Sensitivity of a point of care tick-test for the development of Lyme borreliosis.

Background: A commercially available self-test for the detection of Borrelia burgdorferi sensu lato in ticks was evaluated for its ability to predict erythema migrans formation.
Findings: The self-test was performed on 127 Ixodes ricinus from 122 humans that reported tick bites at enrolment and occurrence of symptoms during follow-up. The self-test gave negative results on all the 122 individuals, 14 of whom reported erythema migrans (EM) at follow-up of which 10 were confirmed by their GP. The estimated sensitivity of the self-test for prediction of EM formation is 0% (95% CI: 0%-28%).
Conclusions: This self-test is not suitable for reducing the number needed to treat in a post-exposure prophylaxis setting as it already missed all the obvious early Lyme borreliosis cases.