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News Release

Media Contact: Tom Grant

Published on November 13, 2001

Press Release

Smallpox Information

In the wake of concerns about bioterrorism, there are a lot of questions being asked about smallpox. The following is information about smallpox gleaned from news reports, the Centers for Disease Control and Adventist HealthCare's infection control practitioners.

Routine vaccination against smallpox ended in 1972 and the smallpox infection was eliminated throughout the world in 1977. Currently, there is no known outbreak of smallpox anywhere in the world. Public health experts say an outbreak of smallpox is less likely than the release of anthrax, but are more concerned about it because smallpox is contagious and is much more deadly, making it one of the most potent biological weapons.

Smallpox is caused by variola virus. The incubation period is about 12 days (the range is 7 to 17 days) following exposure. Initial symptoms include high fever, fatigue, and head and back aches. A characteristic rash, most prominent on the face, arms, and legs, follows in 2-3 days. The rash starts with flat red lesions that become pus-filled and begin to crust early in the second week. Scabs develop and then separate and fall off after about 3-4 weeks. The majority of patients with smallpox recover, but death occurs in up to 30% of cases.

Unlike anthrax, smallpox is highly contagious and is spread from one person to another by airborne and droplet exposure, and by contact with skin lesions or secretions. Persons with smallpox are most infectious during the first week of illness, which is when the largest amount of virus is present in saliva. However, some risk of transmission lasts until all scabs have fallen off.

Smallpox differs from chickenpox in two important ways: First, smallpox lesions start on the face and extremities, including the palms on the hand and soles of the feet. Chickenpox starts on the trunk of the body. Second, smallpox lesions have synchronous onset. This means that all lesions are in the same stage of development in a given area. This is different from chickenpox which has “waves” of lesions, all in different stages.

A patient with smallpox would be placed on airborne and contact isolation in the hospital, in rooms that are under negative pressure. Any individuals going in the room would wear an N-95 respirator along with gloves and gowns. Only essential personnel would be allowed to enter into the room.

Smallpox Vaccination
For individuals exposed to smallpox, a vaccine exists that can lessen the severity of, or even prevent, illness if given within 4 days after exposure. The vaccine does not actually contain smallpox virus, but another live virus called vaccinia. Routine vaccination against smallpox ended in 1972. The level of immunity, if any, among persons who were vaccinated before 1972 is uncertain; therefore, these persons are assumed to be susceptible. While the vaccine is safe for most people, there are no plans for a national immunization campaign because the vaccine can be harmful or fatal to individuals with eczema or other skin disorders, pregnant women, individuals with immunodeficiency diseases (such as AIDS), those with suppressed immune systems as occurs with leukemia, lymphoma, generalized malignancy or solid organ transplantation, as well as those on chemotherapy treatment.

How an Outbreak Would be Handled
Since smallpox was eradicated worldwide more than 20 years ago, a single outbreak anywhere in the world would be considered a threat and would be assumed to be the work of terrorists. If a smallpox case emerged, officials would order quarantines and vaccinations to build a barrier of immunity around the outbreak. Mass vaccinations would likely stop an outbreak and limit the death toll.

What the U.S. is Doing to Prepare for an Outbreak
U.S. public health officials have advocated an aggressive smallpox strategy, including the stockpiling of vaccine. Currently, the United States has approximately 15.4 million doses of the old vaccine on hand. (Government researchers say it may be possible to dilute those doses to vaccinate 50-77 million people if necessary). Last year, an order was placed for an additional 40 million doses (an order that has since been increased to 54 million), scheduled for delivery by late next year. Recently, the U.S. Health and Human Services Department announced plans to initiate a contract for 250 million more doses, or enough for "every man, women and child" in the United States. The goal is to create a total stockpile of 304 million doses of the new smallpox vaccine.

Sources: Centers for Disease Control; Washington Post news reports; Adventist HealthCare Infection Control Practitioners

For more informaiton on smallpox, please reference the following web site:

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