Dr Dan Horton


Reader In Veterinary Virology, School Research Director
MA VetMB MSc PhD FHEA MRCVS DipECZM

Academic and research departments

School of Veterinary Medicine.

Biography

Areas of specialism

Veterinary Science

My qualifications

1999
MA Zoology
University of Cambridge
2002
Vet MB
University of Cambridge
2005
MSc Wild Animal Health
Royal Veterinary College and Institute of Zoology, London
2009
PhD
University of Cambridge
2014
Diplomate of the European College of Zoological Medicine (Wildlife Population Health sub-speciality)
European College of Zoological Medicine
2016
Graduate Certificate in Higher Education
University of Surrey

Research

Research interests

Supervision

Postgraduate research supervision

My teaching

My publications

Publications

Louisa Elizabeth Wallace (2020)Dengue virus antagonism of the Aedes aegypti IMD immune response. University of Surrey

Dengue virus (DENV) is the most significant arthropod-borne virus (arbovirus) of humans, primarily transmitted by Aedes aegypti mosquitoes. Currently there are no specific therapeutics and the existing vaccine exhibits limited efficacy. Therefore, vector control remains the best approach to manage disease spread.

We previously demonstrated that DENV-2 infection does not induce innate immunodeficiency (IMD) signalling in the Ae. aegypti Aag2 cell line, recapitulating in vivo data from other groups. Furthermore, prior infection with DENV-2 reduces IMD signalling activation by classical immune stimuli. This project aimed to identify DENV-2 antagonist(s) responsible for this immune inhibition using an RT-qPCR-based screening platform in which IMD signalling is stimulated in cells expressing DENV-2 proteins individually. Our results identified NS4A as a tentative antagonist, which can now be used to enhance our understanding of Ae. aegypti antiviral immunity by investigating virus-host interactions.

The study of vector immunity is hampered by the lack of tools such as antibodies and cell lines. Our group previously created CRISPR-Cas9 knockout Aag2 cell lines, which lack genes essential in the innate immune pathways. These knockout cell lines were created from clonally selected Aag2 cells derived from the heterogeneous parental cell line, and this report also describes the final characterisation of these clones. Results confirm that the cells are embryonic in origin, which confounded our sex analysis. Aag2 clones were confirmed to be persistently infected insect-specific viruses, cell fusing agent virus and Phasi Charoen-like virus. Transfection efficiencies were also determined for the clones of interest. Finally, mutations introduced by CRISPR-Cas9 were characterised in cells derived from one of the clonally selected lines, with one clone identified as the intended mutant, however the IMD pathway-deficient cell clones were determined as wild type.

Ultimately insights into vector antiviral immunity may contribute towards development of transmission-incompetent mosquitoes, thereby reducing the global burden of dengue.

Foot-and-mouth disease virus (FMDV) typically exists within a replication site as a heterogeneous population. This diversity allows FMDV populations to rapidly adapt to new selection pressures, for example an immune response. High-throughput sequencing (HTS) technologies allow for this sequence diversity to be characterised, however challenges still exist to distinguish real biological variation from process-introduced error. To improve variant calling accuracy, artificial DNA and RNA based populations containing sequence variants at known positions and frequencies were created. These were used to systematically investigate the impact of different laboratory and bioinformatics protocols on variant calling and error generation in HTS datasets. Analysis revealed that variants as low as 0.2% could be predicted in all DNA populations and RNA samples with a high amount of template. While decreasing the amount of RNA input required higher frequency percentage thresholds and more technical replicates to maintain accuracy. The optimised pipeline was applied to FMDV infected epithelium samples derived from vaccinated cattle and identified capsid surface bound substitutions associated with immune escape, all of which were unique to individual viral populations. In order to establish more control over the viral and antibody input, an in vitro experiment was performed with FMDV passaged in the presence of sub-neutralising antibody serum derived from vaccinated cattle. HTS analysis identified capsid surface bound immune escape associated substitutions, unique to individual viral populations. This thesis includes a novel systematic approach to accurately characterise low-frequency variants and demonstrates the evolutionary nature of FMDV, with results suggesting at an individual replication site, immune escape evolution is a stochastic process. Characterising immune escape associated substitutions within FMDV populations has the capacity to improve the fundamental understanding of FMDV evolution which in turn can be used to inform vaccine design and FMD control strategies.
Rift Valley fever phlebovirus (RVFV) is an arbovirus of medical and veterinary importance causing severe disease and mortality in humans and ruminants in endemic regions in Africa and the Arabian Peninsula. Understanding the capability, and limiting factors, of temperate British mosquitoes to support replication and transmission of RVFV is critical in order to understand the potential for RVFV establishment were it introduced to the UK. Using in vitro cell culture the effect of temperature on viral replication kinetics independently of the mosquito was investigated; demonstrating temperatures below 20˚C negatively affect RVFV replication. The full replication cycle was supported at 20˚C in vitro, and this was confirmed within in vivo mosquito experiments with wild-caught Aedes detritus demonstrating a transmission potential for RVFV at 20˚C and 25˚C. Experiments with two colonised lines of Cx. pipiens further demonstrated the transmission potential for RVFV by mosquitoes present in the UK. A novel RNA in situ hybridisation technique substantiated this result showing widespread dissemination of virus from the primary site of infection and evidence of secondary sites of replication within a single mosquito. Characterisation of the consensus sequence of RVFV propagated within these British mosquitoes in comparison to an in vivo mouse model showed potential for virus adaptation when switching between disparate hosts. Reproducible changes at the consensus level within each host had not previously been shown in early passages of RVFV in studies utilising in vitro models of replication. This suggests that RVFV replication generates genomic variation that may lead to adaptations that could promote potential survival in temperate regions. Taken together these findings indicate that transmission of RVFV within the UK by indigenous mosquitoes is possible. However, factors affecting mosquito survival including temperatures greater than 20˚C and ingestion of the higher virus dose (10^7 PFU/mL) will limit the likelihood of such events occurring.
U Zieger, DA Marston, R Sharma, A Chikweto, K Tiwari, M Sayyid, B Louison, H Goharriz, K Voller, AC Breed, D Werling, AR Fooks, DL Horton (2014)The Phylogeography of Rabies in Grenada, West Indies, and Implications for Control, In: PLOS NEGLECTED TROPICAL DISEASES8(10)ARTN e3251 PUBLIC LIBRARY SCIENCE
S Pathak, DL Horton, S Lucas, D Brown, S Quaderi, S Polhill, D Walker, E Nastouli, A Nunez, EL Wise, AR Fooks, M Brown (2014)Diagnosis, management and post-mortem findings of a human case of rabies imported into the United Kingdom from India: a case report, In: VIROLOGY JOURNAL11ARTN 63 BIOMED CENTRAL LTD
MK Morters, S McNabb, DL Horton, AR Fooks, JP Schoeman, HR Whay, JLN Wood, S Cleaveland (2015)Effective vaccination against rabies in puppies in rabies endemic regions, In: VETERINARY RECORD177(6)pp. 150-+ BMJ PUBLISHING GROUP
S Lumley, DL Horton, DA Marston, N Johnson, RJ Ellis, AR Fooks, R Hewson (2016)Complete Genome Sequence of Rift Valley Fever Virus Strain Lunyo, In: Genome Announcements4(2)pp. e00170-16
Using next-generation sequencing technologies, the first complete genome sequence of Rift Valley fever virus strain Lunyo is reported here. Originally reported as an attenuated antigenic variant strain from Uganda, genomic sequence analysis shows that Lunyo clusters together with other Ugandan isolates.
Alessio Lorusso, Valeria Marini, Annapia Di Gennaro, Gaetano Federico Ronchi, Claudia Casaccia, Grazia Carelli, Giuseppe Passantino, Nicola D’Alterio, Vincenzo D’Innocenzo, Giovanni Savini, Federica Monaco, Daniel Horton (2019)Antigenic relationship among zoonotic flaviviruses from Italy, In: Infection, Genetics and Evolution68pp. 91-97 Elsevier
Here we report studies of the antigenic relationship of West Nile virus (WNV) and Usutu virus (USUV), two zoonotic flaviviruses from Italy, together with a Japanese encephalitis virus (JEV) strain and compared them with their genetic relationship using the immunodominant viral E protein. Thirty-nine isolates and reference strains were inactivated and used to immunize rabbits to produce hyper immune sera. Serum samples were tested by neutralization against all isolates and results visualized by generating antigenic map. Strains of WNV, USUV, and JEV grouped in separate clusters on the antigenic map. JEV was closer antigenically to USUV (mean of 3.5 Antigenic Unit, AU, equivalent to a 2-fold change in antibody titer) than to WNV strains (mean of 6 AU). A linear regression model predicted, on average, one unit of antigenic change, equivalent to a 2-fold change in antibody titer, for every 22 amino acid substitutions in the E protein ectodomain. Overall, antigenic map was demonstrated to be robust and consistent with phylogeny of the E protein. Indeed, the map provided a reliable means of visualizing and quantifying the relationship between these flaviviruses. Further antigenic analyses employing representative strains of extant serocomplexes are currently underway. This will provide a more in deep knowledge of antigenic relationships between flaviviruses.
G Massei, AR Fooks, DL Horton, R Callaby, K Sharma, IP Dhakal, U Dahal (2016)Free roaming dogs in Central Nepal: demographics, health and public knowledge, attitudes and practices, In: Zoonoses and Public Health Wiley
In Nepal most dogs are free to roam and may transmit diseases to humans and animals. These dogs often suffer from malnutrition and lack basic health care. Minimal information is available about their demographics and about public attitudes concerning dogs and diseases. We carried out a study in Chitwan District (central Nepal), to collect baseline data on free-roaming owned dog demographics, assess knowledge, attitudes and practices of dog owners concerning dogs and rabies, evaluate rabies vaccination coverage and anthelmintic treatment of dogs, measure dogs’ response to rabies vaccination and assess dog health through body condition scores and parasites. We conducted household interviews with owners of free-roaming female dogs (n=60) and administered dogs with rabies vaccination and anthelmintics. Dog owners regularly fed free-roaming dogs but provided minimal health care; 42% of respondents did not claim ownership of the dog for which they provided care. We collected skin, faecal and blood samples for parasite identification and for measuring rabies virus-specific antibodies. Ninety-two percent of dog owners were aware of the routes of rabies virus transmission but only 35% described the correct post-exposure prophylaxis (PEP) following a dog bite. Twenty-seven percent of the dogs had measurable rabies virus-specific antibody titres and 14% had received anthelmintics in the previous year. Following rabies vaccination, 97% of dogs maintained an adequate antibody titre for > 6 months. Most dogs appeared healthy, although haemoprotozoans, endoparasites and ectoparasites were identified in 12%, 73% and 40% of the dogs, respectively. Poor skin condition and parasite load were associated. Seventy-four percent of the females had litters in one year (mean litter size= 4.5). Births occurred between September and February; we estimated 60% mortality in puppies. We concluded that vaccination coverage, PEP awareness and anthelmintic treatment should be emphasized in educational programmes focussed on animal welfare, veterinary and public health.
DA Marston, LM McElhinney, RJ Ellis, DL Horton, EL Wise, SL Leech, D David, X de Lamballerie, AR Fooks (2013)Next generation sequencing of viral RNA genomes, In: BMC GENOMICS14ARTN 444 BIOMED CENTRAL LTD
DL Horton, MZ Ismail, ES Siryan, ARA Wali, HE Ab-dulla, E Wise, K Voller, G Harkess, DA Marston, LM McElhinney, SF Abbas, AR Fooks (2013)Rabies in Iraq: Trends in Human Cases 2001-2010 and Characterisation of Animal Rabies Strains from Baghdad, In: PLOS NEGLECTED TROPICAL DISEASES7(2)ARTN e2075 PUBLIC LIBRARY SCIENCE
DA Marston, DL Horton, C Ngeleja, K Hampson, LM McElhinney, AC Banyard, D Haydon, S Cleaveland, CE Rupprecht, M Bigambo, AR Fooks, T Lembo (2012)Ikoma Lyssavirus, Highly Divergent Novel Lyssavirus in an African Civet, In: EMERGING INFECTIOUS DISEASES18(4)pp. 664-667 CENTERS DISEASE CONTROL
LM McElhinney, DA Marston, S Leech, CM Freuling, WHM van der Poel, J Echevarria, S Vazquez-Moron, DL Horton, T Mueller, AR Fooks (2013)Molecular Epidemiology of Bat Lyssaviruses in Europe, In: ZOONOSES AND PUBLIC HEALTH60(1)pp. 35-45 WILEY-BLACKWELL
DL Horton, LM McElhinney, DA Marston, JLN Wood, CA Russell, N Lewis, IV Kuzmin, RAM Fouchier, ADME Osterhaus, AR Fooks, DJ Smith (2010)Quantifying Antigenic Relationships among the Lyssaviruses, In: JOURNAL OF VIROLOGY84(22)pp. 11841-11848 AMER SOC MICROBIOLOGY
GR Pant, DL Horton, M Dahal, JN Rai, S Ide, S Leech, DA Marston, LM McElhinney, AR Fooks (2011)Characterization of rabies virus from a human case in Nepal, In: ARCHIVES OF VIROLOGY156(4)pp. 681-684 SPRINGER WIEN
VA Brugman, DL Horton, LP Phipps, N Johnson, AJC Cook, AR Fooks, AC Breed (2013)Epidemiological perspectives on West Nile virus surveillance in wild birds in Great Britain, In: EPIDEMIOLOGY AND INFECTION141(6)pp. 1134-1142 CAMBRIDGE UNIV PRESS
Lisa Yon, J. Paul Duff, Erik O. Ågren, Károly Erdélyi, Ezio Ferroglio, Jacques Godfroid, Jean Hars, Gete Hestvik, Dan Horton, Thijs Kuiken, Antonio Lavazza, Iwona Markowska-Daniel, An Martel, Aleksija Neimanis, Frank Pasmans, Stephen Price, Francisco Ruiz-Fons, Marie-Pierre Ryser-Degiorgis, Frederik Widén, Dolores Gavier-Widén (2018)Recent changes in infectious diseases in European wildlife, In: Journal of Wildlife Diseases55(1)pp. 3-43 Wildlife Disease Association
Many infectious diseases originating from or carried by wildlife impact wildlife conservation and biodiversity, livestock health, and/or human health. We provide an update on changes in the epidemiology of 25 selected infectious wildlife–related diseases in Europe (from 2010-2016) that had an impact, or may have a future impact, on the health of wildlife, livestock, and humans. These pathogens were selected based on their: (1) identification in recent Europe–wide projects as important surveillance targets, (2) inclusion in European Union (EU) legislation as pathogens requiring obligatory surveillance, (3) presence in recent literature on wildlife-related disease in Europe since 2010, (4) inclusion in key pathogen lists released by the Office International des Epizooties (OIE), (5) identification in conference presentations and informal discussions on a group email list by a European network of wildlife disease scientists from the European Wildlife Disease Association, or (6) identification as pathogens with changes in their epidemiology during 2010–2016. The wildlife pathogens or diseases included in this review are: avian influenza virus, seal influenza virus, lagoviruses, rabies virus, bat lyssaviruses, filoviruses, canine distemper virus, morbilliviruses in aquatic mammals, bluetongue virus, West Nile virus, hantaviruses, Schmallenberg virus, Crimean-Congo hemorrhagic fever virus, African swine fever virus, amphibian ranavirus, hepatitis E virus, bovine tuberculosis (Mycobacterium bovis), tularemia (Francisella tularensis), brucellosis (Brucella spp.), salmonellosis (Salmonella spp.), Coxiella burnetii , chytridiomycosis, Echinococcus multilocularis, Leishmania infantum, and chronic wasting disease. Further work is needed to identify all of the key drivers of disease change and emergence, as they appear to be influencing the incidence and spread of these pathogens in Europe. We present a summary of these recent changes over a specified time period to discuss possible commonalities and drivers of disease change and to identify directions for future work on wildlife related diseases in Europe. Many of the pathogens are entering Europe from other continents, while at the same time others are expanding their ranges inside and beyond Europe. Surveillance for these wildlife-related diseases at a continental scale is therefore important for planet-wide assessment, awareness of, and preparedness for, the potential risks they may pose to wildlife, domestic animal, and human health.
DL Horton, B Lawson, A Egbetade, C Jeffries, N Johnson, AA Cunningham, AR Fooks (2013)Targeted surveillance for Usutu virus in British birds (2005-2011), In: VETERINARY RECORD172(1) BMJ PUBLISHING GROUP
KS Baker, R Suu-Ire, J Barr, DTS Hayman, CC Broder, DL Horton, C Durrant, PR Murcia, AA Cunningham, JLN Wood (2014)Viral antibody dynamics in a chiropteran host, In: JOURNAL OF ANIMAL ECOLOGY83(2)pp. 415-428 WILEY-BLACKWELL
AD Goddard, NM Donaldson, DL Horton, R Kosmider, LA Kelly, AR Sayers, AC Breed, CM Freuling, T Mueller, SE Shaw, G Hallgren, AR Fooks, EL Snary (2012)A Quantitative Release Assessment for the Noncommercial Movement of Companion Animals: Risk of Rabies Reintroduction to the United Kingdom, In: RISK ANALYSIS32(10)pp. 1769-1783 WILEY-BLACKWELL
DA Marston, LM McElhinney, AC Banyard, DL Horton, A Nunez, ML Koser, MJ Schnell, AR Fooks (2013)Interspecies protein substitution to investigate the role of the lyssavirus glycoprotein, In: JOURNAL OF GENERAL VIROLOGY94pp. 284-292 SOC GENERAL MICROBIOLOGY
DA Marston, RJ Ellis, DL Horton, IV Kuzmin, EL Wise, LM McElhinney, AC Banyard, C Ngeleja, J Keyyu, S Cleaveland, T Lembo, CE Rupprecht, AR Fooks (2012)Complete Genome Sequence of Ikoma Lyssavirus, In: JOURNAL OF VIROLOGY86(18)pp. 10242-10243 AMER SOC MICROBIOLOGY
DL Horton, LM McElhinney, CM Freuling, DA Marston, AC Banyard, H Goharrriz, E Wise, AC Breed, G Saturday, J Kolodziejek, E Zilahi, MF Al-Kobaisi, N Nowotny, T Mueller, AR Fooks (2015)Complex Epidemiology of a Zoonotic Disease in a Culturally Diverse Region: Phylogeography of Rabies Virus in the Middle East, In: PLOS NEGLECTED TROPICAL DISEASES9(3)ARTN e0003 PUBLIC LIBRARY SCIENCE
B Lawson, A Dastjerdi, S Shah, D Everest, A Nunez, A Pocknell, D Hicks, DL Horton, AA Cunningham, RM Irvine (2015)Mortality associated with avian reovirus infection in a free-living magpie (Pica pica) in Great Britain, In: BMC VETERINARY RESEARCH11ARTN 20 BIOMED CENTRAL LTD
J Schatz, AR Fooks, L McElhinney, D Horton, J Echevarria, S Vazquez-Moron, EA Kooi, TB Rasmussen, T Mueller, CM Freuling (2013)Bat Rabies Surveillance in Europe, In: ZOONOSES AND PUBLIC HEALTH60(1)pp. 22-34 WILEY-BLACKWELL
AT Gilbert, AR Fooks, DTS Hayman, DL Horton, T Mueller, R Plowright, AJ Peel, R Bowen, JLN Wood, J Mills, AA Cunningham, CE Rupprecht (2013)Deciphering Serology to Understand the Ecology of Infectious Diseases in Wildlife, In: ECOHEALTH10(3)pp. 298-313 SPRINGER
N Johnson, C Freuling, D Horton, T Mueller, AR Fooks (2011)Imported Rabies, European Union and Switzerland, 2001-2010, In: EMERGING INFECTIOUS DISEASES17(4)pp. 753-754 CENTERS DISEASE CONTROL
DTS Hayman, N Johnson, DL Horton, J Hedge, PR Wakeley, AC Banyard, S Zhang, A Alhassan, AR Fooks (2011)Evolutionary History of Rabies in Ghana, In: PLOS NEGLECTED TROPICAL DISEASES5(4)ARTN e1001 PUBLIC LIBRARY SCIENCE
AR Fooks, AC Banyard, DL Horton, N Johnson, LM McElhinney, AC Jackson (2014)Current status of rabies and prospects for elimination, In: LANCET384(9951)pp. 1389-1399 ELSEVIER SCIENCE INC
DTS Hayman, AR Fooks, D Horton, R Suu-Ire, AC Breed, AA Cunningham, JLN Wood (2008)Antibodies against Lagos bat virus in megachiroptera from West Africa, In: EMERGING INFECTIOUS DISEASES14(6)pp. 926-928 CENTER DISEASE CONTROL
DL Horton, AC Banyard, DA Marston, E Wise, D Selden, A Nunez, D Hicks, T Lembo, S Cleaveland, AJ Peel, IV Kuzmin, CE Rupprecht, AR Fooks (2014)Antigenic and genetic characterization of a divergent African virus, Ikoma lyssavirus, In: JOURNAL OF GENERAL VIROLOGY95pp. 1025-1032 SOC GENERAL MICROBIOLOGY
F Cliquet, C Freuling, M Smreczak, WHM Van der Poel, DL Horton, AR Fooks, E Robardet, E Picard-Meyer, T Müller (2010)Development of harmonised schemes for monitoring and reporting of rabies in animals in the European Union, In: Scientific Report submitted to EFSA (Q-2010–00078)
AB Ludi, DL Horton, Y Li, M Mahapatra, DP King, NJ Knowles, CA Russell, DJ Paton, JL Wood, DJ Smith, JM Hammond (2014)Antigenic variation of foot-and-mouth disease virus serotype A., In: J Gen Virol95(Pt 2)pp. 384-392
The current measures to control foot-and-mouth disease (FMD) include vaccination, movement control and slaughter of infected or susceptible animals. One of the difficulties in controlling FMD by vaccination arises due to the substantial diversity found among the seven serotypes of FMD virus (FMDV) and the strains within these serotypes. Therefore, vaccination using a single vaccine strain may not fully cross-protect against all strains within that serotype, and therefore selection of appropriate vaccines requires serological comparison of the field virus and potential vaccine viruses using relationship coefficients (r1 values). Limitations of this approach are that antigenic relationships among field viruses are not addressed, as comparisons are only with potential vaccine virus. Furthermore, inherent variation among vaccine sera may impair reproducibility of one-way relationship scores. Here, we used antigenic cartography to quantify and visualize the antigenic relationships among FMD serotype A viruses, aiming to improve the understanding of FMDV antigenic evolution and the scope and reliability of vaccine matching. Our results suggest that predicting antigenic difference using genetic sequence alone or by geographical location is not currently reliable. We found co-circulating lineages in one region that were genetically similar but antigenically distinct. Nevertheless, by comparing antigenic distances measured from the antigenic maps with the full capsid (P1) sequence, we identified a specific amino acid substitution associated with an antigenic mismatch among field viruses and a commonly used prototype vaccine strain, A22/IRQ/24/64.
NS Lewis, JM Daly, CA Russell, DL Horton, E Skepner, NA Bryant, DF Burke, AS Rash, JLN Wood, TM Chambers, RAM Fouchier, JA Mumford, DM Elton, DJ Smith (2011)Antigenic and Genetic Evolution of Equine Influenza A (H3N8) Virus from 1968 to 2007, In: JOURNAL OF VIROLOGY85(23)pp. 12742-12749 AMER SOC MICROBIOLOGY
R Suu-Ire, L Begeman, A Banyard, A Breed, C Drosten, E Eggerbauer, C Freuling, L Gibson, H Goharriz, Daniel Horton, D Jennings, I Kuzmin, D Marston, Y Ntiamoa-Baidu, S Sbarbaro, D Selden, E Wise, T Kuiken, A Fooks, T Müller, J Wood, A Cunningham (2018)Pathogenesis of bat rabies in a natural reservoir: comparative susceptibility of the straw-colored fruit bat (Eidolon helvum) to three strains of Lagos bat virus, In: PLOS Neglected Tropical Diseases.12(3)e0006311 Public Library of Science
Rabies is a fatal neurologic disease caused by lyssavirus infection. People are infected through contact with infected animals. The relative increase of human rabies acquired from bats calls for a better understanding of lyssavirus infections in their natural hosts. So far, there is no experimental model that mimics natural lyssavirus infection in the reservoir bat species. Lagos bat virus is a lyssavirus that is endemic in straw-colored fruit bats (Eidolon helvum) in Africa. Here we compared the susceptibility of these bats to three strains of Lagos bat virus (from Senegal, Nigeria, and Ghana) by intracranial inoculation. To allow comparison between strains, we ensured the same titer of virus was inoculated in the same location of the brain of each bat. All bats (n = 3 per strain) were infected, and developed neurological signs, and fatal meningoencephalitis with lyssavirus antigen expression in neurons. There were three main differences among the groups. First, time to death was substantially shorter in the Senegal and Ghana groups (4 to 6 days) than in the Nigeria group (8 days). Second, each virus strain produced a distinct clinical syndrome. Third, the spread of virus to peripheral tissues, tested by hemi-nested reverse transcriptase PCR, was frequent (3 of 3 bats) and widespread (8 to 10 tissues positive of 11 tissues examined) in the Ghana group, was frequent and less widespread in the Senegal group (3/3 bats, 3 to 6 tissues positive), and was rare and restricted in the Nigeria group (1/3 bats, 2 tissues positive). Centrifugal spread of virus from brain to tissue of excretion in the oral cavity is required to enable lyssavirus transmission. Therefore, the Senegal and Ghana strains seem most suitable for further pathogenesis, and for transmission, studies in the straw-colored fruit bat.
AR Fooks, DL Horton, N Johnson, B Toth, HC Roberts (2011)Changes to pet travel rules: rabies, ticks and tapeworms, In: VETERINARY RECORD169(4)pp. 97-98 BRITISH VETERINARY ASSOC
E Robardet, S Andrieu, TB Rasmussen, M Dobrostana, DL Horton, P Hostnik, I Jaceviciene, T Juhasz, T Mueller, F Mutinelli, A Servat, M Smreczak, E Vanek, S Vazquez-Moron, F Cliquet (2013)Comparative assay of fluorescent antibody test results among twelve European National Reference Laboratories using various anti-rabies conjugates, In: JOURNAL OF VIROLOGICAL METHODS191(1)pp. 88-94 ELSEVIER SCIENCE BV
MK Morters, TJ McKinley, DL Horton, S Cleaveland, JP Schoeman, O Restif, HR Whay, A Goddard, AR Fooks, IM Damriyasa, JLN Wood (2014)Achieving Population-Level Immunity to Rabies in Free-Roaming Dogs in Africa and Asia, In: PLOS NEGLECTED TROPICAL DISEASES8(11)ARTN e3160 PUBLIC LIBRARY SCIENCE
D Horton, E Wise (2011)Raising awareness of rabies., In: The Veterinary record16911pp. 271-271
DTS Hayman, AR Fooks, JM Rowcliffe, R McCrea, O Restif, KS Baker, DL Horton, R Suu-Ire, AA Cunningham, JLN Wood (2012)Endemic Lagos bat virus infection in Eidolon helvum, In: EPIDEMIOLOGY AND INFECTION140(12)pp. 2163-2171 CAMBRIDGE UNIV PRESS
DM Healy, DL Horton (2013)Claire L. leffries, Ashley C. Banyard, In: Neuroviral Infections: RNA Viruses and Retroviruses2pp. 373-373 CRC Press
DL Horton, K Voller, B Haxton, N Johnson, S Leech, T Goddard, C Wilson, LM McElhinney, AR Fooks (2009)European bat lyssavirus type 2 in a Daubenton's bat in Scotland, In: VETERINARY RECORD165(13)pp. 383-384 BRITISH VETERINARY ASSOC
K Brunker, K Hampson, DL Horton, R Biek (2012)Integrating the landscape epidemiology and genetics of RNA viruses: rabies in domestic dogs as a model, In: PARASITOLOGY139(14)pp. 1899-1913 CAMBRIDGE UNIV PRESS
T Nolden, AC Banyard, S Finke, AR Fooks, D Hanke, D Hoeper, DL Horton, TC Mettenleiter, T Mueller, JP Teifke, CM Freuling (2014)Comparative studies on the genetic, antigenic and pathogenic characteristics of Bokeloh bat lyssavirus, In: JOURNAL OF GENERAL VIROLOGY95pp. 1647-1653 SOC GENERAL MICROBIOLOGY
G Garcia, AA Cunningham, DL Horton, TWJ Garner, A Hyatt, S Hengstberger, J Lopez, A Ogrodowczyk, C Fenton, JE Fa (2007)Mountain chickens Leptodactylus fallax and sympatric amphibians appear to be disease free on Montserrat, In: Oryx4103pp. 398-401 Cambridge Univ Press
Sarah Lumley, Daniel Horton, LLM Hernandez-Triana, N Johnson, AR Fooks, R Hewson (2017)Rift Valley fever virus: Strategies for maintenance, survival and vertical transmission in mosquitoes, In: Journal of General Virology98(5)pp. 875-887 Microbiology Society
Rift Valley fever virus (RVFV) is a mosquito-borne arbovirus causing severe disease in humans and ruminants. Spread of RVFV out of Africa has raised concerns that it could emerge in Europe or the USA. Virus persistence is dependent on successful infection of, replication in, and transmission to susceptible vertebrate and invertebrate hosts, modulated by virus-host and vector-virus interactions. The principal accepted theory for the long term maintenance of RVFV involves vertical transmission (VT) of virus to mosquito progeny, with the virus surviving long inter-epizootic periods within the egg. This VT hypothesis however, is yet to be comprehensively proven. Here, evidence for and against the VT of RVFV is reviewed along with the identification of factors limiting its detection in natural and experimental data. The observation of VT for other arboviruses in the genera alphavirus, flavivirus and orthobunyavirus are discussed within the context of RVFV. The review concludes that VT of RVFV is likely but that current data are insufficient to irrefutably prove this hypothesis.
E. HASANOV, S. ZEYNALOVA, M. GELEISHVILI, E. MAES, E. TONGREN, E. MARSHALL, A. BANYARD, L. M. MCELHINNEY, A. M. WHATMORE, A. R. FOOKS, DANIEL HORTON (2017)Assessing the impact of public education on a preventable zoonotic disease: rabies, In: Epidemiology and Infection146(2)pp. 227-235 Cambridge University Press
Effective methods to increase awareness of preventable infectious diseases are key components of successful control programs. Rabies is an example of a disease with significant impact, where public awareness is variable. A recent awareness campaign in a rabies endemic region of Azerbaijan provided a unique opportunity to assess the efficacy of such campaigns. A cluster-cross sectional survey concerning rabies was undertaken following the awareness campaign in 600 households in 38 randomly selected towns, in districts covered by the campaign and matched control regions. This survey demonstrated that the relatively simple awareness campaign was effective at improving knowledge of rabies symptoms and vaccination schedules. Crucially, those in the awareness campaign group were also 1·4 times more likely to report that they had vaccinated their pets, an essential component of human rabies prevention. In addition, low knowledge of appropriate post-exposure treatment and animal sources of rabies provide information useful for future public awareness campaigns in the region and other similar areas.
KL Mansfield, DL Horton, N Johnson, L Li, ADT Barrett, DJ Smith, SE Galbraith, T Solomon, AR Fooks (2011)Flavivirus-induced antibody cross-reactivity, In: JOURNAL OF GENERAL VIROLOGY92pp. 2821-2829 SOC GENERAL MICROBIOLOGY
AGC Vaux, G Gibson, LM Hernandez-Triana, RA Cheke, F McCracken, CL Jeffries, DL Horton, S Springate, N Johnson, AR Fooks, S Leach, JM Medlock (2015)Enhanced West Nile virus surveillance in the North Kent marshes, UK, In: PARASITES & VECTORS8 BIOMED CENTRAL LTD
AC Banyard, DL Horton, C Freuling, T Mueller, AR Fooks (2013)Control and prevention of canine rabies: The need for building laboratory-based surveillance capacity, In: ANTIVIRAL RESEARCH98(3)pp. 357-364 ELSEVIER SCIENCE BV
M Viana, S Cleaveland, J Matthiopoulos, J Halliday, C Packer, ME Craft, K Hampson, A Czupryna, AP Dobson, EJ Dubovi, E Ernest, R Fyumagwa, R Hoare, JGC Hopcraft, DL Horton, MT Kaare, T Kanellos, F Lankester, C Mentzel, T Mlengeya, I Mzimbiri, E Takahashi, B Willett, DT Haydon, T Lembo (2015)Dynamics of a morbillivirus at the domestic-wildlife interface: Canine distemper virus in domestic dogs and lions, In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA112(5)pp. 1464-1469 NATL ACAD SCIENCES
KL Mansfield, AC Banyard, L McElhinney, N Johnson, DL Horton, LM Hernandez-Triana, AR Fooks (2015)Rift Valley fever virus: A review of diagnosis and vaccination, and implications for emergence in Europe, In: VACCINE33(42)pp. 5520-5531 ELSEVIER SCI LTD
K Brunker, DA Marston, DL Horton, S Cleaveland, AR Fooks, R Kazwala, C Ngeleja, T Lembo, M Sambo, ZJ Mtema, L Sikana, G Wilkie, R Biek, K Hampson (2015)Elucidating the phylodynamics of endemic rabies virus in eastern Africa using whole-genome sequencing., In: Virus Evolution1(1) Oxford University Press
Many of the pathogens perceived to pose the greatest risk to humans are viral zoonoses, responsible for a range of emerging and endemic infectious diseases. Phylogeography is a useful tool to understand the processes that give rise to spatial patterns and drive dynamics in virus populations. Increasingly, whole-genome information is being used to uncover these patterns, but the limits of phylogenetic resolution that can be achieved with this are unclear. Here, whole-genome variation was used to uncover fine-scale population structure in endemic canine rabies virus circulating in Tanzania. This is the first whole-genome population study of rabies virus and the first comprehensive phylogenetic analysis of rabies virus in East Africa, providing important insights into rabies transmission in an endemic system. In addition, sub-continental scale patterns of population structure were identified using partial gene data and used to determine population structure at larger spatial scales in Africa. While rabies virus has a defined spatial structure at large scales, increasingly frequent levels of admixture were observed at regional and local levels. Discrete phylogeographic analysis revealed long-distance dispersal within Tanzania, which could be attributed to human-mediated movement, and we found evidence of multiple persistent, co-circulating lineages at a very local scale in a single district, despite on-going mass dog vaccination campaigns. This may reflect the wider endemic circulation of these lineages over several decades alongside increased admixture due to human-mediated introductions. These data indicate that successful rabies control in Tanzania could be established at a national level, since most dispersal appears to be restricted within the confines of country borders but some coordination with neighbouring countries may be required to limit transboundary movements. Evidence of complex patterns of rabies circulation within Tanzania necessitates the use of whole-genome sequencing to delineate finer scale population structure that can that can guide interventions, such as the spatial scale and design of dog vaccination campaigns and dog movement controls to achieve and maintain freedom from disease.
L Both, AC Banyard, C van Dolleweerd, DL Horton, JK-C Ma, AR Fooks (2012)Passive immunity in the prevention of rabies, In: LANCET INFECTIOUS DISEASES12(5)pp. 397-407 ELSEVIER SCIENCE INC
I. F. Saldanha, B. Lawson, H. Goharriz, J. Rodriguez-Ramos Fernandez, S. K. John, A. R. Fooks, A. A. Cunningham, N. Johnson, D. L. Horton (2019)Extension of the known distribution of a novel clade C betacoronavirus in a wildlife host, In: Epidemiology and Infection147e169pp. 1-8 Cambridge University Press
Disease surveillance in wildlife populations presents a logistical challenge, yet is critical in gaining a deeper understanding of the presence and impact of wildlife pathogens. Erinaceus coronavirus (EriCoV), a clade C Betacoronavirus, was first described in Western European hedgehogs (Erinaceus europaeus) in Germany. Here, our objective was to determine whether EriCoV is present, and if it is associated with disease, in Great Britain (GB). An EriCoV-specific BRYT-Green® real-time reverse transcription PCR assay was used to test 351 samples of faeces or distal large intestinal tract contents collected from casualty or dead hedgehogs from a wide area across GB. Viral RNA was detected in 10.8% (38) samples; however, the virus was not detected in any of the 61 samples tested from Scotland. The full genome sequence of the British EriCoV strain was determined using next generation sequencing; it shared 94% identity with a German EriCoV sequence. Multivariate statistical models using hedgehog case history data, faecal specimen descriptions and post-mortem examination findings found no significant associations indicative of disease associated with EriCoV in hedgehogs. These findings indicate that the Western European hedgehog is a reservoir host of EriCoV in the absence of apparent disease.
JS Evans, DL Horton, AJ Easton, AR Fooks, AC Banyard (2012)Rabies virus vaccines: Is there a need for a pan-lyssavirus vaccine?, In: VACCINE30(52)pp. 7447-7454 ELSEVIER SCI LTD
B Yakobson, I Goga, CM Freuling, AR Fooks, V Gjinovci, B Hulaj, D Horton, N Johnson, J Muhaxhiri, I Recica, D David, R O'Flaherty, N Taylor, T Wilsmore, T Mueller (2014)Implementation and monitoring of oral rabies vaccination of foxes in Kosovo between 2010 and 2013-An international and intersectorial effort, In: INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY304(7)pp. 902-910 ELSEVIER GMBH, URBAN & FISCHER VERLAG
Denise Marston, Daniel Horton, Javier Nunez, Richard Ellis, Richard Orton, Nicholas Johnson, Ashley Banyard, Lorraine McElhinney, Conrad Freuling, Müge Firat, Nil Ünal, Mueller Thomas, Anthony Fooks (2017)Genetic analysis of a rabies virus host shift event reveals within-host viral dynamics in a new host, In: Virus Evolution3(2)vex038 Oxford University Press
Host shift events play an important role in epizootics as adaptation to new hosts can profoundly affect the spread of the disease and the measures needed to control it. During the late 1990s, an epizootic in Turkey resulted in a sustained maintenance of rabies virus (RABV) within the fox population. Utilisation of Bayesian inferences to investigate whole genome sequences from a cohort of fox and dog brain tissues from Turkey demonstrated that the epizootic occurred in 1997 (+/- 1 year). Furthermore, these data indicate that the epizootic was most likely due to a host shift from locally infected domestic dogs, rather than an incursion of a novel fox or dog RABV. No evidence was detected for virus adaptation to foxes at consensus sequence level; therefore, the deep sequence data was analysed to investigate the influence of sub-consensus populations on host shift events. Viral heterogeneity was measured in all RABV samples; viruses in the early phase after the host shift had increased heterogeneity, in relation to those in the later stage, possibly indicating a role in establishing transmission within a new host. The dynamics of majority and minority variants are consistent with genetic drift, rather than positive selection. The transient expansion of sub-consensus viral populations in the new host species likely represents the virus adapting to a new environment, perhaps due to increased replication within the CNS resulting in a larger population of viruses, or reflecting the lack of host constraints present in the new host reservoir.
E Wright, S McNabb, T Goddard, DL Horton, T Lembo, LH Nel, RA Weiss, S Cleaveland, AR Fooks (2009)A robust lentiviral pseudotype neutralisation assay for in-field serosurveillance of rabies and lyssaviruses in Africa, In: VACCINE27(51)pp. 7178-7186 ELSEVIER SCI LTD
This project focused on two facets of equine infectious anaemia virus (EIAV) biology; genomic characterisation and virus isolation. A lack of published full genome sequences has led to a poor understanding of genomic variation in the field and inability to design molecular detection methods. Equally the technically demanding nature of equine macrophages has led to much research EIAV being conducted using cell lines that cause viral adaption. Post mortem tissues from six and serum from one British outbreak cases were used to both sequence the full genome of novel field strains and develop a reproducible cell culture system that minimises adaption. Sequencing using primer walking and Sanger sequencing yielded the gag and pol of a symptomatic case but the high variability of the env prevented effective primer design. Next generation sequencing (NGS) was then used to avoid the requirement for sequence specific primers. The full genomes of the three symptomatic viruses were resolved. Two asymptomatic cases were also sequenced but no virus specific reads were returned. One symptomatic virus yielded a high coverage allowing a population analysis which showed the majority of variants localised to the gp90 glycoprotein. Each sequenced British genome added a new EIAV phylogenetic group with each group showing nucleic acid divergence of ~30% from the others. To develop a culture system that minimises adaption, primary monocytes were differentiated to macrophages using M-CSF and autologous equine serum, and successfully infected with the Wyoming strain. The system was used to successfully isolate virus from horses with clinical signs of infection. The activation of the macrophages had little effect on virus replication and dendritic cells appeared to be unable to support efficient replication. Variation was seen between different monocyte isolations so the effect of single cytokines was tested, with IL-4 found to improve EIAV replication reproducibly.