EVANS, ALICE (1881-1975)

American microbiologist

The bacteriologist Alice Evans was a pioneer both as a scientist and as a woman. Evans discovered that the Brucella bacteria, contracted from farm animals and their milk, was the cause of undulant fever in humans, and responded by fighting persistently for the routine, improved pasteurization of milk, eventually achieving success. She was the first woman president of the Society of American Bacteriologists (now American Society of Microbiology). Although marginalized early in her career, Evans overcame many obstacles and lived to see her discoveries repeatedly confirmed. She had a major impact on microbiology in the United States and the world, and received belated honors for her numerous achievements in the field.

Alice Catherine Evans was born on January 29, 1881, in the predominantly Welsh town of Neath, Pennsylvania, the second of William Howell and Anne Evans' two children. William Howell, the son of a Welshman, was a surveyor, teacher, farmer, and Civil War veteran. Anne Evans, also Welsh, emigrated from Wales at the age of 14. Evans received her primary education at the local district school. She went on to study at the Susquehanna Institute at Towanda, Pennsylvania. She wished to go to college but, unable to afford tuition, took a post as a grade school teacher. After teaching for four years, she enrolled in a tuition-free, two-year course in nature study at the Cornell University College of Agriculture. The course was designed to help teachers in rural areas inspire an appreciation of nature in their students. It changed the path of Evans' life, however, and she never returned to the schoolroom.

At Cornell, Evans discovered her love of science and received a B.S. degree in agriculture. She chose to pursue an advanced degree in bacteriology and was recommended by her professor at Cornell for a scholarship at the University of Wisconsin. She was the first woman to receive the scholarship, and under the supervision of E. G. Hastings, Evans studied bacteriology with a focus on chemistry. In 1910, she received a Master of Science degree in bacteriology from Wisconsin. Although encouraged to pursue a Ph.D., Evans accepted a research position with the University of Wisconsin Agriculture Department's Dairy Division and began researching cheese-making methods in 1911. In 1913, she moved with the division to Washington, D.C., and served as bacteriological technician in a team effort to isolate the sources of contamination of raw cow's milk, which were then assumed to be external.

On her own, Evans began to focus on the intrinsic bacteria in raw cow's milk. By 1917, she had found that the bacterium responsible for undulant or "Malta" fever (later called brucellosis, after the responsible pathogen) was similar in important respects to one associated with spontaneous abortions in cows, and that the two bacteria produced similar clinical effects in guinea pigs. Prevailing wisdom at the time held that many bovine diseases could not be transmitted to humans. That year she presented her findings to the Society of American Bacteriologists; her ideas were received with skepticism that may have been more due to her gender and level of education than her data.

In 1918, Evans was asked to join the staff of the United States Public Health Service by director George McCoy. There, she was absorbed in the study of meningitis. Although she was unable to continue her milk studies during this time, support for Evans' findings was trickling in from all over the world. By the early 1920s, it was recognized that undulant fever and Malta fever were due to the same bacteria, but there was still resistance to the idea that humans could contract brucellosis by drinking the milk of infected cows. Because the symptoms of brucellosis were so similar to those of influenza, typhoid fever, tuberculosis, malaria, and rheumatism, it was not often correctly diagnosed. Evans began documenting cases of the disease among humans in the U.S. and South Africa, but it was not until 1930, after brucellosis had claimed the lives of a number of farmers' children in the U.S., that public health officials began to recognize the need for pasteurization.

In 1922, Evans, like many others who researched these organisms, became ill with brucellosis. Her condition was chronic, plaguing her on and off for almost 23 years, and perhaps providing her with new insight into the disease. As the problem of chronic illness became widespread, Evans began surveying different parts of the U.S. to determine the numbers of infected cows from whom raw milk was sold, and the numbers of chronic cases resulting from the milk.

In 1925, Evans was asked to serve on the National Research Council's Committee on Infectious Abortion. In this capacity, Evans argued for the pasteurization of milk, a practice that later became an industry standard. In recognition of her achievements, Evans was in 1928 elected the first woman president of the American Society of Bacteriologists. In 1930, she was chosen, along with Robert E. Buchanan of Iowa State University, as an American delegate to the First International Congress of Bacteriology in Paris. She attended the second Congress in London in 1936 and was again able to travel widely in Europe. She returned to the United States and eventually was promoted to senior bacteriologist at the Public Health Service, by then called the National Institute of Health. By 1939, Evans had changed her focus to immunity to streptococcal infections and in 1945, she retired. Evans, who never married, died at the age of 94 on September 5, 1975, in Alexandria, Virginia.