Lyme Disease Testing

Direct tests such as PCR, FISH, and culture are more informative when patients have active infection but insufficient antibody response. Lyme disease remains a clinical diagnosis, with laboratory results used as supportive evidence rather than definitive proof. Testing immediately after suspected exposure will almost always produce a false negative because antibodies usually take three to four weeks to appear. About 15% of patients may not produce enough antibodies for indirect tests to become positive despite active infection. The T-spot or IGXSpot test detects T-helper cell activation and rises earlier than conventional serology. Specialty Lyme labs are preferred when clinical suspicion is high but standard testing is negative.