RT Journal Article T1 Epidemiology of Tick-Borne Relapsing Fever in Endemic Area, Spain. A1 Domínguez, María Carmen A1 Vergara, Salvador A1 Gómez, María Carmen A1 Roldán, María Esther K1 Borrelia hispanica K1 Jarisch-Herxheimer reaction K1 Spain K1 arthropodborne disease K1 bacteria K1 endemic borreliosis K1 tick-borne relapsing fever K1 vector-borne infections K1 zoonoses AB Tick-borne relapsing fever (TBRF) is caused by spirochetes of Borrelia bacteria. We collected data on all TBRF cases in a TBRF-endemic area in southwest Spain during 1994-2016. We analyzed data from 98 patients in whom TBRF was diagnosed by light microscopy and analyzed the relationship between climatic data and TBRF incidence. Most cases occurred a rural environment during summer and autumn. We describe demographic, epidemiologic, clinical, and analytical characteristics, treatment, and occurrence of Jarisch-Herxheimer reaction. Most patients had fever and headache, and laboratory test results included elevated C-reactive protein, thrombocytopenia, and neutrophilia. No patients died, but 10.1% had Jarisch-Herxheimer reaction. B. hispanica was the infecting species in 12 cases with PCR results. Clinicians often do not suspect TBRF because clinical signs and symptoms vary; therefore, it is likely underdiagnosed, even in disease-endemic areas. YR 2020 FD 2020 LK http://hdl.handle.net/10668/15395 UL http://hdl.handle.net/10668/15395 LA en DS RISalud RD Apr 8, 2025