The diagnosis of spirochetoses is generally resolved nowadays, but the diagnosis of borreliosis is an exception, which presents a problem on all continents.

Currently both direct and indirect tests exist.

The biggest problem of direct tests is that there are very limited options for taking samples in which the concentration of pathogens is sufficient for their detection. E.g. culture from skin biopsy samples collected from the area of the classic early symptom, ECM (Erythema Chronicum Migrans) can produce good results. However, ECM is only present in 20-30 percent of European cases, and not all patients consult a physician in this stage. Furthermore, ECM is considered a specific symptom of diagnostic value, hence further investigation may not be necessary.

In addition to biopsy samples, it is possible to test the blood or other body fluids, but the concentration and the absolute amount of pathogens in these samples is generally low. In general 50-200 microlitres of blood/serum samples are processed during the tests, which do not always contain a sufficient amount of bacteria for PCR-based or microscopic tests.

In the case of indirect methods the main problem is that the tests are dependent on both the immune response of the host and the behaviour of the pathogen (e.g. immunogenicity shift) (16). The level of seropositivity required for successful diagnostic testing may not be present in the early stage of the disease (11); In addition, the IgM-IgG transition of the immune response may be blocked (10).

References
  1. Early detection and persistence of antibodies to Borrelia burgdorferi in persons with Lyme disease. Magnarelli LA, Anderson JF. 1987., Zentralbl Bakteriol Mikrobiol Hyg A., pp.: 263(3):392-9.
  2. Detection of serum antibodies against Borrelia burgdorferi with some commercially available serological tests. Melby K, Steinbakk M, Jensenius M, Figenschau KJ. 1990 Dec., NIPH Ann., pp.: 13(2):37-44.
  3. Regulation and expression of bba66 encoding an immunogenic infection-associated lipoprotein in Borrelia burgdorferi. Clifton DR, Nolder CL, Hughes JL, Nowalk AJ, Carroll JA. 2006., Mol Microbiol., old.: 243-58.