Research Article

A high prevalence of mixed trypanosome infections in tsetse flies in Sinfra, Côte d'Ivoire, detected by DNA amplification

D. K. Masigaa1 p1, J. J. McNamaraa2, C. Laveissièrea3, P. Truca3 and W. C. Gibsona1

a1 Department of Pathology and Microbiology, School of Veterinary Science, University of Bristol, Longford House, Bristol BS18 7DY, UK

a2 Department of Clinical Veterinary Science, University of Bristol, Longford House, Bristol BS18 7D Y, UK

a3 Institut Pierre Richet/OCCGE, BP 1500, Bouaké, Côte d'Ivoire


The prevalence of various species and subgroups of trypanosomes in the Sinfra area of C⊚te d'Ivoire was determined using the polymerase chain reaction (PCR). Using this technique to amplify specific satellite DNA targets, it was possible to identify developmental-stage trypanosomes in the midguts and the proboscides of tsetse without expansion of parasite populations. The predominant tsetse species in the area was Glossina palpalis, while G. pallicera and G. nigrofusca were also present. Microscopical examination of 811 non-teneral flies revealed an infection rate of 14% in midguts and/or proboscides. Three subgroups of Trypanosoma congolense (Savannah, Forest & Kilifi), T. simiae, T.godfreyi, West African T. vivax and T. brucei ssp. were identified using PCR. T. congolense Forest was the most abundant of the Nannomonas trypanosomes. Approximately 40% of all infections were mixed, and there was a significantly higher prevalence of apparently mature T. brucei ssp. trypanosomes than has previously been reported. The present study demonstrates that PCR facilitates the easy identification of mature trypanosome infections in tsetse, providing a reliable estimation of trypanosomiasis challenge.

(Received April 19 1995)

(Revised July 03 1995)

(Accepted July 03 1995)


p1 Present address and address for reprint requests: Kenya Trypanosomiasis Research Institute, P.O. Box 362, Kikuyu, Kenya