The national atlas of tsetse flies and African animal trypanosomosis in Ethiopia

Epidemiology and Economic Cost of Trypanosomosis Among SmallHolder Cattle Herders in Arba Minch and Zuria Districts, Gamo Zone, Ethiopia

A significant limitation to cattle production is animal trypanosomosis, which threatens household food security and livelihoods. In addition to stalling livestock productivity, the disease has a devastating impact on animal health. Besides, halting livestock productivity, the disease has a devastating effect on health. Thus, the objectives this study was to assess the epidemiology, and financial impacts of bovine trypanosomosis on livestock producers' in Arba Minch and Zuria districts of Gamo zone, Ethiopia, from December 2021 to January 2023. Both repeated survey and cross-sectional study were carried out to assess the economic losses, estimate the prevalence and assess the determinants of bovine trypanosomosis. Direct microscopy was applied using buffy coat method to detect trypanosome parasite. The study included 182 households and 384 bovine species. Bovine trypanosomosis caused substantial economic losses through cattle mortality, drug purchases, and the oxen's loss of draft power. Also, farmers spent a significantly (P < .05) higher amount of money treating trypanosomosis than all other diseases combined. The annual losses per household were estimated to be 9528 ± 1754 Ethiopian Birr (ETB) (95% CI: 6065-12 992) (US$ 176.4) which were spent on purchasing trypanocidal drugs per year per household. The overall mortality from bovine trypanosomiasis was 8.8%. Many farmers prioritized draft power losses as the most significant impact of the disease. Analysis of blood samples also showed a 7.8% overall prevalence of bovine trypanosomosis. The disease burden was significantly (P < .05) higher in the black body coat animals compared to white ones. This study showed that trypanosomosis is an important animal health problem and a potential threat to health and productivity of cattle in Arba Minch and zuria districts of Gamo, Southern Ethiopia. The common trypanocidal drugs were administered by the farmers themselves. Hence, policymakers and professionals should prevent irrational drug use and regularly monitor local trypanocide usage.

Prevalence of bovine trypanosomosis and tsetse fly density in Loka Abaya and Derara districts in Sidama Regional State, Ethiopia

Animal trypanosomosis is a significant livestock disease with economic and social repercussions, reducing the supply of animal products and restricting the utilization of animals for traction and transportation. In Ethiopia, it is prevalent and poses a major hindrance to the advancement of animal production. This repeated cross-sectional study was aimed at assessing seasonal variation in bovine trypanosomosis prevalence and tsetse fly density and identifying the potential risk factors in the Loka Abaya and Derara districts of the Sidama National Regional State. Blood samples were collected from 964 cattle, 484 samples during the dry season, and 480 during the wet season. The buffy coat method was employed to analyze these samples. Furthermore, 78 standard NGU traps were set up at various locations in the two districts during both seasons for entomological investigation. The overall apparent prevalence of trypanosomosis was 9% (95% CI 7.3-11.0), without a significant difference (p > 0.05) between the dry season (7.4%) and wet season (10.6%). The apparent prevalence was significantly higher in Loka Abaya (11.8%) than in Derara (6.3%) district (OR = 2.04; p = 0.003) and in cattle with black coat color (29%) than in mixed color (6.8%) (OR = 5.3; p < 0.001). The majority of infections were caused by Trypanosoma congolense (70%), followed by T. vivax (29%), and mixed infections (1%) with the two species. The average packed cell volume (PCV) was significantly (p < 0.0001) lower in infected animals (20.7 ± 4%) compared to uninfected ones (25.5 ± 5.4%), in cattle examined during the dry season (24.1 ± 6%) versus the wet season (26.1 ± 4.7%), in cattle sampled from the Loka Abaya district (24.2 ± 5.5%) versus Derara district (26 ± 5.3%), and in cattle with poor body condition (23.6 ± 5.7%) compared to those with good body condition (26.5 ± 5.3%). A total of 5282 flies were captured during the study, with 4437 (84%) being tsetse flies (Glossina pallidipes), 439 (8.3%) Tabanids, 190 (3.6%) Stomoxys spp., and 216 (4.1%) Musca spp. The apparent density (AD) of G. pallidipes was 28.4 flies/trap/day, showing no statistically significant difference between wet (32.1) and dry (24.6) seasons (p > 0.05). The AD of G. pallidipes was significantly (p < 0.001) higher in the Loka Abaya district (57.3) than in the Derara district (0.9). The study highlights a moderate trypanosomosis apparent prevalence and high AD of G. pallidipes, showing significant variation between the study districts but no seasonal difference. The observed apparent prevalence of trypanosomosis and tsetse fly density notably affects animal health and productivity. As a result, strategies for vector control like insecticide-treated targets, trypanocidal medications for infected animals, and community-based initiatives such as education and participation in control programs are recommended.

What is needed to achieve effective and sustainable control of African animal trypanosomosis?

A welcome resurgence in African animal trypanosomosis (AAT) research has resulted in advances in capabilities, foundational datasets, and understanding. Additionally, there is the prospect of the first new trypanocide in >60 years. However, it is vital to ensure that advances translate to improved and sustainable control in the field. A recent meeting, the Symposium on African Livestock Trypanosomes - Tanzania, convened stakeholders from across the spectrum of AAT research and control to ask how this can be achieved. Current constraints on progress were defined, as were critical gaps and opportunities that need addressing. There is a requirement and opportunity for the AAT research community to communicate, collaborate, and coordinate to maintain momentum and achieve the ultimate goal of sustainable AAT control.

Trypanosome Infection in Cattle and Associated Vectors in Etang District of Gambella, Ethiopia

Background

Bovine trypanosomosis produces significant economic losses due to anemia, loss of body condition, and emaciation. The disease is transmitted biologically by tsetse flies and mechanically by biting flies such as Tabanus and Stomoxys. Therefore, this research is aimed at estimating the prevalence of bovine trypanosomosis and the apparent density of its vectors in the Etang Special District.

Methods

A cross-sectional study was employed from November 2016 to April 2017 for the prevalence and entomological survey. Trypanosoma species were identified using buffy coat and Giemsa staining techniques. Besides, the entomological surveys were conducted using NGU, pyramidal, biconical, and monoconical traps. The vectors were identified to their genus level based on their morphological features like size, color, wing venation, and proboscis.

Result

A total of 457 bovine blood samples were collected and tested, of these 16 (3.50%) animals were positive for trypanosomosis. Similarly, 13 T. vivax (81.25%) and 3 T. congolense (18.75%) were the trypanosome species detected. The prevalence in the young (2.56%) and adult (3.99%) age groups was not statistically significant (P > 0.05). However, there were significant (P < 0.05) differences in prevalence between body condition scores, where poor is 6.31%, medium is 1.30%, and good is 0%. Moreover, the difference in mean PCV values between the parasitemic (20.97) and aparasitemic (28.58) groups was statistically significant (P < 0.05). Glossina flies were not found, although 1756 Tabanus and 52 Stomoxys biting flies were gathered. Accordingly, the overall apparent density of Glossina flies was zero (0), with biting flies (20.54) recorded per trap per day. Moreover, the apparent density of Tabanus and 52 Stomoxys was 39.01 and 1.18, respectively.

Conclusion

This study confirmed that trypanosomosis and abundant mechanical vectors continue to be problems in the study area, resulting in cattle productivity losses. As a result, strategic management and prevention methods for trypanosomosis and associated vectors should be prioritized. Further investigation of vector needs to be conducted to clear out tsetse presence.

Epidemiological study on cattle trypanosomiasis and its vectors distributions in the Gambella regional state, southwestern Ethiopia

African animal trypanosomosis is a parasitic disease that causes significant economic losses in livestock due to anaemia, loss of condition, emaciation, and mortality. It is a key impediment to increased cattle output and productivity in Ethiopia. Cross-sectional entomological and parasitological studies were performed in the Gambella Region state of southwestern Ethiopia to estimate the prevalence of bovine trypanosomosis, apparent fly density, and potential risk factors. Blood samples were taken from 546 cattle for the parasitological study and analyzed using the buffy coat technique and stained with Giemsa. A total of 189 biconical (89) and NGU (100) traps were deployed in the specified districts for the entomological survey. The overall prevalence of trypanosomosis at the animal level was 5.5% (95% CI: 3.86-7.75). Trypanosoma vivax (50.0%), T. congolense (30.0%), T. brucei (20.0%), and no mixed trypanosome species were found. The prevalence of trypanosomosis was significantly (p < 0.05) affected by altitude, body score conditions, age, mean packed cell volume (PCV), and peasant associations, while sex and coat color had no significant effect. According to the entomological survey results, a total of 2303 flies were captured and identified as tsetse (Glossina pallidipes (5.3%)) and G. fuscipes fuscipes (3.3%) and other biting flies (Tabanus (60.1%) and Stomoxys (31.3%)). In the current study, the overall apparent density was 4.1 flies/trap/day. This study shows that trypanosomosis remains a significant cattle disease in the Gambella regional state even during the dry season. Thus, the findings support the necessity to improve vector and parasite control measures in the area.

The elimination of human African trypanosomiasis: Monitoring progress towards the 2021-2030 WHO road map targets

BACKGROUND

Human African trypanosomiasis (HAT) is a neglected tropical disease that usually occurs in rural areas in sub-Saharan Africa. It caused devastating epidemics during the 20th century. Sustained, coordinated efforts by different stakeholders working with national sleeping sickness control programmes (NSSCPs) succeeded in controlling the disease and reducing the number of cases to historically low levels. In 2012, WHO targeted the elimination of the disease as a public health problem by 2020. This goal has been reached and a new ambitious target was stated in the WHO road map for NTDs 2021-2030 and endorsed by the 73rd World Health Assembly: the elimination of gambiense HAT transmission (i.e. reducing the number of reported cases to zero). The interruption of transmission was not considered as an achievable goal for rhodesiense HAT, as it would require vast veterinary interventions rather than actions at the public health level.

METHODOLOGY/PRINCIPAL FINDINGS

Data reported to WHO by NSSCPs were harmonized, verified, georeferenced and included in the atlas of HAT. A total of 802 cases were reported in 2021 and 837 in 2022. This is below the target for elimination as a public health problem at the global level (< 2000 HAT cases/year); 94% of the cases were caused by infection with T. b. gambiense. The areas reporting ≥ 1 HAT case/10 000 inhabitants/year in 2018-2022 cover a surface of 73 134 km2, with only 3013 km2 at very high or high risk. This represents a reduction of 90% from the baseline figure for 2000-2004, the target set for the elimination of HAT as a public health problem. For the surveillance of the disease, 4.5 million people were screened for gambiense HAT with serological tests in 2021-2022, 3.6 million through active screening and 0.9 million by passive screening. In 2021 and 2022 the elimination of HAT as a public health problem was validated in Benin, Uganda, Equatorial Guinea and Ghana for gambiense HAT and in Rwanda for rhodesiense HAT. To reach the next goal of elimination of transmission of gambiense HAT, countries have to report zero cases of human infection with T. b. gambiense for a period of at least 5 consecutive years. The criteria and procedures to verify elimination of transmission have been recently published by WHO.

CONCLUSIONS/SIGNIFICANCE

HAT elimination as a public health problem has been reached at global level, with seven countries already validated as having reached this goal. This achievement was made possible by the work of NSSCPs, supported by different public and private partners, and coordinated by WHO. The new challenging goal now is to reach zero cases by 2030. To reach this goal is crucial to maintain the engagement and support of donors and stakeholders and to keep the involvement and coordination of all partners. Along with the focus on elimination of transmission of gambiense HAT, it is important not to neglect rhodesiense HAT, which is targeted for elimination as a public health problem in the WHO road map for NTDs 2021-2030.

An Atlas of Surra in Spain: A Tool to Support Epidemiological Investigations and Disease Control

Trypanosomosis is a global animal issue, causing significant economic losses, particularly in Africa. In Spain, only one pathogenic species, Trypanosoma evansi, has been identified so far. It was first detected in a dromedary camel in the Canary Islands in 1997. Since then, numerous cases of the disease, known as Surra, have been diagnosed, prompting various studies and efforts in control and surveillance. Given the lack of a comprehensive database that consolidates the most relevant data in this area, the development of a national atlas, with a focus on the Canary Islands, to incorporate all available information on T. evansi in Spain became a necessity. For the development of the atlas, a repository was constructed, encompassing a range of datasets and documents spanning from 1997 to 2022. Information from each source, and in particular georeferenced locations and results of blood tests on animals, were extracted and integrated into a comprehensive database. A total of 31 sources were analysed, providing a total of 99 georeferenced locations and 12,433 animal samples. Out of these samples, 601 (mostly from dromedaries) were found to be positive for T. evansi. The Card Agglutination Test for T. evansi (CATT/T. evansi), a serological test, was the most commonly used diagnostic method, and it showed a higher prevalence for all tested animal species. Positive cases were mainly concentrated in the Canary Islands, specifically in the eastern islands, with isolated cases found in the province of Alicante (Iberian Peninsula). This atlas provides an overview of the history and occurrence of Surra in Spain, and it represents a valuable tool for future control initiatives and for research. Still, the need for more studies remains, especially for further testing of potential hosts other than camelids and for the examination of their potential transmission vectors.

Prevalence of African animal trypanosomiasis among livestock and domestic animals in Uganda: a systematic review and meta-regression analysis from 1980 to 2022

African animal trypanosomiasis (AAT) is one of the major constraints to animal health and production in sub-Saharan Africa. To inform AAT control in Uganda and help advance along the progressive control pathway (PCP), we characterized AAT prevalence among eight host species in Uganda and explored factors that influence the prevalence variation between studies. We retrieved AAT prevalence publications (n = 2232) for Uganda (1980-2022) from five life sciences databases, focusing on studies specifying AAT detection methods, sample size, and the number of trypanosome-positive animals. Following PRISMA guidelines, we included 56 publications, and evaluated publication bias by the Luis Furuya-Kanamori (LFK) index. National AAT prevalence under DNA diagnostic methods for cattle, sheep and goats was 22.15%, 8.51% and 13.88%, respectively. Under DNA diagnostic methods, T. vivax was the most common Trypanosoma sp. in cattle (6.15%, 95% CI: 2.91-10.45) while T. brucei was most common among small ruminants (goats: 8.78%, 95% CI: 1.90-19.88, and sheep: 8.23%, 95% CI: 4.74-12.50, respectively). Northern and Eastern regions accounted for the highest AAT prevalence. Despite the limitations of this study (i.e., quality of reviewed studies, underrepresentation of districts/regions), we provide insights that could be used for better control of AAT in Uganda and identify knowledge gaps that need to be addressed to support the progressive control of AAT at country level and other regional endemic countries with similar AAT eco-epidemiology.

Livestock producers' knowledge, attitude, and behavior (KAB) regarding antimicrobial use in Ethiopia

Introduction

Inappropriate antimicrobial use (AMU) in livestock production is an important aspect of the global burden of antimicrobial resistance (AMR). In Ethiopia, a low-income country with a large and increasing livestock population, AMU in food animals is not properly regulated. Hence, farmers are fully free to use antimicrobials to their (perceived) benefit. Therefore, understanding farmers' mindsets is important to improve antimicrobial stewardship in the livestock sector.

Methods

This cross-sectional study was conducted to assess livestock disease management practices and knowledge, attitude, and behavior (KAB) among livestock producers regarding AMU, residues, and resistance, as well as factors potentially explaining differences in KAB. We determined the KAB of livestock owners of three selected districts of central and western Ethiopia (n = 457), using a pretested questionnaire administered through face-to-face interviews. Logistic regression was used to evaluate the association between potential explanatory variables and the KAB scores of the respondents.

Results

The results showed that 44% of the farmers used antimicrobials in the past few years, where antibiotics (21%) and trypanocides (11%) were most widely used to manage livestock diseases. Furthermore, most farmers showed poor knowledge about AMU, residues, and AMR (94%) and unfavorable attitudes (<50% correct answers) toward contributing factors for AMR (97%). On the contrary, 80% of the respondents had overall good behavior scores (≥50% correct answers) related to AMU. Multivariate analysis results showed that having good knowledge, keeping ≥2 animal species, and the occurrence of ≥4 livestock diseases on the farm in a year were strong predictors of bad behavior scores (p < 0.05). The findings of the current investigation also revealed that the incidence of livestock diseases on the farm and a higher level of formal education significantly contributed to better knowledge and desirable attitudes but bad AMU behavior.

Conclusion

A low level of awareness about and undesirable attitudes toward AMU and AMR could potentially affect farmers' behavior toward judicious AMU, thus requiring awareness creation efforts on livestock disease management practices.