▁B . ▁herm si i ▁has ▁more ▁rela ps es ▁and ▁is ▁responsible ▁for ▁more ▁fatal ities , ▁while ▁the ▁disease ▁caused ▁by ▁B . ▁rec urrent is ▁has ▁longer ▁feb rile ▁and ▁af eb rile ▁intervals ▁and ▁a ▁longer ▁inc ub ation ▁period . ▁▁ ▁Di agn osis ▁ ▁Direct ▁tests ▁include ▁culture ▁of ▁Bor rel ia ▁from ▁skin , ▁blood , ▁or ▁c ere bro sp inal ▁fluid ▁( CS F ), ▁and ▁detection ▁of ▁gen etic ▁material ▁by ▁polym er ase ▁chain ▁reaction ▁in ▁skin , ▁blood , ▁or ▁syn ov ial ▁fluid . ▁Two - t ier ed ▁ser ological ▁testing ▁is ▁performed ▁for ▁differential ▁diagn osis ▁of ▁Bor rel ia ▁in fection . ▁The ▁first - t ier ▁tests ▁detect ▁specific ▁ant ib od ies ▁( Ig M ▁and ▁Ig G ▁together ▁or ▁separately ) ▁and ▁include ▁en zym e - link ed ▁imm uno ass ays ▁( e . g . ▁EL IS As ) ▁and ▁imm un of lu ores cent ▁ass ays . ▁Pos itive ▁results ▁for ▁first - t ier ▁tests ▁are ▁confirmed ▁using ▁second - t ier ▁testing . ▁The ▁second ▁tier ▁consists ▁of ▁standard ized ▁imm un ob lot ting , ▁either ▁by ▁using ▁Western ▁bl ots ▁or ▁bl ots ▁strip ed ▁with ▁di agnost ically ▁important ▁pur ified ▁ant ig ens . ▁Pos itive ▁results ▁for ▁second - t ier ▁tests ▁are ▁confir mat ory ▁for ▁the ▁presence ▁of ▁Bor rel ia '' ▁in fection . ▁S pi ro ch etes