Skin is a critical interface for Trypanosoma brucei transmission

Trypanosoma brucei (Tb) is transmitted by the bite of the tsetse fly and causes animal and human African trypanosomiases. Sleeping sickness due to Trypanosoma brucei gambiense is targeted for elimination by the World Health Organization (WHO). Traditionally viewed as bloodstream parasites, trypanosomes' distribution has been re-evaluated since Tb is primarily present in extravascular spaces, particularly in the skin. These skin-dwelling forms remain poorly characterized but have profound implications for transmission and could impact diagnosis, treatment, and elimination efforts. We propose the dermis as a critical compartment, serving as both an anatomical reservoir sustaining parasite persistence and a direct interface between hosts. This article will focus on skin-resident parasites to review current knowledge and formulate key research questions that warrant further investigation.