dc.description.abstract | In this research, blood samples and ticks from wild game animals from nine different research
areas in the Netherlands were examined on the presence of several pathogen groups. The
goal of this research is to map the Dutch tick population and the pathogens that they carry
with them and also to investigate whether wild game animals fulfil a reservoir function for tickbound
diseases.
255 ticks, of which 17 came from a fallow-deer and 238 came from roe deer, were sent to the
UCTD by hunters from nine different areas. Furthermore, 68 blood samples, of which one
came from a fallow-deer and 67 came from roe deer, were sent.
The species, gender and stadia of the ticks were first determined. Next, DNA was extracted
from the blood samples and the ticks. The DNA was examined by PCR and RLB for the
presence of several pathogen groups. The following pathogens were particularly searched
for: Babesia/Theileria, Bartonella, Borrelia, Ehrlichia/Anaplasma, Rickettsia and Nicolleia.
The results showed that all the ticks that were used in this research belonged to the species
Ixodes ricinus. 7 out of 255 ticks were nymphs, 41 ticks were male adults and 207 ticks were
female adults. DNA was only extracted from adult ticks.
Results that were obtained from the RLB show the following rates of infection in ticks:
Babesia/Theileria: 9,1% (B. catch-all, B. divergens, B. venatorum, B. canis-2), Bartonella: 19,5% (B.
catch-all, B. schoenbuchensis), Borrelia: 0%, Ehrlichia/Anaplasma: 25,5% (E/A catch-all, E. canis/ovina,
E. schotti, A. marginale, A. phagocytophilum), Rickettsia: 52,8% (R. catch-all, R. helvetica, R. massilae, R.
conorii, R sp. (DnS14/raoultii), Nicolleia: 21,6% (N. catch-all).
In the blood samples from roe deer, the following pathogens were found.
Babesia/Theileria: 70,1% (B. catch-all, B. divergens, B. venatorum), Bartonella: 64,2% (B. catch-all, B.
schoenbuchensis), Ehrlichia/Anaplasma: 22,4% (E/A catch-all, A. marginale, A. phagocytophilum),
Rickettsia: 10,4% (R. catch-all, R. helvetica, R. massilae), Nicolleia: 1,5% (N. catch-all). Roe deer seem
to fulfil a reservoir role for these pathogens.
In the blood sample from the fallow deer, no pathogens were found.
The transmission of Babesia/Theileria from host to ticks seems to be inefficient. Borellia
wasn’t found in blood or in ticks. Antibodies might play a role here. Different tick populations
can show a variable susceptibility for Borrelia species. Therefore, vector competence can
differ within one tick species. Rickettsia, Ehrlichia/Anaplasma, Bartonella en Nicolleia were
commonly found in blood samples as well as in ticks. The transmission from host to tick and
vice versa seems to be efficient.
Conclusions cannot be made regarding results of autopsy by pathological examination. | |