The shifting landscape of tick-borne zoonoses: tick-borne encephalitis andLyme borreliosis in Europe

The two major vector-borne diseases of northern temperate regions, tick-bor ne encephalitis (TBE) and Lyme borreliosis (LB), show very different epidem iological patterns, but both have increased significantly in incidence sinc e the 1980s. Insight into the temporal dynamics of TBE, gained from statist ical analysis of spatial patterns integrated with biological explanation, s uggests that the recent increases in TBE cases in Central Europe and the Ba ltic States may have arisen largely from changes in human behaviour that ha ve brought more people into contact with infected ticks. Under forecast cli mate change scenarios, it is predicted that enzootic cycles of TBE virus ma y not survive along the southern edge of their present range, e.g. in Slove nia, Croatia and Hungary, where case numbers are indeed decreasing. New foc i, however, are predicted and have been observed in Scandinavia. At the sam e time, human impact on the landscape, increasing both the habitat and wild life hosts of ticks, has allowed tick populations to multiply significantly . This probably accounts for a genuine emergence of LB, with its high poten tial transmission rate, in both the USA and Europe, although the rate of em ergence has been exaggerated by improved surveillance and diagnosis.