Alice Catherine Evans is a noted bacteriologist and the first female director of the USDA Animal Industry Service. She first discovered that Malta fever (wave fever) in humans was caused by infection with Brucella, and proved that the route of infection was bacteria-containing milk, thus promoting the law to force the full pasteurization of milk, saving countless life.
She has devoted her whole life to the research of bacterial infectious diseases. Although she was a woman and did not have a Ph.D., and suffered many unequal treatment, she was finally recognized by the scientific community and was elected to the American Bacteriological Society 's first female president.
After retirement, she still actively strives for women's career development, and gives speeches about women's career development, especially emphasizing the importance of women in the field of scientific research. She is a role model for the microbiology and public health community, and a hero for justice.
Alice Kathleen Avens (hereinafter referred to as Avens) was born on January 29, 1881, in a farm family in Neath, Pennsylvania, USA. His grandfather settled here in 1831 from Wales, England. His father, William Howell Evans, was a farmer and teacher who had fought in the Civil War. Her mother, Anne B. Evans, immigrated with her family from Wales, England when she was 14 years old.
Evans attended local elementary and secondary schools with her brother Morgan Evans, but she didn't attend Susquehanna Collegiate Institute in Towanda, Pennsylvania until she graduated , After graduating in 1901, because her family was poor and could not pay the tuition fees for continuing to study at university, Ai Wensi only got primary school as a teacher, which was one of the few jobs that women could find at that time.
She taught elementary school for 4 years until her brother told her that Cornell University's College of Agriculture had a free 2-year natural science program for teachers in remote areas. So she applied immediately, and got into Cornell University, where she received a bachelor's degree in agriculture two years later.
Cornell University was the center of agronomy at the time and had a program to train elites in agricultural science, including the famous entomologist Professor John Henry Comstock (1849-1931) and vertebrates Professor Whitehead (Burt Green Wilder, 1841-1925) and others.
During her 2 years of study, Elvens chose the then-new bacteriology as her research topic. Her supervisor was a dairy microbiologist, Professor William A. Stocking (1840-193).0), where she learned a lot of bacteriology expertise.
After earning a bachelor's degree in agronomy in 1908, Avens received a University of Wisconsin scholarship to study bacteriology, the first time this scholarship was awarded to a woman, through the strong recommendation of her advisor. Here she pursued her master's degree under the supervision of Dr. E.G. Hastings (1872-1953), and another professor of chemistry and nutrition, McCollum (who later discovered vitamins A and D). Elmer V. McCollum). Avens completed her studies in 1910 with a master's degree.
Her supervisor, Dr. Hastings, hoped that Elvens would stay and pursue her Ph.D. A necessary condition for engaging in scientific research, so Elvens decided to find a research job in the laboratory first.
Fortunately, Professor Hastings happens to be commissioned by the USDA to direct a dairy research unit for the animal industry on the University of Wisconsin campus. So Evans became a research assistant hired by the unit. Her work was mainly to study the improvement of cheese flavor, and the manufacture of cheese was one of the main industries in Wisconsin.
In order to enrich her professional knowledge during her work, Ai Wensi also takes a course at the university every year. She worked here for 3 years and worked with Professor Hastings and a chemistProfessor E.B. Hart of the department co-authored four papers.
In the summer of 1913, Elvens was transferred to the newly established Bureau of Animal Industry of the Washington Department of Agriculture. When she checked in, Ewens discovered that she had become the department's first female employee.
In her later memoirs: "According to a rumor, bad news about a female researcher's joining came to a meeting of the Animal Industry Bureau, and everyone panicked. ; one stenographer also described the presence of almost all of them falling out of their chairs.” Nonetheless, Ewens received a warm welcome when he reported, and the Director, Dr. B. G. Rawl, and the Research Department Director Lore A, Rogers does not exclude a female researcher from joining the team. Her research in this lab is about bacteria in cow's milk and how these bacteria get into cow's milk.
She first studied Bang's disease, which causes abortion in cattle, and Brucellosis, a goat disease.
Previous scientists believed that brucellosis in goats and Ban's disease, which caused abortion in cattle, were two different diseases. This was because Bruce thought that the pathogens of brucellosis in goats and Maltese fever were a kind of spherical disease. Micrococcus melitensis, the bacterium that causes bovine abortion, is a bacillusthe reason.
But after research and identification by Evans, it was proved that both are caused by the same bacterium. In order to commemorate Bruce's contribution to the first study of this disease, later generations changed the name of the pathogenic bacterium to Brucella. abortus). Ai Wensi's discovery, radically changed the human concept of milk safety.
Evens lived in a time when everyone believed that the fresher the milk was, the safer and more nutritious it was, but Elwens found that wasn't the case. This is very similar to Bruce's previous discovery of Malta fever from drinking unclean raw goat's milk. She cultivated the pathogenic bacteria of the two, and then carried out a careful inspection, and unexpectedly found that the two had a high degree of similarity.
Evens then published her findings at the American Society of Bacteriology in 1917 and hypothesized that drinking contaminated raw cow's milk could cause disease, and wrote a formal paper published the following year in the Journal of Infectious Diseases ( Journal of Infectious Diseases).
However, no one believes that the same bacteria can cause common diseases in animals and humans at the same time, and if they did, they should have been discovered by other microbiologists. Which round got Elwens - a woman without a Ph.D. portion!
But facts speak louder than words. A San Francisco scientist, Karl F. Meyer, first confirmed Elwens' discovery in 1920, and the followingIn the past 4 years, 10 scientists from 7 countries have successively published the same conclusion. This important discovery was finally recognized, and after Evans' death, the Washington Post obituary wrote: "This is the most outstanding medical discovery of the first 25 years of this century."
It is also worth mentioning that while studying Maltese fever, Elvens also unfortunately contracted the disease in 1922, which was very common in the early microbiology community. For the next 20 years, she suffered from the disease, sometimes for a month, with constant fever and pain, and her body temperature would rise and fall repeatedly.
To make matters worse, this symptom is often mistaken for fantasy, which is one of the hallmarks of the disease. Ewens once said: "It is unbearable to be misunderstood as a liar when you are really sick." Despite this, she is not discouraged, and she has always maintained a humorous mood to face this annoying disease and care for others. patients, keep in touch with them and provide advice by writing letters.
Pasteurization was invented by French microbiologist Pasteur (Louis Pasteur, 1822-1895) in 1864. It is a method of sterilizing food by heating. He found that at a temperature of 55 to 60 degrees Celsius, the Heating the freshly fermented wine for 30 minutes can inhibit the growth of miscellaneous bacteria and prevent the wine from becoming sour. This method is not to completely sterilize the microorganisms in the wine, but to reduce the bacteria to a safe level. On the one hand, it can prevent the wine from becoming sour, and on the other hand, it can alsoTo preserve the taste and flavor of the brewed wine.
But the move has come under unprecedented pressure, including from dairy suppliers and farmers raising dairy cattle, because the pasteurization process increases the cost of dairy products. On the other hand, the general public does not think that cow's milk can transmit diseases, and it is necessary to heat and sterilize it. But Elwens is unwavering, and she continues to push for full pasteurization of milk with a strong will.
The well-known biographer Paul de Kruif also wrote an article in the September 1929 issue of Ladies' Home Journal praising her achievements, making Ewens more aware of the public. Contribution to public health.
In the United States, it wasn't until 1930 that public health officials finally agreed with Elvens, passing a law that only pasteurized cow's milk could be sold. After years of fighting alone, Aiwens' research results have finally been recognized by the world, and it has also benefited the health of countless human beings.
◎ This article is excerpted from / "The Hidden Behind the Microscope: Female Scientists Who Changed the World" by Liu Zhongkang and Zhong Jintang ◎ Image source/Taiwan Commercial Press‧Dazhi Image/Shutterstock
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