LYME BORRELIOSIS HABITAT ASSESSMENT

Tick ecologists throughout Europe provided descriptions of Lyme borrel iosis habitats according to a standardised format and data for 105 hab itats in 16 countries were received. The data showed that high risk si tuations, as defined by the presence of large numbers of B. burgdorfer i sensu lato-infected nymphal I. ricinus, occur in heterogeneous decid uous woodland, usually with a recreational function and with a diverse fauna, usually including deer. Large numbers of ticks occurred in som e other habitats, but infection prevalence was usually low. The situat ion for adult I. ricinus was similar but less clearly defined. Tick in fection rates were found to be lower in western Europe than in the eas t, and the infection rate in I. persulcatus, the most easterly vector species, was markedly higher than in I. ricinus. In the vast majority of habitats the infection rate in adult I. ricinus was greater than in nymphs. Larvae were rarely found to be infected.