"Could this really happen?" Of course it can happen, look through out History

No sooner had the First World War ended than the Spanish flu pandemic 

Epidemics and pandemics: 

their impacts on human history though out the world 

Smallpox

CDC: Deadly 'Contagion' outbreak is possible

NEW HANOVER COUNTY, NC (WECT) – Contagion has infected enough moviegoers to catch the top spot at the box office, making $23.1 million in its first weekend.

It was directed by Steven Soderbergh and stars an A-list cast that includes Matt Damon, Kate Winslet, Jude Law and Gwyneth Paltrow.

The thriller is centered on the threat posed by a deadly disease and an international team of doctors contracted by the CDC to deal with the outbreak,according to IMDB.

After seeing the movie or even just seeing previews many people are asking, "Could this really happen?"

According to the CDC, "Not only could it happen, CDC scientists are working 24/7 to find out if it's happening right now."

The deputy director of the CDC sent an email to health officials to help them separate fact from fiction as questions roll in as a result of the movieContagion.  In the email she explains the CDC plays a key role in homeland security by maintaining the ability to detect and respond to outbreaks like the one in the film.

[CDC Contagion controlling real global disease outbreaks]

1918-1919 – The "Spanish Flu" circles the globe (though someexpertsthink it may have started in the U.S.). Caused by an H1N1 fluvirus, it is the worst influenzapandemic(and subsequently, epidemic) to date. There are more than half a million U.S.deaths; worldwide death estimates range from 20 million to 100 million. According to WebMD, "The pandemic comes before the era of antibiotics -- which are now essential in treating the secondary bacterialinfectionsthat often kill flu-weakenedpatients-- so it's difficult to say whether this flu would have the same dreadful impact in the modern world. But it is a very frightening disease, with very highdeathrates among young, previouslyhealthyadults."

Learn more:http://www.naturalnews.com/026178_flu_influenza_bird.html#ixzz1Y64n98V4

In epidemiology, an epidemic (επι (epi)- meaning "upon or above" and δεμος (demos)- meaning "people"), occurs when new cases of a certain disease, in a given human population, and during a given period, substantially exceed what is expected based on recent experience. The disease is not required to be communicable.^{[citation needed]} An epidemic may be restricted to one locale, or it may be global, in which case it is called a pandemic. A few cases of a very rare disease may be classified as an epidemic, while many cases of a common disease (such as the common cold) would not.

The CDC created a website that explains to the public what could happen if there was a deadly contagious disease outbreak in the United States.  The organization says it is always preparing for, and working to prevent, the next pandemic.  I'll include the website that they mentioned and forgot to add

CDC   and I'll add The World Health Organizations as well  WHO

One of the worst ways for the human population to be thinned is to die from disease. Millions of people each year have perished as a result of one of any number of seemingly unstoppable diseases. Throughout history mankind has suffered the crippling and mortal effects of a ravaging disease brought on by any number of target factors ranging from animals to one single human host. Here are but ten, in no particular order, that have decimated humankind since the earliest recordings.