There have surely been pandemic outbreaks since the beginning of time. Our recorded history of these events covers outbreaks of plague, cholera, typhus and influenza. The Spanish flu of 1918 killed more people than any other illness in recorded world history — an estimated 20 million to 50 million worldwide, including roughly 550,000 in the United States. In addition to the 1918 flu, there have been two other pandemic outbreaks in the last century (that have spread worldwide within a year of being detected).
- The "Asian flu" H2N2 was detected in China in February 1957. By June of that year it had spread to the United States, causing about 70,000 deaths.
- In early 1968 the "Hong Kong flu" H3N2 was detected in Hong Kong and spread to the U.S. later that year, causing 34,000 deaths.
The H3N2 virus is still in circulation today and is included in this year’s flu vaccine. Both of these started in Asia and, like the 1918 flu, contained a combination of human and avian influenza virus.
Now, nearly 100 years later, the population is larger and better connected than at any time in our history. The ability to travel anywhere in the world in a matter of hours provides the ability to spread disease at an unheard of pace. While our technology and understanding of disease and medicine has increased dramatically, another outbreak like this would still be devastating. The most likely culprit for a new pandemic is expected to be H5N1 Avian Influenza or "bird flu." This is the strain that has been spreading since 2003 and has shown limited ability to be transmitted from animals to humans. To date, there have been 318 cases of human infection with 192 resulting in death.
There was concern a few years back that Severe Acute Respiratory Syndrome (SARS) might become the next pandemic. It has been classified by some as a pandemic (although it spread to other countries, it did not spread worldwide). From November 2002 to July 2003, there were over 8,000 known cases of the disease and over 700 deaths. According to statistics from the WHO report, this was an overall mortality rate of 9.6 percent.
The H5N1 Avian Flu was first identified in 1996 in China. The first known case of human infection was in 1997. There were 18 cases, resulting in 6 deaths. Since that time it has spread through at least a dozen countries and resulted in nearly 200 deaths.