III.

Symptoms, Diagnosis, and Treatment

After a person is infected with the smallpox virus, about 12 days pass before the person begins to feel sick, a time known as the incubation period. During the incubation period, while the infected person still feels healthy, the smallpox virus multiplies in the lymph nodes, lungs, and other tissues. By the 12th day the virus moves into the bloodstream, producing sudden and dramatic symptoms that include high fever of 39º to 41ºC (102º to 106ºF), headache, muscular and abdominal pain, and vomiting. Within two to three days the virus spreads to the skin and the rash appears. At first the rash takes the form of skin spots known as macules. By the second day of the rash, as infection worsens within the skin cells, the spots become raised lesions called papules; by the seventh day these papules fill with pus and are referred to as pustules. Smallpox patients become most infectious during the week following the appearance of the rash.

In the most extreme forms of smallpox, the virus causes bleeding underneath the skin, giving the skin a charred appearance, as if burned. In these cases the virus causes massive tissue damage to skin and to internal organs, and victims bleed heavily from the mouth and other body openings. Such cases are referred to as black pox and they are almost invariably fatal.

The exact cause of death in smallpox cases is not entirely understood, but it can include shock, cardiovascular complications, and bacterial toxins from secondary infections. In those who survive the illness, the infection runs its course in about two weeks; the pustules form scabs and finally drop off within roughly a month.

Physicians diagnose smallpox by removing fluid from skin lesions and preparing slides on which the virus can be detected through an electron microscope. Laboratory tests can also check blood samples for antibodies to the smallpox virus—a sure sign that the virus is present. However, during the smallpox epidemics of the 20th century, medical workers in the developing nations of Africa and Asia did not always have such sophisticated diagnostic methods available. Medical personnel generally identified cases by the appearance of the skin rash. The texture of the lesions themselves—described as feeling like pellets when rolled between the fingers—provided another sure sign of smallpox.

There is no cure, or even a specific treatment, for a smallpox infection. In modern outbreaks, medical care usually consisted of bed rest and the treatment of symptoms: the use of intravenous fluids to prevent dehydration, sedatives to keep patients calm, and aspirin or codeine to relieve pain in the head and muscles. Antibiotic drugs such as penicillin or tetracycline were also administered to treat secondary bacteria infections. In an effort to minimize scarring of the skin, smallpox lesions were kept clean with warm antiseptic baths and dusting powders.