The positive predictive value of Borrelia burgdorferi serology in the light of symptoms of patients sent to an outpatient service for tick-borne diseases.

OBJECTIVE

By using the published incidence of Lyme borreliosis in endemic regions of the World, and the sensitivity and specificity data of the best Lyme serological tests, we computed the positive predictive value of Borrelia burgdorferi antibody testing.

METHODS

The calculation of predictive value was based on Bayes' theorem. We also analyzed the frequency distribution of the specific and non-specific symptoms and complaints of 27,194 patients sent to the Centre for Tick-borne Diseases in Budapest from 1986 to 2008.

RESULTS

This evaluation demonstrated that practitioners often use Lyme serology in a "trial and error" way, without any reasonable ground. According to our calculation the positive predictive value of the best Lyme antibody tests if applied in this way is <9.1%.

CONCLUSION

Our study suggests that the present practice of applying Lyme serological tests may result in more harm than benefit.