How fast can smallpox be spread

In Asia, a technique known as variolation involved deliberately infecting a person by blowing dried smallpox scabs up their nose. Those who received this treatment contracted a mild form of the disease, developing a lifelong immunity. A key breakthrough came in when an experiment by English doctor Edward Jenner showed that inoculation using closely related cowpox could protect against smallpox.

Jenner's discovery paved the way for later vaccination programs—especially crucial since there is no effective treatment for smallpox. In , a year when some 10 million to 15 million people contracted smallpox, the World Health Organization launched a worldwide eradication campaign based on vaccination. Gradually, the disease was pushed back to the Horn of Africa, and the last known natural case occurred in Somalia in Despite being consigned to the history books, there's still a chance of smallpox coming back to haunt us—as a biological weapon.

Such fears escalated dramatically in the United States following the September 11, , terrorist attacks. While the risk of such a bioterror attack is considered very low, the U. All rights reserved. Smallpox Inspections A young Native American boy in Yukon Territory is checked for smallpox and vaccinated against the disease in this circa photograph. Early Victims Smallpox is thought to have originated in India or Egypt at least 3, years ago.

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Epic floods leave South Sudanese to face disease and starvation. In , the World Health Organization WHO announced that smallpox was wiped out — the first and only time in history that an infectious disease was declared eliminated from the planet.

Although smallpox infection was wiped out many years ago, samples of the variola virus that causes smallpox were saved in laboratories. Some people have expressed concern that terrorists could try to get access to these stored virus samples with the aim of spreading smallpox infection. Despite talk about the possibility of terrorists spreading smallpox as a biological weapon, the reality is that this probably wouldn't happen for a couple of reasons. First, terrorists would need access to the virus samples, and the few research laboratories that keep them have security measures to guard them.

Also, it would be extremely difficult for a group to take the time to produce a large amount of the variola virus without being detected. After the September 11, , terrorist attacks and the anthrax scare that same year, the U. Today, there's enough vaccine on hand to protect the American people in the event of a smallpox outbreak.

Public health officials have a rapid response plan ready to vaccinate anyone exposed to the disease, as well as people who come into contact with them. Smallpox These are smallpox lesions on the skin of the trunk. Request an Appointment at Mayo Clinic. Share on: Facebook Twitter. Show references Friedman HM, et al. The epidemiology, pathogenesis and clinical manifestations of smallpox. Accessed Feb. Smallpox vaccine: Drug information. Smallpox vaccine: Patient drug information.

Hall JB, et al. Biological warfare. In: Principles of Critical Care. New York, N. Centers for Disease Control and Prevention. Frequently asked questions and answers on smallpox. World Health Organization. Smallpox also can be spread through direct contact with infected bodily fluids or contaminated objects such as bedding or clothing.

The symptoms of smallpox begin with high fever, head and body aches and sometimes vomiting. A rash follows that spreads and progresses to raised bumps and pus-filled blisters that crust, scab and fall off after about three weeks, leaving a pitted scar. After exposure, it takes between 7 and 17 days for symptoms of smallpox to appear average incubation time is 12 to 14 days.

During this time, the infected person feels fine and is not contagious. Smallpox can be diagnosed based on the patient's clinical signs and symptoms. The disease can be definitively diagnosed by isolation of the virus from the blood or lesions, or by identification of antibodies in the blood made in response to the virus.