In this paper, we present two case studies that summarize our journey of design and evaluation of ICTs for community-based dengue prevention, around these two emerging needs: the first one centered around the design of weekly message notifications to volunteers, and the second centered around a better UX to organize the weekly house-by-house visits of volunteers. Based on experiments with messages in the field and 12 think aloud sessions, we learned the type of messages that were more helpful to volunteers, including those containing real data from the project, and we were able to mitigate the dependence on facilitators implicit knowledge about the community when organizing the weekly work of volunteers.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCIA