In Western Europe the incidence of tick-borne encephalitis (TBE) has increased over the last 30 years, coupled with changes in distribution. Modifications in the TBE enzootic cycle, through a combination of changes in temperature, vertebrate abundance and habitat suitability may have increased the risk of TBE in recent years. In Switzerland, analysis using satellite-derived climate data demonstrated that the environment of areas with TBE since the 1980s and areas that recently became endemic for TBE have become more similar between 2001 and 2009. This was coupled with an increase in April, May and June temperature, which could have affected the tick population and/or human exposure to ticks. Deer and boar abundance also changed in some cantons. In Germany, spatio-temporal modelling demonstrated the importance of temperature, vertebrate abundance and unemployment in the incidence and distribution of TBE between 2001 and 2009. Changes in TBE reporting, April, May and June temperature, vertebrate abundance and pesticide use may have contributed to increases in TBE in 1992 and 2001. Human exposure patterns, however, appear to be as important as the enzootic cycle in shaping the incidence of TBE, not only in determining the overall trend but also in interacting with the weekly, seasonal and yearly patterns of tick hazard to give the observed incidence. In Switzerland, in weeks with warm, sunny weather, human exposure to ticks is promoted and short-term increases in tick bites are seen. Human outdoor activity also shifts the seasonal pattern of tick bites, when compared with tick questing. There was no apparent increase in time spent in outdoor activities between the 1990s and 2000s in Italy, Germany and Austria, but survey data demonstrated that walking and hiking were already popular activities across Europe by the 1990s. The popularity of mushroom and berry foraging as a source of income in Latvia, Lithuania and Poland, coupled with the expense of vaccination, provide an inverse link between economic wellbeing and TBE risk. Correspondingly, in 2009, the economic recession was associated with an increase with TBE in these three countries.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:581132 |
| Date | January 2012 |
| Creators | Godfrey, Elinor |
| Contributors | Randolph, Sarah; Rogers, David |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:fd0a7241-b85f-4d49-abe4-a5ec4057c96e |
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