Over the centuries, many epidemic diseases have wiped out huge portions of the population. From cholera and small pox to the Black Death and influenza, the wide and rapid spread of diseases have decimated populations, yet in a way, have led to much of the modern world's treatments and cures. Still, epidemics arise, including the Bird Flu contagion, reported in humans since 1997.
Smallpox
Smallpox was one of the earliest diseases that spread in an epidemic as early as 10,000 BCE. The disease produces first a rash, then blisters. It is unique to human beings and is contracted through breathing in the virus. It was one of the first diseases for which inoculation was used to fight. The World Health Organization declared smallpox eradicated in 1979, the only known disease so declared.
Black Death
Bubonic plague first appeared in Europe in the middle 1300s and is considered one of the deadliest pandemics ever. The first wave of the Black Death is thought to have killed up to 100 million people. It may have started in Asia and was carried around the world by fleas feasting on black rats. The plague returned periodically until at least the 17th century and still occurs occasionally throughout the world. It returned in the mid-19th century, again originating in Asia and killing approximately 12 million people worldwide.
Typhus
Typhus is spread through lice on humans. The first epidemic of the disease occurred in the 15th century during a siege in modern day Spain. It also has been known to spread quickly in prison populations and other groups of people in squalid conditions packed tightly together. The disease is estimated to have taken 3 million lives during World War I in Russia alone. These days, it is treatable with antibiotics.
Influenza
The first influenza epidemic that spread worldwide was recorded in the early 1700s, but the most well-known pandemic of it was during and following World War I. This Spanish Flu spread rapidly around the world, partly because of soldiers carrying it with them as they returned home from the war. Scientists believe a full third of the world's population was infected between 1918 and 1920. It was nearly as cataclysmic as the Black Death, wiping out up to 100 million people, far more than were killed in battle in the war. New strains of flu appear nearly every year. In 2009, swine flu or H1N1, was declared a pandemic after its appearance first in Mexico and then throughout the world.
