Prevalence of bovine trypanosomosis in the Faro and Deo, and Vina divisions in Cameroon: outcome of 20 years of tsetse control

Antivectorial control measures against trypanosomosis have been conducted in the savanna area of Cameroon for more than two decades. To evaluate their impact on the disease prevalence, three zones (vector cleared, interface and vector infested) were located on the Adamawa plateau. Blood samples collected from 349 animals living in these areas were examined by the buffy coat technique to determine trypanosome infection rates, parasitemia levels and packed cell volume (PCV). Single or mixed trypanosome infections were detected in 40.7% of the animals. Trypanosoma congolense was the predominant etiological agent identified. At least two trypanosome species occurred in 9.2% of the cattle examined with the association of T. congolense and T. vivax being the most common. Trypanosomosis prevalence was 61.1, 21.4 and 24.7% in the vector-infested, interface and vector-cleared areas, respectively. PCV values lower than or equal to 25% (infection indicators) occurred in 12.6% of the 349 animals examined, but only 75% of these were infected with trypanosomes. There was a negative correlation (r = -0.19; p 0.05) in the infection prevalence in the different animal age groups. Trypanosome infection rates were significantly higher (χ2 = 6.00; p < 0.05) in males (46.1%) than in females (35.6%). These findings showed that trypanosomosis was endemic in the region and that there was reinfestation of areas previously cleared of vectors. Strategies of participative management and sustainable maintenance of pastures should be sought out

Livestock Owner\'s Perception On Trypanosomosis And Associated Treatment On The Adamaoua Plateau In Cameroon Ten Years After Tsetse Eradication

Ten years after the tsetse eradication campaign, a survey using a structured questionnaire was conducted on the Adamaoua plateau in Cameroon to obtain qualitative and quantitative information from cattle owners about mains frequent bovines diseases, the use of trypanocidal drugs and insecticides pour-on to control trypanosomosis in cattle. Trypanosomosis was the main frequent and lethal disease. Buffer zone cattle owners used preferably isometamidium chloride rather than diminazene aceturate, whereas those of tsetse-free and tsetse-infested valley used the two trypanocides especially to treat disease episodes were perceived to be trypanosomosis. Pyrethoids was the main pour-on used to control trypanosomosis in the three zones. They were generally obtained from veterinary chemist and market, and breeders themselves administered slightly more than ¾ of them. Study suggests to extension workers the improvement of the use of veterinary products.Dix ans après la campagne d\'éradication des glossines, des enquêtes ont été menées sur le plateau de l\'Adamaoua au Cameroun pour recueillir auprès des éleveurs du bétail des informations qualitatives et quantitatives au sujet des principales maladies bovines, l\'usage des trypanocides et insecticides «pour-on» pour contrôler la trypanosomose chez le bétail. La trypanosomose était la maladie la plus fréquente et la plus mortelle. Les éleveurs de la zone tampon utilisaient plus le chlorure d\'isométamidium que l\'acéturate de diminazène, alors que ceux de la zone assainie et infestée utilisaient en même temps les deux trypanocides pour traiter des épisodes de maladie qu\'ils percevaient être la trypanosomose. Les insecticides à base de pyrèthre étaient les principaux «pour-on» utilisés pour contrôler la trypanosomose dans les trois zones. Ces produits étaient achetés auprès des pharmacies vétérinaires et du marché local, et les trois-quarts de ces produits étaient administrés par les éleveurs euxmêmes. L\'étude suggère aux agents de vulgarisation l\'amélioration de l\'usage de produits vétérinaires.Bulletin of Animal Health and Production in Africa Vol. 54 (4) 2006: pp. 260-27

Parasitological prevalence of bovine trypanosomosis in Faro and Deo division Cameroon, Ten years after the tse-tse eradication campaign

Dix ans après la campagne d'éradication des glossines, une enquête transversale visant à déterminer la prévalence de la trypanosomose et l’identification des espèces de trypanosome en présence a été effectuée dans le département du Faro & Deo, plateau de l’Adamaoua, Nord Cameroun. Au total, 302 bovins adultes ont été examinés dans vingt localités différentes appartenant soit à la zone assainie, tampon ou infestée. Les techniques de diagnostic utilisées consistaient en un examen de la couche leucocytaire sur fond noir, un examen d’un frottis mince colore et une évaluation de l’hématocrite. La prévalence totale de la trypanosomose bovine était de 14,6%, mais variait significativement par zone. Elle était élevée en zone infestée 35.1% et basse dans la zone assainie (4.3%) et tampon (5.3%); et aucune différence significative (P =0.051 > 0.05) n’été observé entre la zone tampon et le plateau. Parmi les animaux positifs, 43.2%, 13.6%, 9.1%, 13.6% et 20.5% étaient causes par Trypanosoma congolense, Trypanosoma vivax, Trypanosoma brucei, et des infections mixtes (T. congolense et T. vivax) et (T. congolense, T. brucei et T. vivax) respectivement. L’hématocrite des animaux positifs et négatifs allait de 16 à 40 pour cent et de 15 à 46 pour cent, respectivement. L’hématocrite moyen des animaux négatifs (29,6±5.7%) était significativement plus élevé que l’hématocrite moyen des animaux positifs (26,9±6.4%) (P = 0.003 < 0.05). Vu le risque de trypanosomose sur le plateau, une stratégie de contrôle appropriée est fortement recommandée.Ten years after the tsetse eradication campaign, a cross sectional survey to determine the prevalence of trypanosomosis and identifying the species of trypanosomes infecting cattle was conducted in the Adamaoua plateau, North Cameroon. A total of 302 adult cattle were examined at twenty different localities. Field examination of the buffy coat, stained thin blood film examination and packed cell volume (PCV) evaluation were thediagnostic techniques used. The overall prevalence of bovine trypanosomosis was 14.6%. However, the prevalence differed significantly between zones. It was higher in the valley (35.1%) and lower in the buffer zone and the plateau (5.3% and 4.3% respectively); no significant difference (P = 0.051) was found between the buffer zone and plateau. Among the positive animals, 43.2%, 13.6%, 9.1%, 13.6% and 20.5% werefrom Trypanosoma congolense, T. vivax , T. brucei and mixed infection (T. congolense & T. vivax) and (T. congolense, T. brucei & T. vivax), respectively. The mean PCV of positive and negative animals ranged between 16 - 40 % and 15 - 46%, respectively. The mean PCV of negative animals (29.6±5.7%) was significantly higher than the mean PCV of positive animals (26.9±6.4%) (P < 0.05). Because of the risk of trypanosomosis on the plateau, appropriate control strategies need to be put in place urgently

Evaluation sur le terrain et sur souris de la résistance des trypanosomes des bovins du plateau de l'Adamaoua au Cameroun à l'acéturate de diminazène et au chlorure d'isométamidium

Based on a survey in a few villages of the department of Faro et Deo, the village of Kontcha, where the highest trypanosomosis prevalence (32.5%) was observed, was selected to evaluate the resistance of trypanosomes to diminazene and isometamidium. Two groups of 40 head of cattle each were treated on day 0 either with diminazene or with isometamidium. The animals were monitored every other week for a period of two months using the buffy coat technique to assess the level of parasitemia. The percentages of trypanosome infected animals in the groups treated with diminazene and isometamidium were 32.5 and 27.5%, respectively. The survival analysis and mean hazard ratio (1.38) suggested resistance to isometamidium and a reduced protective activity of this drug. Several animals treated with diminazene at 7 mg/kg tested positive two weeks after treatment, indicating a strong suspicion of resistance to this trypanocidal compound. These field results were corroborated by the standard mouse test using six Trypanosoma congolense isolates. Sensitivity tests using 1 mg/kg isometamidium chloride and 20 mg/kg diminazene aceturate showed that all isolates were resistant at least to one of the drugs, whereas four isolates were resistant to both drugs. This study shows for the first time the presence in Cameroon of drug-resistant trypanosome strains

Prevalence and incidence of bovine trypanosomosis on the Adamaoua plateau in Cameroon 10 years after the tsetse eradication campaign

Between March 2004 and February 2005, the monthly incidence of trypanosome infections was measured in cattle from nine sentinel herds in the Adamaoua province of Cameroon. Three herds of 20 cattle each were kept on the plateau which has been cleared from tsetse flies about 10 years ago, three other herds were grazing in the tsetse infested valley whereas the last three were herded in the buffer zone. The cross-sectional study showed that the initial trypanosomosis prevalence was 1.8, 5.2 and 2.0% on the plateau, in the buffer zone and the valley, respectively. During the longitudinal study, the trypanosomosis incidence was high in the valley (3.7-20%) and the buffer zone (1.8-13.4%), whereas it was significantly lower (0-2.1%) on the plateau. Tsetse flies, mainly Glossina morsitans submorsitans and a few G. tachinoides, were caught in the valley and the buffer zone, but none on the plateau. The data indicate a low trypanosomosis risk on the plateau. Further entomological studies, however, are required to clarify the origin of the trypanosome infections on the plateau