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.