Wildlife communities and One health

Within this research line, I study the relationship between the occurrence of different wildlife species and the presence and density of parasites and pathogens. So far, my main focus has been on ticks and tick-borne diseases, studying the relationship between the availability of different host species and the prevalence of tick-borne pathogens. I collaborate with public health officials, to bring this new ecological knowledge to policy makers, with the aim of making prevention methods more effective.

The number of ticks and the number of people diagnosed with tick-borne diseases are on the rise in many parts of the world. However, we still know relatively little about the ecology of the tick species that transmits most diseases in Europe (the sheep tick – Ixodes ricinus) and the different tick-borne pathogens that the sheep tick transmits.

Currently, I have only one project that fits within this research line, while I did my PhD on this topic.

Forest fragmentation and tick-borne diseases 

In this project, we study the interactions between forest fragmentation, wildlife communities, ticks and tick-borne pathogens. We selected 20 plots over a gradient in forest fragmentation in the middle of Sweden and study how forest fragmentation influences the wildlife community. We then link the availability of wildlife as hosts for ticks and tick-borne pathogens to tick densities and pathogen prevalence in questing ticks. We focus on three pathogens: the bacteria Anaplasma phagocytophilum and Borrelia burgdorferi s.l, and the tick-borne encephalitis virus. The PhD project of Nannet Fabri (of which I am a co-supervisor) is linked to this project, as she measures vegetation, catches ticks and traps rodents in the same plots.

The wild life of tick-borne pathogens

For my PhD thesis, I studied the influence of different vertebrate host species on the dynamics of sheep tick populations and seven different bacterial pathogens that are transmitted by the sheep tick. I found that small mammals, thrushes and deer are the most important hosts for the sheep tick. Small rodents and thrushes are also the most important species transmitting tick-borne pathogens to the sheep tick. The behaviour and density of these species are the main determinants of tick-borne disease risk as measured by the number of infected ticks in an area.

My Phd thesis can be downloaded here: http://edepot.wur.nl/393112