The unearthed grave of 13 individuals in London who are believed to have lost their lives to the "Black Death" has raised some interesting theories as to what caused the infamous plague. It has also raised an important question: Do we still have to worry about a disease that is supposed to have died out in most parts of the world over 50 years ago?

Due to how the skeletons were aligned and pottery found along-side them, archeologists have estimated that the grave held the remains of 50,000 bodies and was most likely used in the 14th century when plague first reached Europe from Asia.

Plague is defined as a bacterial infection that can be contracted by humans through rodents and their fleas. Types of plague include Bubonic, Pneumonic and Septicemic Plague.

Accounts of plague related outbreaks are well documented throughout different time periods around the world. The earliest records of the disease date back to 541 A.D. when the Plague of Justinian claimed 10,000 lives a day in Constantinople (modern day Turkey).

The most recent outbreak of plague took place in China from 1855 to 1959. During its spread, researchers discovered rats with similar plague like symptoms to humans and fleabites covering the bodies of infected humans.

But what are the chances of an outbreak happening in today's world?

There are approximately seven reported plague cases a year in the United States.

Less than a year ago a plague case was reported in Oregon after a woman helped her friend save a cat that was choking on a mouse. The friend she was helping had also contracted the infection just three months prior to this incident. The two Oregon residents were treated and made full recoveries.

So what are the chances? Possible, but not likely. Conditions for the plague to spread must be completely inhabitable, rodent infested and vast. As long as the right modern antibiotics are utilized, someone infected with the disease should make a full recovery.