Laboratory for Medical Entomology
The Laboratory of Medical Entomology deals with arthropods of veterinary and zoonotic relevance (insects and mites including ticks) which can be ectoparasites and vectors of disease agents.
Among other haematophagous ectoparasites and vectors, mosquitoes (Diptera, Culicidae), biting midges (Diptera, Ceratopogonidae) and ticks (Acari) are studied which may transmit the agents of important animal diseases and zoonoses during blood-feeding. These include the causative agents of bluetongue disease, Schmallenberg disease, West Nile fever, Rift Valley fever, and African Swine fever. Particular attention is paid to invasive species such as the Asian tiger mosquito Aedes albopictus and the Asian bush mosquito Aedes japonicus, which have recently been introduced into Germany and are characterised by a high vector potential. However, indigenous blood-feeding species are also considered, as their biology, ecology and vector competences are often insufficiently examined.
The ecoepidemiologically, infectiologically and genetically oriented research activities combine classical field and modern laboratory methods. In the field, for example, studies are carried out on the distribution, seasonal dynamics, host preference and feeding behaviour of potential vector species. In the laboratory, infectiological and molecular examinations are conducted as to the pathology, mechanisms of transmission, vector competence, transmission dynamics and interactions between disease agent, vector and vertebrate host. Insectaries for rearing arthropods and high security containments for infection and transmission studies are available at the FLI’s facilities.
Mosquito monitoring in Germany
In collaboration with six partners from other German research institutions, the occurrence and spatiotemporal distribution of mosquito species in Germany are assessed, while collected mosquitoes are examined for pathogens. The study is planned to run for three years (2015-2018) and is funded by the Federal Office for Agriculture and Food (BLE) /Federal Ministry of Food and Agriculture (BMEL).
It consists of five sub-projects:
- a spatially representative monitoring by means of mosquito traps randomly distributed over Germany and operated during the seasonal activity of mosquitoes;
- a passive monitoring by means of the citizen science project “Mückenatlas” (mosquito atlas) where citizens are requested to submit mosquitoes collected in their private surroundings. (www.mueckenatlas.de);
- a pathogen screening where mosquitoes are collected en masse in floodplains and are examined for pathogens;
- the observation and surveillance of the further spread of the Asian bush mosquito Ae. japonicus in Germany;
- an invasive monitoring where potential ports of entry of mosquitoes (motorways, airports, wholesale nurseries etc.) are purposefully sampled by mosquito traps. The obtained data are meant to serve as a basis for a substantiated risk assessment of the future occurrence of mosquito-borne diseases in Germany.
VectorNet is an ECDC (European Centre for Disease Prevention and Control) and EFSA (European Food Safety Authority) funded European network (running period 2014-2018) for the collection and the exchange of data on the geographical distribution of arthropod vectors (mosquitoes, biting midges, sand flies, ticks) in the EU and its neighbouring countries as well as on their transmission of disease agents to humans and animals. By screening the literature and direct contact to national experts distribution data (presence/absence, abundance) are accumulated and validated. They will be presented as maps on the homepage of the project and will be updated every three months. The geographical gaps identified are intended to be filled by targeted data collection in the field which will be planned, coordinated and carried out together with regional scientists. In the framework of these activities, standardized protocols for sampling in the field and for processing the arthropods in the laboratory are elaborated. Further technical documents (e.g. fact sheets) are prepared and made available on the homepage of the programme. Moreover, as the case may be, ad hoc and emergency requests from ECDC/EFSA on vector-borne disease outbreaks will be dealt with.
The ‚Laboratory of Medical Entomology‘ directly contributes to the mosquito group of the VectorNet consortium.
African Swine Fever-Research Network
In the framework of this interdisciplinary house-funded project (running period 2015-2018), which has been implemented because of the continuing westward spread of African Swine fever (ASF) from eastern European regions, aspects of the pathogenesis, immunology, vaccine development, protein expression, genomic structure, epidemiology and transmission of African Swine Fever virus (ASFV) or ASF, respectively. The ‚Laboratory of Medical Entomology‘ participates with vector studies on ticks. For this purpose, colonies of the vector species of ASF (Ornithodoros spec.) will be established at FLI. Developmental stages of the ticks will be infected with ASF actively via blood-feeding on a host animal, through membranes or via glass capillaries, or passively per microinjection. The susceptibility of the ticks for various virus types and mutants will be examined under selected conditions (e.g. different temperatures, infection doses etc.) by testing the ticks by qPCR for virus presence and titres at various time points post infection. The time-dependent virus replication in the ticks and the migration route of the virus through the tick will be followed by molecular, immunohistochemical and electron microscopical methods. In vitro and in vivo infection and transmission studies will be compared with regard to efficiency.
Blood meal identification in indigenous biting midge species of the genus Culicoides
Since indigenous putative vectors of bluetongue and Schmallenberg viruses cannot be reared in the laboratory and thus are not available for controlled laboratory studies, including infection experiments, indirect evidence for their vector roles must be found. In this house-funded long-term study, blood-fed biting midges of the genus Culicoides, which were collected across Germany during various previous projects and are still captured at some sites, are tested for the contents of their midgut by molecular techniques. The identification of the blood origin cannot only provide clues to the host preference of the various biting midge species but, in combination with data on virus detection in these species, may also suggest infection sources and reservoir hosts of the viruses.