In 1952, he joined the biometry division of the N.C.I. and worked there until 1976, when he became a senior epidemiologist with the Illinois Cancer Council.

"It is unethical to do this trial," said a leading critic, Dr. Michele Grandolfo, a senior epidemiologist with the Superior Health Institute in Rome.

"You rob Peter to pay Paul," said Dr. Shirley L. Fannin, senior epidemiologist in the Los Angeles County Department of Health Services.

Pasteurization is the best way to insure that bacteria is killed, said Dr. John Kobayashi, a senior epidemiologist with the Washington State Health Department.

That rate "is not good news," said Karen Stanecki, a senior epidemiologist at Unaids.

"To our surprise, we did not find any infections among the cullers," said Dr. Supamit Chunsuttiwat, a senior epidemiologist in Thailand's Ministry of Public Health.

"It's a growing problem," said Janet B. Croft, a senior epidemiologist in the cardiovascular health division of the Centers for Disease Control and Prevention.

She is a senior epidemiologist at the Merck Research Laboratories in Blue Bell, Pa.

Some senior epidemiologists disagree.

"We expect to have many more deaths from dysentery than cholera," said Serge Male, the senior epidemiologist for the United Nations High Commissioner for Refugees.