[HIGHLIGHTS] Twenty viruses surveilled, arrive from Africa and Asia, mosquito danger

Special surveillance 20 viruses around the world that are spreading fast. Those who come from Africa, but also from exotic countries, are worried.

"We must not lower our guard," says Fabrizio Pregliasco, medical director of the IRCCS Galeazzi Hospital. The focus is on Dengue, Zika, Chikungunya, and West Nile viruses, which are part of arboviruses, a group of viruses that are transmitted to humans through mosquito bites.