Animal Reservoirs and Residual ‘Foci’ of Trypanosoma Brucei Gambiense Sleeping Sickness in West Africa

  • D. H. Molyneux


The epidemiology of T. b. gambiense is reviewed in the light of recent findings, and potential animal reservoir hosts are listed. The discovery of distinct zymodemes in pigs with isozyme characteristics identical with stocks previously isolated only from man, and the human plasma resistant character (BIIT positive) of these stocks, is indicative of a zoonotic source of infection of man in some areas of West Africa. The likely epidemiological differences between savanna and forest foci are emphasised.

The focality of West African sleeping sickness is discussed in relation to the various hypotheses which have been propounded to explain this phenomenon. Recent observations which suggest Glossina can move longer distances on wind fields than hitherto supposed, and its possible implications as an explanation of some residual foci, is discussed. The possible impact of onchocerciasis on the distribution of foci is mentioned.

Key Words

Trypanosomiasis T. b. gambiense Glossina Epidemiology Reservoir hosts West Africa 


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  1. Allsop R. (1972a) Immobilization of game animals in trypanosomiasis research. Bull. Wld. Hlth. Org. 47, 815–819.Google Scholar
  2. Allsop R. (1972b) The role of game animals in the maintenance of endemic and enzoonotic trypanosomiasis in the Lambwe Valley, South Nyanza District, Kenya. Bull. Wld. Hlth. Org. 47, 735–746.Google Scholar
  3. Ashford R. W. (1977) The comparative ecology of Leishmania aethiopica. In Ecologie des Leishmaniases Colloques Internationaux du Cnrs No. 239, 233–240.Google Scholar
  4. Bruce D., Hamerton A. E., Bateman H. R., Mackie F. P. and Lady Bruce (1911) Sleeping sickness and other diseases of man and animals in Uganda during the years 1908–9–10. Repts. Sleep. Sickn. Comm. Roy. Soc. No. 11.Google Scholar
  5. Corson J. F. (1938) A third note on a strain of Trypanosoma gambiense transmitted by Glossina morsitans. Ann. trop. Med. Parasit. 32, 245–248.CrossRefGoogle Scholar
  6. Denecke K. (1941) Menschenpathogene Trypanosomes des Hundes auf Fernando Po. Ein Beitrag zur Epidemiologie der Schlafkrankheit. Arch. F. Hyg. Bakt. 166, 331–348.Google Scholar
  7. Duke H. L. (1912) Antelope and their relation to trypanosomiasis. Proc. R. Soc. B 85, 156–169.CrossRefGoogle Scholar
  8. Duke H. L. (1913) Rept. Sleep. Sickn. Comm. R. Soc. No. 13.Google Scholar
  9. Duke H. L. (1928) Studies on the Bionomics of the Polymorphic Trypanosomes of Man and Ruminants. Final Report of the League of Nations International Commission on Human Trypanosomiasis.Google Scholar
  10. Duviard D. (1977) Migrations of Dysdercus spp. (Hemiptera: Pyrrhocoridae) related to the movements of the Inter-Tropical Convergence Zone in West Africa. Bull. ent. Res. 67, 185–204.CrossRefGoogle Scholar
  11. Fraser A. D. and Duke H. L. (1912) Repts. Sleep. Skkn. Comm. R. Soc. No. 12.Google Scholar
  12. Frezil J. L. and Carnevale P. (1976) Le problème du réservoir de virus et du maintien des foyers de trypano-somiase humaine en Afrique Centrale. Cah. O.R.S.T.O.M. sér. Ent. méd. Parásitol. 14, 307–313.Google Scholar
  13. Gibson W., Mehlitz D., Lanham S. M. and Godfrey D. G. (1978) The identification of Trypanosoma brucei gambiense in Liberian pigs and dogs by isoenzymes and by resistance to human plasma. Tropenmed. Parasit. 29, 335–345.Google Scholar
  14. Godfrey D. G. (1978) Identification of economically important parasites. Nature, Lond. 273, 600–604.CrossRefGoogle Scholar
  15. Godfrey D. G. and Killick Kendrick R. (1967) Cyclically transmitted infections of Trypanosoma brucei, T. rhodesiense and T. gambiense in chimpanzees. Trans. R. Soc. trop. Med. Hyg. 61, 781–791.CrossRefGoogle Scholar
  16. Godfrey D. G. and Kilgour V. (1976) Enzyme electrophoresis in characterizing the causative organism of Gambian trypanosomiasis. Trans. Roy. Soc. trop. Med. Hyg. 70, 219–224.CrossRefGoogle Scholar
  17. Gray A. R. (1970) A study of antigenic relationships of isolates of T. brucei collected from a herd of cattle kept in one locality for 5 years. J. gen. Microbiol. 62, 301–313.CrossRefGoogle Scholar
  18. Gray A. R. (1972) Variable agglutinogenic antigens of Trypanosoma gambiense and their distribution among isolates of the trypanosome collected in different places in Nigeria. Trans. Roy. Soc. trop. Med. Hyg. 66, 263–284.CrossRefGoogle Scholar
  19. Janssens P. G. (1971) Review of the sleeping sickness situation. Tropenmed. Parasit. 22, 213–224.Google Scholar
  20. Joshua R. A., Herbert W. J. and White R. G. (1978) Acquisition by Trypanosoma brucei brucei of potential infectivity for man by passage through birds. Lancet 1, 724–725.CrossRefGoogle Scholar
  21. Kleine F. K. and Fischer W. (1911) Die Rolle der Sangetiere bei der Verbretung der Schlafkrankheit und Trypanosomen befunde sei Sangetierea am Tanganyika. Z. Hyg. Infekt. 70, 1–23.CrossRefGoogle Scholar
  22. LaveissiEre C. (1976) Un Foyer de tryanosomiase humaine sans glossines: Ouahigouya (Republiqe de Haute-Volta). Cah. O.R.S.T.O.M. sér. Ent. méd. Parasitol. 14, 359–367.Google Scholar
  23. LaveissiEre C. and Boreham, P. F. L. (1976) Ecologie de Glossina tachinoides Westwood, 1850, en savane humide d’Afrique de l’Ouest. Part I. Preferences trophiques. Cah. O.R.S.T.O.M. sér. Ent. méd. Parasitol. 14, 187–200.Google Scholar
  24. Larivière M. (1957) Receptivite du Cricetomys gambianus (Rat de Gambie) au Trypanosoma gambiense. C. r. Soc. Biol. 151, 1349.Google Scholar
  25. Le Berre R., Walsh J. F., Davies J. B., Philippon B. and Garms R. (1978) Control of onchocerciasis: medical entomology—a necessary pre-requisite to socioeconomic development. In Proceedings of Medical Entomology Centenary Symposium, November 1977, pp. 70–75. Royal Soc. Trop. Med. Hyg., London.Google Scholar
  26. Mehlitz D. (1977) The behaviour in the blood incubation infectivity test of four Trypanozoon strains isolated from pigs in Liberia. Trans. Roy. Soc. trop. Med. Hyg. 71, 86.CrossRefGoogle Scholar
  27. Mehlitz D. (1978) Untersuchungen zur Empfänglichkeit von Mastomys natalensis fur Trypanosoma (Trypanozoon) brucei gambiense. Tropenmed. Parasit. 29, 101–107.Google Scholar
  28. Mehlitz D. (1979) Trypanosome infections in domestic animals in Liberia. Tropenmed. Parasit. 30, 212–219.Google Scholar
  29. Mesnil F. and Blanchard M. (1912) Infections des Poules du aux Trypanosoma gambiense et T. rhodesiense. C. r. Soc. Biol. 72, 938–940.Google Scholar
  30. Molyneux D. H. (1971) Observations on naturally occurring mammals as reservoir hosts of Trypanosoma brucei gambiense. International Scientific Committee for Trypanosomiasis Research, 13th Meeting Lagos. Commission for Technical Cooperation in Africa South of the Sahara, pp. 81–84.Google Scholar
  31. Molyneux D. H. (1973) Animal reservoirs and Gambian trypanosomiasis. Ann. Soc. Belge. Med. trop. 53, 605–618.Google Scholar
  32. Molyneux D. H., Baldry D. A. T., Van Wettere P., Takken W. and De Raadt P. (1978) The experimental application of insecticides from a helicopter for the control of riverine populations of Glossina tachinoides in West Africa. I. Objectives, experimental area and insecticides evaluated. Pans 24, 391–403.CrossRefGoogle Scholar
  33. Molyneux D. H., Baldry D. A. T. and Fairhurst C. P. (1979) Tsetse movement in wind fields: possible epidemiological and entomological implications for trypanosomiasis and its control. Acta trop. 36, 53–65.PubMedGoogle Scholar
  34. Nash T. A. M. (1978) A review of mainly entomological research which has aided the understanding of human trypanosomiasis and its control. Medical Entomology Centenary Symposium Proceedings, 23–25 Nov. 1977, pp. 39–47.Google Scholar
  35. Newton B. A. (1976) Biochemical Approaches to the taxonomy of kinetoplastid flagellates. In Biology of the Kinetoplastida (Ed. by Lumsden W. H. R. and Evans, D. A.) Vol. 1, pp. 405–434. Academic Press, London.Google Scholar
  36. Page W. A. and McDonald W. A. (1959) An assessment of the degree of man-fly contact exhibited by Glossina palpalis at water holes in northern and southern Nigeria. Ann. Trop. Med. Parasit. 53, 162–165.CrossRefGoogle Scholar
  37. De Raadt P. and Seed J. R. (1977) Trypanosomes causing disease of man in Africa. In Parasitic Protozoa, Vol. 1. pp. 175–237. Academic Press, New York.Google Scholar
  38. Rainey R. C. (1974) Biometeorology and insect flight: some aspects of energy exchange. Ann. Rev. Ent. 19, 407–434.CrossRefGoogle Scholar
  39. Rickman L. R. and Robson J. (1970) The testing of proven Trypanosoma brucei and T rhodesiense strains by the blood incubation infectivity test. Bull. Wld. Hlth. Org. 42, 911–916.Google Scholar
  40. Roubaud E. (1920) Les mouches tsetses en Afrique Occidentale Française. Nos connaissances actuelles sur leure historie et leur role pathogène. Bull. corn. Et. Hist. Sci. d’AOF 3, 257–300.Google Scholar
  41. Scott D. (1970) The epidemiology of Gambian sleeping sickness. In The African Trypanosomiases (Ed. by Mulligan H. W. and Potts W. H.), pp. 614–644. Allen & Unwin, London.Google Scholar
  42. Thomson K. D. B. (1969) Sleeping sickness in the northern states of Nigeria. An outline of the present situation (May 1968). WHO TRYP/INF/69.32, 7pp. plus map (unpublished document).Google Scholar
  43. Van den Berghe L., Chardome M. et Peel E. (1963) Demonstration par transmission cyclique du role possible de quatre petits mammiferes africains comme reservoirs de trypanosomes du groupe brucei. Ann. Soc. Belge. Med. Trop. 2, 157–162.Google Scholar
  44. Van Hoof L. M. J. (1947) Observations on trypanosomiasis in the Belgian Congo. Trans. R. Soc. trop. Med. Hyg. 40, 728–761.Google Scholar
  45. Watson H. J. C. (1962) The domestic pig as a reservoir of T. gambiense. In International Committee for Trypanosomiasis Research, Ccta Publications No. 88, 327.Google Scholar
  46. Wijers D. J. B. (1960) Studies on the behaviour of trypanosomes belonging to the brucei subgroup in the mammalian host. Ph.D. Thesis, University of Amsterdam, 151 pp.Google Scholar
  47. Woo P. T. K. and Soltys M. A. (1969) The experimental infections of reptiles with Trypanosoma brucei. Ann. trop Med. Parasit. 63, 35–38.CrossRefGoogle Scholar
  48. Yesufu H. M. (1971) Experimental transmission of Trypanosoma gambiense to domestic animals. Ann. trop. Med. Parasit. 65, 341–347.CrossRefGoogle Scholar
  49. Yorke W. & Blacklock B. (1915) The reservoir of human trypanosomiasis in Sierra Leone. Ann. trop. Med. Para-sit. 9, 383–390.CrossRefGoogle Scholar
  50. Zillman U. and Mehlitz D. (1979) The natural occurrence of Trypanozoon in domestic chickens in Ivory Coast. Tropenmed. Parasit. 30, 244–248.Google Scholar

Copyright information

© ICIPE 1980

Authors and Affiliations

  • D. H. Molyneux
    • 1
  1. 1.Department of BiologyUniversity of SalfordSalford, Greater ManchesterUK

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