Smallpox

Smallpox was an infectious disease caused by Variola virus. It spread easily from person to person, usually through close contact or sometimes through contaminated objects.

People with smallpox would first feel very sick with fever and sometimes throw up. Then, they would get sores inside their mouths and a rash on their skin that turned into fluid-filled blisters. These blisters would dry up and fall off, often leaving scars.

The disease could be dangerous, and many people who got it died, especially babies. Smallpox has been around for thousands of years, with evidence found in ancient Egyptian mummies. It caused many deaths throughout history, including among many people in the New World.

The good news is that through hard work and science, smallpox was eliminated worldwide. This happened because of a special vaccine created by a man named Edward Jenner in 1796. By 1980, the World Health Organization announced that smallpox was gone forever, making it the first disease in history to be completely wiped out. Today, only a few samples of the virus are kept safe in special laboratories.

Classification

There were two main forms of smallpox. Variola major was the more serious and common type. Variola minor was less common and caused milder disease.

Most cases of smallpox were of the ordinary type. In this form, the skin would start with flat spots that become raised bumps. These bumps would then fill with fluid, becoming blisters. Over time, the blisters would crust over and fall off, often leaving marks on the skin. The rash was usually most noticeable on the face and the ends of the arms and legs.

Signs and symptoms

Smallpox began with symptoms like those of other common illnesses, such as influenza and the common cold. People would feel very hot, tired, have headaches, and muscle aches. Sometimes, they also felt sick to their stomachs and threw up.

Later, small red spots would appear inside the mouth and on the skin. These spots would grow and change, creating the rash that is well-known from this disease. The spots usually first showed up on the face and then spread to the rest of the body.

Cause

Smallpox was caused by the Variola virus, which is part of the Poxviridae family and the Orthopoxvirus genus.

The disease likely began in African rodents thousands of years ago. There were two types of the virus: a more severe form and a milder form. The milder form helped lower death rates in places like the United States and Europe in the early 1900s. The last known case of smallpox was in 1977, and the disease was officially declared gone from the world in 1980.

The Variola virus is shaped like a brick and can only infect humans. It reproduces inside cells and spreads through close contact with infected people.

Mechanism

When someone breathed in the variola virus, it entered their mouth, throat, and breathing tubes. The virus then moved to nearby lymph nodes and started to grow. After about 12 days, many infected cells broke apart. This caused the virus to spread through the blood, a stage called viremia. The virus then grew more in the spleen, bone marrow, and lymph nodes.

Diagnosis

Before scientists had special tests, doctors could tell if someone had smallpox by looking at the hard bumps on the skin. Now, there are better ways to check, like looking at tiny parts of the virus under special microscopes.

Scientists can also grow the virus in a part of a chicken egg to see if it causes certain changes. There are also quick tests that can show if the virus is present.

Sometimes, another illness called chickenpox can look like smallpox. But there are ways to tell them apart. For example, chickenpox does not usually affect the palms of the hands or the soles of the feet.

Prevention

One of the first ways people found to fight smallpox was through a method called inoculation. This meant giving a tiny bit of the virus to help a person's body learn to fight it. This method started long ago in places like India, Africa, and China.

Later, a doctor named Edward Jenner found a better way in 1796. He discovered that using a safe virus from cows, called cowpox, could stop smallpox without making people sick. This new method was called vaccination.

Today, the smallpox vaccine uses a safe virus to help people’s bodies fight the disease. The vaccine is given with a special needle that gently pokes the skin a few times. After getting the vaccine, a small bump forms and turns into a blister that later becomes a scab. This shows the body is building protection. The vaccine works well and helps protect against other similar viruses too.

Treatment

Getting a smallpox vaccination within three days of exposure can stop or make the illness much milder for most people. If the vaccination is given four to seven days after exposure, it might still help a little or make the disease less severe. Besides vaccination, treatment focuses on helping the body, like caring for wounds, controlling infections, giving fluids, and sometimes using a ventilator to help with breathing.

There are medicines that can help treat smallpox. In 2018, a drug called tecovirimat was approved especially for this purpose. Another medicine, Brincidofovir, was approved in 2021 to treat smallpox caused by the variola virus.

Prognosis

Smallpox could be very serious, especially for young children. The lighter form of the disease, called variola minor, was less severe. The more serious form, variola major, could be very dangerous.

In the worst cases, people could die about two weeks after getting sick. The illness could cause serious problems in the body. Some people had trouble breathing or problems with their brains. Many survivors had deep scars, especially on their faces.

History

Main article: History of smallpox

Disease emergence

See also: Native American disease and epidemics, History of smallpox in Mexico, and List of epidemics and pandemics

The first signs of smallpox appeared in old writings from ancient India and China. Researchers studied a mummy from Egypt. Smallpox likely spread from Egypt to India and later to China and Japan. In Japan, a big outbreak happened in the 700s. Many cultures had gods linked to smallpox, like the Yoruba god Sopona and the Hindu goddess Shitala.

Some think smallpox may have started later, around the year 1588.

It is unclear when smallpox arrived in Europe and southwestern Asia. It is not mentioned in the Bible or in ancient Greek and Roman writings. The Antonine Plague in the Roman Empire might have been smallpox. By the Middle Ages, smallpox became common in Europe, especially after the Crusades.

Smallpox was not in the Americas before European explorers arrived. It reached the Caribbean in 1507 and the mainland in 1520 with Spanish settlers. Many Native Americans died because they had no immunity. Smallpox also caused problems in North America and later reached Australia in 1789.

By the mid-1700s, smallpox was common worldwide except in some places like Australia. In Europe, it caused many deaths each year. Some places used a method called variolation to protect people, but vaccination in the late 1800s was better. By the mid-1900s, two types of smallpox existed in Africa.

Eradication

See also: Smallpox vaccine and Inoculation

The first known way to protect against smallpox was in China, where people used powdered smallpox scabs. This could cause a mild case and make people immune.

The English doctor Edward Jenner showed in 1796 that cowpox could protect against smallpox. This led to more efforts to stop smallpox. Countries like Russia, Britain, and the United States started vaccination programs.

By 1950, efforts began to eliminate smallpox in the Americas. In 1967, the World Health Organization started a global effort called Target Zero. This involved finding and isolating cases and vaccinating people nearby.

The last natural case of smallpox was found in Somalia in 1977. The world was officially free of smallpox in 1980.

Costs and benefits

The effort to stop smallpox involved many people and cost about US$300 million from 1967 to 1979. This has saved money since no vaccinations or treatments are needed now. Smallpox may have caused many deaths in the last century, so stopping it was a big success.

Since eradication

The last known case of smallpox happened in the United Kingdom in 1978. All remaining samples of the virus are kept in two special labs. Scientists have discussed destroying these samples, but some think they could help develop new medical treatments. In 2014, old vials of smallpox were found in a lab and safely destroyed. There have been concerns about the safety of these labs.

Society and culture

Biological warfare

In 1763, a conflict called Pontiac's War began when a group of Native American leaders tried to resist British control over the Great Lakes area. During this time, a British leader named Henry Bouquet used a tricky method against the Native Americans. He gave blankets with the smallpox illness to some leaders near Fort Pitt to spread the illness.

During World War II, scientists from the United Kingdom, the United States, and Japan looked into using smallpox as a weapon. But they never used big plans because they thought it would not work well, thanks to the vaccine.

In 1947, a factory for making smallpox weapons was built in the Soviet Union. In 1971, an outbreak happened during testing on an island in the Aral Sea. This caused some deaths, including children. Later, the Soviet government let some inspections happen, but the full story of its activities was still unclear.

Notable cases

Many famous people in history had smallpox. For example, Sitting Bull, the Lakota Chief, and several emperors and rulers from different countries got the disease. Some, like the Kangxi Emperor of China, lived, while others, like Emperor Komei of Japan, did not.

In Europe, the disease sometimes changed who would become the next ruler. For example, Louis XV of France became king partly because others ahead of him had died from smallpox or similar illnesses.

In the United States, Presidents George Washington, Andrew Jackson, and Abraham Lincoln all had smallpox but got better. Washington got it during a visit to Barbados in 1751.

Tradition and religion

Because smallpox was so dangerous, many cultures created gods or goddesses related to the disease. In China, people worshipped a goddess named T’ou-Shen Niang-Niang. They tried to keep her happy by using kind words for the disease and setting up shrines in homes of those affected.

In West Africa, the Yorùbá people believed in a deity named Sopona, linked to smallpox and other serious diseases. Sopona was both feared and seen as a healer.

In India, the goddess Shitala was linked to smallpox. People worshipped her in shrines, hoping to avoid the disease or find healing.