FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Med Vet Entomol / The spatial and seasonal distribution of African horse sickn...
Medical and veterinary entomology1997; 11(3); 203-212; doi: 10.1111/j.1365-2915.1997.tb00397.x

The spatial and seasonal distribution of African horse sickness and its potential Culicoides vectors in Morocco.

Abstract: African horse sickness (AHS) is a vector-borne, infectious disease of equines that is caused by African horse sickness virus (AHSV). The only proven field vector is the biting midge Culicoides imicola, although C. obsoletus and C. pulicaris are suspected vectors. There was a recent epizootic of AHS in Iberia (1987-90) and Morocco (1989-91). In 1994-45 a total of 3887 light trap samples were taken from twenty-two sites distributed over most of Morocco. Culicoides imicola was found to be very widely dispersed, with the greatest catches in the low-lying northwestern areas (between Tangier and Rabat) and at Marrakech. Culicoides imicola was absent at one site only, near Settat. Culicoides imicola was found at altitudes ranging from 4 to 1275 m and in climatic conditions ranging from subhumid to saharan. In general, the catch of C.imicola peaked in late summer and autumn, with a smaller peak in spring. In areas where the insect appears most abundant at least one adult C.imicola per night may be caught in a light trap at all times of year, thus providing a possible means of viral overwintering. Culicoides obsoletus and C.pulicaris are also widely distributed in Morocco but trap catches were much lower than for C.imicola. Peak catches occurred in spring, and late summer and autumn. Other frequently caught species were C.circumscriptus, C.newsteadi, C.puncticollis and members of the odibilis subgenus. In general, the findings for C.imicola correspond well with the distribution of disease outbreaks during the epizootic. Although disease outbreaks were widespread in the country, the greatest number of reported cases was in the northwest (1989-90); in 1991 there were also significant numbers in Marrakech province. No cases were reported in a large area to the west of the Atlas mountains (including Settat) despite the presence of a large equine population. It is likely that during the epizootic the virus overwintered in the northwest (1989) and in Marrakech province (1990). Disease outbreaks occurred from July to December, with a peak from September to November. An unexplained phenomenon is the large number of reported cases of AHS in mules in Chefchaouen province in 1990, despite the apparent low abundance of C.imicola at a site at Chefchaouen. It is argued that C.obsoletus and C.pulicaris were probably of little significance to the epidemiology of AHS in Morocco in 1989-91.
Get Full Text
Publication Date: 1997-07-01 PubMed ID: 9330250DOI: 10.1111/j.1365-2915.1997.tb00397.xGoogle 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
  • Comparative Study
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

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 discusses the distribution of African Horse Sickness and its possible vectors in Morocco. The investigation reveals that a midge known as Culicoides imicola, which has been found to be the only proven vector, is very widely disbursed, especially in the low-lying northwestern areas and Marrakech.

Introduction

  • The research paper focuses on the distribution of African Horse Sickness (AHS), an infectious disease affecting horses and caused by a virus. The disease is transmitted by Culicoides imicola, a specific species of biting midge.
  • The study also includes the potential role of other Culicoides species such as C. obsoletus and C. pulicaris which are suspected vectors.

Methods and Sampling

  • In 1994-95, 3887 light trap samples were taken from twenty-two sites distributed over most parts of Morocco to study the distribution of these vectors.
  • The presence and dispersal of the midge Culicoides imicola were studied across different altitudes and climatic conditions.

Findings

  • Culicoides imicola was found to be widespread, occurring in areas from 4 to 1275 meters of altitude and in climates ranging from subhumid to Saharan.
  • The greatest catches of Culicoides imicola were in the low-lying northwestern areas (between Tangier and Rabat) and in Marrakech.
  • This midge shows two population peaks during the year, one in spring and the most significant one in late summer and autumn, offering a potential channel for the virus to survive during winter.
  • Other variants such as Culicoides obsoletus and C. pulicaris were also found in Morocco, but their population was much lower compared to C. imicola. Their population also peaked in spring, and again in late summer and autumn.

Distribution and Outbreaks

  • The location and timing of AHS outbreaks matched quite well with the distribution of Culicoides imicola. Most cases of AHS were reported in the northwest and in Marrakech province.
  • An unexplained anomaly was the high number of reported AHS cases in mules in Chefchaouen province in 1990, even though Culicoides imicola was less abundant there.

Conclusion

  • The research suggests that the species Culicoides obsoletus and C. pulicaris probably did not significantly contribute to the spread of African Horse Sickness in Morocco during 1989-91, primarily because their populations were much lower than that of Culicoides imicola.

Cite This Article

APA
Baylis M, el Hasnaoui H, Bouayoune H, Touti J, Mellor PS. (1997). The spatial and seasonal distribution of African horse sickness and its potential Culicoides vectors in Morocco. Med Vet Entomol, 11(3), 203-212. https://doi.org/10.1111/j.1365-2915.1997.tb00397.x

Publication

Medical and veterinary entomology
ISSN: 0269-283X
NlmUniqueID: 8708682
Country: England
Language: English
Volume: 11
Issue: 3
Pages: 203-212

Researcher Affiliations

Baylis, M
  • Institute for Animal Health, Pirbright, U.K.
el Hasnaoui, H
    Bouayoune, H
      Touti, J
        Mellor, P S

          MeSH Terms

          • African Horse Sickness / epidemiology
          • African Horse Sickness / transmission
          • Animals
          • Ceratopogonidae
          • Geography
          • Horses
          • Insect Vectors
          • Morocco / epidemiology
          • Population Density
          • Seasons

          Citations

          This article has been cited 22 times.
          1. Zahri A, Ahlamine M, Abou-Elaaz FZ, Talimi H, El Berbri I, Balenghien T, Bourquia M. Diversity of biting midges, mosquitoes and sand flies at four dog shelters in rural and peri-urban areas of Central Morocco. Parasite 2024;31:57.
            doi: 10.1051/parasite/2024057pubmed: 39331804google scholar: lookup
          2. de Klerk J, Tildesley M, Labuschagne K, Gorsich E. Modelling bluetongue and African horse sickness vector (Culicoides spp.) distribution in the Western Cape in South Africa using random forest machine learning. Parasit Vectors 2024 Aug 21;17(1):354.
            doi: 10.1186/s13071-024-06446-8pubmed: 39169433google scholar: lookup
          3. Ashby M, Moore R, King S, Newbrook K, Flannery J, Batten C. Designing a Multiplex PCR-xMAP Assay for the Detection and Differentiation of African Horse Sickness Virus, Serotypes 1-9. Microorganisms 2024 May 3;12(5).
            doi: 10.3390/microorganisms12050932pubmed: 38792762google scholar: lookup
          4. 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
          5. Kettani K, Ebejer MJ, Ackland DM, Bächli G, Barraclough D, Barták M, Carles-Tolrá M, Černý M, Cerretti P, Chandler P, Dakki M, Daugeron C, Jong H, Dils J, Disney H, Droz B, Evenhuis N, Gatt P, Graciolli G, Grichanov IY, Haenni JP, Hauser M, Himmi O, MacGowan I, Mathieu B, Mouna M, Munari L, Nartshuk EP, Negrobov OP, Oosterbroek P, Pape T, Pont AC, Popov GV, Rognes K, Skuhravá M, Skuhravý V, Speight M, Tomasovic G, Trari B, Tschorsnig HP, Vala JC, von Tschirnhaus M, Wagner R, Whitmore D, Woźnica AJ, Zatwarnicki T, Zwick P. Catalogue of the Diptera (Insecta) of Morocco- an annotated checklist, with distributions and a bibliography. Zookeys 2022;1094:1-466.
            doi: 10.3897/zookeys.1094.62644pubmed: 35836978google scholar: lookup
          6. Fairbanks EL, Brennan ML, Mertens PPC, Tildesley MJ, Daly JM. Re-parameterization of a mathematical model of African horse sickness virus using data from a systematic literature search. Transbound Emerg Dis 2022 Jul;69(4):e671-e681.
            doi: 10.1111/tbed.14420pubmed: 34921513google scholar: lookup
          7. Aguilar-Vega C, Bosch J, Fernández-Carrión E, Lucientes J, Sánchez-Vizcaíno JM. Identifying Spanish Areas at More Risk of Monthly BTV Transmission with a Basic Reproduction Number Approach. Viruses 2020 Oct 13;12(10).
            doi: 10.3390/v12101158pubmed: 33066209google scholar: lookup
          8. Belkharchouche M, Berchi S, Mathieu B, Rakotoarivony I, Duhayon M, Baldet T, Balenghien T. Update of the Culicoides (Diptera: Ceratopogonidae) species checklist from Algeria with 10 new records. Parasit Vectors 2020 Sep 10;13(1):463.
            doi: 10.1186/s13071-020-04335-4pubmed: 32912306google scholar: lookup
          9. Quaglia AI, Blosser EM, McGregor BL, Runkel AE 4th, Sloyer KE, Erram D, Wisely SM, Burkett-Cadena ND. Tracking Community Timing: Pattern and Determinants of Seasonality in Culicoides (Diptera: Ceratopogonidae) in Northern Florida. Viruses 2020 Aug 25;12(9).
            doi: 10.3390/v12090931pubmed: 32854272google scholar: lookup
          10. Aguilar-Vega C, Fernández-Carrión E, Lucientes J, Sánchez-Vizcaíno JM. A model for the assessment of bluetongue virus serotype 1 persistence in Spain. PLoS One 2020;15(4):e0232534.
            doi: 10.1371/journal.pone.0232534pubmed: 32353863google scholar: lookup
          11. Leta S, Fetene E, Mulatu T, Amenu K, Jaleta MB, Beyene TJ, Negussie H, Kriticos D, Revie CW. Updating the global occurrence of Culicoides imicola, a vector for emerging viral diseases. Sci Data 2019 Sep 30;6(1):185.
            doi: 10.1038/s41597-019-0197-0pubmed: 31570721google scholar: lookup
          12. Garros C, Labuschagne K, Dommergues L, Ben M, Balenghien T, Muñoz F, Bakhoum MT, Cardinale E, Guis H. Culicoides Latreille in the sun: faunistic inventory of Culicoides species (Diptera: Ceratopogonidae) in Mayotte (Comoros Archipelago, Indian Ocean). Parasit Vectors 2019 Mar 22;12(1):135.
            doi: 10.1186/s13071-019-3379-xpubmed: 30902107google scholar: lookup
          13. Diarra M, Fall M, Fall AG, Diop A, Lancelot R, Seck MT, Rakotoarivony I, Allène X, Bouyer J, Guis H. Spatial distribution modelling of Culicoides (Diptera: Ceratopogonidae) biting midges, potential vectors of African horse sickness and bluetongue viruses in Senegal. Parasit Vectors 2018 Jun 8;11(1):341.
            doi: 10.1186/s13071-018-2920-7pubmed: 29884209google scholar: lookup
          14. White SM, Sanders CJ, Shortall CR, Purse BV. Mechanistic model for predicting the seasonal abundance of Culicoides biting midges and the impacts of insecticide control. Parasit Vectors 2017 Mar 27;10(1):162.
            doi: 10.1186/s13071-017-2097-5pubmed: 28347327google scholar: lookup
          15. Diarra M, Fall M, Lancelot R, Diop A, Fall AG, Dicko A, Seck MT, Garros C, Allène X, Rakotoarivony I, Bakhoum MT, Bouyer J, Guis H. Modelling the Abundances of Two Major Culicoides (Diptera: Ceratopogonidae) Species in the Niayes Area of Senegal. PLoS One 2015;10(6):e0131021.
            doi: 10.1371/journal.pone.0131021pubmed: 26121048google scholar: lookup
          16. Fall M, Diarra M, Fall AG, Balenghien T, Seck MT, Bouyer J, Garros C, Gimonneau G, Allène X, Mall I, Delécolle JC, Rakotoarivony I, Bakhoum MT, Dusom AM, Ndao M, Konaté L, Faye O, Baldet T. Culicoides (Diptera: Ceratopogonidae) midges, the vectors of African horse sickness virus--a host/vector contact study in the Niayes area of Senegal. Parasit Vectors 2015 Jan 21;8:39.
            doi: 10.1186/s13071-014-0624-1pubmed: 25604465google scholar: lookup
          17. Diarra M, Fall M, Fall AG, Diop A, Seck MT, Garros C, Balenghien T, Allène X, Rakotoarivony I, Lancelot R, Mall I, Bakhoum MT, Dosum AM, Ndao M, Bouyer J, Guis H. Seasonal dynamics of Culicoides (Diptera: Ceratopogonidae) biting midges, potential vectors of African horse sickness and bluetongue viruses in the Niayes area of Senegal. Parasit Vectors 2014 Mar 31;7:147.
            doi: 10.1186/1756-3305-7-147pubmed: 24690198google scholar: lookup
          18. 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
          19. Martínez-de la Puente J, Martínez J, Ferraguti M, Morales-de la Nuez A, Castro N, Figuerola J. Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain. Parasit Vectors 2012 Jul 24;5:147.
            doi: 10.1186/1756-3305-5-147pubmed: 22827913google scholar: lookup
          20. Ventim R, Ramos JA, Osório H, Lopes RJ, Pérez-Tris J, Mendes L. Avian malaria infections in western European mosquitoes. Parasitol Res 2012 Aug;111(2):637-45.
            doi: 10.1007/s00436-012-2880-3pubmed: 22427023google scholar: lookup
          21. Guis H, Caminade C, Calvete C, Morse AP, Tran A, Baylis M. Modelling the effects of past and future climate on the risk of bluetongue emergence in Europe. J R Soc Interface 2012 Feb 7;9(67):339-50.
            doi: 10.1098/rsif.2011.0255pubmed: 21697167google scholar: lookup
          22. Acevedo P, Ruiz-Fons F, Estrada R, Márquez AL, Miranda MA, Gortázar C, Lucientes J. A broad assessment of factors determining Culicoides imicola abundance: modelling the present and forecasting its future in climate change scenarios. PLoS One 2010 Dec 6;5(12):e14236.
            doi: 10.1371/journal.pone.0014236pubmed: 21151914google scholar: lookup
          Subscribe to our newsletter
          Join 99,359 horse owners like you who receive our email updates on horse health and nutrition.