Description:The world has changed dramatically since then. Now, every day, up to three million people travel by air to another city, another country, or another continent. Every day, millions of tons of cargo are shipped around the world by air, land and sea. Every day, the constant movement of people and products carries with it the potential to spread highly infectious diseases and other hazards more rapidly than at any time in history. A sudden health crisis in one region of the world is now only a few hours away from becoming a public health emergency in another. In the last five years, WHO has verified more than 1100 epidemic events. Among them was a deadly new disease, SARS - Severe Acute Respiratory Syndrome - which sparked an international alert in 2003. Today, there is a real and continuing threat of a human influenza pandemic that could have much more serious human and economic consequences. The World Health Report 2007 discusses these and other current challenges to global health security and asks: How can a safer future be achieved? It looks at the potential of new tools for collective defence, particularly the revised International Health Regulations (2005) which came into force this year. They are designed to achieve maximum security against the international spread of diseases, and have been expanded to include any emergency with international repercussions for health, including natural disasters and chemical or radionuclear events, whether accidental or deliberate.