Original Research

The 2011 outbreak of African horse sickness in the African horse sickness controlled area in South Africa

John D. Grewar, Camilla T. Weyer, Alan J. Guthrie, Pieter Koen, Sewellyn Davey, Melvyn Quan, Dawid Visser, Esthea Russouw, Gary Bührmann
Journal of the South African Veterinary Association | Vol 84, No 1 | a973 | DOI: https://doi.org/10.4102/jsava.v84i1.973 | © 2013 John D. Grewar, Camilla T. Weyer, Alan J. Guthrie, Pieter Koen, Sewellyn Davey, Melvyn Quan, Dawid Visser, Esthea Russouw, Gary Bührmann | This work is licensed under CC Attribution 4.0
Submitted: 21 December 2012 | Published: 15 November 2013

About the author(s)

John D. Grewar, Veterinary Services, Western Cape Department of Agriculture, South Africa
Camilla T. Weyer, Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, South Africa
Alan J. Guthrie, Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, South Africa
Pieter Koen, Veterinary Services, Western Cape Department of Agriculture, South Africa
Sewellyn Davey, Veterinary Services, Western Cape Department of Agriculture, South Africa
Melvyn Quan, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa
Dawid Visser, Veterinary Services, Western Cape Department of Agriculture, South Africa
Esthea Russouw, Veterinary Services, Western Cape Department of Agriculture, South Africa
Gary Bührmann, Veterinary Services, Western Cape Department of Agriculture, South Africa

Abstract

African horse sickness (AHS) is a controlled animal disease in South Africa, and as a result of the high mortality rates experienced, outbreaks in the AHS controlled area in the Western Cape Province have a significant impact on affected properties as well as on the exportation of live horses from the AHS free zone in metropolitan Cape Town. An outbreak of AHS serotype 1 occurred in the surveillance zone of the AHS controlled area of the Western Cape during the summer of 2011. The epicentre of the outbreak was the town of Mamre in the magisterial district of Malmesbury and the outbreak was confined to a defined containment zone within this area by movement control of all equids and a blanket vaccination campaign. A total of 73 cases of AHS were confirmed during this outbreak, which included four confirmed subclinical cases. The morbidity rate for the outbreak was 16%with a mortality rate of 14%and a case fatality rate of 88%. Outbreak disease surveillance relied on agent identification using polymerase chain reaction (PCR)-based assays, which is novel for an AHS outbreak in South Africa. The source of this outbreak was never confirmed although it is believed to be associated with the illegal movement of an infected animal into the Mamre area. This detailed description of the outbreak provides a sound scientific basis to assist decision making in future AHS outbreaks in the AHS controlled area of South Africa and in countries where AHS is an exotic or emerging disease.

Keywords

equine; epidemic; subclinical; surveillance; vaccination; control; containment zone

Metrics

Total abstract views: 4526
Total article views: 11529

 

Crossref Citations

1. African Horse Sickness Virus: History, Transmission, and Current Status
Simon Carpenter, Philip S. Mellor, Assane G. Fall, Claire Garros, Gert J. Venter
Annual Review of Entomology  vol: 62  issue: 1  first page: 343  year: 2017  
doi: 10.1146/annurev-ento-031616-035010

2. Economic assessment of African horse sickness vaccine impact
Elizabeth F. Redmond, Derrick Jones, Jonathan Rushton
Equine Veterinary Journal  vol: 54  issue: 2  first page: 368  year: 2022  
doi: 10.1111/evj.13430

3. A field investigation of an African horse sickness outbreak in the controlled area of South Africa in 2016
John Duncan Grewar, Camilla Theresa Weyer, Gert Johannes Venter, Lesley Susan Helden, Phillippa Burger, Alan John Guthrie, Peter Coetzee, Karien Labuschagne, Gary Bührmann, Beverley Joan Parker, Peter Neil Thompson
Transboundary and Emerging Diseases  vol: 66  issue: 2  first page: 743  year: 2019  
doi: 10.1111/tbed.13077

4. Development of a Luminex-Based DIVA Assay for Serological Detection of African Horse Sickness Virus in Horses
A. Sánchez-Matamoros, E. Nieto-Pelegrín, C. Beck, B. Rivera-Arroyo, S. Lecollinet, C. Sailleau, S. Zientara, J. M. Sánchez-Vizcaíno
Transboundary and Emerging Diseases  vol: 63  issue: 4  first page: 353  year: 2016  
doi: 10.1111/tbed.12503

5. Designing a Multiplex PCR-xMAP Assay for the Detection and Differentiation of African Horse Sickness Virus, Serotypes 1–9
Martin Ashby, Rebecca Moore, Simon King, Kerry Newbrook, John Flannery, Carrie Batten
Microorganisms  vol: 12  issue: 5  first page: 932  year: 2024  
doi: 10.3390/microorganisms12050932

6. Post‐outbreak African horse sickness surveillance: A scenario tree evaluation in South Africa’s controlled area
John Duncan Grewar, Thibaud Porphyre, Evan S. Sergeant, Camilla Theresa Weyer, Peter Neil Thompson
Transboundary and Emerging Diseases  year: 2020  
doi: 10.1111/tbed.13566

7. Dynamics of African horse sickness virus nucleic acid and antibody in horses following immunization with a commercial polyvalent live attenuated vaccine
C.T. Weyer, J.D. Grewar, P. Burger, C. Joone, C. Lourens, N.J. MacLachlan, A.J. Guthrie
Vaccine  vol: 35  issue: 18  first page: 2504  year: 2017  
doi: 10.1016/j.vaccine.2017.03.005

8. Establishing post‐outbreak freedom from African horse sickness virus in South Africa's surveillance zone
John Duncan Grewar, Evan S. Sergeant, Camilla Theresa Weyer, Lesley Susan van Helden, Beverley Joan Parker, Tasneem Anthony, Peter Neil Thompson
Transboundary and Emerging Diseases  vol: 66  issue: 6  first page: 2288  year: 2019  
doi: 10.1111/tbed.13279

9. The Socioeconomic Impact of Diseases of Working Equids in Low and Middle-Income Countries: A Critical Review
Marta Bonsi, Neil E. Anderson, Gemma Carder
Animals  vol: 13  issue: 24  first page: 3865  year: 2023  
doi: 10.3390/ani13243865

10. A web-based survey of horse owners’ perceptions and network analysis of horse movements relating to African horse sickness distribution in Namibia and South Africa
Danica Liebenberg, Stuart Piketh, Huib van Hamburg
Acta Tropica  vol: 158  first page: 201  year: 2016  
doi: 10.1016/j.actatropica.2016.03.005

11. The socioeconomic impact of equine epizootic lymphangitis in working equids in low and middle-income countries: A scoping review
Marta Bonsi, Neil Euan Anderson, Gemma Carder
Journal of Equine Veterinary Science  vol: 132  first page: 104981  year: 2024  
doi: 10.1016/j.jevs.2023.104981

12. Development of three triplex real-time reverse transcription PCR assays for the qualitative molecular typing of the nine serotypes of African horse sickness virus
Camilla T. Weyer, Christopher Joone, Carina W. Lourens, Mpho S. Monyai, Otto Koekemoer, John D. Grewar, Antoinette van Schalkwyk, Phelix O.A. Majiwa, N. James MacLachlan, Alan J. Guthrie
Journal of Virological Methods  vol: 223  first page: 69  year: 2015  
doi: 10.1016/j.jviromet.2015.07.015

13. African Horse Sickness Caused by Genome Reassortment and Reversion to Virulence of Live, Attenuated Vaccine Viruses, South Africa, 2004–2014
Camilla T. Weyer, John D. Grewar, Phillippa Burger, Esthea Rossouw, Carina Lourens, Christopher Joone, Misha le Grange, Peter Coetzee, Estelle Venter, Darren P. Martin, N. James MacLachlan, Alan J. Guthrie
Emerging Infectious Diseases  vol: 22  issue: 12  first page: 2087  year: 2016  
doi: 10.3201/eid2212.160718

14. Scientific Opinion on the assessment of the control measures of the category A diseases of Animal Health Law: African Horse Sickness
Søren Saxmose Nielsen, Julio Alvarez, Dominique Joseph Bicout, Paolo Calistri, Klaus Depner, Julian Ashley Drewe, Bruno Garin‐Bastuji, José Luis Gonzales Rojas, Christian Gortázar Schmidt, Mette Herskin, Virginie Michel, Miguel Ángel Miranda Chueca, Paolo Pasquali, Helen Clare Roberts, Liisa Helena Sihvonen, Hans Spoolder, Karl Ståhl, Antonio Velarde, Arvo Viltrop, Christoph Winckler, Kris De Clercq, Eyal Klement, Jan Arend Stegeman, Simon Gubbins, Sotiria‐Eleni Antoniou, Alessandro Broglia, Yves Van der Stede, Gabriele Zancanaro, Inma Aznar
EFSA Journal  vol: 19  issue: 2  year: 2021  
doi: 10.2903/j.efsa.2021.6403