Human Parasitic Diseases

Human African trypanosomiasis (HAT) is in decline, thanks to sustained control efforts in recent decades. Yet, its complexity as a disease at the animal–human interface and its potential for resurgence represent a significant concern for the final elimination goal. Understanding the challenges underlying HAT control involves engaging deeply with the epidemiology, ecology, and evolution of trypanosomes and their hosts. Dissecting the importance of parasite-intrinsic biological factors, vector life-history contribution, and host immunological aspects, requires integrated efforts across disciplines. The prospects for control of HAT, reviewed here, comprise a spectrum of developments, from new tools for disease diagnosis and staging, tsetse control, and prevention of transmission, to more effective and non-toxic treatment options, including immune therapies. Although fundamentally pathogenic, trypanosomes can also be carried asymptomatically by their hosts. Trypanotolerance, recently recognized as an important factor in persistence of disease foci, especially for Trypanosoma brucei gambiense, remains an under-studied aspect of HAT epidemiology. With advancing technologies, a better cellular and molecular resolution of trypanosome infection processes is now possible. Integrating these data with quantitative models, and linking mechanistically different aspects of disease across biological scales, could bring key novel insights into HAT control strategies.