Fig. 2.

Assessing the cause of a patient's Lyme-like disease.

^a Perform only in NATA-accredited laboratory.

^b Paired serum testing must be performed. Only consider positive if there is a 4-fold rise in titre, or seroconversion is observed. Positive results without 4-fold rise or seroconversion only indicate past exposure and not current infection. A third serum sample may be required if equivocal.

EM, erythema migrans; ELISA, enzyme-linked immunosorbent assay; IFA, immunofluorescence assay; and EBV, Epstein-Barr virus.