EXploring Phlebotomine sand flies as vectors of arboviruses in South-East Asia cave ECosysTemS

"EXPECTS will study the role of Phlebotomine sand flies in the transmission of arboviruses in caves in Southeast Asia. Vector-borne diseases, particularly those caused by arboviruses, represent a growing public health problem, particularly in low- and middle-income countries in Southeast Asia (e.g., dengue fever, Zika). The unique ecological conditions of caves, which make them unique ecosystems, combined with increasing human activity such as tourism and resource exploitation, significantly increase the risk of zoonotic virus transmission from sandflies to humans. Arboviruses have been detected in sand flies in China, Thailand, and Laos. Despite their known role as vectors, Phlebotomine sand flies and the viruses they transmit remain understudied in Southeast Asia. EXPECTS brings together an international consortium with researchers from eight countries, including seven in Southeast Asia, integrating entomology, virology, ecology, and epidemiology. Its main objectives are: (1) to strengthen vector surveillance in Southeast Asia using advanced diagnostic techniques, (2) to identify the main sandfly species in their ecological niches, (3) to detect, characterize, and isolate arboviruses using molecular, virological, and serological methods, (4) to assess the circulation of these viruses in humans, and (5) to analyze the epidemiological risks associated with human exposure in caves. The scientific innovation of EXPECTS lies in the first large-scale assessment of Phlebotomine sand flies as vectors of arboviruses, particularly in caves containing high densities of sandflies (very stable microclimatic conditions). This project contributes to infectious disease research by expanding the scope of study beyond mosquitoes and ticks. Furthermore, it aligns with the WHO Global Strategy for Vector Control and strengthens public health preparedness by developing scientific capacity in Southeast Asia. The project is structured into four main components (WPs). WP1 includes field surveys and environmental monitoring in selected caves in Southeast Asia. WP2 focuses on laboratory analyses, using molecular diagnostics, metagenomics, and viral isolation to identify and characterize arboviruses. WP3 integrates environmental, entomological, and virological data to develop epidemiological models. Finally, WP4 ensures project sustainability through capacity building, training, risk management, and dissemination of results through scientific publications, conferences, and engagement with public health stakeholders. The consortium brings together leading research teams specializing in sandfly biology, vector ecology, arbovirology, and epidemiology. European institutions are providing technical support and advanced molecular diagnostic tools, while Asian partners are providing field expertise and sample analysis. This collaboration strengthens the consortium's scientific infrastructure and ensures its sustainability beyond the project's duration. EXPECTS is expected to produce significant scientific results as the cave-dwelling sand fly fauna of SE Asia will be inventoried, and numerous species new to science will likely be described. Interactions between sandflies, arboviruses and man will be assessed. These results will inform evidence-based public health policies, particularly in the areas of vector control, risk prevention, and travel medicine, in an ecotourism context that is highly conducive to increasing visitation to these caves. Finally, EXPECTS will enable the creation of a consortium that will be actively involved in addressing any emergence caused by a pathogen transmitted by sandflies."