What is smallpox?

Smallpox is a serious disease caused by the variola virus. It has now been entirely removed from the world through vaccination. It is very contagious and killed millions of people worldwide before the World Health Organization (WHO) began an international immunisation campaign.

In 1980 the WHO announced that smallpox had been eradicated. It was the first infectious disease to have been completely wiped out worldwide. The last case in Australia occurred in 1938. The last reported naturally occurring case anywhere in the word was in Somalia in 1977.

After the disease was officially eradicated, all remaining stocks of the virus worldwide were destroyed, apart from small amounts held in 2 secure laboratories in the United States and Russia.

No one is at risk of catching smallpox in Australia today. The only risk would be if the smallpox virus was used in an act of bioterrorism.

What are the symptoms of smallpox?

In the first few days of the illness, symptoms include:

• fever over 40°C
• headaches
• body aches
• nausea and vomiting
• sore throat

After this, a rash of blisters develops in the mouth and spreads all over the body. The blisters crust over and form scabs. After about 3 weeks, the scabs fall off and leave scars.

What causes smallpox?

Smallpox spreads from person to person by close contact. It is transmitted by inhaling droplets exhaled by a sick person, or by touching surfaces contaminated by body fluids.

How is smallpox diagnosed?

There is no treatment for smallpox. In the past, it caused death in about 3 in every 10 people who caught it.

How is smallpox treated?

If someone were to catch smallpox, they would need fluids and pain-relieving medicines. Antibiotics would be given if the blisters became infected with bacteria. The unwell person and their contacts would be in isolation.

Can smallpox be prevented?

The disease was wiped out through vaccination. The smallpox vaccine is not given routinely anymore. However, if you receive the smallpox vaccine within 3 days of being exposed to the virus, it can prevent you getting sick.

The smallpox vaccine was the first successful vaccine in the world. It was developed by an 18th-century doctor, Edward Jenner, who noticed that milkmaids did not catch smallpox if they had previously had another mild disease, cowpox. Jenner showed that vaccination made people immune to smallpox.

The smallpox vaccine is made from the vaccinia virus. This is a related virus that cannot cause smallpox.

What are the complications of smallpox?

Smallpox can lead to:

• scarring of the skin
• blindness
• pneumonia
• arthritis
• bone infections

If there were ever an outbreak, how would it be managed?

The Australian Government Department of Health and Aged Care has a smallpox emergency management plan. Australia has a supply of the smallpox vaccine to use in case there is ever an outbreak.

The disease would be controlled by vaccinating and isolating anyone who came into contact with an infected person. This would include healthcare workers.

Is monkeypox the same as smallpox?

Monkeypox (or mpox) is a viral illness that is related to smallpox, but they are not the same virus. Monkeypox has similar symptoms to smallpox, but it is usually less severe and most people get better. However, it can potentially be a serious illness.

Resources and support

If there is a smallpox outbreak anywhere in the world, your local state or territory health department can provide information on what precautions to take.