Vector borne diseases caused by viruses revisited
Epizootics of bluetongue and Schmallenberg viruses in Europe and of Rift Valley fever virus (RVFV) outside Africa have demonstrated that viral VBDs have the potential to emerge and spread rapidly at remote distances, and are difficult to control. Therefore, it is paramount to develop a better understanding of the complex relations between vectors, viruses and their hosts. The EU-funded VMERGE (Emerging viral vector borne diseases) project investigated the risk of introduction, emergence and spread of vector-borne viruses associated with mosquitoes. The key objective was to understand vector competence and population dynamics as well as virus transmission. The consortium collected mosquitoes, sera and environmental data and through the development of innovative molecular and serological diagnostic tools, they generated a wealth of data on arbovirus prevalence. Combined with metagenomics analyses, new viruses were identified with a potential interest for human and livestock health, expanding existing knowledge on virus diversity. In addition, scientists analysed the microbiomes of several mosquito vectors, providing for the first time a detailed characterisation of the microbiome composition of this important vector. From a therapeutic perspective, a specific strain of RVFV proved to be a promising vaccine candidate for use in camelid livestock in Europe. In another part of the project, the consortium developed computational methods for assessing the transmission risk of RVFV in endemic areas. These models also helped define the spatial distribution of vectors and determine the climatic events able to favour RVF occurrence. Overall, the availability of predictive models and relevant scenarios are essential for the development of adequate prevention and contingency programmes. The integrative and comprehensive nature of the VMERGE study has laid a strong foundation for the design of epidemiological surveillance and preventive strategies. Considering the substantial production losses accrued due to animal diseases, project deliverables are expected to improve disease detection as well as food security.
Keywords
Vector borne diseases, Rift Valley fever virus, VMERGE, mosquito, microbiome