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

Abstract

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 < 0.001) between parasitemia and PCV values. There was no significant difference (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.