric Administration (NOAA) 1991-2020 Climate Normals were used to derive a Tick Season Risk Index summarizing county-level climatic suitability for tick activity. Primary outcomes included reported human cases, county-level human disease incidence rates (per 100,000 population), and canine positive tests, total tests, and percent-positive values. RESULTS Trend, county burden, TBD incidence rate, and regional graphs illuminate variations that are not apparent in more aggregate state-level analyses. Central metro counties account for the largest number of tests performed and of reported human cases, while eastern, northeastern, and southeastern counties show stronger disproportionate burden signals. Several low-reporting western counties fall within a moderate Tick Season Risk Index range. This index is an exploratory 2-variable climatic screen, not a validated habitat suitability model; it cannot establish tick presence, habitat suitability, or the reasons for sparse case reporting, and no conclusion about surveillance gaps is drawn. CONCLUSIONS This study triangulates human, canine, and climatic data at the county level within a One Health framework, reporting a standardized index. Unlike prior studies, it addresses ehrlichiosis, spotted fever group rickettsiosis (SFR), and tularemia across nearly a century of public records, offering a replicable workflow that reveals discordance between human and canine surveillance. These findings support standardized reporting at the county level, integration of animal health data into human surveillance, and clinician awareness of TBD risks. Interpretation is limited by geolocation by residence rather than exposure and by canine serology that cannot distinguish Ehrlichia species pathogenic to humans.