Synanthropic Birds Influence the Distribution of Borrelia Species: Analysis of Ixodes ricinus Ticks Feeding on Passerine Birds

Abstract
Ixodes ricinus ticks collected from 835 birds and from vegetation in the Czech Republic were analyzed. Host-seeking ticks ( n = 427) were infected predominantly by Borrelia afzelii (25%). Ticks ( n = 1,012) from songbirds (Passeriformes) were infected commonly by Borrelia garinii (12.1%) and Borrelia valaisiana (13.4%). Juveniles of synanthropic birds, Eurasian blackbirds ( Turdus merula ) and song thrushes ( Turdus philomelos ), were major reservoir hosts of B. garinii.