Prevalence of Cattle Trypanosomosis and Apparent Density of Its Fly Vectors in Bambasi District of Benishangul-Gumuz Regional State, Western Ethiopia

Abstract

Trypanosomosis is the most serious disease of cattle, which causes great socioeconomic losses in the country. Its socioeconomic impact is reflected on direct losses due to mortality, morbidity, and reduction in milk and meat production, abortion and stillbirth, and also costs associated with combat of the disease are direct losses. A cross-sectional study was carried out to assess the prevalence of cattle trypanosomosis, and the apparent density and distribution of its fly vectors in selected study areas. The methods employed during the study were buffy coat technique for parasitological study and deploying trap for the collection of tsetse flies. A total of 1512 flies were trapped, and among them, 1162 were tsetse flies while 350 were biting flies. Higher apparent density for tsetse fly (7.7 F/T/D) followed by Stomoxys (0.9 F/T/D), Tabanus (0.8 F/T/D), and Hematopota (0.6 F/T/D) was recorded. Out of 638 examined cattle, the overall prevalence of trypanosomosis in the study area was 9.1% (58/638). Out of positive cases, Trypanosoma congolense (7.7%) was the dominant trypanosome species followed by Trypanosoma vivax (0.9%), Trypanosoma brucei (0.2%), and mixed infection of Trypanosoma brucei and Trypanosoma vivax (0.3%). There was no a significant difference (p>0.05) in trypanosome infection between age, sex, and trypanosome species. The prevalence of trypanosomosis on the bases of body condition was 2.8% for poor, 5.5% for medium, and 0.8% for good body condition. The overall prevalence of anemia was (36.8%), and presence of anemia was higher in trypanosome positive animals (62.5%) than in negative animals (34.3%) which is statistically significant (p<0.05, CI = 1.794–5.471). The overall mean packed cell volume (PCV) value for examined animals was 25.84 ± 0.252SE. Mean (PCV) of parasitaemic cattle (9.1%) was significantly (p<0.05) lower than that of aparasitaemic cattle (90%). This survey showed that trypanosomosis is still a core problem for livestock production of the study area. Therefore, more attention should be given to the control of both the disease and its vectors.

Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia

“…Two species of trypanosomes were identified in the current study areas, namely, T. congolense (68.85%) and T. vivax (31.15%). This study has confirmed the observation of ( 8 , 13 , 16 , 17 , 49 ) in different parts of Ethiopia. The relatively higher predominance of T. congolense infection in cattle suggests the increased contact of cattle with the savanna tsetse flies, particularly G. pallidipes , which are more efficient transmitters of T. congolense than T. vivax in East Africa ( 12 , 50 ).…”

“…The mean PCV of the infected animals (22.56 ± 4.61) was significantly (p < 0.001) lower than that of the noninfected ones (25.3 ± 4.75%). The lower mean PCV value in the infected animals have been reported by authors from different corners of the country (21,22,39,43,49). Variation between infected and non-infected animal mean PCV value indicates that trypanosomosis might be involved in the reducing of the PCV values in the infected animals (30).…”

“…However, studies reported by Mbahin et al ( 47 ) in Kwale county of Coastal Kenya and Kizza et al ( 48 ) in Murchison Falls National Park of Uganda showed higher overall prevalence of 33.9 and 29.6%, respectively. Such variation between reports might be due to the differences in the season of the study period, management system, vector infection rate, animal susceptibility, trypanocidal drug usage, fly control operations, increase of tsetse challenges, and awareness level of the animal owners about the disease in a given study areas ( 44 , 49 ).…”

“…This result was higher than the findings of Park of Uganda showed higher overall prevalence of 33.9 and 29.6%, respectively. Such variation between reports might be due to the differences in the season of the study period, management system, vector infection rate, animal susceptibility, trypanocidal drug usage, fly control operations, increase of tsetse challenges, and awareness level of the animal owners about the disease in a given study areas (44,49). Two species of trypanosomes were identified in the current study areas, namely, T. congolense (68.85%) and T. vivax (31.15%).…”

Glossina pallidipes Density and Trypanosome Infection Rate in Arba Minch Zuria District of Gamo Zone, Southern Ethiopia

“…Other caught biting flies were identified to genera level according to their morphological characteristics such as size, color, wing venation structure, and proboscis [ 26 – 28 ]. The apparent density of the tsetse fly was calculated as the number of tsetse catch/trap/day [ 29 ].…”