ABSTRACT:
Introduction. Soil-transmitted helminth infections remain highly prevalent in Zanzibar despite long-standing public health interventions, including mass drug administration and sanitation programs. The One Health Socio-Ecological Systems framework provides an integrated lens to understand transmission across human, animal, and environmental domains (1). However, it primarily relies on cost–benefit assumptions to explain coordination and cooperation (2). This focus limits its ability to account for social inequalities and normative factors that shape intervention uptake and sustainability in real-world public health settings (3-5). Methods. This paper proposes a conceptual extension of the One Health Socio-Ecological Systems framework through the integration of the Multi-Layered Social Resilience approach (6). Drawing on social resilience theory, this perspective is applied to soil-transmitted helminth control in Zanzibar as a conceptual case scenario. The analysis examines how actors across household, community, and institutional domains mobilize different forms of capital and enabling conditions to cooperate around sanitation and waste disposal management. Results. The integrated approach highlights that effective cooperation for soil-transmitted helminth control depends not only on technical efficiency but also on socially embedded factors such as trust, legitimacy, and unequal access to decision-making power. By distinguishing cooperation across multiple social layers and adopting a bottom-up perspective, the Multi-Layered Social Resilience approach reveals how interventions may succeed or fail depending on whose knowledge, norms, and capacities are recognized. Conceptual cooperation scenarios illustrate how misalignment between institutional strategies and everyday practices can weaken public health outcomes, while cross-level cooperation can enhance social resilience and reduce transmission. Conclusions. Integrating Multi-Layered Social Resilience into the One Health Socio-Ecological Systems framework strengthens its relevance for public health and One Health practice. This approach enables a more realistic understanding of cooperation and supports the design of interventions that are socially grounded, context-sensitive, and better aligned with the conditions required for sustainable soil-transmitted helminth control.