Smallpox in America before Vaccination

Smallpox infects only humans, and only humans transmit smallpox. It comes in many forms, from a hemorrhagic variety that kills all of its victims to milder types with very low death rates. Physicians now categorize smallpox into two main groups, variola major and variola minor. Variola major has afflicted humans for thousands of years. Variola minor first appeared in the late nineteenth century. Individuals suffering from variola major tend to have harsher symptoms, a higher mortality rate, and more severe scarring than variola minor victims. Nineteenth-century physicians also recognized another form of smallpox, varioloid smallpox, which appeared in vaccinated individuals. Like variola minor, varioloid smallpox usually ran a mild course with a very low mortality rate.

Most victims acquire smallpox by inhaling the virus through the respiratory tract, but it also spreads by contact with infected clothing. Smallpox usually incubates eleven to twelve days before the victim shows any signs of the disease. Then, as one late nineteenth-century smallpox expert noted, “smallpox sets in suddenly and with violence.” Victims endure “chills or rigors, and in young children convulsions.” Signs and symptoms include a bad headache, severe backache, and a fever that breaks temporarily when lesions erupt on the victim's skin, mouth, throat, and eyelids, but rises again as the lesions mature into pustules—small pus-containing protrusions—over the next few days. “Constant profuse sweating” rapidly dehydrates smallpox patients, and they suffer greatly from thirst. Depending on the type—variola major, variola minor, or varioloid— lesions can vary from just a few scattered pustules to hundreds of malignant pustules that coalesce over large areas of skin. Breaking out first on the face, palms, and soles, spreading up the legs and arms, they eventually develop into hard, pearly pustules. In cases of confluent smallpox, pustules blend together in pools on the victim's skin, and “the face swells to a shapeless mass, rendering the patient absolutely unrecognizable.” An 1892 medical textbook commented that “at this stage the patient presents a terrible picture, unequalled in any other disease; one which fully justifies the horror and fright with which small-pox is associated in the public mind.”