DiMoC - Diversity components in mosquito-borne diseases in face of climate change

DiMoC

DiMoC - Diversity components in mosquito-borne diseases in face of climate change

Context:

Mosquito-borne pathogens such as chikungunya virus and West Nile virus are an increasing threat of veterinary and public health in Europe. Emerging and re-emerging transmission patterns are influenced by global transport, long-distance travel, and environmental and climatic changes, while vaccination and pharmaceutical treatment is either not available or very limited. The role of biodiversity on disease transmission is becoming evident as far as introduced invasive species and habitat degradation are concerned, but on the other hand, attenuating or promoting effects on the chain of infection remain poorly understood. At the same time, a better understanding has a high potential to advance policy actions and response on the transmission of zoonotic diseases and avoid local or regional outbreaks.

Main objectives of the project:

DiMoC will contribute to better understand the effects of biodiversity in mosquito-borne pathogen transmission. Through the analysis of different organisational (hosts, insects, viruses, human population), spatial (continental, regional, local, organism) and temporal scales (current conditions / future projections), DiMoC will test whether:

Greater diversity in insect-specific virus hosted by mosquitoes results in a reduced relative risk of transmission of a virus through interactions within these populations;

Mosquito diversity is influenced by interspecific interactions (e.g. competition) between species, which translates into different relative transmission risk;

Greater host species diversity reduces the transmission risk due to the dilution effect;

Changes in climatic conditions explain current large-scale patterns of pathogen, vector, and host diversity more than socio-economic conditions;

These results will allow to evaluate whether scenarios and models including climate, landscape diversity, and societal diversity can be used to quantify uncertainty in future trends of risks in pathogen transmission.

Main activities to be implemented:

DiMoC will focus on the European continental scale and on one of its overseas regions and assess relative transmission risk of pathogens. Mosquitoes that can transmit pathogens (called vectors, namely Culex pipiens, Aedes albopictus and Aedes japonicus) will be caught in Belgium, Germany and Italy. The species will be studied to understand the effects of local microhabitat diversity and its influence on interspecific interactions of invasive versus native mosquitoes, which in the end translates to varying vector diversity and abundance.

DiMoC will use cutting-edge approaches such as salivation assays of mosquitoes in Biological Safety Level 3 laboratory to determine the differences in the vector competence for West Nile, chikungunya and Japanese encephalitis viruses.

At a regional scale, the impact of vector, host and virus diversity along a gradient of human-presence and land use (urban, rural and natural) on West Nile Virus transmission risk will be assessed in detail: mosquito captures (from Mexico, France and Germany) will allow to determine mosquito abundance, richness and diversity. Using molecular methods, DiMoC will identify vertebrate blood-meals in mosquitoes to identify the differences in host assemblages within and between studied sites.

Specific activities for dissemination of the project’s outputs:

DiMoC not only intends to fill knowledge gaps, it proactively works with policy and practice. The project has already identified key local to supra-national target organisations and policies to engage with, ranging from local authorities competent for the management of mosquito-borne diseases in Belgium, France (including overseas regions), Germany and Mexico to European institutions, authorities and associations. It will seek to raise awareness of mosquito-borne diseases, but also to influence how authorities are informed. It will involve these stakeholders specifically in assess the relative disease risks in local to continental settings, improving the projects’ work and the uptake of its results into practice. It will in particular seek to develop policy briefs condensing the project results into practice-oriented conclusions for the management of biodiversity and risk mitigation in the context of mosquito-borne diseases.