History of Orbivirus research in South Africa.
Abstract: In the early colonial history of South Africa, horses played an important role, both in general transportation and in military operations. Frequent epidemics of African horsesickness (AHS) in the 18th century therefore severely affected the economy. The first scientific research on the disease was carried out by Alexander Edington (1892), the first government bacteriologist of the Cape Colony, who resolved the existing confusion that reigned and established its identity as a separate disease. Bluetongue (BT) was described for the first time by Duncan Hutcheon in 1880, although it was probably always endemic in wild ruminants and only became a problem when highly susceptible Merino sheep were introduced to the Cape in the late 18th century. The filterability of the AHS virus (AHSV) was demonstrated in 1900 by M'Fadyean in London, and that of the BT virus (BTV) in 1905 by Theiler at Onderstepoort, thus proving the viral nature of both agents. Theiler developed the first vaccines for both diseases at Onderstepoort. Both vaccines consisted of infective blood followed by hyper-immune serum, and were used for many years. Subsequent breakthroughs include the adaptation to propagation and attenuation in embryonated eggs in the case of BTV and in mouse brains for AHSV. This was followed by the discovery of multiple serotypes of both viruses, the transmission of both by Culicoides midges and their eventual replication in cell cultures. Molecular studies led to the discovery of the segmented double-stranded RNA genomes, thus proving their genetic relationship and leading to their classification in a genus called Orbivirus. Further work included the molecular cloning of the genes of all the serotypes of both viruses and clarification of their relationship to the viral proteins, which led to much improved diagnostic techniques and eventually to the development of a recombinant vaccine, which unfortunately has so far been unsuitable for mass production.
Publication Date: 2012-11-13 PubMed ID: 23327123DOI: 10.4102/jsava.v83i1.532Google Scholar: Lookup
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- Historical Article
- Journal Article
- African Horse Sickness
- Diagnosis
- Disease
- Disease control
- Disease Diagnosis
- Disease Etiology
- Disease Management
- Disease Outbreaks
- Disease Surveillance
- Disease Transmission
- Disease Treatment
- Epidemiology
- Equine Health
- Horses
- Infectious Disease
- Molecular biology
- Serotypes
- Vaccine development
- Veterinary Medicine
- Virology
- Virus
Summary
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The research article discusses the history of Orbivirus research in South Africa, including the scientific understanding and management of diseases such as African horsesickness and Bluetongue, linked to the virus.
Background and Historical Perspective
In the early years of South Africa’s colonial history,
- Horses were crucial for transportation and military operations.
- Frequent outbreaks of African horsesickness (AHS) during the 18th century greatly impaired the economy.
- Diseases caused by the Orbivirus, specifically AHS and Bluetongue (BT), were identified and researched by various scientists and (later) government bacteriologists, such as Alexander Edington and Duncan Hutcheon.
- It is suggested that BT was likely always present in wild ruminants, but only became a significant problem when Merino sheep, highly susceptible to the virus, were brought to the Cape in the late 18th century.
Scientific Progress: Discovery and Vaccination
The paper reviews significant developments in understanding and managing those viruses,
- In the early 20th century, the viral nature of AHS and BT were proven when their filterability was demonstrated.
- Early vaccines developed by Theiler involved infective blood followed by hyper-immune serum.
- Further breakthroughs allowed the viruses to be propagated and attenuated in embryonated eggs (in the case of BT) and mouse brains (for AHS).
Molecular Studies, Diagnostics, and Modern Treatment
The last portion of the paper discusses recent advances in the understanding of these diseases,
- Discovery of multiple serotypes of AHS and BT viruses, their transmission methods, and their ability to replicate in cell cultures.
- Molecular studies led to the identification of the structure of the viruses’ segmented double-stranded RNA genomes, confirming their genetic relationship and justifying their classification in a genus called Orbivirus.
- Further molecular research led to the cloning of the genes of all the serotypes of both viruses and resulted in a greater understanding of their relationship to the viral proteins. This facilitated improved diagnostic techniques and eventually the development of a recombinant vaccine.
- Despite these advancements, the article acknowledges the current limitations in mass-producing the new vaccine.
Cite This Article
APA
Verwoerd DW.
(2012).
History of Orbivirus research in South Africa.
J S Afr Vet Assoc, 83(1), 532.
https://doi.org/10.4102/jsava.v83i1.532 Publication
Researcher Affiliations
- University of Pretoria, South Africa. daan.verwoerd@up.ac.za
MeSH Terms
- African Horse Sickness / epidemiology
- African Horse Sickness / history
- African Horse Sickness / prevention & control
- African Horse Sickness / virology
- Animals
- Bluetongue / epidemiology
- Bluetongue / history
- Bluetongue / prevention & control
- Bluetongue / virology
- Ceratopogonidae / virology
- History, 18th Century
- History, 19th Century
- History, 20th Century
- Horses
- Insect Vectors / virology
- Mice
- Orbivirus / classification
- Orbivirus / physiology
- Orbivirus / ultrastructure
- Sheep
- South Africa / epidemiology
- Viral Vaccines / history
- Viral Vaccines / immunology
- Virus Cultivation / history
Citations
This article has been cited 6 times.- Van Schalkwyk A, Coetzee P, Ebersohn K, Von Teichman B, Venter E. Widespread Reassortment Contributes to Antigenic Shift in Bluetongue Viruses from South Africa.. Viruses 2023 Jul 23;15(7).
- Cameron KN, Mombouli JV, Niama FR, Hayes B, Olson SH, Smith BR, Pante J, Roy S, Laudisoit A, Goldstein T, Joly DO, Bagamboula MPassi R, Lange CE. Orbivirus RNA in a Banana Serotine (Afronycteris nanus) Bat in the Republic of the Congo.. Ecohealth 2022 Dec;19(4):443-449.
- Potgieter AC, Wright IM, van Dijk AA. Consensus Sequence of 27 African Horse Sickness Virus Genomes from Viruses Collected over a 76-Year Period (1933 to 2009).. Genome Announc 2015 Sep 10;3(5).
- Nunes SF, Hamers C, Ratinier M, Shaw A, Brunet S, Hudelet P, Palmarini M. A synthetic biology approach for a vaccine platform against known and newly emerging serotypes of bluetongue virus.. J Virol 2014 Nov;88(21):12222-32.
- Caporale M, Di Gialleonorado L, Janowicz A, Wilkie G, Shaw A, Savini G, Van Rijn PA, Mertens P, Di Ventura M, Palmarini M. Virus and host factors affecting the clinical outcome of bluetongue virus infection.. J Virol 2014 Sep;88(18):10399-411.
- Celma CC, Boyce M, van Rijn PA, Eschbaumer M, Wernike K, Hoffmann B, Beer M, Haegeman A, De Clercq K, Roy P. Rapid generation of replication-deficient monovalent and multivalent vaccines for bluetongue virus: protection against virulent virus challenge in cattle and sheep.. J Virol 2013 Sep;87(17):9856-64.
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