In this thesis different parameters influencing the development of Culicoides and an equation
to calculate the risk of Bluetongue transmission so called basic reproduction number R0 are
described. R0 describes the number of secondarily infected individuums through the invasion
of one infected individuum. The first Bluetongue virus outbreak in the Neatherlands during
August 2006 and the recurrent outbreaks in Central Europe mark the actuality of this topic.
The term for the basic reproduction number R0 is simplified and describes the
transmission efficiency midge to host, the transmission efficiency host to midge and the sheep
recovery and death rate. The other parameters are defined as function of the temperature. The
functions used in this equation are the temperature depending midge mortality rate and the
rate of becoming infectious. They are indispensable for calculating the reproduction data
during different environmental conditions.
For simulations of the basic reproduction number over several years the temperature data
from Sept. 1st 2008 till Sept. 30th 2010 for the location Veterinary Medicine University of
Vienna were used. In the same way the data for the number of culicoides hatched during this
period at the Veterinary Medicine University of Vienna were implemented. A first visual
comparison of the different functions showed that the influence of the midge mortality rate
and the rate of becoming infectious is not as big as expected. In a final experiment, the
arithmetic average together with the 95-percent confidence interval was demonstrated. The
results show that till the middle of September 2008, from the end of Juli till the end of August
2009 and from the beginning of June till the end of August 2010 an outbreak of bluetongue
can be estimated.