HHS No surveillance case definition is 100% accurate. There will always be some patients with Lyme disease whose illness does not meet the national surveillance case definition. For this reason, CDC has stated repeatedly that the surveillance case definition is not a substitute for sound clinical judgment. Given other compelling evidence, a physician may choose to treat a patient for Lyme disease when their condition does not meet the case definition.

This article was in Medscape Infectious Disease Newsletter a few days ago.
http://www.medscape.com/viewarticle/500088

From Morbidity & Mortality Weekly Report

Notice to Readers: Caution Regarding Testing for Lyme Disease

CDC and the Food and Drug Administration (FDA) have become aware of commercial laboratories that conduct testing for Lyme disease by using assays whose accuracy and clinical usefulness have not been adequately established. These tests include urine antigen tests, immunofluorescent staining for cell wall-deficient forms of Borrelia burgdorferi , and lymphocyte transformation tests. In addition, some laboratories perform polymerase chain reaction tests for B. burgdorferi DNA on inappropriate specimens such as blood and urine or interpret Western blots using criteria that have not been validated and published in peer-reviewed scientific literature. These inadequately validated tests and criteria also are being used to evaluate patients in Canada and Europe, according to reports from the National Microbiology Laboratory, Public Health Agency of Canada; the British Columbia Centres for Disease Control, Canada; the German National Reference Center for Borreliae; and the Health Protection Agency Lyme Borreliosis Unit of the United Kingdom.

In the United States, FDA has cleared 70 serologic assays to aid in the diagnosis of Lyme disease. Recommendations for the use and interpretation of serologic tests have been published previously.[1] Initial testing should use an enzyme immunoassay (EIA) or immunofluorescent assay (IFA); specimens yielding positive or equivocal results should be tested further by using a standardized Western immunoblot assay. Specimens negative by a sensitive EIA or IFA do not need further testing. Similar assays and recommendations are used in Canada.[2] In the European Union, a minimum standard for commercial diagnostic kits is provided by Conformit� Europ�ene (CE) marking; application and interpretation guidelines appropriate for Europe have been published.[3,4]

Health-care providers are reminded that a diagnosis of Lyme disease should be made after evaluation of a patient's clinical presentation and risk for exposure to infected ticks, and, if indicated, after the use of validated laboratory tests. Patients are encouraged to ask their physicians whether their testing for Lyme disease was performed using validated methods and whether results were interpreted using appropriate guidelines.

References
CDC. Recommendations for test performance and interpretation from the Second National Conference on Serologic Diagnosis of Lyme Disease. MMWR 1995;44:590-1.
Consensus Conference on Lyme Disease. Can Dis Wkly Rep 1991; 17:63-70.
Wilske B, Z�ller L, Brade V, et al. MIQ 12 Lyme-Borreliose. Qualit�tsstandards in der mikrobiologisch-infektiologischen Diagnostik. Munich, Germany: Urban & Fischer Verlag; 2000;1-59. Guidelines available in English at http://nrz-borrelien.lmu.de/miq-lyme/index.html.
Robertson J, Guy E, Andrews N, et al. A European multicenter study of immunoblotting in serodiagnosis of Lyme borreliosis. J Clin Microbiol 2000;38:2097-102.

This is WHY the tests are inaccurate:

Why is testing inaccurate (Western Blot)?

"The levels of antibodies (immunoglobulins) decrease in experimental animals (mice, rats and hamster) by up to 60% when the supply of magnesium is significant reduced.

There is a direct correlation between magnesium deficiencies in rats and reduced immune defense against allergic reactions and cancers, in particular leukaemia and lymphomas."
http://www.1stvitality.co.uk/az/magnesium/

The above website has changed, so go to this pubmed abstract instead:

Proc Soc Exp Biol Med. 1975 Mar;148(3):620-4.

The effect of magnesium deficiency in mice on serum immunoglobulin concentrations and antibody plaque-forming cells.
Elin RJ.

Therefore, magnesium deficiency has profound immunosuppressive capabilities in mice by significantly reducing the number of antibody synthesizing cells and serum immunoglobulin concentrations.

PMID: 1093189 [PubMed - indexed for MEDLINE]

Our own antibodies are not "perfect" fighters against Bb, why?

Characterization of the physiological requirements for the bactericidal effects of a monoclonal antibody to OspB of Borrelia burgdorferi by confocal microscopy.

The bactericidal effect of Fab-CB2 is not dependent on the induction of spirochetal proteases but is dependent on the presence of Ca2+ and Mg2+.

Supplementation of Ca2(+)- and Mg2(+)-free medium with these cations

restored the bactericidal effects of Fab-CB2.

The mechanism by which a Fab fragment of an antibody destroys a bacterium directly may represent a novel form of antibody-organism interaction.

PMID: 9125579

A ``novel form of antibody-organism interaction?'' I don't THINK so!

"E. Required by immunological process. Magnesium, immunity, and allergy: Mg is required for several steps of immunological reactions
1. Lymphoblastic transformation, a prerequisite of secretion of antibodies by lymphoblasts, requires Ca2+ and Mg2+
2. Mg is required for synthesis of proteins, immunoglobulins included
3. Antibody-induced complement activation is Mg dependent
4. The antigen-immunoglobulin-complement reaction induces degranulation of the mastocyte"
http://www.mdschoice.com/elements/elements/major_minerals/magnesium.htm