Infectious diseases are spreading faster than ever before according to the World Health Organization’s annual report.The report says with about 2.1 billion airline passengers flying each year, there is a high risk of another major epidemic such as AIDS, Sars or Ebola fever.The WHO urges increased efforts to combat disease outbreaks, and sharing of virus data to help develop vaccines. Without this, it says, there could be devastating impacts on the global economy and international security.Since the 1970s, 39 new diseases have developed, and in the last five years alone, the WHO has identified more than 1,100 epidemics including cholera, polio and bird flu.