Background: African animal trypanosomosis (AAT) is a major livestock disease in Kenya. Even though, over the years various organizations have collected a vast amount of field data on tsetse and AAT in different parts of the country, recent national-level maps are lacking. To address this gap, a national atlas of tsetse and AAT distribution is being developed by the Kenya Tsetse and Trypanosomosis Eradication Council (KENTTEC) and partners. Methods: All data collected by KENTTEC from 2006 to 2019 were systematically assembled, georeferenced and harmonized. A comprehensive data repository and a spatially-explicit database were created. Input data were collected mainly in the context of control activities, and include both baseline surveys (i.e. pre-intervention) and the subsequent monitoring during and after interventions. Surveys were carried out in four regions (i.e. Western, Rift Valley, Central and Coast), and in 21 of the 47 counties in Kenya. Various devices were used for entomological data collection (i.e. biconical, NGU and H traps, and sticky panels), while the buffy-coat technique was the method used to detect AAT. Results: Tsetse trapping was carried out in approximately 5000 locations, and flies (> 71,000) were caught in all four investigated regions. Six species of Glossina were detected: G. pallidipes (87% of the catches); G. brevipalpis (8%); G. fuscipes fuscipes (4%); G. longipennis (< 1%); G. austeni (< 1%); and G. swynnertoni (< 1%). A total of 49,785 animals (98% of which cattle) were tested for AAT in approximately 500 locations. Of these, 914 animals were found to be infected. AAT was confirmed in all study regions, in particular caused by Trypanosoma vivax (48% of infections) and T. congolense (42%). Fewer cases of T. brucei were found. Conclusions: The development and regular update of a comprehensive national database of tsetse and AAT is crucial to guide decision making for the progressive control of the disease. This first version of the atlas based on KENT-TEC data has achieved a remarkable level of geographical coverage, but temporal and spatial gaps still exist. Other stakeholders at the national and international level will contribute to the initiative, thus improving the completeness of the atlas.

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.

The role of the Kenya Tsetse and Trypanosomiasis Eradication Council (KENTTEC) in the control of animal trypanosomiasis is premised on the fact that a large proportion of animal trypanosomiasis in Kenya is tsetse transmitted. Tsetse distribution in Kenya is characterized by eight discontinuous belts defined by topographical, environmental and land-use. KENTTEC's strategy for control of African animal trypanosomiasis is based on use of community-based organizations for spraying of livestock, control of the vector using various devices such as targets and traps, and development of strategies and policies for use of land after the intervention. The council has developed linkage with research institutions for adaptive and operational research. The council has initiated the development of national atlas by mapping tsetse and animal trypanosomiasis distribution in collaboration with stakeholders at the national, regional, and international levels.

African animal trypanosomosis (AAT), a livestock disease, also known as Nagana, tsetse fly disease, or tsetse disease, is a widespread tsetse-borne disease complex caused by unicellular protozoan parasites belonging to the genus Trypanosoma. It is one of the major constraints to the expansion of livestock rearing and livestock-based industries in Africa. It also constrains mixed farming, human health, and livelihood in tropical Africa. The tsetse fly is the major vector of the disease. Acute disease is characterized by marked depression, intermittent fever, anorexia, anemia, blood-tinged diarrhea, and adenopathy, sometimes petechiae on mucosa, abortion, and death if not treated. Diagnosis is made by observing trypanosome parasites by direct microscopic examination of blood, lymph nodes, edema fluid, or tissues. Treatment is by chemotherapy and chemoprophylaxis. Control is achieved through vector control treatment using available molecules and use of a few available trypanotolerant breeds of animals.