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Field studies of Glossina morsitans Westw. (Dipt., Glossinidae) in relation to Rhodesian sleeping sickness in N'gamiland, Botswana

Published online by Cambridge University Press:  10 July 2009

Frank L. Lambrecht
Affiliation:
c/o University of Arizona Medical College, Department of Community Medicine, Tucson, Arizona 85724, U.S.A.

Extract

Epidemiological studies of Rhodesian sleeping sickness and its vector Glossina morsitans Westw. were made near Motsowi in the western floodplains of the Okovango Swamps, Botswana, during 1967–68. The low apparent densities of the fly (12–27 in three fly rounds compared with 124 in a fourth located in a more densely forested area to the east) and low recapture rates (1·3–3·9%) indicated the Motsowi area to be a feeding ground. Peak densities in January and troughs in October reflected seasonal movements of the fly to and from their dry-season retreats to the east. Most bloodmeals (61%) were on warthog, but 5·5% were on reedbuck in which the Trypanosoma brucei infection rate was 33%. In the Motsowi area the total trypanosome infection rate in G. morsitans was 5·7%,, with T. brucei 0·6%, but the rate varied between localities elsewhere in the Okovango. Man's movements into the fly areas to the east offer the main pathway for transmission of T. brucei, perhaps aided by seasonal movements of reedbuck closer to the settlements. The incidence of human trypanosomiasis is therefore unlikely to be reduced by insecticide campaigns in the farming areas, but livestock will benefit from a reduction in cattle trypanosomiasis.

Type
Research Paper
Copyright
Copyright © Cambridge University Press 1972

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References

Ashcroft, M. T., Burtt, E. & Fairbairn, H. (1959). The experimental infection of some African wild animals with Trypanosoma rhodesiense, T. brucei and T. congolense.—Ann. trop. Med. Parasit. 53, 147161.CrossRefGoogle ScholarPubMed
Atkinson, P. R. (1971). A study of the breeding distribution of Glossina morsitans Westw. in northern Botswana.—Bull. ent. Res. 60, 415426.CrossRefGoogle Scholar
Baker, J. R. & Sachs, R. (1966). The occurrence of trypanosomes in wild animals in an area north-west of the Serengeti National Park, Tanzania: Preliminary Report. Joint WHO/FAO—African Trypanosomiasis Information Service, Tryp/Inf/66.9.Google Scholar
De Andrade Silva, M. A. & Marques Da Silva, J. (1958). On the incidence of trypanosomiasis in game. International Scientific Committee for Trypanosomiasis Research, 7th Meeting, Brussels,25–30 August 1958.London,Commission for Technical Co-operation in Africa South of the Sahara. Publ. no. 41, 269272.Google Scholar
East African Tsetse and Trypanosomiasis Research and Reclamation Organization (1955). Notes for field studies of tsetse flies in East Africa.—2nd edn., 33 pp. Nairobi, Government Printer.Google Scholar
Gear, J. H. S. & De Meillon, B. (1939). Laboratory investigations of two cases of trypanosomiasis contracted in Ngamiland, Bechuanaland.—S. Afr. Med. J. 13, 233236.Google Scholar
Geigy, R., Kauffmann, M. & Beglinger, R. (1967). A survey of wild animals as potential reservoirs of trypanosomiasis in the Ulanga District (Tanzania).—Acta trop. 24, 97108.Google ScholarPubMed
Jackson, C. H. N. (1933). The causes and implications of hunger in tsetse-flies.—Bull. ent. Res. 24, 443482.CrossRefGoogle Scholar
Jackson, C. H. N. (1953). A mixed population of Glossina morsitans and G. swynnertoni.—J. Anim. Ecol. 22, 7886.CrossRefGoogle Scholar
Scott, D. (1968). Botswana Sleeping Sickness Service.Annual Report for 1967 (unpublished).Google Scholar
Scott, D. & Lambrecht, F. L. (1967). Human trypanosomiasis in the N'gamiland and Chobe Districts of Botswana prior to 1966. A retrospective historical and epidemiological review. WHO African Regional Office Trypanosomiasis Control Project in Botswana. Addendum to Quarterly Report. 2nd Quarter 1967. Maun, 5th July 1967.Google Scholar