When context matters: Multilevel determinants of self-reported sexually transmitted infections symptoms among men engaged in transactional sex in 26 Sub-Saharan African countries. - Yaya I; Dah TTE; Kassang P; N'dri KM; Dahourou DL; Ossima AN; Patassi A; Nambiema A; Saka B (BMC public health, 2026)