The procedure, also known as variolation, was controversial. 5 In this procedure a lancet or needle was used to deliver a subcutaneous dose of smallpox material to a susceptible person. The wife of an English ambassador, Lady Montagu, observed inoculation in Turkey, and later had her own child successfully inoculated during a smallpox epidemic in England. 4 The practice of inoculation appears to have arisen independently in several other regions prior to the 17th century, including Africa and India, but the practice did not gain popularity in western Europe until the 18th century. The earliest smallpox prevention efforts date back to at least the 10th century in China, when physicians found that nasal inoculation of susceptible persons with material from smallpox lesions would sometimes provide immunity. The overall mortality rate is about 30%, with most deaths occurring during the second week of illness. Patients are most infectious during the first week of the rash when viral shedding is greatest from ulcerated lesions in the oral mucosa. The lesions become pustular and deep over the subsequent 1 to 2 days, with scab formation by day 10.
3 A maculopapular rash then develops with involvement of the face, mucous membranes, trunk and extremities. 2 After a 10 to 14 day incubation period, the infected person develops severe symptoms with fever, malaise and headache. Persons who have close, prolonged contact with an infected patient are at highest risk. Historical data suggest that smallpox is not highly transmissible, and high population densities are required to sustain transmission. It is transmitted from person to person, and natural infection occurs by inhalation of respiratory droplets or contact with infected material on mucous membranes. Humans are the only known reservoir for this virus. Smallpox is caused by the variola virus, a DNA virus of the genus Orthopoxvirus. 1 Smallpox subsequently changed the course of history and killed millions of people in both the New World and the Old World. The literary record suggests that smallpox became established in the Mediterranean by the third century AD, and it was described in China around the same time. There is no mention of the disease in ancient Greek writings, but plagues of pustular disease in the Roman Empire bore a strong resemblance to smallpox. Smallpox has been a scourge against humanity for at least the past 1500 years, and perhaps much longer than that. HISTORY OF SMALLPOX VACCINATION AND GLOBAL ERADICATION
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