ATLANTA -- On Oct. 26, 1977, a cook in Merka, Somalia, came down with an illness that was to make him famous: History was to record him as the last person in the world to contract naturally occurring smallpox.

The 10th anniversary of this momentous medical milestone -- the eradication of a disease that for centuries caused death and disfigurement -- will be celebrated this week by health officials at the World Health Organization and at the national Centers for Disease Control.

The CDC, which joined the worldwide effort to eliminate smallpox in 1966, will mark 10 years of a smallpox-free world on Thursday with an awards presentation by U.S. Surgeon General C. Everett Koop and a display of smallpox eradication memorabilia. There also will be an address by Dr. Donald A. Henderson, dean of the School of Hygiene and Public Health of Johns Hopkins University.

Henderson was the first director of CDC's smallpox eradication program. He later was assigned to WHO's headquarters in Geneva and became director of the global eradication program to which many nations, including the Soviet Union, contributed.

The only smallpox case diagnosed since 1977 was a laboratory-associated case that claimed the life of a medical photographer at a Birmingham, England, hospital in 1978.

The Somalia smallpox victim, Ali Maow Maalin, recovered from his illness, an isolate of the virus being quickly identified by a CDC virologist, James H. Nakano.

The International Commission on Certification of Smallpox Eradication waited for two years after the Somalia case before declaring the world free of smallpox in 1979. During that period, Nakano recalled, there were many reports of suspected smallpox, but they turned out to be false alarms.

Health officials are not certain when the last case of smallpox in the United States occurred, but they believe it was in 1949 in the lower Rio Grande Valley of Texas.

Today, the smallpox virus is stored at only two places in the world -- Moscow and an Atlanta CDC laboratory -- Nakano said. The virus is kept in tanks of nitrogen at about minus 120 degrees in case it is needed to identify smallpox strains in a future outbreak.

"The consensus is to destroy the virus eventually," said Nakano. ". . . But before we do that, we would like to have the DNA {genetic material} of representative strains so that we would be able to recognize smallpox if there is ever an outbreak."