Alice Catherine Evans

Alice Catherine Evans (January 29, 1881 – September 5, 1975) was an American microbiologist. She became a researcher at the U.S. Department of Agriculture where she investigated bacteriology in milk and cheese. She proved that Bacillus abortus (called Brucella abortus) caused the disease brucellosis (undulant fever or Malta fever) in both cattle and humans, which led to the pasteurization of milk in the US in 1930. Evans was the first woman president elected by the Society of American Bacteriologists.

Evans was born the younger of two children on a farm in Neath, Bradford County, Pennsylvania, to William Howell Evans, a farmer and surveyor, and Anne B. Evans, a teacher. Neath was named after Neath, Wales, where Evans's paternal grandparents had emigrated from in 1831. Between the ages of five and six, Evans was taught at home by her parents and then attended a one-room school house in Neath, where she earned outstanding grades.

She attended the Susquehanna Collegiate Institute in Towanda, where she played on a women's basketball team. Basketball was a new sport open to women, and viewers were shocked by the unladylike sport. At one game, a doctor refused to treat Evans' dislocated finger.

After graduating, Evans became a teacher. In her memoirs, she wrote that she became a teacher because it was the only profession open to women, but she found it boring. Also, like other female scientists during this period, college was not affordable and teaching was seen as the only option. After four years of teaching, she took a free course for rural teachers at Cornell University meant to help them inspire their students to love science and nature. After receiving a scholarship, she wanted to continue her studies in science. Cornell offered bacteriology for free tuition in order to encourage students to pursue the still-new science. While at Cornell, Evans worked as a housekeeper and did clerical work in the alumni library, earning her the nickname "the grind." Evans earned a B.S. in bacteriology from Cornell University in 1909, and was the first woman to receive a bacteriology scholarship from the University of Wisconsin–Madison, where she earned her M.S. the following year. At the end of her studies, her professor Elmer McCollum asked if she would wish to continue her studies, offering her the school's chemistry fellowship. Due to the financial strain of her studies, she decided to enter the workforce instead.

Evans was offered a federal position at the Dairy Division of the Bureau of Animal Industry at the United States Department of Agriculture. She accepted the offer in Madison, Wisconsin, and worked there for three years. She worked on refining the process of manufacturing cheese and butter for improved flavor and investigating the sources of bacterial contamination in milk products. She was the first woman scientist to hold a permanent position as a USDA bacteriologist and as a civil servant, was protected by law. Evans found that only one female scientist worked in the BAI before her. Evans decided she, herself, was hired by accident. Each year, Evans took one undergraduate university course, learning German in order to read research reports (prior to World War I, Germany led bacteriology).

In 1913, Evans relocated to Washington, D.C., where the USDA had finished building a new wing. The Bureau of Animal Industry tried to block women from joining them, but Evans was unwittingly admitted through a loophole. She found the Dairy Division more welcoming than the larger Bureau. While there, she worked with B.H. Rawl, Lore Alford Rogers, William Mansfield Clark, and Charles Thom. When Thom left the Dairy Division, Evans was sent to the University of Chicago to study mycology so she could replace Thom as the mycologist.

Evans became interested in the disease brucellosis and its relationship to fresh, unpasteurized milk. Her investigation focused on the organism Bacillus abortus, known to cause miscarriages in animals. She discovered that the microbe thrived in infected cows as well as animals that appeared healthy. The reports hypothesized that since the bacteria was found in cow's milk, a threat to human health was likely.

Evans decided to investigate this; she wondered whether the disease in cows could be the cause of undulant fever in humans. She experimented on guinea pigs as well, confirming her finding that guinea pigs develop brucellosis after being injected with contaminated raw milk. These results provided experimental validation for her claims and strengthened the case for widespread milk pasteurization. She warned that raw milk should be pasteurized to protect people from various diseases. She reported her findings to the Society of American Bacteriologists in 1917 and published her work in the Journal of Infectious Diseases in 1918. She was met with skepticism, particularly because she was a woman and did not have a Ph.D. Specifically, researchers, veterinarians, and physicians did not believe her finding that Brucella abortus was a zoonotic pathogen that causes disease in humans and animals. After publishing, Evans decided to let the issue rest, knowing that her findings would be tested and verified with time.