So, just got the results back from an ELISA test on IgM and IgG against Borrelia. IgM came back negative but IgG is 1:400 (positive). Can one have lyme's disease with negative IgM and positive IgG? The doc. says it shows a past exposure but i'm currently not infected, i believe that's bull so i want further testing to be done. What's considered as the golden-standard for lyme's testing?