When was smallpox eradicated from the world

Survivors were often left disfigured by pockmarks and scars. Some went blind. Smallpox is likely to have proliferated in densely populated towns of early civilizations before being carried along trade routes and on ships until it had spread worldwide. It continued to plague humanity for more than 3, years ,. Then in the late 18th century a vaccine was discovered.

And thanks to a series of programmes designed to eradicate the disease — which involved identifying all cases and their contacts and ensuring that they were all vaccinated — it was eliminated in the second half of the 20th century.

The disease is caused by the variola virus. Its most notable outward signs are a rash that forms on the face, arms and legs of an infected person although it starts — like many viral infections — with an elevated temperature and tiredness.

The rash develops into clusters of fluid-filled pustules, which can look superficially similar to the chickenpox rash, although the two diseases are caused by different viruses.

Early symptoms include high fever and fatigue. The spots on the skin become filled with clear fluid and later, pus, and then form a crust, which eventually dries up and falls off.

The virus spreads in droplets, much like coronaviruses, and can be expelled into the air via coughing and sneezing. But it can also be passed on via the fluid from smallpox blisters. Typically, someone would need to have been in close proximity to an infected person before catching it themselves. There are no effective treatments or cures for smallpox, but vaccination can be used effectively to prevent infection from developing.

The earliest attempts at immunization involved a process known as variolation. The recipient would usually make a full recovery and develop immunity to smallpox.

But they may also have been shedding the virus and spread the disease to people who subsequently became seriously ill and died. Two people in particular are credited with developing what we now think of as the smallpox vaccine.

The first was farmer Benjamin Jesty, who spotted a link between smallpox and cowpox. Smallpox is an acute contagious disease caused by the variola virus.

It gets its name from the Latin word for "spotted," referring to the raised, pustular bumps that break out over the face and body of those affected. Historically the virus killed around 30 percent of people who caught it. Those who survived were often left blind, sterile, and with deep pitted scars, or pockmarks, on the skin. Spread through direct contact with infected people, body fluids, or contaminated objects such as bedding, the disease had two main types.

Variola major was the most common form—and most lethal. Variola minor produced a milder disease, which was fatal in less than one percent of cases. Two other, rarer forms also existed: hemorrhagic and malignant.

Both invariably resulted in death. Smallpox is thought to have originated in India or Egypt at least 3, years ago. His mummified remains show telltale pockmarks on his skin. The disease later spread along trade routes in Asia, Africa, and Europe, eventually reaching the Americas in the s. Indigenous peoples there had no natural immunity. An estimated 90 percent of indigenous casualties during European colonization were caused by disease rather than military conquest.

Smallpox contributed to the decline of the Aztec Empire , in what is now Mexico, following the virus's arrival with Spanish conquerors in More than three million Aztec succumbed to the disease.

Severely weakened, the Aztec were easily defeated. Likewise, smallpox claimed the life of an Inca emperor and wiped out much of the Inca population in western South America. In Europe, smallpox is estimated to have claimed 60 million lives in the 18th century alone. In the 20th century, it killed some million people globally.

The human fight against smallpox dates back some 2, years. In Asia, a technique known as variolation involved deliberately infecting a person by blowing dried smallpox scabs up their nose. Those who received this treatment contracted a mild form of the disease, developing a lifelong immunity. A key breakthrough came in when an experiment by English doctor Edward Jenner showed that inoculation using closely related cowpox could protect against smallpox.

Though many of the people who contracted smallpox survived, they did not come away unscathed. The rashes left behind severe scars, and some patients became blind from the sickness. The first smallpox immunization was created by Edward Jenner in But it took more than years and a worldwide vaccination program to eradicate the disease. The last known naturally occurring case of smallpox was diagnosed on Oct. We do not really have any treatments even today for smallpox that are proven, tried and tested," Glatt said.

Though the U. Researchers continue to study smallpox, but very few scientists have access to the deadly disease. Prevention of smallpox is based on a worldwide vaccination strategy. Anyone who shows signs of the virus are vaccinated and kept in isolation to prevent any spread of infection by their country's medical authorities.

Anyone who may have come in contact with the potentially infected person is also given the vaccine. The vaccine can prevent or lessen the effects of the virus if it is administered within four days of exposure, according to the Mayo Clinic.

Stockpiles of smallpox vaccines are stored around the world to respond to an epidemic, if that ever occurs. In the U.