Disability as a neglected outcome of neglected tropical diseases: A systematic review

Background Neglected tropical diseases (NTDs) affect more than one billion people worldwide, predominantly in low-resource settings. While substantial progress has been made in reducing transmission and mortality, the long-term disabilities resulting from NTDs remain insufficiently recognized and inadequately addressed within control programs. Objective To identify, describe, and systematize the types of disabilities reported among individuals affected by NTDs, providing a comprehensive overview of the magnitude and diversity of long-term functional impairments associated with these conditions. Methods This systematic review was conducted in accordance with PRISMA 2020 guidelines. A comprehensive search was performed in PubMed, Cochrane Central, Embase, CINAHL, LILACS, and Web of Science databases, without restrictions on language or publication date. Studies reporting long-term disabilities or sequelae in individuals diagnosed with WHO-listed NTDs were included. Data on study characteristics, population demographics, and disability types were extracted and synthesized descriptively. Methodological quality was assessed using design-specific tools (MINORS, CARE checklist, and Jadad scale). Results The initial search identified 958 records across databases. After removal of duplicates (n = 478), 480 records were screened, of which 310 were assessed for full-text eligibility. Following the application of inclusion and exclusion criteria, 130 studies were included in the final analysis, encompassing 551,574 individuals from 25 countries. Overall, 29% (n = 158,104) of evaluated individuals presented with at least one form of disability. Physical and motor impairments were the most prevalent (24.6%, n = 135,683), predominantly associated with leprosy-related neuropathic and musculoskeletal sequelae. Visual impairment was the second most frequent disability (1.81%, n = 10,007), largely attributable to trachoma and onchocerciasis. Cardiovascular, neurological, psychological, and social impairments were also reported. Considerable heterogeneity and underreporting of disability outcomes were observed across studies. Conclusions Disability represents a substantial and underappreciated outcome of NTDs, extending far beyond infection-related morbidity. The high burden of long-term physical, visual, and other functional impairments underscores the urgent need to integrate disability assessment, rehabilitation services, and disability-inclusive development into NTD control strategies. Addressing these gaps is essential to advance patient-centered care and achieve the broader goals of the WHO NTD Roadmap and Universal Health Coverage.