An audit was performed on the laboratory diagnosis of
lyme disease in Scotland. The problem of a significant number of patients with clinical symptoms of
lyme disease being reported as seronegative or equivocal by the confirmatory Western blot test was identified. Comparisons of current practice were made with American and European standards, and the Western blot scoring system revised. When applied retrospectively (April 2003 to March 2004), 39 (33 %) of 116 serum samples previously negative or equivocal became weak positive or stronger. Thirty-one (80 %) of these 39 samples were from patients with clinical details suggestive of early
lyme disease. The changes were implemented and assessed prospectively for 6 months. There was a significant increase in the proportion of equivocal results, with fewer negatives compared to the same time period 1 year previously. This audit has helped clinicians in the diagnosis of
lyme disease and the management of these patients in Scotland.