Smallpox Quiz

Smallpox is caused by the variola virus, a member of the orthopoxvirus family. Other viruses in this family include cowpox, camelpox and monkeypox. When smallpox was prevalent, it had two main forms: variola major and variola minor. Both forms developed similar skin lesions, but the minor form was much less deadly; variola major killed about 30 percent of those infected with it. Two rare forms also existed: hemorrhagic and malignant. The hemorrhagic form developed hemorrhages in the mucous membranes and skin; in the malignant form, the skin lesions remained soft instead of becoming hard with scabs. Both of these rare forms were fatal.

When a person is infected with smallpox, the virus incubates for 12 to 14 days, during which time it causes no symptoms. During this period, the person is not infectious. Once a fever develops, the person can spread the virus through direct and prolonged face-to-face contact, particularly through coughing. Fluids from the blisters of a person with smallpox are infectious. It is not spread by insects or animals.

According to the Centers for Disease Control and Prevention (CDC), one confirmed case of smallpox would be considered a public health emergency.

After the incubation period, the first symptoms of smallpox appear. They resemble the flu: fever of 101 to 104 degrees, headache, back pain, malaise and, occasionally, vomiting. During this stage, the person is contagious. Two to three days after these symptoms begin, a rash appears, first on the face, hands and forearms, and then on the trunk. A rash also forms in the nose and mouth. The rash progresses to raised bumps that fill with fluid and often have a depression in the middle resembling a bellybutton. These bumps break open and release viruses. Then a crust forms, and about two weeks after symptoms begin, the bumps form scabs. The fluid in the blisters is jam-packed with virus. The crusts contain virus also. A person with smallpox is contagious until all the scabs have fallen off. When the scabs fall off, scars remain on the skin.

Chickenpox. Chickenpox lesions are less extensive and are more likely to be on the trunk than on the face, arms and legs.

When smallpox was prevalent, up to 80 percent of people stricken with smallpox came away with deeply pitted scars on the face and other areas of the body. Before smallpox was eliminated, up to a third of all cases of blindness were caused by the disease.

Medication can be given to help ease symptoms. Smallpox infection with variola major is fatal in up to 30 percent of those who contract it.

What's crucial is to keep the virus from spreading. All people who have been in contact with the infected person should be vaccinated. Anyone involved in treating the infected person also should be vaccinated.

Because smallpox does not now occur anywhere in the world, there no longer is a national vaccination program for this disease. The last routine vaccinations for smallpox in this country were given in 1972. Currently, only certain health care workers, emergency response personnel and military personnel have been given the vaccine. Vaccination usually prevents smallpox infection for at least 10 years. If an outbreak of smallpox does occur, people who are in contact with those infected with the virus can be vaccinated. The vaccine, if given up to four days after exposure and before the rash appears, can prevent smallpox infection. The vaccine is a live virus related to smallpox; it does not contain smallpox and cannot cause it. In people who were vaccinated as children, any subsequent infection with the virus would likely cause only a mild form of the disease, health experts say.

The health care provider uses a two-pronged needle that is dipped into the vaccine. The health care provider pricks the skin of the upper arm with the needle several times. The pricking causes a sore spot on the arm. If the vaccine is successful, a red, itchy bump appears where the vaccine was given. After a few days, the bump fills with fluid and begins to drain. A scab then forms. After three weeks, it falls off, leaving a small scar.