In the framework of the Research Project PERIS, the Infectious Diseases Department of Vall d'Hebron leads the creation of a virtual warning platform to evaluate the risk of occurrence of autochthonous arboviruses in Catalonia. Nowadays, these diseases get imported as the affected Catalan citizens are infected elsewhere. Still, the contagion risk in Catalonia through a vector shaped as an arthropod, be it the common mosquito or the tiger mosquito, can happen when an infected person during its transmissibility period gets bitten by a mosquito and this one bites another healthy person. It is important to highlight that the arboviruses are very dangerous diseases, as it is the case of Zika, dengue, chikunguya or the western Nile virus, especially for the vulnerable population as pregnant woman or people with depressed immunity. The increasing presence of the tiger mosquito in the Mediterranean area has become the main threat for the occurrence of autochthonous arboviruses in Catalonia.This warning system or prediction engine is the latest tool resulting from the Integrated Platform for the control of arboviruses in Catalonia (PICAT). This platform contents several institutions that provide information related to the arboviruses and the risk of it becoming autochthonous. By this means, it is expected a close follow up of the presence and evolution of these pathologies in Catalonia.Vall d'Hebron - International Health Program of the Institut Català de la Salut (PROSICS) leads the PICAT in collaboration with the Public Health Agency of Catalonia (ASPCAT), the Public Health Agency of Barcelona (ASPB), and the Public Health Organism of Girona's Council (Dipsalut), the Jordi Gol University Institute for Research Primary Healthcare (IDIAPJGol), Ecological and Forestry Applications Research Centre (CREAF), Catalan Institution for Research and Advanced Studies (ICREA), and the Centre for Advanced Studies of Blanes (CEAB-CSIC), that, supported by "laCaixa" Foundation, bring along the citizen science's project http://www.mosquitoalert.com/en/ Mosquito Alert, Barcelona Institute for Global Health (ISGlobal), and the the Environmental Policies Consortia of Terres de l'Ebre (COPATE), the Mosquito Control Department of Badia de Roses and Baix Ter and the Mosquito Control Department of the County Council of Baix Llobregat.Most of these institutions belong the Interinstitutional Commission for the Prevention and Control of Vector mosquitos in Catalonia, responsible of the surveillance and control of the arboviruses around us. Within the frame of this Commission, a Protocol for the Surveillance and Control of transmitted Arboviruses by Mosquitos in Catalonia had been created, and had been coordinated by ASPCAT and implemented on the field since 2015.Nowadays, "the risk of arboviruses becoming autochthonous is low - explains Dr. Israel Molina, coordinator of the Tropical and Imported Diseases and International Health of the Infectious Diseases Department of Vall d'Hebron-, but it is increasing owing to the occurrence of the tiger mosquito and the importation of arboviruses through the traffic of travelers within Catalonia and endemic areas".A warning system to be ahead of the risk of autochthonous arbovirusesAs Dr. Israel Molina explains, "with PICAT we want to further than having a static picture of the arboviruses in Catalonia. We want to go ahead and detect, in real time, the risk that these diseases become autochthonous". To achieve it is basic to develop a warning system, which will be feed by the information coming from every institution involved in the control of these diseases, and will learn to detect the mentioned risk.The current information at PICAT related to data from arboviruses cases and suspicion of disease, climate data and information of the presence of tiger mosquito in certain areas. The information about the presence of the tiger mosquito comes from the several mosquito control departments and the warnings created by the citizens with the App Mosquito Alert. The future warning system will have as a base the map of citizen's warnings created through the project of citizen science Mosquito Alert and its notifications, confirmations, entomologic study of the notified cases in Catalonia within the frame of actions of the Protocol of Surveilance and Strategy for the tiger mosquito control. The project Mosquito Alert collects pictures of tiger mosquitos, yellow fever mosquitos, and their breeding sites in real time, collected by citizens and the App.Therefore, the warning system is based on a software that will allow the cross-reference of all this information and will work as an algorithm to evaluate the risk of autochthonous arboviruses."As an example, if the Primary Healthcare of a certain area warns about the increase of dengue cases, the citizens alert the increasing presence of the tiger mosquito, and the mosquito control department confirms its occurrence and predict rains that could enhance the mosquito's proliferation, the alarm will be activated, as the optimal conditions for the mosquitoes to bite the infected people and consequently, the creation of autochthonous dengue, are gathered. By this means, we will act before this happens", adds Dr. Israel Molina, who is also a researcher at the Infectious Diseases Reseach Group of Vall d'Hebron Research Institute (VHIR).By this means, the algorithm will be an intelligent warning system that will learn from the new data and the experience gathered, turning every time into a more accurate, efficient and fast tool to evaluate the risk of arboviruses autochthonous appearance. This system expects to provide a virtual supporting tool for the risk alert to the actions of the public health institutions developed within the frame of the Protocol for prevention and control of transmitted arboviruses by Mosquitoes in Catalonia.