Let's Reminisce: Medical serendipity
By Jerry Lincecum
Jun 5, 2018
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Some of you probably remember reading or being told that the “wonder drug” Penicillin was discovered by accident.  Perhaps you even recall an anecdote to the effect that a smart doctor named Alexander Fleming got the mold from the bread of a sandwich.  Like many often-repeated stories, that one is less than accurate.  But the fact remains that a great many important discoveries in the history of medicine did occur serendipitously, as I learned by reading a book entitled Accidental Medical Discoveries: How Tenacity and Pure Dumb Luck Changed the World, by Robert Winters.

With his book written for the general reader, Dr. Winters examines 26 specific examples of important advances in medicine that occurred by chance or “serendipity,” which he defines as “a combination of accident and sagacity.” The latter term indicates that only the “prepared mind” can take advantage of an accidental occurrence to find a new idea or theory.


For example, in his laboratory in the basement of St Mary's Hospital in London, Alexander Fleming noticed a Petri dish containing the bacteria Staphylococcus.  Mistakenly left open, it was contaminated by blue-green mold, which formed a visible growth. There was a kind of “halo” of inhibited bacterial growth around the mold. As a well trained and experienced researcher, Fleming concluded that the mold must have released a substance that killed the bacteria.


This observation occurred in 1928, but Fleming was a notoriously poor communicator, so more than a decade passed before he and two other scientists (named Florey and Chain) managed to demonstrate conclusively that penicillin could be used to kill bacterial infections in human patients. During World War II, penicillin made a huge difference in the number of deaths and amputations caused by infected wounds among Allied forces, saving an estimated 12–15% of lives.  Thus in 1945 Fleming, Chain and Florey shared a Nobel Prize in medicine.


To take another example of an accidental discovery, smallpox was the scourge of humanity for centuries because it was highly contagious.  Smallpox vaccine was introduced by Edward Jenner in 1796. He followed up his chance observation that milkmaids who had caught cowpox did not later catch smallpox.  Once again the key was sagacity: Jenner reasoned that smallpox was so closely related to cowpox that he should try using one to prevent the other.


He showed that inoculating patients with fluid from a cowpox pustule protected them against smallpox.  However, just as the acceptance of penicillin as an antibiotic took a decade, so Jenner had to deal with great opposition and controversy before his discovery was widely accepted; he died without receiving the recognition he deserved.  I remember getting a smallpox vaccination in the 1950s, and the last cases of smallpox in the world occurred in 1978.


The discovery of a cure for stomach ulcers had to overcome the fact that organized medicine adopts a hostile attitude whenever its traditional teachings are attacked.  Peptic ulcer disease (PUD) is a break in the lining of the stomach or the first part of the small intestine.  Two Australian scientists, Robin Warren and Barry Marshall noticed that a corkscrew-shaped bacteria was almost always present around ulcers.  In 1982 they published a paper arguing the bacteria was the cause for ulcers, rather than stress or spicy food as had been assumed before.  This meant that ulcers are a curable infection, which was a revolutionary idea.


After their theory was largely ignored, in a radical act of self-experimentation Marshall drank a Petri dish containing a culture of organisms extracted from a person with an ulcer. Five days later he developed gastritis, and took antibiotics to cure it successfully. After this experiment was published, the new theory began to catch on.  Once again, it took more than a decade, but in 1997, the Centers for Disease Control and Prevention launched a campaign to inform health care providers and consumers about the link between bacteria and ulcers.


These three examples are only a small fraction of the accidental medical discoveries discussed by Robert Winters in his book.


Jerry Lincecum is a retired Austin College professor who now teaches classes for older adults who want to write their life stories.  He welcomes your reminiscences on any subject: