Scotland’s biting midge population carries previously-unknown viruses, according to new research. The study – published in the journal Viruses and carried out by scientists at the MRC-University of Glasgow Centre for Virus Research (CVR) – used high-throughput sequencing to study, for the first time, the total collection of viruses in the biting midge (Culicoides impunctatus).
The scientists discovered several new viruses in the ‘virome’ of the midges, including an alphanodavirus, two rhabdo-like viruses and a chuvirus. These viruses are mainly found in insects and other invertebrates, but some members of the alphanodaviruses naturally infect pigs and herons, sometimes causing death.
The newly-identified viruses were found to be sufficiently different from known species to be categorised as novel. However, there is currently no evidence that these viruses pose a threat to humans. Despite their prevalence in Scotland, midges – small biting flies which are a predominantly a nuisance to humans – are currently understudied. Yet midges are carriers of arboviruses (viral infections transmitted to humans from a group of insects) and were responsible for the emergence and spread of Schmallenberg virus (SBV) in Europe in 2011, and are likely to be involved in the emergence of other arboviruses in Europe.
Lead author Sejal Modha said: “The technology we used allowed us to look at the viruses carried by midges in a way that cannot be done in the laboratory, expanding our knowledge of the insect viruses in a way that could be very useful in future.
“What we found is important because biting midges can be carriers of arboviruses; and although midges are not currently a public health concern in Scotland – and we stress there is nothing for the public to be concerned about – our research gives us a better understanding of midges and the viruses they may carry, helping us prepare for any possible future emerging risks through improved surveillance and knowledge.”