Screeningsonderzoek naar tekengebonden ziekten bij wilde hoefdieren in Nederland.

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.