Main gaps in knowledge and tools that constrain the sustainable control of vector-transmissible animal trypanosomoses

Accepted manuscript of the article published in BMC Veterinary Research (DOI 10.1186/s12917-026-06066-7). This version of the article has been accepted for publication, after peer review, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The file is under embargo until the Version of Record is published. African trypanosomoses (ATs) are a group of diseases caused by several species of trypanosomes that primarily affect livestock, but which, in the case of some subspecies, also cause human African trypanosomiasis (HAT), or sleeping sickness. Whilst the human form of the disease has been eliminated as a public health problem, the animal diseases remain highly prevalent in sub-Saharan Africa. They are responsible for large production losses and substantial indirect costs, placing a heavy burden on the livestock sector and on sustainable development. The majority of trypanosome species are transmitted by tsetse flies only and are therefore confined to sub-Saharan Africa, but some have evolved alternative transmission routes, e.g. through mechanical transmission by biting flies, and have consequently spread to Latin America and Asia, or sexually in equids, without geographical limits. This study summarises the comprehensive analysis available in the DISCONTOOLS database, which highlights major gaps in our understanding and control of these economically significant animal diseases. Following a brief review of basic knowledge on trypanosomes, hosts and vectors, the three pillars of ATs control (diagnosis, treatment and vector control) are presented. Gaps in our knowledge and tools that prevent the full realisation of efficient and cost-effective control are highlighted. In addition to the absence of a vaccine, these include the lack of a point-of-care diagnostic test, the absence of a standardised ELISA, treatment failure linked to inappropriate drug use, insufficient knowledge of vectors distribution and its dynamics in relation to global change, and the lack of environmentally friendly tools for mechanical vector control. Suggestions for improvement are put forward, along with other critical aspects, including the immune response in relevant host species, the translation of experimental results from mice to livestock for vaccine development, the One Health perspective, disease burden assessment, and advances in information systems and evidence-based policies. The progressive and sustainable control of ATs is achievable, provided stakeholders can muster the necessary commitment, including political support and investment.