PLoS Comput. Biol. PLoS Comput. Biol. Unsupervised extraction of epidemic syndromes from participatory influenza surveillance self-reported symptoms Kalimeri Kyriaki Delfino Matteo Cattuto Ciro Perrotta Daniela Colizza Vittoria Guerrisi Caroline Turbelin Clement Duggan Jim Edmunds John Obi Chinelo Pebody Richard Franco Ana O Moreno Yamir Universidad de Zaragoza Meloni Sandro Koppeschaar Carl Kjelso Charlotte Mexia Ricardo Paolotti Daniela 2019 research-article