Abstract
BACKGROUND: Neglected tropical diseases (NTDs), including but not limited to lymphatic filariasis, onchocerciasis, trachoma, schistosomiasis, and soil-transmitted helminths, remain a major public health challenge in Africa. Mass drug administration (MDA) is a key strategy for NTD control and elimination. However, mobile populations such as internally displaced persons (IDPs), nomadic groups, and seasonal workers often face major constraints that reduce MDA effectiveness defined by coverage. Understanding how mobility and its underlying drivers affect MDA implementation is therefore critical to designing inclusive, effective, and equitable intervention strategies. In this review, we aim to map existing evidence on how human population movement influences the outcomes of MDA programs in Africa. METHODS: Following PRISMA-ScR guidelines, we searched using electronic databases Medline (Ovid), Embase, Web of Science, and manually screened additional sources for studies published in English or French between January 2000 and February 19, 2025. Two authors independently extracted data, resolving discrepancies through discussion, or with a third reviewer. We included studies reporting on MDA interventions and mobile or migrant populations in Africa. Data were extracted using a standardized template and synthesized thematically to describe mobility patterns, barriers to access, implementation gaps, and strategies used to improve MDA reach among mobile groups. The thematic synthesis consisted of organizing the extracted data into recurring themes, comparing trends across studies, and grouping similar observations to develop broader themes that reflect common challenges and approaches related to mobile populations. RESULTS: From 6814 studies identified, twenty (20) met the inclusion criteria. The review identified multiple challenges likely to affect MDA equity and effectiveness. Mobility, particularly among nomad pastoralists, seasonal workers, IDPs, and cross-border populations leads to systematic exclusion from MDA campaigns. Barriers included geographic inaccessibility, limited tailored communication, lack of cross-border collaboration/coordination, and rigid campaign schedules. Promising strategies documented were mobility-informed microplanning, cross-border collaboration/coordination, flexible delivery models, enhanced community engagement and integration with other health interventions. The evidence emphasizes the need for adaptive, equity-focused MDA approaches to effectively reach mobile populations. CONCLUSIONS: Population mobility has a significant impact on equitable MDA delivery and can hinder progress toward NTD elimination targets in Africa. Tailored, flexible, and inclusive strategies are urgently needed to ensure mobile populations are reached. Future efforts should focus on developing mobility indicators, pilot-testing adaptive MDA delivery models aligned with movement patterns and strengthening partnerships with neighboring countries and humanitarian organizations.