DETECTION AND IDENTIFICATION OF TRYPANOSOMES BY POLYMERASE-CHAIN-REACTION IN WILD TSETSE-FLIES IN CAMEROON

The prevalence of various species and subgroups of trypanosomes in inf ected flies from three sleeping sickness foci in Cameroon was determin ed by the use of polymerase chain reaction (PCR). The predominant tset se species found were Glossina palpalis palpalis. Microscopical examin ation of 943 non-teneral tsetse flies revealed an average infection ra te of 10.4%. A total of 90 flies were analyzed for trypanosome identif ication with primer sets specific for Trypanosoma (Trypanozoon) brucei s.l., T. (Duttonella) vivax, T. (Nannomonas) simiae, and forest type T. (Nannamonas) congolense. PCR succeeded in identifying 52 of the 90 infected flies. Other primers were also tested on microscope positive/ PCR-negative infections, and trypanosome subgroups were detected (Kili fi type and savannah type T. congolense). PCR amplification allowed id entification of immature infections and revealed mixed-infections. The PCR technique failed to identify 42.2% (38/90) of the parasitological ly positive flies and the reasons for this failure are discussed. (C) 1998 Elsevier Science B.V. All rights reserved.