FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Annals of tropical medicine and parasitology1995; 89(1); 1-15; doi: 10.1080/00034983.1995.11812923

The transmission and geographical spread of African horse sickness and bluetongue viruses.

Abstract: African horse sickness virus (AHSV) and bluetongue virus (BTV) are dsRNA viruses within the genus Orbivirus. Both are able to cause non-contagious, infectious arthropod-borne diseases in their respective vertebrate hosts. AHSV infects equines and occasionally dogs, whereas BTV replicates in ruminants. The disease caused by AHSV is usually at its most severe in horses, whereas certain breeds of sheep are particularly sensitive to BTV infection. AHSV is endemic in sub-Saharan Africa but periodically makes brief excursions beyond this area. BTV occurs much more widely and can be found in a band around the World, stretching from approximately 40 degrees N to 35 degrees S. In the wild, both viruses are transmitted between their vertebrate hosts almost entirely via the bites of arthropod vectors, although dogs can occasionally acquire AHSV by eating virus-contaminated meat and BTV may be infrequently transmitted via infected semen or transplacentally. Because of their reliance upon arthropod vectors, BTV and AHSV have a global distribution which is limited not only by the requirement for susceptible vertebrates but also by the necessity for competent arthropod vectors. The major vectors of AHSV and BTV are certain species of Culicoides biting midge, which are true biological vectors but mosquitoes and/or ticks may also be involved to a greater or lesser extent. Until recently, AHSV has apparently been unable to survive beyond its traditional endemic zones in sub-Saharan Africa for more than 2-3 years at most. This has been interpreted as being due to a number of factors, including the absence of a long-term vertebrate reservoir, a lower prevalence, shorter, seasonal incidence and decreased transmission efficiency of the local vectors and also possibly to the effect of control measures (vector abatement, vaccination). The recent outbreaks of African horse sickness (AHS) in Spain, Portugal and Morocco, which persisted for at least 5 years (1987-1991) therefore seem to have established a new pattern in AHSV survival in an epidemic zone. This extended persistence may be due to the 'all-year-round' presence in the area of adult Culicoides imicola, the major AHSV vector. This is basically an Afro-Asiatic species and its continuous presence in parts of Iberia and may be due to some recent moderation in the climate. Further northerly extensions in the range of Culicoides imicola, in response to 'climatic moderation', cannot be ruled out and could substantially increase the area of Europe 'at risk' to AHS.(ABSTRACT TRUNCATED AT 400 WORDS)
Get Full Text
Publication Date: 1995-02-01 PubMed ID: 7741589DOI: 10.1080/00034983.1995.11812923Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article
  • Research Support
  • Non-U.S. Gov't
  • Review

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research focuses on the transmission and geographical spread of two diseases, African horse sickness and bluetongue viruses. Both diseases are transmitted via arthropod vectors and are studied in the context of their the vectors, the vertebrate hosts, and the environmental conditions that influence their spread.

The Viruses and Their Respective Hosts

  • The African horse sickness virus (AHSV) and bluetongue virus (BTV) are diseases that belong to the genus Orbivirus. Both are non-contagious infectious diseases.
  • AHSV primarily infects horses and, occasionally, dogs, and is especially severe in equines. It is mostly found in areas within sub-Saharan Africa.
  • BTV infects ruminants, with specific breeds of sheep being exceptionally sensitive to the infection. It has a significantly broader geographical distribution, occurring in a band that stretches around the World from approximately 40 degrees N to 35 degrees S.

Transmission Vectors

  • Both these viruses are usually transmitted via arthropod vectors, i.e., through the bites of insects such as mosquitoes or ticks.
  • AHSV can also be contracted by dogs through consumption of virus-contaminated meat. BTV can sometimes spread through infected semen or via intrauterine infection.
  • The spread of these viruses relies heavily on competent arthropod vectors. The primary vectors are certain species of Culicoides biting midge, although mosquitoes and ticks may sometimes be involved.

Geographical Spread and Persistence

  • Historically, AHSV has been unable to persist outside its endemic zones in sub-Saharan Africa for more than 2-3 years due to factors such as the lack of a long-term reservoir, lower prevalence, seasonal incidence, decreased transmission efficiency of the local vectors, and possibly control measures like vector abatement and vaccination.
  • Recent outbreaks in Spain, Portugal, and Morocco that persisted for at least five years (1987-1991) seem to indicate a change in this pattern.
  • Extended persistence may be due to the all-year-round presence of Culicoides imicola, the primary AHSV vector, in these regions – this might be due to a recent change in climate, rendering the area more apt for hosting the vector.
  • If the range of Culicoides imicola continues to extend further north due to climatic moderation, it could put a larger area of Europe at risk of AHSV.

Cite This Article

APA
Mellor PS, Boorman J. (1995). The transmission and geographical spread of African horse sickness and bluetongue viruses. Ann Trop Med Parasitol, 89(1), 1-15. https://doi.org/10.1080/00034983.1995.11812923

Publication

Annals of tropical medicine and parasitology
ISSN: 0003-4983
NlmUniqueID: 2985178R
Country: England
Language: English
Volume: 89
Issue: 1
Pages: 1-15

Researcher Affiliations

Mellor, P S
  • Institute for Animal Health, Pirbright Laboratory, Woking, Surrey, U.K.
Boorman, J

    MeSH Terms

    • Africa South of the Sahara / epidemiology
    • African Horse Sickness / epidemiology
    • African Horse Sickness / transmission
    • Animals
    • Arthropod Vectors
    • Bluetongue / epidemiology
    • Bluetongue / transmission
    • Ceratopogonidae
    • Culicidae
    • Horses
    • Insect Vectors
    • North America / epidemiology
    • Seasons
    • Sheep
    • Spain / epidemiology
    • Ticks

    References

    This article includes 134 references

    Citations

    This article has been cited 36 times.
    1. Zouyed I, Boussena S, Ramdani N, Damerdji HE, Benavides JA, Medkour H. Spatiotemporal Dynamics of Emerging Foot-and-Mouth Disease, Bluetongue, and Peste Des Petits Ruminants in Algeria. Viruses 2025 Jul 17;17(7).
      doi: 10.3390/v17071008pubmed: 40733624google scholar: lookup
    2. Payan-Carreira R, Simões M. Bluetongue's New Frontier-Are Dogs at Risk?. Vet Sci 2025 May 20;12(5).
      doi: 10.3390/vetsci12050505pubmed: 40431598google scholar: lookup
    3. Hu XB, Xu J, Zhang Y, Meng FH, Tian ZC, Guan GQ, Luo JX, Yin H, Du JZ. Monoclonal antibody and B-cell epitope mapping of the VP7 protein in bluetongue virus. Virol J 2025 Apr 30;22(1):129.
      doi: 10.1186/s12985-025-02733-7pubmed: 40307924google scholar: lookup
    4. Celina SS, King S, Ashby M, Harris K, Polo N, Alishani M, Robaj A, Hamidi A, Sylejmani D, Batten C, Černý J. Re-Emergence of BTV-4 in Sheep Farms in Kosovo, 2020: A Retrospective Study. Transbound Emerg Dis 2023;2023:3112126.
      doi: 10.1155/2023/3112126pubmed: 40303726google scholar: lookup
    5. Hanekom J, Ebersohn K, Penzhorn L, Quan M, Leisewitz A, Guthrie A, Fosgate GT. Bluetongue Virus Infection in Farm Dogs Exposed to an Infected Sheep Flock in South Africa. Transbound Emerg Dis 2024;2024:2446398.
      doi: 10.1155/2024/2446398pubmed: 40303113google scholar: lookup
    6. Kim K, Xu T, Kannan Villalan A, Chi T, Yu X, Jin M, Wu R, Ni G, Sui S, Wang Z, Wang X. Environmental and Historical Determinants of African Horse Sickness: Insights from Predictive Modeling. Transbound Emerg Dis 2024;2024:5586647.
      doi: 10.1155/2024/5586647pubmed: 40303017google scholar: lookup
    7. Huang C, Wang J, Ruan Z, Wu J, Lin Y, Cao C, Yang J, Weng Q, Jin Y, Chen P, Hua Q. Real-Time Reverse Transcription Multienzyme Isothermal Rapid Amplification for Rapid Detection of African Horse Sickness Virus. Transbound Emerg Dis 2025;2025:1852368.
      doi: 10.1155/tbed/1852368pubmed: 40302746google scholar: lookup
    8. Tayebwa DS, Hyeroba D, Dunn CD, Dunay E, Richard JC, Biryomumaisho S, Acai JO, Goldberg TL. Viruses of free-roaming and hunting dogs in Uganda show elevated prevalence, richness and abundance across a gradient of contact with wildlife. J Gen Virol 2024 Jul;105(7).
      doi: 10.1099/jgv.0.002011pubmed: 39045787google scholar: lookup
    9. Frisch V, Fuehrer HP, Cavalleri JV. Relevant Brachycera (Excluding Oestroidea) for Horses in Veterinary Medicine: A Systematic Review. Pathogens 2023 Apr 6;12(4).
      doi: 10.3390/pathogens12040568pubmed: 37111454google scholar: lookup
    10. Jones LM, Hawes PC, Salguero FJ, Castillo-Olivares J. Pathological features of African horse sickness virus infection in IFNAR(-/-) mice. Front Vet Sci 2023;10:1114240.
      doi: 10.3389/fvets.2023.1114240pubmed: 37065248google scholar: lookup
    11. Wang Y, Ong J, Ng OW, Songkasupa T, Koh EY, Wong JPS, Puangjinda K, Fernandez CJ, Huangfu T, Ng LC, Chang SF, Yap HH. Development of Differentiating Infected from Vaccinated Animals (DIVA) Real-Time PCR for African Horse Sickness Virus Serotype 1. Emerg Infect Dis 2022 Dec;28(12):2446-2454.
      doi: 10.3201/eid2812.220594pubmed: 36417933google scholar: lookup
    12. Bekker S, Potgieter CA, van Staden V, Theron J. Investigating the Role of African Horse Sickness Virus VP7 Protein Crystalline Particles on Virus Replication and Release. Viruses 2022 Oct 4;14(10).
      doi: 10.3390/v14102193pubmed: 36298748google scholar: lookup
    13. Nelson E, Thurston W, Pearce-Kelly P, Jenkins H, Cameron M, Carpenter S, Guthrie A, England M. A Qualitative Risk Assessment for Bluetongue Disease and African Horse Sickness: The Risk of Entry and Exposure at a UK Zoo. Viruses 2022 Feb 28;14(3).
      doi: 10.3390/v14030502pubmed: 35336912google scholar: lookup
    14. Abdelsalam NR, Balbaa MG, Osman HT, Ghareeb RY, Desoky EM, Elshehawi AM, Aljuaid BS, Elnahal ASM. Inheritance of resistance against northern leaf blight of maize using conventional breeding methods. Saudi J Biol Sci 2022 Mar;29(3):1747-1759.
      doi: 10.1016/j.sjbs.2021.10.055pubmed: 35280531google scholar: lookup
    15. Gao H, Wang L, Ma J, Gao X, Xiao J, Wang H. Modeling the current distribution suitability and future dynamics of Culicoides imicola under climate change scenarios. PeerJ 2021;9:e12308.
      doi: 10.7717/peerj.12308pubmed: 34760364google scholar: lookup
    16. More S, Bicout D, Bøtner A, Butterworth A, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Mertens P, Savini G, Zientara S, Broglia A, Baldinelli F, Gogin A, Kohnle L, Calistri P. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): bluetongue. EFSA J 2017 Aug;15(8):e04957.
      doi: 10.2903/j.efsa.2017.4957pubmed: 32625623google scholar: lookup
    17. Du J, Gao S, Tian Z, Guo Y, Kang D, Xing S, Zhang G, Liu G, Luo J, Chang H, Yin H. Transcriptome analysis of responses to bluetongue virus infection in Aedes albopictus cells. BMC Microbiol 2019 Jun 10;19(1):121.
      doi: 10.1186/s12866-019-1498-3pubmed: 31182015google scholar: lookup
    18. Courtejoie N, Bournez L, Zanella G, Durand B. Quantifying bluetongue vertical transmission in French cattle from surveillance data. Vet Res 2019 May 14;50(1):34.
      doi: 10.1186/s13567-019-0651-1pubmed: 31088555google scholar: lookup
    19. Veiga J, Martínez-de la Puente J, Václav R, Figuerola J, Valera F. Culicoides paolae and C. circumscriptus as potential vectors of avian haemosporidians in an arid ecosystem. Parasit Vectors 2018 Oct 1;11(1):524.
      doi: 10.1186/s13071-018-3098-8pubmed: 30269688google scholar: lookup
    20. Pudar D, Petrić D, Allène X, Alten B, Ayhan N, Cvetkovikj A, Garros C, Goletić T, Gunay F, Hlavackova K, Ćupina AI, Kavran M, Lestinova T, Mathieu B, Mikov O, Pajović I, Rakotoarivony I, Stefanovska J, Vaselek S, Zuko A, Balenghien T. An update of the Culicoides (Diptera: Ceratopogonidae) checklist for the Balkans. Parasit Vectors 2018 Aug 13;11(1):462.
      doi: 10.1186/s13071-018-3051-xpubmed: 30103828google scholar: lookup
    21. Oluwayelu D, Adebiyi A, Tomori O. Endemic and emerging arboviral diseases of livestock in Nigeria: a review. Parasit Vectors 2018 Jun 7;11(1):337.
      doi: 10.1186/s13071-018-2911-8pubmed: 29880024google scholar: lookup
    22. Du J, Xing S, Tian Z, Gao S, Xie J, Chang H, Liu G, Luo J, Yin H. Proteomic analysis of sheep primary testicular cells infected with bluetongue virus. Proteomics 2016 May;16(10):1499-514.
      doi: 10.1002/pmic.201500275pubmed: 26989863google scholar: lookup
    23. Onyango MG, Michuki GN, Ogugo M, Venter GJ, Miranda MA, Elissa N, Djikeng A, Kemp S, Walker PJ, Duchemin JB. Delineation of the population genetic structure of Culicoides imicola in East and South Africa. Parasit Vectors 2015 Dec 24;8:660.
      doi: 10.1186/s13071-015-1277-4pubmed: 26704134google scholar: lookup
    24. Zwart L, Potgieter CA, Clift SJ, van Staden V. Characterising Non-Structural Protein NS4 of African Horse Sickness Virus. PLoS One 2015;10(4):e0124281.
      doi: 10.1371/journal.pone.0124281pubmed: 25915516google scholar: lookup
    25. Nielsen SA, Banta G, Rasmussen AM, Skovgård H. Community analysis of biting midges (Culicoides Latr.) on livestock farms in Denmark. Parasitol Res 2014 Dec;113(12):4525-33.
      doi: 10.1007/s00436-014-4142-zpubmed: 25326377google scholar: lookup
    26. Rigot T, Conte A, Goffredo M, Ducheyne E, Hendrickx G, Gilbert M. Predicting the spatio-temporal distribution of Culicoides imicola in Sardinia using a discrete-time population model. Parasit Vectors 2012 Nov 22;5:270.
      doi: 10.1186/1756-3305-5-270pubmed: 23174043google scholar: lookup
    27. Pérez JM, García-Ballester JA, López-Olvera JR, Serrano E. Monitoring bluetongue virus vectors in Andalusia (SW Europe): Culicoides species composition and factors affecting capture rates of the biting midge Culicoides imicola. Parasitol Res 2012 Sep;111(3):1267-75.
      doi: 10.1007/s00436-012-2961-3pubmed: 22610444google scholar: lookup
    28. Morag N, Saroya Y, Braverman Y, Klement E, Gottlieb Y. Molecular identification, phylogenetic status, and geographic distribution of Culicoides oxystoma (Diptera: Ceratopogonidae) in Israel. PLoS One 2012;7(3):e33610.
      doi: 10.1371/journal.pone.0033610pubmed: 22438964google scholar: lookup
    29. Randolph SE, Rogers DJ. The arrival, establishment and spread of exotic diseases: patterns and predictions. Nat Rev Microbiol 2010 May;8(5):361-71.
      doi: 10.1038/nrmicro2336pubmed: 20372156google scholar: lookup
    30. Bouwknegt C, van Rijn PA, Schipper JJ, Hölzel D, Boonstra J, Nijhof AM, van Rooij EM, Jongejan F. Potential role of ticks as vectors of bluetongue virus. Exp Appl Acarol 2010 Oct;52(2):183-92.
      doi: 10.1007/s10493-010-9359-7pubmed: 20358393google scholar: lookup
    31. Chiam R, Sharp E, Maan S, Rao S, Mertens P, Blacklaws B, Davis-Poynter N, Wood J, Castillo-Olivares J. Induction of antibody responses to African horse sickness virus (AHSV) in ponies after vaccination with recombinant modified vaccinia Ankara (MVA). PLoS One 2009 Jun 22;4(6):e5997.
      doi: 10.1371/journal.pone.0005997pubmed: 19543394google scholar: lookup
    32. Hofmann MA, Renzullo S, Mader M, Chaignat V, Worwa G, Thuer B. Genetic characterization of toggenburg orbivirus, a new bluetongue virus, from goats, Switzerland. Emerg Infect Dis 2008 Dec;14(12):1855-61.
      doi: 10.3201/eid1412.080818pubmed: 19046507google scholar: lookup
    33. Wilson A, Mellor P. Bluetongue in Europe: vectors, epidemiology and climate change. Parasitol Res 2008 Dec;103 Suppl 1:S69-77.
      doi: 10.1007/s00436-008-1053-xpubmed: 19030888google scholar: lookup
    34. Mehlhorn H, Schmahl G, Schumacher B, D'Haese J, Walldorf V, Klimpel S. Effects of Bayofly on specimens of Culicoides species when incubated in hair taken from the feet of previously treated cattle and sheep. Parasitol Res 2008 Feb;102(3):519-22.
      doi: 10.1007/s00436-007-0842-ypubmed: 18188598google scholar: lookup
    35. Mehlhorn H, Schmahl G, D'Haese J, Schumacher B. Butox 7.5 pour on: a deltamethrin treatment of sheep and cattle: pilot study of killing effects on Culicoides species (Ceratopogonidae). Parasitol Res 2008 Feb;102(3):515-8.
      doi: 10.1007/s00436-007-0841-zpubmed: 18183424google scholar: lookup
    36. Mehlhorn H, Walldorf V, Klimpel S, Jahn B, Jaeger F, Eschweiler J, Hoffmann B, Beer M. First occurrence of Culicoides obsoletus-transmitted Bluetongue virus epidemic in Central Europe. Parasitol Res 2007 Jun;101(1):219-28.
      doi: 10.1007/s00436-007-0519-6pubmed: 17385085google scholar: lookup
    Subscribe to our newsletter
    Join 100,151 horse owners like you who receive our email updates on horse health and nutrition.