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Smallpox: Facts and Details

What is smallpox?

Smallpox is a serious, contagious, and sometimes fatal infectious disease. It is caused by the variola virus. The majority of people with smallpox recover, but death may occur in up to 30% of cases.

How is smallpox spread?

Generally, direct and fairly prolonged face-to-face contact is required to spread smallpox from one person to another. It can also be spread through direct contact with infected bodily fluids or contaminated objects such as bedding or clothing. Rarely, smallpox has been spread by virus carried in the air in enclosed settings such as buildings, buses, and trains. Smallpox is not known to be spread by insects or animals.

What are the symptoms of smallpox?

The symptoms of smallpox begin with a high fever, head and body aches, and sometimes vomiting. A rash follows that spreads and progresses to bumps and pusfilled blisters that crust, scab, and fall off after about three weeks, leaving a pitted scar.

After exposure, it takes between seven and 14 days for symptoms of smallpox to develop (average time is 12 to 14 days). During this time, the infected person feels fine and is not contagious.

A person with smallpox is sometime contagious with onset of fever, but becomes most contagious with the onset of rash. He or she is contagious until the last smallpox scab falls off.

Should I get the vaccine?

Because the smallpox virus has been eliminated, there is no specific treatment for it. A smallpox vaccine does exist but because there is a very low risk of disease due to elimination, it is not available to the general public unless an outbreak occurs. If people were to become infected, a supply of vaccine will be available. People with smallpox can benefit from medicine to control fever or pain and antibiotics for any secondary bacterial infections that may occur.

If someone is exposed to smallpox, is it too late to get a vaccination?

Vaccination within three days of exposure will completely prevent or significantly modify smallpox in the vast majority of persons. Vaccination four to seven days after exposure likely offers some protection from the disease and may reduce the severity of the disease. 

More Information on Small Pox

Sedgwick County is leading a coordinated effort through the health department to assure the health and safety of its citizens in the event of a bioterrorism incident. Contact the Public Health Emergency Management Office (PHEM) to learn more.  

Centers for Disease Control & Prevention (CDC) & U.S. Department of Health & Human Services smallpox site: