Research

We focus on the following three major research lines:

 

  1. Determination of vector capacity (vector competence, vector abundance in space and time, vectors’ host preferences) of arthropods as a basis for risk assessment of vector transmission in Switzerland.

The major focus of our group are vector capacity studies with biting midges as vectors of bluetongue and Schmallenberg viruses, and mosquitoes as vectors of West Nile, Zika, Usutu viruses and filariae (Dirofilaria spp.). Newly initiated projects aim at determining the vector capacity of biting flies and mosquitoes for the Lumpy Skin Disease virus (in collaboration with the Institute of Virology, University of Zürich, and the Institute of Virology and Immunology, Mittelhäusern) and for Francisella tularensis (in collaboration with the Institute of Veterinary Bacteriology, Vetsuisse Bern).

Vector competence studies are done with laboratory-reared insects or, preferably, with field-collected ones. They are performed in a biosafety level 3 laboratory under realistic temperature conditions (fluctuating temperatures). Vector abundances (spatio-temporal diversity and occurrence) are determined in the frame of ongoing projects at midland and pre-alpine areas, focusing on putative ‘hot-spots’ of transmission. Host preferences are identified by blood-meal analyses of collected vectors and by experimental approaches using animal-baited traps or olfactometers.

 

  1. Development of molecular tools (MALDI-TOF mass spectrometry, loop-mediated isothermal amplification of DNA [LAMP]) for accurate, rapid and cost-efficient identification of vector arthropods.

We were the first group to apply mass-spectrometry for the identification of arthropod vectors, and have a large database containing species from different taxa (in collaboration with Mabritec SA, www.mabritec.com). Most importantly, we could show that data obtained on the two most common MALDI-TOF platforms are compatible. Thus, this approach has a very high potential to become state-of-the-art for the laboratory-based identification of arthropod vectors. As an alternative, we are developing LAMP assays for their identification which is a field applicable technique including in high-throughput format.

 

  1. Research on the biology of vectors and evaluation of novel control options.

We discovered that biting midges require sugar meals before blood-feeding, and this could be exploited for their control (so-called ‘toxic sugar baits’). Established alternative techniques for insect control (sterilization by irradiaton, autodissemination of mosquito-growth regulators) have been evaluated for their applicability with regard to the invasive mosquito species Aedes japonicus, which is a concern in Switzerland and which is considered a control target in first evaluations by the Authorities. Breeding habitats of biting midges are being identified by conventional approaches (emergence traps, physical isolation of larvae) and by molecular techniques (eDNA; detection of DNA by qPCR in putative breeding substrates). Recently initiated research on the thermal ecology of vectors, in collaboration with the UZH Department of Evolutionary Biology and Environmental Studies, will yield insights into the nature of their preferred resting habitats (and this feature is of high significance for vector competence studies).