Borrelia infections cannot be completely excluded due to negative serological tests:

• „In the case of ELISA, positive or borderline results were observed in only 24 patients (53.3%).“(Wojciechowska-Koszko et al., Feb. 2011)
• „32 patients had specific antiborrelial antibodies confirmed by using the westernblot in spite of negative ELISA…In patients with persisting difficulties it is necessary to use the westernblot test…It is probably due to the very low production of specific antibodies caused also by the status of immune-deficiency detected in all our patients.“ (Durovska et al., 2010)
• „The number of IgM- and/or IgG-positive ELISA results…ranged from 34 to 59%...Comparison of immunoblots yielded large differences in inter-test agreement…Remarkabably, some immunoblots gave positive results in samples that had been tested negative by all eight ELISAs.“ (Ang CW et al., Jan. 2011)

Laboratories should test for "VIsE" (Variable major protein-like sequence Expressed) in the ELISA and SeraSpot test systems. VIsE describes the ability of the 'chameleon' Borrelia burgdorferi to constantly change its surface protein structure VIsE in vivo in order to avoid being identified by the immune system. VIsE has the highest sensitivity when searching for antibodies against Borrelia burgdorferi.

The SeraSpot MicroArray analyzes the following Borrelia burgdorferi IgG- and IgM-antibodies and Borrelia burgdorferi subspecies:
VlsE (B.b. afzelii), p39 (B.b. afzelii), p58 (B.b. garinii), p100 (B.b. afzelii), OspC (B.b. afzelii + B.b. garinii + B.b. sensu stricto), DbpA (B.b. afzelii + B.b. garinii + B.b. sensu stricto).