epidemiological study of endemic relapsing fever in hamadan province, western iran

background: endemic relapsing fever remains under diagnosed in our area according to a low index of suspicion among clinicians, as well as its difficult diagnosis. the goal of this study was to present the epidemiological aspects of the disease in western iran. methods: in this analytical-descriptive cross-sectional study, the epidemiological and clinical aspects of relapsing fever were investigated in hamadan province, western iran from 1999 to 2013. a confirmed patient was defined as a person who had both febrile illness and detected spirochetes by wright-giemsa or dark-field microscopy in a periph­eral blood smear. for the statistical analysis, the statistical software spss was used. results: during the study period, 276 cases of relapsing fever were recorded that 146 were male. due to the age group distributions, most of the patients aged less than 20 yr. patients noticed from april through march, most cases were reported in september (53 cases, 19.2%). considering time trend of the mentioned disease between 1999 and 2013 showed an increasing trend of disease from 1999 to 2003 (from 2.5% to 21.0%), while the prevalence of dis­ease had a decreasing trend after than from 21.0% in 2003. conclusion: the rate of endemic relapsing fever is similar in both male and female genders, but its prevalence re­duced by increase of age. the trend of the changes in prevalence of the mentioned disease has shown to be down­ward in recent years probably due to improving health policies especially among children and adolescents and par­ticularly in rural areas.