<prompt> Peripheral blood smear of a patient with relapse of a fever seven days after remittance is shown. True statement about the etiological agent-The only reservoir is humansVector is hard tick or body louseIt is non-cultivable on cell free media.Soft tick or body louse can transmit the disease  <response>: Loosely wound spiral forms on peripheral blood smear shows Borrelia. Diagnosis is relapsing fever. Louse-borneEpidemic Relapsing fever Tick-borneendemic relapsing fever Cause-Borrelia recurrentis At least 15 spp- B.duttonii, B.parkeri, B.hermsii B. turicata Tends to occur as epidemic Sporadic cases in endemic areas Vector-body louse Vector-soft tick Inoculation of louse feces into skin Transmitted by bite of soft tick No extra-human reservoir Rodents and other mammals Disease -severe. Disease -milder. CFR-4-40 CFR-1-4 Relapses-12 Frequent relapses 