Consider that the global population doubled between 1967 and 2010. That makes 3.5 billion more hosts for mutating viruses. Add to that the disturbing trend of parents not vaccinating their children, which led to measles outbreaks in the U.S. and Germany in the past two years.
The recent Ebola outbreak in West Africa killed more than 11,000 people. The rising prevalence of antibiotic-resistant bacteria only adds to this risk. A pandemic would have wide-ranging effects on business: deaths would significantly reduce workforce, businesses where an infected employee worked may have to shutter for decontamination, health care systems would be overloaded and supplies would likely run short. In big cities like London or New York, disrupted local economies could also have global impact.