Borreliae in Ixodid Ticks Biting Humans andProphylaxis of Lyme Borreliosis

Overview

We examined by dark field microscopy 195 of 209 Ixodes ricinus ticks that were removed fromhumans in the Czech Republic (mainly in southern Moravia) during 1997–2001. The majority of theticks were nymphs (62%), 31% were females and 7% larvae; 10.7% of the nymphs, 20.3% of the femalesbut no larvae were found to be infected with B. burgdorferi s.l., the agent of Lyme borreliosis (LB).This observation supports for Central Europe the conclusions drawn from North America aboutnymphal ixodid ticks as the most important vector stage in transmission of LB. In the course of theyear, we found the highest proportion of infected nymphal and female ticks taken off humans inJune. The detection of borreliae in a human-biting tick is an important step that enables the generalpractitioner to prescribe prophylactic antimicrobial treatment and to reduce significantly the riskof Lyme disease in the patient.

Key words:
ticks – Ixodes ricinus – Lyme disease – Borrelia burgdorferi s.l. – diagnostics –prophylaxis.