Two dangerous viruses are back in the spotlight, reminding health officials how quickly infectious diseases can become serious threats. Hantavirus, often linked to rodents, can cause severe heart and lung complications and has no specific treatment or vaccine, while certain strains can even spread b etween people. Ebola remains one of the world's most feared diseases, with some outbreaks killing up to half of those infected, although vaccines and antivirals have improved outcomes for some strains. ...read more read less