African horse sickness virus

African horse sickness virus (AHSV) is the cause of one of the most devastating infectious diseases of horses and related species such as zebra and donkeys. Several different forms of African horse sickness occur, and in some cases can kill up to 90% of the infected animals. In contrast to the severe clinical prognosis in horses, donkeys and zebra are generally resistant to AHSV and can act as viral reservoirs.

AHSV is an Orbivirus related to bluetongue virus (BTV). There are nine distinct AHSV serotype strains (AHSV-1 to -9) circulating worldwide. Like BTV, AHSV is an arbovirus transmitted between infected and uninfected animals by the biting midge.

Researchers in the CVR focus on developing new vaccines for AHSV. 

Contact: Massimo Palmarini

Bluetongue virus

Bluetongue is one of the major infectious diseases of ruminants (cattle, sheep, deer etc) and is caused by bluetongue virus (BTV). BTV is an arthropod-borne virus (arbovirus) in the Reoviridae family, and is transmitted from infected to uninfected mammalian hosts by Culicoides biting midges. There are at least 26 BTV serotype strains (BTV-1 to BTV-26) circulating worldwide.

BTV infection in mammalian hosts ranges from non-apparent to severe clinical symptoms, which are generally associated with damage to small blood vessels.

Research in the CVR focuses on understanding virus and host factors affecting the clinical outcome of this disease.

Contact: Massimo Palmarini

 Electronmicrograph of bluetongue virus

Bunyamwera virus

Bunyamwera virus (BUNV) is the prototype of the family Bunyaviridae, and causes a mild febrile illness in humans. It is named after the area in western Uganda where it was first isolated. BUNV remains an important research model: it was the first bunyavirus whose genome was completely sequenced, and significantly was the first segmented genome negative sense RNA virus that was recovered (rescued) entirely from cloned cDNA.

Research in CVR uses BUNV to investigate aspects of bunyavirus glycoprotein processing and as a screening tool to determine interferon-stimulated genes that have anti-viral activity against bunyaviruses.

Contact: Xiaohong Shi & Ingeborg van Knippenberg 

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Fluorescently labelled Bunyamwera viral proteins in cells, viewed by confocal microscopy

Canine distemper virus

Canine distemper virus (CDV) is a widespread morbillivirus of carnivores. CDV is thought to have arrived in Europe in the mid-18th century when an epidemic spread across the continent. While known for many years as a virus of domestic dogs, CDV has been appearing in new areas and causing disease and mortality in a diverse range of wildlife species; from Ethiopian wolves, black-footed ferrets and Lake Baikal seals, to giant pandas, lions and tigers.

CVR researchers are developing novel assays for the rapid and accurate quantification of the immune (neutralising antibody) responses elicited by CDV infection and vaccination. These technologies enable them to examine the cross-immunity afforded by field strains of virus from distinct lineages and geographical origins, and the level of protection afforded by current CDV vaccines.

Contact: Brian Willett, Margaret Hosie

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Camera trap photo of an Amur tiger. Credit: WCS Russia Programme

Chikungunya virus

Chikungunya virus (CHIKV) is a single stranded positive sense RNA virus belonging to the genus Alphavirus of the family Togaviridae. It has become an increasingly important arbovirus in tropical and subtropical regions, resulting in febrile and arthralgic disease in humans. After the large outbreak in the Indian Ocean in 2004 CHIKV infections have spread throughout the Indian Ocean and Africa into Southern Europe, and since 2014 into the Americas. CHIKV is spread by aedine mosquitoes, with Aedes aegypti being the most important vector, and more recently Aedes albopictus following a change in the envelope protein.

Research at the CVR focuses on the interaction between the virus and it mosquito-vector, specifically the innate immune response and how this influences vector competence and transmission.

Contact: Alain Kohl, Emilie Pondeville 

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Mosquito vector: Aedes albopictus

Dengue virus

Dengue virus (DENV) is a mosquito-borne flavivirus, and the most important arbovirus worldwide. There are four distinct but related serotypes (DENV-1, DENV-2, DENV-3, DENV-4) which are principally spread by female Aedes aegypti mosquitoes, an insect which associates closely with humans. It is estimated that over 2.5 billion people (greater than 40 % of the world’s population) live in dengue-endemic areas in more than 100 countries worldwide, placing them at risk from dengue and severe dengue (dengue hemorrhagic fever and dengue toxic shock syndrome) infections, for which there is currently no vaccine or specific treatment. The emergence and recurrence of DENV has become more frequent with larger epidemics and more severe symptoms.

Research at the CVR focuses on the interactions between DENV and mosquito innate immune pathways, and the effects of Wolbachia symbionts on DENV transmission by Aedes mosquitoes, including field trials for DENV control.       

Contact: Alain Kohl, Steve Sinkins

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Drosophila C virus

Drosophila C virus (DCV) is an insect specific positive-sense single-stranded RNA virus and a member of the Dicistroviridae family. Transmitted by feeding, it has been found to infect both wild and laboratory strains of drosophila. Natural infections can lead to death in larval populations, but is not thought to be lethal in adults. However, when injected into the thorax of adult flies the virus is highly pathogenic. Experiments using DCV have been instrumental in examining the innate immune response to virus in drosophila, and as such the virus is widely used in laboratories.

Research at the CVR focuses on the study the interaction between the bacterial endosymbiont Wolbachia and DCV – Wolbachia is known to protect against DCV infection in flies.

Contact: Alain Kohl

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Endogenous viral elements

Endogenous viral elements (EVEs) are the heritable, remnants of ancient viruses (‘paleoviruses’) that infected the ancestors of modern species. Although most of these viruses are extinct as free-existing elements, we can study them using the information embedded in genomes. For example, an incredible 8% of the human genome is comprised of DNA sequences derived from ancient retroviruses. Just as the study of fossils has been vital in helping biologists to understand the origin and evolution of modern species, the study of paleoviruses can provide a unique insight into the biology of contemporary viruses.

CVR researchers have developed bioinformatics platforms to screen for these elements, providing data that can be used to establish histories of viral interaction with host genomes, which can underpin the development of strategies for control and monitoring of emerging viruses.

Contact: Rob Gifford

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EVEs and the genomic fossil record

Epstein-Barr virus

Epstein-Barr virus (EBV) is a human herpesvirus with a worldwide distribution. Over 90% of adults are persistently infected by EBV and infection usually occurs in early childhood. In developed countries, primary infection is often delayed until adolescence or early adulthood and can result in infectious mononucleosis (glandular fever). This is a benign, self-limiting disease that is frequently associated with prolonged fatigue. EBV is also associated with malignant diseases including a range of lymphomas and nasopharyngeal and gastric carcinoma. It is estimated that the virus causes 1.8% of cancer deaths.

Research in the CVR is focused on understanding why some individuals develop EBV-associated Hodgkin lymphoma, the commonest type of EBV-associated lymphoma. Ultimately this will inform strategies to prevent and treat this malignant disease.

Contact: Ruth Jarrett

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Visualisation of EBV in the tumour cells of Hodgkin lymphoma

Feline calicivirus

Feline calicivirus (FCV) is an important respiratory pathogen of cats. The virus often persists following infection and cats may shed virus for months and become lifelong carriers. Despite widespread vaccination, around 10% of the UK's 11 million cats carry FCV (current vaccines do not achieve sterilising immunity, they prevent overt disease). FCV has been implicated in the feline chronic gingivostomatitis complex, a significant welfare concern. Moreover, virulent systemic strains of FCV have emerged that cause high mortality, often in vaccinated cats. Improved FCV vaccines are needed.

CVR researchers aim to advance our understanding of immunity induced by FCV vaccines, as it is not yet clear how FCV vaccines protect against clinical disease. This work will also contribute to understanding immunity to the closely related human norovirus (NoV). Each year, NoV infections kill 200,000 children under five years of age in the developing world, and are a leading cause of acute gastroenteritis and deaths in the elderly and immunocompromised. Studying FCV may provide valuable insights into the mechanisms of immunity to NoV.

Contact: Brian Willett, Margaret Hosie

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Image: Atomic resolution model of FCV decorated with a soluble fragment of its cellular receptor JAM-A.

Structural virologists in the CVR are investigating cell attachment and entry in FCV, using cryogenic electron microscopy and 3D image reconstruction.

Contact: David Bhella

Feline leukaemia virus

Feline leukaemia virus (FeLV) is a gammaretrovirus that infects domestic cats and wild felids, including wildcats, lynxes and African big cats. Infection with FeLV is the primary cause of cancer in domestic cats worldwide.

FeLV infection is generally diagnosed by the detection of viral protein (p27) in the blood of the infected cat. With the introduction of diagnostic tests, and widespread use of effective vaccines, the prevalence of FeLV infection has decreased greatly over the past 20 years. Associated with this decreasing prevalence is an increased risk of false-positive results in diagnostic tests. The reliable identification of FeLV-infected cats is a priority, especially for cat shelters, as the prognosis for infected cats is poor.  

CVR researchers are investigating whether current diagnostic tests are failing to detect some regressive FeLV genotypes, and whether cats harbouring such FeLV genotypes have the potential to produce replication-competent viruses that might be transmitted to other cats.

Contact: Brian Willett, Margaret Hosie

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FeLV was discovered in 1964 by Bill Jarrett at the University of Glasgow

Feline immunodeficiency virus

Feline immunodeficiency virus (FIV) is a lentivirus that attacks the immune system of the domestic cat, inducing clinical signs of immunodeficiency. Infection can lead to other infections or lymphomas. Studies of immunodeficiency in natural infection has shown that in some cats the clinical signs are mild, which likely reflects differences amongst circulating strains as well as host factors. Many FIV-infected cats have an apparently normal life expectancy, while others develop signs similar to those of human AIDS patients.

CVR researchers are investigating immunity to FIV infection and the use of surrogate markers to provide an objective measure of disease progression in infected cats. They have shown that the type of virus (phenotype) circulating in infected cats switches with the onset of immunodeficiency, indicating that viral "phenotyping" could assist with identifying the stage of infection in cats diagnosed with FIV. Knowledge of the phenotypes that are transmitted and dominate in early infection may inform the design of more efficacious FIV vaccines.

Contact: Brian Willett, Margaret Hosie

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CD134, the cellular receptor of immune cells to which FIV binds

Hantaan & Puumala viruses

Hantaan (HTNV) and Puumala (PUUV) viruses are members of the Hantavirus genus of emerging and reemerging zoonotic viruses in the family Bunyaviridae. Hantaviruses are maintained as persistent infections in rodents, insectivores, and bats. Some hantaviruses, such as Hantaan (HTNV) and Puumala (PUUV) viruses, can infect humans. HTNV causes haemorrhagic fever with renal syndrome (HFRS) in the Far East with a mortality rate up to 10%, while PUUV causes a milder form of HFRS, termed nephropathia epidemica, in Western Europe with a mortality rate of less than 1%.

Research in the CVR focuses on developing systems to study the interactions of these viruses with the innate immune response.

Contact: Agnieszka Szemiel & Xiaohong Shi 

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Hepatitis C virus

Hepatitis C virus (HCV) infects an estimated 2.2% of the world population, which equates to about 130 million people. The virus usually establishes a chronic infection in the liver that promotes serious hepatic disorders such as decompensated cirrhosis and hepatocellular carcinoma over a period that can take decades. Chronic HCV infection is a global healthcare problem due to uncoordinated intervention strategies to halt the spread of infection, lack of diagnosis and poor access to therapy. The virus has a positive-sense RNA genome, which is a highly variable in nucleotide sequence. As a consequence, developing anti-viral compounds that cure infection has been challenging and no vaccine is available.

CVR researchers are investigating the genetic diversity of HCV at the human population level; the immune response & host factors that control infection; design and development of a HCV B-cell vaccine.

Contact: John Mclauchlan, Arvind Patel, Emma Thomson

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Variation of HCV genotype 1a sequences in Scotland and other countries.

Viral hepatitis programme

Herpes simplex virus 1

Herpes simplex virus (HSV-1) is a DNA virus that infects humans, establishing a life-long latent infection within sensory nerves. Like all members of the Herpesviridae family, HSV-1 can periodically reactivate causing new episodes of disease (e.g. coldsores). Whilst in most cases this is not serious, reactivation in people with impaired immune systems can be severe and even life threatening.

CVR researchers are investigating factors controlling the life-cycle of this virus, from latency to activation, and how it interacts with (and avoids) the human antiviral defences.

Contact: Chris Boutell

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Structure of HSV-1 capsid, solved by cryomicroscopy and 3D reconstruction

Human cytomegalovirus

Human cytomegalovirus (HCMV) is one of nine herpesviruses known to infect humans. Infection is not obvious, but poses a serious risk to people who have immature or impaired immune systems - it is the major viral cause of birth defects, and is a leading cause of illness in transplant patients. Infection may also be involved with chronic conditions, including chronic allograft rejection, atherosclerosis and immuno-senescence. Given the threat in these settings, there is a need for new antiviral drugs and a vaccine.

Research in the CVR focuses on the genomics of HCMV during clinical infections, in particular characterising viral genes and relating their diversity to HCMV infectivity and ability to cause disease. Work also extends to the genomics of other herpesviruses of medical or veterinary importance.

Contact: Andrew Davison

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Genetic map of HCMV strain 'Merlin', which has the largest genome (236 kbp) of all known human viruses. Characterisation of HCMV has helped pave the way to new HCMV disease diagnostics.

Human Herpesvirus 6A and B

Human herpesvirus 6A and B (HHV-6A and B) are two closely related herpesviruses of the Roseolovirus genus. Most healthy adults in Europe, Japan and the USA are infected by HHV-6B, whereas HHV-6A infection is more common in Africa. Primary infection by HHV-6B can give rise to roseola infantum (sixth disease) and viral reactivation can have serious consequences in immunocompromised people. HHV-6A and B are unique among human herpesviruses in that they can integrate into the telomeres of human chromosomes. In around 1-3% of the population, HHV-6 is integrated in every cell in the body and passed on to subsequent generations in a Mendelian fashion—a phenomenon referred to as inherited chromosomally integrated HHV-6 (iciHHV-6). Little is known about the consequences of iciHHV-6.

Researchers at the CVR are investigating the prevalence, disease associations, genomics and evolution of iciHHV-6 using samples and data from large population-based studies.

Contact: Ruth Jarrett

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Identification of iciHHV-6 using droplet PCR.

Human Immunodeficiency Virus (HIV-1)

Human immunodeficiency virus 1 (HIV-1), the virus responsible for the AIDS pandemic, has infected nearly 75 million people since it entered human populations around a century ago. The emergence of HIV-1/AIDS went largely unnoticed for over half a century before being recognized as a global health threat in the 1980s. HIV-1 infection is currently incurable and if left untreated, the majority of infected individuals will progress to AIDS. Although no effective vaccine exists, HIV infection can be manageable as many effective antiretroviral drugs are now available. When given in combination, these antiretrovirals can potentially lower viral loads for decades, delaying or eliminating the progression to AIDS.

Research in the CVR is focused on understanding the ability of our antiviral defences to block the replication of HIV-1 and related simian immunodeficiency viruses (SIVs). We hope to learn the molecular details of how these viruses overcome the defences of a 'new' host, in order to understand the cross-species transmission, emergence and establishment of immunodeficiency viruses in human populations.

Contact: Sam Wilson

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 Image of HIV and blood cells courtesy of dream designs. Source: www.freedigitalphotos.net

Human papillomaviruses

Human papillomaviruses (HPV) cause a range of diseases from common warts on the hands to cancers, such as cervical cancer — the third most common cancer of women worldwide. HPV also cause cancers of the mouth & throat, with a dramatic increase in the incidence of this in recent years, particularly in males of developed countries. So far, around 190 HPVs have been identified. Most humans are infected with many different types of these viruses, but infections are usually harmless. However, a subset of 'high risk' HPV have a higher probability of causing disease that can lead to cancer. For HPV infection of the cervix, early detection by smear test has resulted in around a 50% reduction in cervical cancers. The new HPV vaccine is expected to reduce the incidence of cervical cancer even more in years to come.

Researchers in the CVR are working to improve diagnosis of HPV-related disease, and to develop new drugs that could reduce spread of the virus.

Contact: Sheila Graham

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 Cells infected with HPV

Influenza A virus

Influenza A viruses (IAV) are enveloped, single-stranded negative-sense RNA viruses and are classified within the family Orthomyxoviridae. IAV particles vary in size and shape, and show significant variations among strains, being either spherical or filamentous. Clinical isolates, in particular, frequently form filaments that can be many microns long.

IAVs cause seasonal epidemics in which many millions of people worldwide become infected. The emergence of these strains are influenced by molecular, evolutionary and ecological factors, however, the relative contributions of these factors are unknown.

Researchers at the CVR are seeking to understand the role of evolution, ecology, and molecular adaptations on viral emergence by combining phylogenetics and reverse genetics technology with experimental infections in powerful lab-based culture systems.

The influenza viruses under study include those of human, dog, horse, pig and bat; indeed, two new strains were recently discovered in American bats, but little is known about their epidemiology in natural bat communities.

Contact: Pablo Murcia, Daniel Streicker, Edward Hutchinson

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Section through a tomogram of purified influenza A Udorn/72, a filamentous strain.

CVR researchers are also investigating the structure and function of filamentous forms of IAV to establish how these particles form and initiate infection. They use cryogenic electron tomography to determine how virion proteins come together to form filaments, and are developing methods to image the infectious process to high-resolution in biologically relevant tissue under cryogenic conditions.

Contact: David Bhella

Insect-specific viruses

Insect specific viruses (ISV) are often characterized by their specificity to replicate in certain insects (e.g. mosquitoes) and inability to replicate in vertebrate cells. Mosquito-specific viruses belonging to the Flavivirus genus were the first discovered, but others have also been identified in recent years – but this highlights that many mosquitoes in the wild are infected with mosquito specific viruses.

Little is known about the transmission of ISVs, but data suggest they propagate mainly by vertical transmission (parent to progeny). Some of these ISVs are related to mosquito-borne viruses, such as the flaviviruses – dengue and West Nile virus.

Recently, it has been reported that mosquitoes infected with mosquito-specific viruses can influence the infection and transmission of mosquito-borne human pathogenic viruses.

Research at the CVR focuses on the interaction between the mosquito-specific viruses and the mosquito innate immune response, as well as their effect on the infection and transmission of pathogenic mosquito-borne viruses.

Contact: Alain Kohl

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O'nyong-nyong virus

O'nyong-nyong virus (ONNV) is ONNV is the only known arbovirus to be transmitted by Anopheles mosquitoes, such as the African malaria vector An. gambiae. Most other mosquito-transmitted arboviruses are spread by aedine species including Aedes aegypti and Ae. albopictus, as well as culicine and otherspecies. ONNV is an alphavirus from the Togaviridae family and is closely related to chikungunya virus – though, it has a more restricted geographical range, limited to the African continent. Human infections result in fever, joint pains, rashes and headaches and ONNV has been identified as the causative agent of large epidemics in E Africa.

Previous research at the CVR has investigated the interactions between ONNV and the antiviral immune pathways of An. gambiae. 

Contact: Alain Kohl

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Oropouche virus

Oropouche virus (OROV) is a medically important orthobunyavirus that causes frequent outbreaks of a febrile illness in the northern parts of Brazil. Over half a million OROV infections have occurred in >30 outbreaks since its isolation in 1955. In an urban environment, OROV is transmitted to humans by the midge Culicoides paraensis. The natural host of the virus is the pale-throated three-toed sloth. Recently OROV has been isolated outside the current known epidemic zone in Brazil, while OROV reassortant viruses capable of infecting humans have been isolated in Peru and Venezuela indicating that OROV maybe circulating more widely in South America than previously appreciated.

Researchers at the CVR have recently developed a reverse genetics system to enable molecular characterization of this important yet poorly studied emerging viral zoonosis.

Contact: Ben Brennan

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Peste des petits ruminants

Peste des petits ruminants (PPRV) is a morbillivirus of small ruminants. A close relative of measles, PPRV is endemic in many areas of Africa, the Middle East, Central and Southern Asia and China, and causes a devastating disease that threatens both food security and the livelihoods of smallholders. PPRV has been identified as a top priority global disease of livestock by the Office International des Epizooties (OIE).

CVR researchers are developing novel assays for PPRV neutralising antibodies. These assays will facilitate the rapid and accurate quantification of antibody responses to vaccination, underpinning global eradication programmes, enabling the identification of potential host populations to be targeted for surveillance and providing an early warning of impending outbreaks of PPR in ruminants.

Contact: Brian Willett, Margaret Hosie

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Rabies virus

Rabies virus is one of the earliest known and most notorious zoonotic pathogens. Untreated, it has a case fatality ratio approaching 100% and despite the availability of vaccines since the time of Pasteur, it still kills 60-70,000 people – and many thousands of livestock – every year. Paradoxically, although it can infect and kill any mammalian species, in nature, rabies virus persists in host species-specific epidemiological cycles, mostly in bats and carnivores. Each of these cycles has arisen from an historical jump between species.

Research at the CVR focuses on understanding both the fundamental ecological and evolutionary drivers of viral jumps between species and developing evidence base strategies for the management of rabies at the interface of wildlife, humans and domestic animals. To do this, we use a combination of molecular evolutionary techniques, field studies and mathematical modeling.

Contact: Daniel Streicker

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The common vampire bat (Desmodus rotundus) is the primary source of human and livestock rabies in the Americas. Credit: Daniel Streicker

Respiratory syncytial virus

Respiratory syncytial virus (RSV) is an important viral agent of childhood respiratory tract disease worldwide, causing pneumonia and bronchiolitis in infants. Reinfection is common throughout life, and RSV is also associated with severe illness in the elderly. No vaccine is available, and antivirals are of limited efficacy. RSV has a non-segmented, negative-sense RNA genome and is classified within the pneumovirinae sub-family of the Paramyxoviridae family. Related viruses include measles virus, mumps virus, parainfluenza viruses, canine distemper virus and the emerging pathogens Nipah and Hendra viruses.

Research in the CVR focuses on understanding the structure and assembly of the RSV virion and replicative complexes. We use cryomicroscopy and computational image reconstruction methods to calculate structures for components of the virion that play critical roles in the infectious process, including viral attachment and entry and RNA synthesis. These methods are also being applied to other important paramyxoviruses, in particular parainfluenza viruses.

Contact: David Bhella

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Atomic resolution model of the RSV nucleocapsid, calculated from cryomicroscopy and crystallographic data

Rift Valley fever

Rift Valley fever (RVF) is the most important vector-borne viral zoonosis in Africa. It is transmitted by mosquitoes and can cause severe clinical symptoms in humans and ruminants. RVF outbreaks in livestock cause abortions in pregnant ewes and high mortality rates in young animals. The disease in humans is most commonly a self-limited influenza-like syndrome. However, in severe cases RVF can lead to hepatitis, retinitis, meningo-encephalitis, signs of hemorrhages and death. The recent introduction of this member of the Bunyavirideae into the Arabian Peninsula has raised concerns about the possible spread of RVFV throughout Southern Europe.

At the CVR we work to understand molecular mechanisms of the virus life cycle, pathogenesis and spread to help the development of new antivirals to combat this disease.

Contact: Alain Kohl and Ben Brennan

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Fluorescently labelled RVF viral proteins in kidney cells, viewed by confocal microscopy

Schmallenberg virus

Schmallenberg virus (SBV) is a virus of ruminants that emerged in Northern Europe in 2011. SBV is an arbovirus that spreads between mammalian hosts primarily by Culicoides biting midges. SBV infection causes a mild disease in adult cattle characterized by reduced milk production, fever and diarrhoea. However, SBV infection of susceptible pregnant animals can be associated with congental malformations or stillbirth in lambs and calves.

SBV belongs to the genus Orthobunyavirus within the Bunyaviridae, and is related to other viruses often associated with mutations in the unborn young of ruminants, especially in Asia, Africa and Oceania. Researchers in the CVR work on the interaction of the virus with the antiviral responses of the mammalian & insect host, and in developing new vaccine platforms for SBV and related viruses.

Contacts: Alain Kohl, Massimo Palmarini & Xiaonhong Shi

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Section through SBV infected spinal cord

Semliki forest virus

Semliki forest virus (SFV) is a single stranded positive sense RNA virus belonging to the genus Alphavirus of the family Togaviridae.  It was first isolated from mosquitoes in Uganda in 1942 and is found in central, eastern and southern Africa. It is transmitted by mosquito bites and can cause disease in animals and humans; although their natural host and major mosquito vector is not known. SFV has been used as a model virus for biological research (viral life cycle, viral neuropathy and insect immunity) for many years, due to its broad host range, similarities to other pathogenic viruses (such as chikungunya virus and O`Nyong-Nyong virus) and easy manipulation of the virus.

Research at the CVR uses SFV as model virus to investigate the interaction between the virus and the mosquito-vector, specifically the innate immune response and how this influences vector competence and transmission, and the effects of Wolbachia symbionts on virus transmission.

Contact:  Alain Kohl, Emilie Pondeville, Steve Sinkins

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Semliki forest virus from purified cellculture supernatant (90,000x magnification). By Gleiberg at de.wikipedia [CC BY-SA 2.0], from Wikimedia Commons

Severe fever with thrombocytopenia syndrome virus

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging 
tick-borne pathogen first reported in China in 2009. Phylogenetic analysis of the 
viral genome showed it represents a new lineage within the Phlebovirus genus, distinct from the existing sandfly fever and Uukuniemi virus groups, in the family Bunyaviridae. SFTS disease is characterized by gastrointestinal symptoms, chills, 
joint pain, myalgia, thrombocytopenia, leukocytopenia and some haemorrhagic manifestations, with a case fatality rate of about 2-15%. 


Work at the CVR aims to understand the molecular mechanisms of pathogenesis of this novel and emerging pathogen.

Contact: Ben Brennan

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Fluorescently labelled SFTSV viral proteins in cells, viewed by confocal microscopy

Tick-borne encephalitis virus

Tick borne encephalitis virus (TBEV) is a single stranded positive sense RNA virus belonging to the genus Flavivirus of the family Flaviviridae. It is transmitted by ixodine ticks to mammals, including humans and results in a disease of the central nervous system (like meningitis, encephalitis and meningoencephalitis) with a mortality rate of 1-2%. It can be divided in three subgroups: Western European (transmitted mainly by Ixodes ricinus), Siberian and Eastern (transmitted mainly by Ixodes persulcutus).

A vaccine exists only for the Western European subgroup and not for the others, which are the more pathogenic ones. TBEV is present in many parts of Europe, former Soviet Union and Asia.

Research at the CVR focuses on the interaction between the virus and it tick-vector, specifically the innate immune response and how this influences vector competence and transmission. 

Contact:  Alain Kohl

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European deer tick (Ixodes ricinus)

Uukuniemi virus

Uukuniemi virus (UUKV) is a tick-borne member of the Phlebovirus genus in the Bunyaviridae family. First isolated in Uukuniemi (Finland), UUKV has served as a safe laboratory model to investigate aspects of bunyavirus replication, structural and architectural determination, glycoprotein studies and entry into mammalian cells. Antibodies to UUKV – or a very similar virus(es) – have been detected in humans, birds, rodents and cows. However, UUKV does not seem to cause disease in these species.

Researchers in the CVR are using UUKV to compare with the pathogenic tick-borne phleboviruses, such as SFTSV, to investigate the molecular basis for pathogenicity

Contact: Ben Brennan

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Zika virus

Zika virus (ZIKV) is a mosquito-transmitted arbovirus in the genus Flavivirus of the Flaviviridae family. Although it was first identified in 1947 it caused limited and sporadic cases in Africa and Asia until 2007 when the first significant outbreak occurred in Micronesia. Since then outbreaks have occurred in French Polynesia, New Caledonia, the Cook Islands, Easter Island and the Americas.  Infection is normally asymptomatic however the most recent outbreaks have been linked to an increase in neurological symptoms such as Guillain-Barré syndrome and microcephaly. Its unprecedented spread, coupled with the associated neurological conditions, led to the WHO declaring it a global health emergency in February 2016.      

Research at the CVR focuses on the interactions between the virus and the immune system and interactions with Wolbachia symbionts in the mosquito; developing genetic techniques to understand its biology; and potential novel control measures (including Wolbachia), treatments and vaccine candidates.   

Contact: Alain Kohl, Claire Donald, Steve Sinkins

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 Image of an adult Aedes Aegypti mosquito.