Smallpox

Smallpox is a highly infectious viral disease caused by the variola virus.

What are the symptoms of smallpox?

The incubation time between exposure and disease is between seven and 17 days following exposure, with the average being 12 days. The following are the most common symptoms of smallpox. However, each individual may experience symptoms differently.

Initial symptoms include:

• High fever, fatigue, head and back aches

Most often, two to three days after initial symptoms a distinct rash appears with the following characteristics:

• The rash starts with flat, red spots, usually on the face, arms, and legs
• Rash become small pus-filled bumps and starts to crust over early in the second week
• Scabs form which then separate and fall off after three to four weeks

The symptoms of smallpox may resemble other medical conditions or problems. Always consult a physician for a diagnosis.

How is smallpox transmitted?

Smallpox can be spread from person to person through infected saliva. A person is most contagious during the first week of the illness. Risk of transmission remains until scabs have fallen off.

What is the treatment for smallpox?

Specific treatment for smallpox will be determined by your physician based on:

• Your age, overall health, and medical history
• Extent of the condition
• Your tolerance for specific medications, procedures, or therapies

Most patients with smallpox recover. However, about 30 percent of smallpox cases are fatal. The smallpox vaccine, even when given four days after exposure, can lessen or even prevent illness.

If a person becomes ill, treatment may include supportive therapy such as intravenous fluids, fever and pain control, and antibiotics for secondary bacterial infections. Research is ongoing to evaluate new antiviral agents as treatment for smallpox.

About the smallpox vaccine

Routine vaccinations against smallpox ended in the United States in 1972. However, the vaccine still exists and, when given during early symptoms of smallpox, can lessen the severity of the illness. Immunity among people vaccinated before 1972 is uncertain.

The United States keeps an emergency supply of smallpox vaccine. Always consult your physician for more information. If any confirmed cases are identified, they will be immediately reported to public health authorities and be appropriately isolated. Contacts of cases will be vaccinated.

The history of smallpox

Smallpox was common prior to and during the nineteenth century, but by 1977 the disease was eliminated from the world. In 1980, the World Health Organization (WHO) declared smallpox extinct and recommended that all countries stop vaccination.

However, the virus is still maintained at laboratories at the Centers for Disease Control and Prevention (CDC) in the United States and at the State Center for Research on Virology and Biotechnology in Novosibirsk, Russia. Smallpox was used as a biological weapon (an infectious agent or toxic chemical that is intended to cause mass destruction) as early as the French and Indian Wars in the 1700s.

Deliberate reintroduction of smallpox as a biological weapon is still a threat.