S679 Document heading doi: 10.1016/S2222-1808(14)60706-4 襃 2014 by the Asian Pacific Journal of Tropical Disease. All rights reserved. The seven-year longitudinal study on relapsing fever borreliosis in Western Iran Hamid Kassiri 1* , Ali Kasiri 2 , Mansour Karimi 1 , Elnaz Kasiri 3 , Masoud Lotfi 1 1 School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 2 School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran 3 Mazandaran University of Medical Sciences, Sari, Iran Asian Pac J Trop Dis 2014; 4(Suppl 2): S679-S683 Asian Pacific Journal of Tropical Disease journal homepage: www.elsevier.com/locate/apjtd *Corresponding author: Hamid Kassiri, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Tel: +986113738269 Fax: +986113738282 E-mail: Hamid.Kassiri@yahoo.com Foundation Project: Supported partially by Chancellor for Research Affairs of Ahvaz Jundishapur University of Medical Sciences with project numbers 88S14 and 88S15. 1. Introduction Tick borne relapsing fever (TBRF) or endemic relapsing fever is an acute infectious zoonotic disease and sporadically distributed throughout rural areas of the globe [1,2] . TBRF is characterized by recurrent episodes of fever and a variety of nonspecific signs (such as vomiting, chills, abdominal pain, headache, myalgia and arthralgia), which are related to spirochetemia. It has an incubation period of 4 to 18 (or more) d. The infection is affirmed by observing the spirochetes (Borrelia spp.) on blood smear under a microscope, during one of the periods of fever. TBRF often responds to antibiotic treatment [3-6] . This recurrent febrile illness is reported from Africa, South America, North America, Europe and Asia [2,7-9] . Soft ticks (Acari: Ixodida: Argasidae) perform a major role in transmission of TBRF [10] . Borrelia species are transferred to persons via the bite of infected Ornithodoros spp. ticks. Borrelia spp. alter their surface antigens, causing frequent stimulation of the body immune system by the latest antigen and a pyrexial response by the sick [3,11-13] . Ornithodoros spp. have nightly blood-feeding habits and pain-free bites. The Borrelia spp. can survive for many years in their long-lived vectors. Attainment of human TBRF is universally limited to the geographical range of the Ornithodoros tick vectors. The host reservoirs of Borrelia PEER REVIEW ABSTRACT Objective: To determine the epidemiologic and clinical features of tick borne relapsing fever in Kurdistan Province during 2000-2006. Methods: In this cross-sectional clinic-based study, target group was all population of Kurdistan Province. In order to screen patients based on national protocol we diagnosed cases based on clinical symptoms together with the presence of Borrelia in blood smears that are stained with Wright-Geimsa. Positive cases after identifying were treated. Also we completed a questionnaire for all patients. The data were analysed by SPSS for getting descriptive indicators (relative and absolute frequency tables) . Results: The numbers of tick borne relapsing fever cases recorded during 2000 to 2006 were as follows: 14, 8, 17, 36, 22, 10 and 31, respectively. A total of 138 patients (50.8% males, 49.2% females) were studied. The most prevalent clinical manifestations were fever (100%), chills (92.7%) and headache (76.1%). Laboratory tests performed on patients showed the presence of Borrelia persica in blood smears. Most of the cases (42%) were in the age group 10-19 years old and 86.2% of them were under 30 years old. Nearly 92% of the patients were resident of the villages. About 37.7% and 25.4% of cases were students and housewives, respectively. Approximately 66% of cases were observed in summer. In 70% of cases, the buildings that they lived in were very old. Cattle or sheep were found in the homes of 89.1% of patients. Conclusions: Due to the relatively high infection rate and economic consequences of this disease on the person and the community, we should take measures to prevent its prevalence by carrying out educational programs. Contents lists available at ScienceDirect Article history: Received 5 Jun 2014 Received in revised form 15 Jun 2014 Accepted 25 Jun 2014 Available online 29 Jul 2014 Keywords: Epidemiology Demography Tick borreliosis Iran