Advances needed for improving leprosy diagnosis in Brazil.

INTRODUCTION: Leprosy remains a major public health challenge in Brazil, where delayed diagnosis sustains transmission and disability. Despite advances in diagnostic research, slit-skin smear microscopy remains the only laboratory diagnostic criterion recommended by WHO among the cardinal signs, despite its limited effectiveness. This diagnostic gap underscores the need to evaluate emerging and complementary approaches. Early and accurate case detection is central to the Global Leprosy Strategy and Sustainable Development Goals. AREAS COVERED: This narrative review examines Brazil's leprosy diagnostic landscape, highlighting the strengths and limitations of the existing diagnostic pathway, including reliance on clinical expertise, limited access to complementary laboratory methods, and the impact of socioeconomic inequalities on timely case detection. It discusses emerging diagnostic technologies, including point-of-care tests, molecular assays, digital health, artificial intelligence, and precision public health, and their potential to improve early detection, particularly of paucibacillary disease and household contacts. It also emphasizes strengthening Primary Health Care, workforce training, contact surveillance, research, and stigma reduction to advance leprosy control. EXPERT OPINION: Integrating innovative diagnostics with stronger Primary Health Care, workforce training, contact surveillance, research, and stigma reduction is essential. Equitable, evidence-based implementation can accelerate early diagnosis, reduce disability, and interrupt transmission in Brazil.