Prevalence of Bovine Trypanosomosis and Its Associated Risk Factor in Hawa Galan District, Kelem Wollega Zone of Ethiopia

An analytical cross-sectional study was performed between November 2015 and April 2016 at Hawa Galan woreda, Kelem Wollega Zone, Oromia Region, Ethiopia, to estimate the proportion of cattle with trypanosomosis and to evaluate the elements associated with the prevalence of bovine trypanosomosis. A haemoparasitological examination of the Buffy coat method was implemented to determine the proportion of trypanosomosis-positive cattle. A study population of 428 bovines was randomly selected from three peasant associations (PAs) and tested for the presence of the disease. Findings of the laboratory results indicate that among all animals tested at the study time, 26 (6%) animals were positive for the disease. Among the positive results, the proportion of trypanosome species was Trypanosoma congolense 18 (69.3%) and Trypanosoma vivax 8 (30.7%). The prevalence at the selected PAs was 12.5%, 3.8%, and 3% for Lemlem, Madawalkituma, and Ifajiru, respectively. From this finding, the relationship has a statistically significant variation ( P < 0.05) among peasant associations and body condition state, and the proportion was significantly greater ( P < 0.05) in animals categorized under poor body condition score. The relationships between age and sex of cattle show no statistically significant variation among them ( P > 0.05). This study indicates that the proportion of trypanosomosis was greater in anemic (PCV<24%) cattle than nonanemic (PCV≥24%). Therefore, based on this finding, the proportion of bovine trypanosomosis is evident that can cause a major effect on the health of cattle in the study population in the study area. So, effective control methods could be applied to decrease the disease and its related economic loss.

A Preliminary Study on the Relationship between Parasitaemia and Cytokine Expression of Peripheral Blood Cells in Trypanosoma vivax-Experimentally Infected Cattle

Trypanosoma vivax outbreaks have been reported with increasing frequency worldwide, causing significant economic losses in livestock. Though several studies have suggested that cytokine responses may influence infection caused by Trypanosoma sp., their exact role remains unclear and may vary according to the animal species and parasite strain. The present study aimed to evaluate cytokine expression of peripheral blood cells from three Girolando dairy cows experimentally infected with T. vivax. For this purpose, blood samples were collected prior to the inoculation on the day of inoculation (D0), the day after inoculation (D1), and then every seven days up to 119 days after infection (DAI). Each animal presented a unique pattern of cytokine expression. While a tendency of a Th1 cytokine response was observed during the patent phase (presence of circulating parasites), an increase of Th2 cytokine expression was found at the beginning of the sub-patent phase (low parasitaemia or aparasitaemic periods). In animals that presented a better control of parasitaemia, IL-6 and IFNγ increased during most of the trial period. On the other hand, the cow that presented reduction of IL-1β, IL-2, and TNFα during the entire period did not control parasitaemia properly. A balance between the Th1 and Th2 profile is beneficial for parasite control and animal health. The results found in the present study are a first step towards elucidating the dynamics of cattle’s inflammatory response against T. vivax, requiring future studies focusing on the role of key cytokines on the controlling of parasitaemia in different stages of bovine trypanosomosis.

Prevalence of Trypanosome Species in Cattle Near Ruma National Park, Lambwe Valley, Kenya: An Update From the Historical Focus for African Trypanosomosis

The effective control of diseases in areas shared with wildlife depends on the validity of the epidemiologic parameters that guide interventions. Epidemiologic data on animal trypanosomosis in Lambwe valley are decades old, and the recent suspected outbreaks of the disease in the valley necessitate the urgent bridging of this data gap. This cross-sectional study estimated the prevalence of bovine trypanosomosis, identified risk factors, and investigated the occurrence of species with zoonotic potential in Lambwe valley. The area is ~324 km2, of which 120 km2 is the Ruma National Park. Blood was sampled from the jugular and marginal ear veins of 952 zebu cattle between December 2018 and February 2019 and tested for trypanosomes using the Buffy Coat Technique (BCT) and PCR-High-Resolution Melting (HRM) analysis of the 18S RNA locus. Risk factors for the disease were determined using logistic regression. The overall trypanosome prevalence was 11.0% by BCT [95% confidence interval (CI): 9.0–13.0] and 27.9% by PCR-HRM (95% CI: 25.1–30.8). With PCR-HRM as a reference, four species of trypanosomes were detected at prevalences of 12.7% for T. congolense savannah (95% CI: 10.6–14.8), 7.7% for T. brucei brucei (CI: 6.0–9.4), 8.7% for T. vivax (CI: 6.9–10.5), and 1.3% for T. theileri (CI: 0.6–2.0). About 2.4% of cattle had mixed infections (CI: 1.4–3.41). No human-infective trypanosomes were found. Infections clustered across villages but were not associated with animal age, sex, herd size, and distance from the park. Approximately 85% of infections occurred within 2 km of the park. These findings add to evidence that previous interventions eliminated human trypanosomosis but not bovine trypanosomosis. Risk-tailored intervention within 2 km of Ruma Park, especially in the north and south ends, coupled with stringent screening with molecular tools, could significantly reduce bovine trypanosomosis.

Prevalence and risk factors for trypanosome infection in cattle from communities surrounding the Murchison Falls National Park, Uganda

Background Bovine trypanosomosis transmitted by tsetse flies is a major constraint to cattle health and productivity in all sub-Saharan countries, including Uganda. The objectives of this study were to determine the prevalence of bovine trypanosomosis and identify its associated risk factors and the species of trypanosomes associated with the disease. Methodology A cross-sectional study was conducted around Murchison Falls National Park, Uganda from January 2020 to April 2020. Trypanosomes were detected in blood samples by PCR analysis targeting the internal transcribed spacer 1 (ITS-PCR assays), and trypanosomes in positive blood samples were sequenced. Results Of 460 blood samples collected and tested, 136 (29.6%) were positive for trypanosome infections and 324 (70.4%) were negative. The overall trypanosome prevalence was 29.6% (95% confidence interval 25.4–33.8%), attributed to three trypanosome species. Of these three species, Trypanosoma vivax was the most prevalent (n = 130, 28.3%) while the others were detected as mixed infections: T. vivax + Trypanosomacongolense (n = 2, 0.4%) and T. vivax + Trypanosomaevansi (n = 1, 0.2%). There were significant differences in trypanosome prevalence according to sex (χ2 = 62, df = 1, P < 0.05), age (χ2 = 6.28, df = 2, P = 0.0043) and cattle breed (χ2 = 10.61, df = 1, P = 0.001). Conclusions Trypanosomosis remains a major limitation to cattle production around Murchison Falls National Park and interventions are urgently needed. In our study, the prevalence of trypanosome infections was high, with T. vivax identified as the most prevalent species. Age, sex and breed of cattle were risk factors for trypanosome infection. Graphical Abstract

Bovine trypanosomosis and its vectors: prevalence and control operations in Kellem Wollega, Western Ethiopia

A cross-sectional study was conducted to estimate the prevalence of bovine trypanosomosis and to assess farmers’ perception of the disease and its control operations. From October to April 2012, a total of 586 cattle were sampled for the prevalence study. Buffy coat procedure and haematocrit value determination were performed. To capture the fly that was involved in the transmission dynamics, one hundred monopyramidal traps were deployed for 72 hours. A semi-structured questionnaire was conducted to study farmers’ perceptions of the diseases and their control operations. Trypanosomal infections were diagnosed in only 8.7 % (51) of animals. The overall prevalence of trypanosome infection in cattle was significantly varied between study districts (33.1% Dale Sadi and 66.9% Dale Wabera). Most infections were due to Trypanosoma congolense (81.8%) followed by T. vivax (15.6%) and mixed infections (2.6%). The association of hematological value changes and trypanosome infections was profound. The overall Packed Cell Volume (PCV) values of sampled cattle were 25.8%. A significant (P< 0.05) variation in PCV values was recorded in infected (20.8%) and non-infected (26.5%) cattle. In the study period, a total of 2055 flies were captured and of which 92% belong to the genus Glossina followed by Stomoxys and Tabanids. Four types of tsetse species (G. pallidpes, G. m. morsitans, G. tachinoides, and G. f. fuscipes) were identified. The questionnaire survey revealed that trypanosomosis is the most important problem for agricultural activity and animal production in the study areas. Farmers are well aware of the problem, means of transmission, and the different control methods. Integrating tsetse control program with other trypanosomosis control options is recommended.

Host Related Risk Factors of Bovine Trypanosomosis and Vector Density in Halu District of Ilubabor Zone, West Ethiopia

Background Trypanosomosis is disease caused by unicellular parasites, trypanosome, found blood and other tissue of vertebrates; including livestock, wild life and people. It is a serious disease in domestic livestock causing a significant negative impact on food production and economic growth in many parts of the world, particularly in sub-Saharan Africa. Its epidemiology and impact on livestock production are largely determined by the prevalence and distribution of the disease and its vectors in the affected area. Aim To assess the host related risk factors of bovine trypanosomosis and apparent density of tsetse flies in four peasant associations of the study area. In relation to the host risk factors, the prevalence of bovine trypanosomosis was highest in those animals with poor body condition. Results The overall 5.32% prevalence of bovine trypanosomosis was recorded from 432 blood sample collected from randomly selected animals using Buffy coat method. Trypanosoma congolense was the dominant species 14 (60.87%). However, it was not statistically significant between sex of animals (p>0.05). The mean packed cell volume (PCV) value of the infected animals was lower (20.65%±2.85) compared to non-infected animals (25.74%±4.80). There was statistically significant difference (p<0.05) in the PCV values of infected and non-infected animals. Moreover, animals with different body condition exhibited statistically significant variation (p<0.05) in the prevalence of trypanosomosis. Overall an apparent density of the flies was 2.42 f/t/d by using mono-pyramidal and biconical traps. It indicated that, G. morsitance submorsitance, G. pallidipes and G. tachinoides were tsetse flies species caught. Conclusion Finally, this work showed that trypanosomosis is an important disease affecting the health and productivity of cattle in the district. Hence, due attention should be given to this sector so as to improve livestock production and agricultural development in the area.

Impact of Landscape and Season on the Ecological Distribution of Tabanidae and Stomoxyinae, Mechanical Vectors of Bovine Trypanosomosis in the Forest of Sanaga Maritime and Savanna of Ngaoundere, Cameroon

Background: Huge pasture areas in sub-Saharan Africa are heavily infested by tabanids and stomoxyines whose distribution across season and in different landscape differs and is poorly described in Cameroon. Methods: A longitudinal entomological prospection (January 2017 to December 2017) was carried out in the savanna of Ngaoundere and forest of the Sanaga Maritime of Cameroon, using three trap-types (Nzi, Biconical and Vavoua). A total of 18 traps were used in this study with nine in each site.Results: In the forest, 44317 Stomoxys belonging to four species were captured with an apparent density of 136.78 flies per trap and day (f/t/d). Twelve species of tabanids were collected with 3524 individuals with an apparent density of 10.87 f/t/d. Stomoxys niger niger was the most abundant species while for tabanids, Tabanus taeniola (48.63%) was most represented. In the savanna, 4501 (13.89 f/t/d) Stomoxys were collected and regrouped under five species with S. n. niger (70.91%) highly represented and 547 (1.68 f/t/d) tabanids collected and regrouped under 10 species with Tabanus taeniola as the most dominant species. Trap apparent density (ADT) varied with sampled sites, seasons and the prevailing weather conditions in the forest and savanna.Conclusion: From the present finding, it can be deduced that T. taeniola and S. n. niger were the most abundant and indicate the risk of mechanical transmission of dangerous pathogens such as bovine trypanosomosis.