Five clinical cases document alpha-gal syndrome (AGS) following tsetse fly bites in Uganda and Rwanda, with patients developing red meat allergies despite no prior tick exposure. Laboratory analysis confirmed Ugandan Glossina fuscipes fuscipes flies produce alpha-gal epitopes and express galactosyltransferases necessary for alpha-gal synthesis. Two cases received formal AGS diagnosis, while additional patients showed consistent symptoms after multiple fly encounters. This represents the first documented evidence that tsetse flies can trigger the same IgE-mediated red meat allergy traditionally associated with lone star tick bites. The finding expands our understanding of AGS beyond tick-borne transmission and suggests multiple arthropod vectors may contribute to this emerging allergy syndrome. Given tsetse flies' geographic range across sub-Saharan Africa, this discovery has significant implications for allergy diagnosis and management in regions where these flies are endemic but ticks are less prevalent. The research validates citizen science approaches for identifying novel disease vectors and highlights the need for broader arthropod screening in unexplained food allergy cases. While the sample size remains limited, the molecular evidence supporting alpha-gal production by tsetse flies provides a compelling biological mechanism for these clinical observations.