Project: Vector competence of European mosquitoes to Rift Valley fever virus.

Rift Valley fever virus (RVFV) is an arbovirus infecting humans and livestock after amplification in wild animals. It is readily transmitted through several mosquito genera including Aedes and Culex mosquitoes, and has a large host range. The recent expansion of the geographical range of RVFV clearly indicates that RVFV is not restricted to Africa. It has been proposed that a single infected person or animal that enters a naive country is sufficient to initiate an outbreak. This transmission scenario is becoming more probable due to the expansion of worldwide trade and travel. We aim to further understand the vector biology of natural RVFV vectors and their counterparts in Europe to assess and the risk of RVFV to be established in Europe, and how vectors can be manipulated to prevent the risk of RVFV transmission. Five work packages have been designed to answer the following questions: - Two complexes of sibling species are composed of potential RVFV vectors. The Culex pipiens and Aedes vexans complexes have a worldwide distribution (temperate as well as tropical sub-species). Whereas the taxonomic status of Culex pipiens is largely resolved, what are the phylogenetic relationships between the members of the Aedes vexans complex, and the distribution/population dynamics of individual species in a European model setting? - Aedine and culicine species might show differences in vector competence to RVFV. Are the European counterparts of these mosquitoes as RVFV vectors in the field competent to transmit RVFV, and can RVFV adapt to european mosquitoes? What environmental factors can influence maintenance and vertical transmission in a tropical mosquito model? - Arboviruses replicate in mosquito vectors with minimal cytopathological effects. Interactions between the replicating virus and the mosquito immune system control this phenomenon, and immunity also influences subsequent virus transmission. The mosquito innate immune response to RVFV has not been analysed and we propose to use a transcriptomics approach to analyse what it consists of (RNAi, other pathways), followed by functional tests. - The bacterium Wolbachia is widely used in symbiosis-based control strategies against viruses. What would be the effect of Wolbachia on the vector competence of mosquitoes to RVFV? Expected results: The expertise of the different partners will be of great benefit to tackle questions on RVFV vector biology and provide answers to key questions in RVFV emergence and spread. Indeed, a better knowledge of RVFV vectors and factors controlling RVFV replication as well as novel transmission control strategies will be helpful to apprehend RVFV emergence and control.

Acronym RiftVectors
Duration 31/12/2013
Website visit project website
Network EMIDA
Call 2nd EMIDA Joint Call on Emerging and Major Infectious Diseases of Livestock

Project partner

Number Name Role Country
Department for Environment, Food and Rural Affairs United Kingdom
University of Glasgow Coordinator United Kingdom
Biotechnology and Biological Sciences Research Council United Kingdom
University of Oxford United Kingdom
Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana Italy
Institut Pasteur France
Ministry of Health - Department for Veterinary Public Health, Nutrition and Food Safety Italy
French National Research Agency France