Borrelia burgdorferi DNA in the urine of treated patients with chronic lyme disease symptoms. A PCR study of 97 cases

We isolated spirochetes from the blood of 2 of 36 patients in Long Island and Westchester County, New York, who had signs and symptoms suggestive of Lyme disease. The spirochetes were morphologically similar and serologically identical to organisms recently found to infect lxodes dammini ticks, which are endemic to the area and have been epidemiologically implicated as vectors of Lyme disease. In both patients, there was a rise in specific antispirochetal antibodies in paired specimens of serum. We conclude that the l. dammini spirochete has an etiologic role in Lyme disease.

Bites from the hard tick Amblyomma americanum are associated with a Lyme disease-like illness in the southern United States. To identify possible etiologic agents for this disorder, A. americanum ticks were collected in Missouri, Texas, New Jersey, and New York and examined microscopically. Uncultivable spirochetes were present in approximately 2% of the ticks. Borrelia genus-specific oligonucleotides for the flagellin and 16S rRNA genes were used for amplification of DNA. Products were obtained from ticks containing spirochetes by microscopy but not from spirochete-negative ticks. Sequences of partial genes from spirochetes in Texas and New Jersey ticks differed by only 2 of 641 nucleotides for flagellin and 2 of 1336 nucleotides for 16S rRNA. Phylogenetic analysis showed that the spirochete was a Borrelia species distinct from previously characterized members of this genus, including Borrelia burgdorferi. Gene amplification could be used to detect these spirochetes in ticks and possible mammalian hosts.

There are currently no accepted criteria for positive Western blots in Lyme disease. In a retrospective analysis of 225 case and control subjects, the best discriminatory ability of test criteria was obtained by requiring at least 2 of the 8 most common IgM bands in early disease (18, 21, 28, 37, 41, 45, 58, and 93 kDa) and by requiring at least 5 of the 10 most frequent IgG bands after the first weeks of infection (18, 21, 28, 30, 39, 41, 45, 58, 66, and 93 kDa). When these definitions were tested in a prospective study of all 237 patients seen in a diagnostic Lyme disease clinic during a 1-year period and in 74 patients with erythema migrans or summer flu-like illnesses, the IgM blot in early disease had a sensitivity of 32% and a specificity of 100%; the IgG blot after the first weeks of infection had a sensitivity of 83% and a specificity of 95%. Among patients with indeterminate IgG responses by ELISA, 6 of 9 patients with active Lyme disease had positive blots compared with 2 of 34 patients with other illnesses (P < .001). Thus, Western blotting can be used to increase the specificity of serologic testing in Lyme disease.