RESUMO
Relapsing fever is caused by the Borrelia species of spirochetes. Louse-borne epidemics of the disease may happen but the endemic disease is generally transmitted to humans by the bite of an infected tick (Ornithodorus). Clinical and laboratory findings of tick-borne relapsing fever in children in the north-west of Iran, Qazvin, were evaluated. This study was conducted from September 1992 to September 2012. Records from 53 cases of tick-borne relapsing fever (TBRF) were reviewed. In positive cases, febrile illness, and spirochetes were recognized in peripheral blood preparations. Of the 53 children younger than 12 years, fifty two percent were male and about one third (34%) of the patients were in the age range of 7-12 years. The disease is recorded through the whole year but its peak occurs during summer (52.8%) and autumn (32.1%). Sixty eight percent of patients were living in urban areas but had frequent travel to rural area. Thirty two percent of the cases were living in rural areas where their dwellings were close to animal shelters. All (100%) of the 53 subjects were febrile. Travellers to the rural areas with high prevalence of the disease should be attentive of the risk of tick-borne relapsing fever and use suitable control measures. Consequently relapsing fever should be considered when patients who live in or have vacationed in north-west of Iran show a recurring febrile illness.