In science, credit goes to the man who convinces the world, not to whom the idea first occurs.Francis Darwin
Epidemiology certainly has much more contributors than can be described in a single article. So this will be a list of 12 of the most famous epidemiologists who had largely influenced the field. Note that it is sorted by date and not by importance of the contribution.
[460 B.C. – 377 B.C.]
Hippocrates was an ancient Greek physician (although whether he was one person or a group of people is still debated).
Rationalizing medicine by attributing disease to natural causes instead of spiritual.
His essay On airs, waters and places advocated studying environmental factors as predictors of:
- The types of diseases present in a given place
- Their appropriate cure
This is in contrast with the views at his time that epidemics were divine punishments [Source].
Although population thinking and comparison of groups of individuals were not clear in Hippocrates texts [Source], he is still described by many as the father of epidemiology.
2. Girolamo Fracastoro
[1478 – 1553]
Girolamo Fracastoro was an Italian polymath.
Proposing the idea of contagionism well before it was proved by the germ theory of disease in the late 19th century.
Fracastoro’s idea was that epidemic diseases were caused by toxic chemicals transmitted from one person to another via direct contact, air or clothing.
He described these toxic chemicals as rapidly multiplying seeds or bodies.
Note that the idea that a disease can spread from one person to another was already proposed earlier in history by Thucydides [Source]. Fracastoro however, provided a more detailed description of this theory.
3. John Graunt
[1620 – 1674]
John Graunt was an English businessman.
Analyzing data from the bills of mortality. These data were collected weekly for over 50 years to monitor the plague in England.
Before Graunt medicine took a holistic approach to treat patients and disease was thought to be caused by an imbalance between the body and its environment. This view focused on studying the individual, as everyone has a unique experience and interaction with their surroundings. Therefore, ancient medicine dealt with single cases and not so much with populations and groups.
Graunt observed that plague mortality had an irregular shape as opposed to all other causes combined which presented a regular and predictable pattern. Therefore, changes in this pattern can be used a signal of disease outbreaks [Source].
Analyzing population data opened the possibility to understand disease in an unprecedented way and marked the beginning of epidemiological reasoning about public health.
4. Thomas Sydenham
[1624 – 1689]
Thomas Sydenham was an English Physician.
His book Observationes Medicae where he described in details a large number of diseases. He was known for being a critic of medical theories of his time.
Sydenham helped in the formulation of disease as a generic concept, characterized by symptoms and causes shared by all the carriers. This enabled the study of health problems by combining information from several patients instead of studying each one as a separate and unique case.
5. Percivall Pott
[1714 – 1788]
Percivall Pott was an English surgeon.
Being the first who discovered that an environmental factor can be the cause of cancer.
Specifically he observed that men whose work involved cleaning chimney (exposed to ashes and soot) had a higher risk of developing scrotal cancer.
Pott’s observations marked the beginning of modern epidemiology, which deals with infectious and non-infectious diseases alike. [Source]
6. James Lind
[1716 – 1794]
James Lind was a Scottish physician.
Conducting an experiment to prove that citrus fruits cured scurvy.
Back in his time, it wasn’t known that scurvy was caused by vitamin C deficiency, however, it was known that sailors had a high risk of developing scurvy.
Lind theorized that this had to do with their diet.
So he devised an experiment on 12 sailors who had scurvy, divided them into 6 groups of 2, and gave each group a different dietary supplement, one of which received citrus fruits.
The results were clear that citrus fruits were a better treatment than the other options.
Lind’s method of comparing treatments did not only provide an effective treatment of scurvy, it was also a major step in epidemiology for leading to what we now know as clinical trials, which provide the highest level of evidence of all study designs.
7. Edward Jenner
[1749 – 1823]
Edward Jenner was an English Physician.
Performing the first smallpox vaccination on an 8-year-old boy using matter from lesions in a person infected with cowpox — a common infection among dairy maids.
Jenner later inoculated the boy with matter from a smallpox pustule and the child never developed the disease.
Jenner devoted so much of his time to promote the idea of vaccination.
He did not attempt to become rich from his discovery, on the contrary, he even built a room in his garden where he vaccinated the poor for free [source].
Jenner’s work ultimately lead to the eradication of smallpox and is viewed as an important contribution to preventive medicine in general.
Note that his work was all based on observations and not on biology as it precedes the discovery of viruses in the 1890s.
8. Edwin Chadwick
[1800 – 1890]
Sir Edwin Chadwick was an English social reformer.
Reforming the poor laws. He used quantitative methods to prove that there is a correlation between poor living conditions and disease [Source].
Chadwick believed that “bad night air” or miasma was the cause of diseases and epidemics.
Therefore health measures such as providing clean drinking water and building a sewage system will lead to better health outcomes. Although based on a theoretically wrong hypothesis, his system proved to be effective.
Chadwick’s use of scientific methods to guide social and health policy changes was an important landmark in the history of epidemiology.
9. William Farr
[1807 – 1883]
William Farr was an English epidemiologist.
Using statistics to study medical issues, he also developed a system to record the causes of death and monitor outbreaks.
Farr is considered the founder of modern concepts of surveillance.
10. John Snow
[1813 – 1858]
John Snow was an English physician.
Discovering that cholera is waterborne by using data he gathered from the 1854 outbreak in London.
Snow plotted the cases of cholera on a map of the affected area and discovered that these clustered around a pump in Broad Street. Therefore, he concluded that cholera was spread through contaminated water and not polluted air as was believed at the time.
Snow is considered the father of modern epidemiology.
11. Ignaz Semmelweis
[1818 – 1865]
Ignaz Semmelweis was a Hungarian physician.
Advocating that physicians should wash their hands before attending pregnant women in order to reduce post-delivery infection and mortality.
Semmelweis came to this conclusion after observing that post-delivery mortality in women delivered by physicians was 7 to 9 times more likely than those delivered by midwives. He hypothesized that this was due to the handling of corpses during autopsies before attending pregnant women, something the physicians did and the midwives did not do. He then confirmed his hypothesis using a controlled trial.
However, his empirical results were rejected by the medical community because:
- They conflicted with the scientific and medical theories at the time
- Semmelweis waited 14 years before publishing these results
- He was arrogant and insulting to his peers who did not agree with him [Source]
Semmelweis is known as the father of infection control.
12. Austin Bradford Hill
Austin Bradford Hill was an English epidemiologist and statistician.
Demonstrating, in collaboration with Richard Doll, an association between smoking and lung cancer. He was also a pioneer in using randomized clinical trials.
Mostly known by epidemiologists as founder of the “Bradford Hill criteria” to infer causal relationships, although Hill himself did not believe in a set of rules to infer causation [Source].
Bradford Hill is described as the greatest medical statistician of the 20th century, despite the fact that he held no degree in either medicine or statistics [Source].