Researchers at The Pirbright Institute have identified a suitable model midge species which will enable transmission studies of the Schmallenberg virus (SMV). Schmallenberg virus is spread by midges and causes deformities in lambs and calves when dams are infected during pregnancy. The results of the team’s research are of particular importance as the midges responsible for spreading the virus in the UK cannot currently be maintained under laboratory conditions, despite being extremely abundant on farms. The discovery will aid future research into SMV and improve our understanding of its transmission.
The study was funded by the UK Department for Environment, Food and Rural Affairs (Defra), the European Union and BBSRC and the key results were published on Friday 8 March 2013, in the journal PLOS ONE
As part of the project, Dr Eva Veronesi demonstrated that a colony line of midges maintained at The Pirbright Institute can be successfully infected using a strain of Schmallenberg virus originally isolated in Germany.
Dr Veronesi said: ”Understanding how Schmallenberg virus replicates in our colony midges is hugely important in standardising techniques to identify vectors in Europe. Not only that, but it also allows us to examine rates of Schmallenberg virus replication at different temperatures, which impacts on speed of spread and also whether the virus can be passed from adult midges to their offspring. All these studies would be impossible to perform with midges collected from the field.”
Dr Simon Carpenter, Head of Entomology at The Pirbright Institute said: “Eva’s work is of great importance in providing us with a reliable source of fully infected midges capable of transmitting the virus. Without this we would be reliant upon field populations of midges that only occur during part of the year as adults and which are only present under suitable weather conditions. This discovery demonstrates the national capability role of midge colony maintenance at The Pirbright Institute in providing data that is useful not only to the UK but also our colleagues in mainland Europe involved in combating the spread of Schmallenberg virus.”
The Pirbright Institute constitutes a unique national capability for the UK, providing high bio-containment level laboratories and facilities and an insectary to combat newly emerging and re-emerging insect-transmitted viruses. The Schmallenberg virus replication research in Culicoides is part of a wider project of world-leading interdisciplinary and complementary expertise in genomics, entomology and virology to systematically investigate the vector competence of the midge colonies at the Institute.