As malaria cases continue to decline in Asia, an integrated service delivery approach is ever more urgent to ensure that no malaria and fever cases are missed, and that malaria health workers continue contributing to broader infectious disease control efforts. However, despite its perceived merit, translating integrated surveillance into practice poses several systemic challenges. This article aims to identify what is hindering improved processes for integrating diagnostic and surveillance services for febrile illnesses. Data from peer-reviewed and grey literature were reviewed using a systems approach based on the World Health Organisation health systems building blocks to fully understand the connections between different elements and system implications of integration. We include snippets from Sri Lanka, Myanmar, Malaysia and Nepal, highlighting expanded diagnostic integration best practices. This review provides a foundation for 'integration roadmaps' that can be adapted to different contexts and guide national stakeholders on the operational and political steps for a successful integration model. Such a model