▁ ▁Rel aps ing ▁fe ver ▁ ▁Rel aps ing ▁fe ver ▁( R F ) ▁bor re li osis ▁often ▁occurs ▁with ▁severe ▁b acter emia . ▁Tw enty - five ▁species ▁of ▁Bor rel ia ▁ ▁are ▁known ▁to ▁cause ▁rela ps ing ▁fe ver . ▁While ▁most ▁species ▁use ▁the ▁soft ▁tick ▁family ▁Arg as idae ▁as ▁their ▁vector , ▁some ▁out liers ▁ ▁live ▁in ▁hard ▁t icks ▁or ▁l ice . ▁Rel aps ing ▁fe ver ▁can ▁be ▁spread ▁ep ide m ically ▁through ▁l ice ▁or ▁en dem ically ▁through ▁t icks . B . ▁rec urrent is , ▁a ▁common ▁species ▁underlying ▁rela ps ing ▁fe ver , ▁is ▁transm itted ▁by ▁the ▁human ▁body ▁l ouse ; ▁no ▁other ▁animal ▁res er voir ▁of ▁B . ▁rec urrent is ▁is ▁known . ▁B . ▁rec urrent is ▁inf ect s ▁the ▁person ▁via ▁m uc ous ▁memb ran es ▁and ▁then ▁inv ades ▁the ▁blood stream . ▁ ▁Other ▁tick - bor ne ▁rela ps ing ▁in fe ctions ▁are ▁acquired ▁from ▁other ▁species , ▁such ▁as ▁B . ▁herm si i , ▁B . ▁par ker i , ▁or ▁B . ▁mi y am oto i , ▁which ▁can ▁be ▁spread ▁from ▁rod ents , ▁and ▁serve ▁as ▁a ▁res er voir ▁for ▁the ▁in fection , ▁via ▁a ▁tick ▁vector . ▁B . ▁herm si i ▁and ▁B . ▁rec urrent is ▁cause ▁very ▁similar ▁dise ases , ▁although ▁the ▁disease ▁associated ▁with