American Journal of Epidemiology Vol. 128, No. 1: 39-45
Copyright © 1988 by The Johns Hopkins University School of Hygiene and Public Health
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OUTBREAKS OF SMALLPOX DUE TO VARIOLATION IN CHINA, 19621965
Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences P.O. Box 130, Branch Box 11, Beijing 100850, People's Republic of China
Send reprint requests to Dr. D. A. Henderson, The Johns Hopkins School of Hygiene and Public Health, 615 N. Wolfe St., Baltimore, MD 21205
In 1985, previously unknown outbreaks of smallpox were uncovered which had occurred in Shanxi Province and Nei Monggol Autonomous Region in northern China during 19621965, several years after smallpox transmission was thought to have been interrupted. During field investigation, the authors learned that most of the cases were known to local health officials but had not been officially reported to national authorities. All were among persons who had been variolated or were their close contacts. Variolation is an ancient method of protection against naturally acquired smallpox that was officially proscribed in the early 1950s but was renewed in remote areas when smallpox vaccination activities were interrupted during the three-year famine of 19591962, following the "great leap forward" program of 1958. It was found that the variolators in Shanxi Province and Nei Monggol Autonomous Region inoculated persons with the use of powdered smallpox scabs mixed with human milk, and that they obtained fresh supplies of scabs every 612 months by variolating relatives and friends. The health authorities responded by capturing the variolators, confiscating their variolation material and equipment, and vaccinating the population. The last known cases occurred in 1965, and the practice of variolation is now believed to be extinct.
smallpox; smallpox virus; variolation