Dorothy Andersen studied cystic fibrosis in the United States during the early 1900s. In 1935, Andersen discovered lesions in the pancreas of an infant during an autopsy, which led her to classify a condition she named cystic fibrosis of the pancreas. In 1938, Andersen became the first to thoroughly describe symptoms of the medical condition cystic fibrosis. Commonly mistaken for celiac disease prior to the 1900s, Andersen defined cystic fibrosis as the build-up of pancreatic fluid in the body caused by the blockage of pancreatic ducts, and she determined that the two conditions were symptomatically different. Andersen developed an early method for diagnosing cystic fibrosis. By conceptualizing cystic fibrosis and defining its symptoms, Andersen laid the foundation for treatments that enabled infants diagnosed with the disease to survive into adulthood.

Hideyo Noguchi researched bacteria, including Treponema pallidum, the bacterium that causes syphilis, in Japan and the US during the early 1900s. Syphilis is a bacterial infection that spreads primarily through sexual transmission and can cause symptoms such as rashes, genital sores, and even organ damage. Noguchi recognized that Treponema pallidum causes neurosyphilis, which is when the syphilis infection spreads to the covering of the brain, the brain itself, or the spinal cord. Before Noguchi’s work, researchers knew about Treponema pallidum and the symptoms of the disease but did not know that untreated syphilis could lead to neurosyphilis. Additionally, Noguchi worked to alter and improve methods to diagnose syphilis. Noguchi’s work helped future researchers and doctors better diagnose people with syphilis, assisted them in understanding how to treat the disease’s long-term side effects, and helped them reduce the spread of syphilis, including between pregnant people and their fetuses.