The Lyme Disease Foundation and the Centers for Disease Control and Prevention say that the diagnosis must be clinical, based on signs and symptoms. False negatives and false positives can occur.
Laboratories use different detection criteria, cutoff points, types of measurements and reagents.
Western blot produces bands indicating the immune system's reactivity to Bb . Laboratories differ in their interpretation and reporting of these bands. This may be useful for detecting LD in patients taking antibiotics or on symptom flare-up. Culturing of the bacteria is difficult and can take months. Staining of tissue is time-consuming and has a low yield.