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Tsetse flies are the cyclical vector of human and animal African trypanosomiasis. To improve vector control in order to achieve the elimination of human African trypanosomiasis (HAT) and boost the control of animal diseases, investigations have been undertaken on the tripartite association between tsetse, trypanosome, and symbionts. It is in this light that Sodalis glossinidius and different trypanosomes were identified in Glossina palpalis palpalis caught in Fontem in southern Cameroon. For this study, DNA was extracted from whole flies, and S. glossinidius and different trypanosome species were identified by polymerase chain reaction (PCR). Statistical analyses were performed to compare the trypanosome and S. glossinidius infection rates and to look for an association between these microorganisms. Of the 274 G. p. palpalis caught, 3.3% (9/274) were teneral. About 35% (96/274) of these flies harbored S. glossinidius. Of the 265 non-teneral flies, 37.7% were infected by trypanosomes. The infection rates of Trypanosoma congolense “forest type” and Trypanosoma vivax were 26.04% and 18.11%, respectively. About 6.41% of tsetse harbored mixed infections of T. congolense and T. vivax. Of the 69 tsetse with T. congolense infections, 33.33% (23/69) harbored S. glossinidius while 71.86% (69/96) of flies harboring S. glossinidius were not infected by trypanosomes. No association was observed between S. glossinidius and trypanosome infections. Some wild tsetse harbor S. glossinidius and trypanosomes, while others have no infection or are infected by only one of these microorganisms. We conclude that the presence of S. glossinidius does not favor trypanosome infections in G. p. palpalis of the Fontem focus.

Following confirmed cases of trypanosomosis in military working dogs, a cross-sectional study was undertaken to evaluate the source of infection and determine the prevalence of canine infection with Trypanosoma congolense in the urban focus of Abidjan, Ivory Coast. Blood from 123 dogs were collected and subjected to PCR using specific primers for Trypanosoma congolense "forest type". In addition, an entomological study was conducted in an urban area near the forest surronding the military camp. The observed prevalence was 30.1% and PCR positivity to Trypanosoma congolense was not significantly associated with sex or age of animals. This study demonstrates the high contamination rate of dogs in enzootic zones, the potential risk of introduction of the disease in free animal populations and the ability of Glossina palpalis to adapt to urban areas and to transmit trypanosomosis in such areas. The factors leading to a possible emergence of canine trypanosomiasis in enzootic zones need further investigations.

L'étude des anomalies de la reproduction a été faite par dissection de 11012 mouches tsé-tsé capturées pendant un an dans les différents habitats forestiers de G. palpalis palpalis à Daloa en Côte d ’Ivoire. La proportion de femelles avec des anomalies était très faible, de l'ordre de 0,79 %. Sur 87 glossines présentant des anomalies, 93,10 % étaient dues à des avortements, 5,77 % à des blocages d'ovulation et 1,13 % à des pupaisons in utero. Les anomalies ont été enregistrées dans toutes les classes d'âge étudiées : 0,78 % chez les jeunes pares (sur un échantillon de 6398 glossines) et 0,80 % chez les vieilles pares (4614 glossines). Nos résultats indiquent donc que les anomalies surviennent à n'importe quel stade du cycle de gestation de la femelle. Les auteurs proposent donc d'augmenter les anomalies de la reproduction à l'aide de substances chimiques, afin d'améliorer l'efficacité de la lutte à l'aide de supports attractifs toxiques en zone forestière.