African horse sickness

OIE Reference Laboratory Reports

Activities in 2011

Name of disease (or topic) for which you are a designated OIE Reference Laboratory: / African horse sickness
Address of laboratory: / Institute for Animal Health
Ash Road
Pirbright
Woking
UNITED KINGDOM
Tel.: / +44 (0)1483 232441
Fax: / +44 (0)1483 232448
e-mail address:
website: / www.iah.ac.uk
Name (including Title and Position) of Head of Laboratory (Responsible Official): / Dr David Paton
Director of Science
Name (including Title and Position) of OIE Reference Expert: / Dr Chris Oura
Name (including Title and Position) of writer of this report
(if different from above): / Dr Carrie Batten and Prof Peter Mertens


Part I: Summary of general activities related to the disease

1. Test(s) in use/or available for the specified disease/topic at your laboratory

Test / For / Specificity / Total
AHSV ELISA / Antibody / AHSV / 178
AHSV real time RT-PCR / Antigen / AHSV / 1
AHSV VI / Virus / AHSV / 0
SNT / Antibody / AHSV / 0

2. Production and distribution of diagnostic reagents

Type of reagent / Amount supplied nationally
(including for own use) / Amount supplied to other countries
AHSV 2 GHA2010/03 / 2ml to Spain
AHSV reference sera (serotypes 1-9) / 2ml of each to AHVLA / 2ml of each to Switzerland and China

Part II: Activities specifically related to the mandate
of OIE Reference Laboratories

3. International harmonisation and standardisation of methods for diagnostic testing or the production and testing of vaccines

a) Establishment and maintenance of a network with other OIE Reference Laboratories designated for the same pathogen or disease and organisation of regular inter-laboratory proficiency testing to ensure comparability of results

b) Organisation of inter-laboratory proficiency testing with laboratories other than OIE Reference Laboratories for the same pathogens and diseases to ensure equivalence of results

During 2011 the AHS OIE Reference Laboratory at IAH Pirbright participated in the annual AHS ring trial supplied by the AHS EU Reference Laboratory, Algete, Spain. This consisted of a panel of serum and inactivated virus samples for ELISA and RT-PCR respectively. Representatives of the OIE reference laboratory attended the annual AHS ring trial meeting (29th November, Brussels, Belgium) where the results were presented and discussed with other national reference laboratories within the EU.

4. Preparation and supply of international reference standards for diagnostic tests or vaccines

Reference standards of viruses are prepared as part of an ongoing programme of maintenance of virus and reagent stocks and for QA purposes.

Reference antiserum was supplied to Switzerland and China.

5. Research and development of new procedures for diagnosis and control

A research project designed (funded by Defra and Pfizer/Fort-Dodge) to increase our understanding of cross-protective (cross-serotype) immunity / protection in African horse sickness virus infections is being undertaken. These studies build on previous work with a recombinant Modified Vaccinia Ankara (MVA) expressing VP2 of AHSV-4, which raises neutralising antibodies in horses (a generally accepted marker for immunity and protection). The protective capacity of this recombinant MVA is currently being tested in a mouse model that was developed for this purpose in collaboration with scientists at CISA, Madrid (the other European Reference Laboratory for AHS).

As part of an ongoing PhD project, full genome sequence data for the ten genome segments of each of the reference strains of the nine AHSV serotypes has been generated. This will form an initial data set of a sequence database for future molecular epidemiology studies of these viruses (in a similar manner to that already created for BTV). The data has provided a basis for development of AHSV group-specific diagnostic real-time RT-PCR assays, targeting AHSV genome segments 1 and 9. Initial evaluation is good and further optimisation and validation is ongoing. Additionally, prototype serotype specific RT-PCR assays (targeting Seg-2) have been developed and used to serotype recent outbreaks of AHSV in Ethiopia, validation is ongoing.

Work with the highly sensitive serotype-specific real-time RT-PCR assays for AHSV types 1-9 indicated that some of the earliest strains of AHSV contained small amounts of heterologous serotypes. These strains have now been plaque picked to generate monotypic isolates, that will provide a more reliable reference set for individual ‘types’.

6. Collection, analysis and dissemination of epizootiological data relevant to international disease control

No positive RT-PCR samples have been received this year, thus no virus isolation of new strains or genome sequencing has occurred.

7. Maintenance of a system of quality assurance, biosafety and biosecurity relevant to the pathogen and the disease concerned

The Non vesicular reference laboratories which include the OIE AHSV reference laboratory are registered to ISO9001, the AHSV real time RT-PCR and ELISA are accredited to ISO17025.

8. Provision of consultant expertise to OIE or to OIE Member Countries

Members of the OIE reference laboratory participated in several AHS working group meetings organized by Defra and the Horse Trust during the year.

9. Provision of scientific and technical training to personnel from other OIE Member Countries

An IAH OIE twinning project with Biopharma, Morocco came to an end in December 2011 and in order to finish up the project two members of staff from Biopharma attended IAH for 10 days to receive training in diagnostic techniques.

10. Provision of diagnostic testing facilities to other OIE Member Countries

None

11. Organisation of international scientific meetings on behalf of OIE or other international bodies

None

12. Participation in international scientific collaborative studies

Participated (as a partner) in EU FP7 ‘OrbiVac’ grant (coordinated by P.Roy ) London School of Hygiene and Tropical Medecine. Development of vaccines for BTV, EHDV & AHSV. IAH role to participate in development of relevant diagnostic assay systems, particularly DIVA assays.

Defra grant (A673) Development of novel subunit vaccines & Viral delivery mechanisms for AHSV antigens. Work in the UK funded by Defra, with 10% funded by Pfizer / Fort-Dodge. This grant supports collaborative links with Pfizer/Fort-Dodge (in Spain), and with Javier Ortego (Head of the Orbivirus Research Group Valdeolmos (in Spain). This involves development of mouse model systems for BTV and AHSV and also involves development of novel AHSV vaccine candidates.

13. Publication and dissemination of information relevant to the work of OIE (including list of scientific publications, internet publishing activities, presentations at international conferences)

¡  Presentations at international conferences and meetings

Chris Oura: Equine Encephalosis and African Horse Sickness in the Gambia. Epizone 5th annual meeting, 11th April-14th April 2011, Arnhem, The Netherlands.

Katarzyna Bachanek-Bankowska, Sushila Maan, Carrie Batten, Geoff Sutton, Chris Oura, Peter Mertens (2011) AHSV: current molecular-epidemiological situation in Sub-Saharan Africa Oral presentation for the Epizone Bluetongue virus satellite Symposium in Arnhem 13th April 2011-04-15.

Manjunatha N Belaganahalli, Sushila Maan, Narender Maan, Kyriaki Nomikou, Houssam Attoui and Peter P. C. Mertens. Sequencing and genetic characterization of orbiviruses as a new approach to their classification, molecular identification and diagnosis. Talk and Abstract presented at the 5th Annual Meeting of EPIZONE in Arnhem, Netherlands from 11-14th April 2011.

Houssam Attoui “Establishment of rescue technologies for dsRNA viruses at IAH”. Talk presented at Co-ordination meeting of the OrbiNet EMIDA consortium in Maisons Alfort, Paris on 9th May 2011.

Chris Oura: Equine Encephalosis and African Horse Sickness in Africa. Epizone AHSV annual ring trial meeting, 29th November 2011, Tervuren, Belgium.

Narender S. Maan, Sushila Maan, Kyriaki Nomikou, Kasia Bankowska, Manjunatha N. Belaganahalli, Christian Potgieter and Peter P.C. Mertens. Development of novel Real-time RT-PCR assays for identification and typing of Equine encephalosis virus (EEV). Talk and Abstract presented at the XXth National Conference of Indian Virological Society on Managing Emerging and Re-emerging Plant, Animal, Human and Aquatic Viral Diseases: One Health Perspective organized by the National Research Centre on Equines, Sirsa Road, Hisar-125001, Haryana, India from 29-31st December 2011.

¡  Scientific publications in peer-reviewed journals

J.E. Crafford, A.J. Guthrie, M Van Vuuren, P.P.C Mertens, J.N. Burroughs, P.G. Howell, C. A. Batten and C. Hamblin. A competitive ELISA for the detection of group-specific antibody to equine encephalosis virus (2011). Journal of virological methods. 174, 60-64.

Chris A L Oura, Philip Ivens, Katarzyna Bachanek-Bankowska, Abid Bin-Tarif, Demba B Jallow, Corinne Sailleau, Sushila Maan, Peter Mertens, Carrie Batten. (2011) African Horse Sickness: Circulation of a live attenuated vaccine-derived strain. Epidemiology and Infection Epidemiol Infect. 2011 May 9:1-4. [Epub ahead of print] DOI: 10.1017/S095026881100080X

C. A. L Oura, C.A. Batten, P.A.S Ivens, M. Balcha, A. Alhassan, D. Gizaw, M. Elharrak D. B. Jallow, M. Sahle, N Maan, P.C Mertens. S. Maan. Equine encephalosis virus: Evidence for circulation beyond southern Africa. Epidemiol Infect. 2011 Dec 14:1-5. [Epub ahead of print] doi:10.1017/S0950268811002688

Karin Aharonson-Raz, Amir Steinman, Velizar Bumbarov, Sushila Maan, Narender Singh Maan, Kyriaki Nomikou, Carrie Batten, Christiaan Potgieter, Yuval Gottlieb, Peter Mertens, Eyal Klement (2011) The Isolation and Phylogenetic Grouping of Equine Encephalosis Virus in Israel. Emerging Infectious Diseases 17 (10), 1883-6. DOI: http://dx.doi.org/10.3201/eid1710.110350.

Narender S. Maan, Sushila Maan, Kyriaki Nomikou, Manjunatha N. Belaganahalli, Katarzyna Bachanek-Bankowska and Peter P.C. Mertens (2011) Serotype specific primers and gel-based RT-PCR assays for ‘typing’ African horse sickness virus: identification of strains from Africa. Published in PLoS ONE on Oct 20 2011 available online at http://dx.plos.org/10.1371/journal.pone.0025686. doi:10.1371/journal.pone.0025686

Attoui, H., Mertens, P. P. C., Becnel, J., Belaganahalli, S., Bergoin, M., Brussaard, C. P., Chappell, J. D., Ciarlet, M., del Vas, M., Dermody, T. S., Dormitzer, P. R., Duncan, R., Fang, Q., Graham, R., Guglielmi, K. M., Harding, R. M., Hillman, B., Makkay, A., Marzachì, C., Matthijnssens, J., Milne, R. G., Mohd Jaafar, F., Mori, H., Noordeloos, A. A., Omura, T., Patton, J. T., Rao, S., Maan, M., Stoltz, D., Suzuki, N., Upadhyaya, N. M., Wei, C. and Zhou, H. (2011) The family Reoviridae, in Virus Taxonomy , ninth report of the International Committee for the Taxonomy of Viruses. Elsevier Academic Press.

Belhouchet M, Mohd Jaafar F, Firth AE, Grimes JM, Mertens PP, Attoui H. (2011) Detection of a fourth orbivirus non-structural protein. PLoS One. 2011;6(10):e25697. Epub 2011 Oct 12. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025697 doi:10.1371/journal.pone.0025697

J. Castillo-Olivares, E. Calvo-Pinilla, I. Casanova, K. Bankowska, R. Chiam, J.M. Nieto, J. Ortego and P.P.C. Mertens. (2011) A Modified Vaccinia Ankara Virus (MVA) Vaccine Expressing African Horse Sickness Virus (AHSV) VP2 Protects Against AHSV Challenge in an IFNAR - / - Mouse Model. Plos One.

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Annual reports of OIE Reference Centres, 2011 3