GENEVA — Infectious diseases are emerging more quickly and spreading faster around the globe than ever and becoming increasingly difficult to treat, the World Health Organization (WHO) said on Thursday. With billions of people moving around the planet every year, the U.N. agency said in its annual World Health Report: ‘An outbreak or epidemic in one part of the world is only a few hours away from becoming an imminent threat somewhere else.’ WHO director-general Margaret Chan said mass travel could facilitate the rapid spread of infectious diseases. ‘No country can shield itself from invasion by a pathogen incubating in an airline passenger or an insect hiding in a cargo hold,’ Chan told reporters. The U.N. agency warned that there was a good possibility of another major scourge like AIDS, SARS or Ebola fever with the potential of killing millions appearing in the coming years. ‘Infectious diseases are now spreading geographically much faster than at any time in history,’ the WHO said. It said it was vital to keep watch for new threats like the emergence in 2003 of SARS, or Severe Acute Respiratory Syndrome, which spread from China to 30 countries and killed […]