Diagnosis ofEarly LymeDisease byPolymerase ChainReaction Amplification andCulture ofSkinBiopsies from Erythema Migrans Lesions

Current laboratory diagnosis ofLymedisease relies ontests forthedetection ofantibodies toBorrelia burgdorfieri, theetiologic agent ofthedisease. These tests areoften unreliable because ofalack ofsensitivity and specificity andtest-to-test variability. Thepurpose ofthis study wastoevaluate thesensitivity andspecificity ofpolymerase chain reaction (PCR)amplification fordetection ofB.burgdorfieri inskinbiopsy specimens. Forty-six 2-mmskinbiopsy samples wereobtained from44patients withaclinical diagnosis oferythema migrans, 9ofwhomwerereceiving antibiotic therapy atthetimeofbiopsy. Specimens wereground inBSK mediumwithseparate aliquots taken forculture andPCR.Ofthespecimens fromtheuntreated group, 57% (21of37)werepositive byculture and22%(8of37)wereculture negative; 22%(8of37)ofthecultures were uninformative because ofcontamination. Bycomparison, 22(59%) of37specimens werepositive byPCR amplification. Of21culture-positive samples, 13(62%)werealsopositive byPCR analysis. Thus,the sensitivity ofthePCRwas59to62%,based oneither aclinical orcultural diagnosis ofuntreated Lymedisease. Noneoftheninespecimens fromantibiotic-treat ed patients grewinculture, whereas twooftheninewere