Abstract
Tick-borne diseases are a public health issue. To predict vector tick abundance and activity, it is necessary to understand the driving factors for these variables. In this study, the activity of Ixodes ricinus was investigated in forest and meadow habitats in Germany with a focus on abiotic factors. Ixodes ricinus adults, nymphs and larvae were caught by flagging over a period of 2 years. Microclimatic and weather conditions were recorded at the collection sites. Statistical models were applied to describe correlations between abiotic factors and tick activity in univariable and multivariable analyses. Tick activity was observed in a broad range of air temperature between 3 and 28 °C, and air humidity varied between 35 and 95%. In general, tick activity of nymphs and larvae was higher in forest habitats than that in meadows. With the exception of a single specimen of Dermacentor reticulatus, all ticks were Ixodes ricinus, most of them nymphs (63.2% in 2009 and 75.2% in 2010). For the latter, a negative binomial mixed-effects model fitted best to the observed parameters. The modelling results showed an activity optimum between 20 and 23 °C for air temperature and between 13 and 15 °C for ground temperature. In univariable analyses, the collection site, month, season, ground and air temperature were significant factors for the number of ticks caught and for all life stages. In the multivariable analysis, temperature, season and habitat turned out to be key drivers. Ixodes ricinus positive for RNA of tick-borne encephalitis virus was only found at a single sampling site. The results of this study can be used in risk assessments and to parameterise predictive models.
Highlights
Tick- and other vector-borne diseases represent a public health issue of increasing importance (Maier et al 2003; Hartelt et al.2008; Habedank et al 2008)
Some previous studies documented the spatial (Lindgren et al 2000; Materna et al 2008) and temporal distribution of ticks (Dautel et al 2008); others described a raising incidence of Lyme borreliosis (LB) and tick-borne encephalitis (TBE) virus (TBEV) and found that the increase was associated with changes in weather and climate (Bormane et al 2004; Daniel et al 2008; Lindgren et al 2006; Süss 2008; Süss et al 2010; Süss et al 2008)
Further studies suggested that high summer temperatures in Northern Europe might cause an increase in the transmission of tick-borne diseases in late autumn and early spring, as the majority of the tick population becomes active in the latter part of the year (Gray 2008)
Summary
Tick- and other vector-borne diseases represent a public health issue of increasing importance (Maier et al 2003; Hartelt et al.2008; Habedank et al 2008). Some previous studies documented the spatial (Lindgren et al 2000; Materna et al 2008) and temporal distribution of ticks (Dautel et al 2008); others described a raising incidence of LB and TBE virus (TBEV) and found that the increase was associated with changes in weather and climate (Bormane et al 2004; Daniel et al 2008; Lindgren et al 2006; Süss 2008; Süss et al 2010; Süss et al 2008). Empirical long-term studies are required to investigate the possible influence of the climate change on the spatial and temporal distribution of ticks and tick-borne diseases (Eisen 2008). Korenberg (2009) summarised factors possibly influencing the formation of a natural TBE focus These factors included virus prevalence, vector occurrence and host activity as well as socio-economic and climate changes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
