WebMD
Font Size

Smallpox

Smallpox is a potentially deadly infection caused by the variola virus. The infection causes severe illness, including a high fever, followed by a rash all over the body that looks like blisters.

Smallpox symptoms develop about 12 days after exposure. The disease usually is not contagious until the rash first appears. As scabs form, the chance of passing on the disease decreases.

Smallpox was a worldwide problem in the past. But because of a widespread vaccination program, it was declared eradicated (no longer a naturally occurring disease) by the World Health Organization (WHO) in 1980.

There may be a risk that the smallpox virus could be manufactured by people in order to threaten or harm others.

ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerChristine Hahn, MD - Epidemiology
Last RevisedDecember 27, 2012

WebMD Medical Reference from Healthwise

Last Updated: December 27, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.