Early Efforts at Control : Variolation, Vaccination, and Isolation and Quarantine

Besides killing many of those who were infected, an attack of smallpox left most of its survivors pockmarked, and it was realized in ancient times that pockmarked persons never caught smallpox again . By accident, it was found that persons who were infected with smallpox via a scratch on the skin suffered a much less severe form of the disease . Long ago, in places in which smallpox had become endemic, a connection must have been made between these observations, and attempts to ameliorate the severity of smallpox were initiated by administering the pustular fluid or the dried scabs to persons who had not had smallpox. The disease which followed such artificial infection was like smallpox, but usually much milder . In some such way, the practice arose of inoculation with smallpox pus or scabs-or "variolation" as it was eventually called, to distinguish it from vaccination. It may have developed independently in China and India, because different routes of inoculation, nasal and cutaneous respectively, were used in these countries. It was said to have been introduced into Egypt by the Mamelukes in the 13th century, and was known in North and western Africa, at least from the late 17th century. It is impossible to know whether it was indigenous in Africa or spread to that