- Ebola, SARS and swine flu are just a few of the deadly diseases outbreaks in recent years
- Global networks provide early warning of potential outbreaks
- Airborne diseases pose the biggest threat to global health, say experts
Vital Signs is a monthly program bringing viewers health stories from around the world.
(CNN)It swept across 214 countries worldwide and killed more than 18,000 people. The 2009 H1N1 influenza outbreak, dubbed "swine flu," put the entire world on alert. The outbreak was declared to be a global pandemic until August 2010.