Table 3.

Sensitivity and Specificity of Serodiagnostic Algorithms for Acute Erythema Migrans

Sensitivity and Specificity	First-Tier Tests Alone			Modified 2-Tiered Testing Protocols			Conventional 2-Tiered Testing
	WCS EIA	C6	VlsE CLIA	WCS EIA f/b C6 EIA	WCS EIA f/b VlsE CLIA	VlsE CLIA f/b C6 EIA	WCS EIA f/b IgM/IgG WBs
Sensitivity, %
Acute-phase EM (n = 55)	49 [.02]	65 [<.0001]	55 [.003]	38 [.22]	36 [.30]	54 [.003]	25
Convalescent-phase EM (n = 47)	77 [.05]	81 [.01]	72 [.13]	72 [.13]	66 [.40]	72 [.13]	55
Specificity, %
Overall (n = 1277)	97.4 [<.0001]	98.4 [.02]	98.1 [.003]	99.5 [1.00]	99.5 [1.00]	99.3 [.63]	99.5

Bracketed numbers represent the P values for the comparison with conventional 2-tiered testing.

Abbreviations: CLIA, chemiluminescence immunoassay; EIA, enzyme immunoassay; EM, erythema migrans; f/b, followed by; IgG, immunoglobulin G; IgM, immunoglobulin M; VlsE, variable major protein-like sequence, expressed; WB, Western blot; WCS, whole-cell sonicate.