TABLE 5.
Serology results at acute- and convalescent-phase blood drawsa
| Testing | No. of participants or no. of participants with the indicated result/total no. tested (%) |
|||
|---|---|---|---|---|
| Type 1A | Type 1B | Type 2 (all) | EC (all) | |
| Acute-phase visit | 148 | 48 | 102 | 252 |
| Whole-cell lysate ELISA + | 35/82 (43) | 6/24 (25) | 10/58 (17) | 15/133 (11) |
| C6 peptide ELISA + | 62/148 (42) | 8/48 (17) | 15/102 (15) | 14/252 (5) |
| VlsE/pepC10 ELISA + | 23/60 (38) | 7/20 (35) | 9/33 (27) | 14/97 (14) |
| IgM immunoblotting + | 44/148 (30) | 5/48 (10) | 17/102 (17) | 13/252 (5) |
| IgG immunoblotting + | 12/148 (8) | 1/48 (2) | 6/102 (6) | 4/252 (2) |
| Two-tier testing + (STTTA)b | 43/148 (29) | 5/48 (10) | 12/102 (12) | 6/252 (2) |
| Convalescent-phase visit | 83 | 31 | 46 | NA |
| Whole-cell lysate ELISA + | 18/38 (47) | 2/12 (17) | 3/20 (15) | NA |
| C6 peptide ELISA + | 42/83 (49) | 4/31 (13) | 8/46 (17) | NA |
| VlsE/pepC10 ELISA + | 15/43 (35) | 4/15 (27) | 8/18 (44) | NA |
| IgM immunoblotting + | 27/83 (33) | 4/31 (13) | 7/46 (15) | NA |
| IgG immunoblotting + | 6/83 (7) | 1/31 (3) | 5/46 (11) | NA |
| Seroconversionc | 3/83 (4) | 1/31 (3) | 3/46 (7) | NA |
Abbreviations and definitions: +, positive; STTTA, standard two-tiered testing algorithm; NA, not applicable; type 1A, EM lesion size of >5 cm; type 1B, EM/annular lesion size of ≤5 cm. For participants enrolled as type 1 and type 2, positive whole-cell lysate, C6 peptide, and VlsE/pepC10 ELISA results include both positive and equivocal results. Serologic testing was performed at Mayo Clinic (MC) or Stony Brook University (SB).
An STTTA positive result is a positive or equivocal whole-cell lysate ELISA, C6 peptide ELISA, or VlsE/pepC10 ELISA result followed by a positive IgM immunoblotting or IgG immunoblotting result using the STTTA result at the acute-phase blood draw.
Seroconversion was indicated by a positive IgG immunoblotting result at the convalescent-phase blood draw following a negative IgG immunoblotting result at the acute-phase blood draw.