Relapsing Fever, Tick-borne

The goal of this clinical trial is to compare standard treatment (5 days of doxycycline) vs single dose doxycycline for the prevention of tick-borne relapsing fever in soldiers who found bite marks on their bodies after an activity that includes contact with the ground or staying at a site suspected of being infected with ticks. The main question\[s\] it aims to answer are: * Testing whether preventive treatment with a single dose of doxylin at a dose of 200 mg is effective in preventing recurrent fever, and if so, at what rate * Checking the profile and rate of side effects in each one of the proposed treatment protocols Participants will be treated with standard treatment (5 days of doxycycline) or single dose doxycycline.